WO2007089607A2 - Rna silencing agents for use in therapy and nanotransporters for efficient delivery of same - Google Patents

Abstract

The present invention provides nanotransporters and delivery complexes for use in delivery of nucleic acid molecules and/or other pharmaceutical agents in vivo and in vitro. In addition, the invention features chemically-modified RNA silencing agents (e.g., siRNAs) that are stable in vivo and silence target RNA that is associated with a metabolic disorder, as well as delivery complexes comprising said RNA silencing agents in association with the nanotransporters of the invention. The featured RNA silencing agents and delivery complexes are effective therapeutics for targeting disease genes, e.g., genes involved in metabolic disorders.

Description

RNA SΪLENCING AGENTS FOR USE IN THERAPY AND NANOTRANSPORTERS FOR EFFICIENT DELIVERY OF SAME

RELATED APPLICATIONS This application claims the benefit of USSN 60/762,956, entitled

"Nanotransporters for Efficient Delivery of Nucleic Acid and Other Pharmaceutical Agents," filed on January 26, 2006, USSN 60/762,951, entitled "RNA Interference Agents for Use in Therapy of Metabolic Disorders", filed on January 26, 2006, USSN 60/762,957, entitled "RNA Interference Agents for Use in Therapy", filed on January 26, 2006. The entire contents of these applications are hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

RNA interference (RNAi) is the process whereby double-stranded RNA (dsRNA) induces the sequence-specific degradation of homologous mRNA. Although RNAi was first discovered in Caenorhabditis elegans (Fire et al., 1998), similar phenomena had been reported in plants (post-transcriptional gene silencing [PTGS]) and in Neurospora crassa (quelling) (reviewed in Hammond et al., 2001; Sharp, 2001). It has become clear that dsRNA-induced silencing phenomena are present in evolutionarily diverse organisms, e.g., nematodes, plants, fungi and trypanosomes (Bass, 2000; Cogoni and Macino, 2000; Fire et al., 1998; Hammond et al., 2001; Ketting and Plasterk, 2000; Matzke et al., 2001; Sharp, 2001; Sijen and Kooter, 2000; Tuschl, 2001; Waterhouse et al., 2001). Biochemical studies in Drosqphila embryo lysates and S2 cell extracts have begun to unravel the mechanisms by which RNAi works (Bernstein et al., 2001; Tuschl et al, 1999; Zamore et al., 2000).

Although RNAi has proven to have tremendous potential as a new therapeutic strategy, there remains a need for RNAi agents that are optimized for use in vivo. Another goal is to efficiently deploy therapeutic RNAi agents to specifically targeted sites or tissues. Accordingly, delivery systems that are non-toxic, immunogenic and biodegradable are needed. SUMMARY OF THE INVENTION

The present invention is based, in part, upon the synthesis and formulation of novel nanotransporters for use as delivery agents of RNA silencing agents, as well as other nucleic acid molecules and/or pharmaceutical agents. In exemplary aspects, the nanotransporters of the invention comprise a central core with at least one functional surface group attached. In exemplary embodiments, the core of the nanotransporter is a nanoparticle (e.g., a dendrimer, e.g. a polylysine dendrimer) or a nanotube (e.g., a single-walled nanotube or a multi-walled nanotube). The functional surface groups are chosen for their ability to increase the functionality of the nanotransporter, e.g., to increase cell targeting specificity, to increase delivery of the nanotransporter the target cell, and/or to impart a precise biological function. In one embodiment the functional surface group is at least one of a lipid, cell type specific targeting moiety, fluorescent molecule, and charge controlling molecules. RNA silencing agents of the invention, as well as other nucleic acid molecules (e.g., other RNA silencing agents (e.g., siRNAs, miRNAs, shRNAs), antisense molecules, ribozymes, etc.) and/or pharmaceutical agents (e.g., polynucleotides, proteins, polypeptides, peptides, chemotherapeutic agents, and/or antibiotics), can be operably linked (e.g., conjugated or otherwise associated with) to the core for target specific delivery.

In another embodiment, the invention provides a method for delivering a nucleic acid molecule (e.g., an RNA silencing agent (e.g., an siRNA) of the invention) and/or a pharmaceutical agent to a cell, the method comprising, contacting the cell with a nanotransporter (e.g., a nanotransporter of the invention) that is operably Linked to the nucleic acid molecule and/or pharmaceutical agent, thereby delivering the nucleic acid molecule and/or pharmaceutical agent to the cell. In one embodiment, the cell that is contacted is a human cell.

In other aspects, the invention provides improved RNA silencing agents for use in the treatment of diseases and disorders, e.g., metabolic diseases or disorders. Ia other aspects, the invention provides nanotransporters and use of said nanotransporter for the targeted delivery of RNA silencing agents and other nucleic acid agents in vivo.

In one aspect, the present invention is directed to at least one small interfering RNA (siRNA), comprising a sense strand and an antisense strand, wherein (a) the antisense strand has a sequence sufficiently complementary to a target mRNA sequence to direct target-specific RNA interference (RNAi); (b) the strands are modified at both ends with more than one chemically modified nucleotides such that in vivo stability is enhanced as compared to a corresponding unmodified siRNA; and (c) the antisense strand retains the ability to form an A-form helix when in association with a target RNA. In one embodiment, at least 3-6 of the 5' and V terminal nucleotides of the strands are modified. In one embodiment, at least 4-5 of the 5^J and 3' terminal nucleotides of the strands are modified. In one embodiment, the modified nucleotides are 2'-fluoro modified ribonucleotides and backbone-modified nucleotides. In one embodiment, the 2'-fluoro modified ribonucleotides are 2'-fϊuoro uridine and 2'-fluoro cytidine. In one embodiment, the backbone-modified nucleotides contain a phosphorothioate group.

In one embodiment, the antisense strand and target mRNA sequences are 100% complementary. In one embodiment, the antisense strand and target mRNA sequences comprise at least one mismatch. In one embodiment, the modified nucleotide does not effect the ability of the antisense strand to adopt A-form helix conformation comprising a normal major groove when base-pairing with the target mRNA sequence.

In one embodiment, the strands are between about 10 and 50 residues in length. In one embodiment, the strands are between about 18 and 25 residues in length, e.g., 21 residues in length. In one embodiment, the strands align such that the siRNA has overhang ends, e.g., such that the siRNA has 2-nucleotide overhang ends. In one embodiment, the siRNA is chemically synthesized.

In one embodiment, the siRNA targets ApoB mRNA or RJP-140 mRNA, e.g., ApoB mRNA in a region capable of encoding a ApoB mutation, ApoB mRNA and wild type ApoB mRNA, RJP-140 mRNA in a region capable of encoding a RJP-140 mutation, and/or RIP-140 mRNA and wild type RJP-140 mRNA.

In one aspect, the present invention also includes a method of activating target- specific RNA interference (RNAi) in a cell comprising introducing into said cell the any of the siRNA described herein, said siRNA being introduced in an amount sufficient for degradation of target mRNA to occur, thereby activating target-specific RNAi in the cell.

In one aspect, the present invention also includes a method of activating target- specific RNA interference (RNAi) in an organism comprising administering to said organism the siRNA of any one of the preceding claims, said siRNA being administered in an amount sufficient for degradation of the target rnRNA to occur, thereby activating target-specific RNAi in the organism.

In some embodiments, degradation of the target mRNA is such that the protein specified by said target mRNA is decreased by at least 10%, e.g., by at least 20%. In one aspect, the present invention also includes a method of treating a disease or disorder associated with the activity of a protein specified by a target mRNA in a subject, comprising administering to said subject the siRNA of any one of the preceding claims, said siRNA being administered in an amount sufficient for degradation of the target mRNA to occur, thereby treating the disease or disorder associated with the protein.

The present invention also includes a method for treating at least one metabolic disease or disorder selected from the group consisting of obesity, diabetes and high cholesterol in a subject comprising administering a siRNA of any of the preceding claims, such that the metabolic disease is treated. In some embodiments, the metabolic disease or disorder is obesity and the weight of the subject decreases by at least 5% as compared to the weight of the subject before administration of the composition. In some embodiments, the metabolic disease or disorder is diabetes and the glucose level of the subject is lowered by at least about 5% as compared to the glucose level of the subject before administration of the composition. In some embodiments, the metabolic disease or disorder is high cholesterol and the cholesterol level of the subject decreases by at least 5% as compared to the cholesterol level of the subject before administration of the composition.

Other features and advantages of the invention will be apparent from the following detailed description, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic representation of the architecture of an exemplary nanotransporter.

Figure 2 is a schematic representation of an exemplary nanotransporter delivery device with multiple functional surface groups attached.

Figure 3 is a schematic representation of the interaction of the nanotransporter DiOleoyl-LDG3 with siRNA. Figures 4A-4D depict the synthetic scheme used to produce a polylysine dendrimer generation four ("LDG4") from component monomers (Figure 4A), LDGl (Figure 4B), LDG2 (Figure 4C), and LDG3 (Figure 4D).

Figure 5 is a depiction of the synthetic scheme used to produce a low molecular weight polylysine dendrimer.

Figures 6A-C are depictions of synthetic schemes used to produce an oleoyl derivative (Figure 6A), a polyethylene glycol (PEG) derivative (Figure 6B)₃ or a cholesterol derivative (Figure 6C) for use as a Up id functional surface group.

Figure 7 is a depiction of the synthetic scheme used to produce an oleoylic acid derivative for use as a lipid functional surface group.

Figure 8 is an example of a nanotransporter comprising a lipid functional surface group conjugated to a core comprised of a low molecular weight polylysine dendrimer.

Figure 9 is a depiction of the synthetic scheme used to produce a fluorescein labeled oleoyl polylysine dendrimer generation four. Figures 10A-B are examples of nanotransporters comprising a fluorescein labeled octyl-PEG polylysine dendrimer generation four (Figure 10A) or fluorescein labeled cholesterol polylysine dendrimer generation four (Figure 10B).

Figure 11 is a schematic representation of a nanotransporter comprising a LDG4 core, lipid functional surface group, and a cell type specific targeting moiety, conjugated with a nucleic acid molecule.

Figure 12 is a depiction of the synthetic scheme used to produce an HBOLD nanotransporter comprising a LDG4 core, an oleoyl derivative functional surface group, and a cyclic CNGRC targeting moiety.

Figure 13 is a depiction of the synthetic scheme used to produce an HBOLD nanotransporter comprising an LDG4 core, an oleoyl derivative functional surface group, and a cyclic CKGGRAKDC targeting moiety for targeting siRNAs to adipose tissue.

Figure 14 is a schematic representation of the conjugation of a nucleic acid molecule to a nanotransporter. Figure 15 is a depiction of the synthesis of lung cell specific peptide using a

MBHA resin

Figure 16 is a schematic representation of an siRNA conjugated to lung cell specific peptide. Figure 17 is a depiction of the synthetic scheme used to produce nanotransporters comprising a nanotube core, conjugated with siRNA.

Figure 18 depicts the chemical formula of "HBOLD," an exemplary nano transporter of the present invention. Figure 19 graphically depicts results from an in vitro cell toxicity assay which shows viability of cells exposed to the HBOLD nanotransporters of the invention.

Figure 20 graphically depicts results from an in vitro cell assay showing that HBOLD :siRNA delivery complex is able to silence ApoB mRNA.

Figure 21 depicts constructs used for testing in vivo efficacy of apoB siRNA: HBOLD delivery complex.

Figure 22 shows results from a Western blot which demonstrates reduced ApoB protein expression from cells exposed to ApoB siRNA.

Figure 23 graphically depicts total cholesterol levels in plasma, showing that the ApoB siRNArHBOLD delivery complexes are able to reduce plasma cholesterol levels. Figure 24 graphically depicts results from in vivo silencing of ApoB using the

HBOLD:siRNA delivery complexes of the invention.

Figure 25 graphically depicts results from an in vivo assay demonstrating lack of immunostimulation using the ApoB siRNA:HBOLD nanotransporter of the invention.

Figure 26 depicts the chemical formula of "NOP-7," an exemplary oleoyl-lysine dendrimer nanotransporter of the present invention.

Figure 27 depicts the ¹H NMR spectrum of NOP-7 in DMSO-d₆.

Figure 28 is a depiction of a MALDI-TOF MS analysis of NOP-7.

Figures 29A and D are graphical depictions of the results of dynamic light scattering experiments showing that the average diameter of NOP-7 (Figure 29A) and a delivery complex comprising NOP-7 and siRNA ("iNOP-7") (Figure 29B).

Figures 3OA and B graphically depict apoB mRNA expression levels (Figure 3 IA) and cell viability (Figure 30B) of FL83B cells treated for 24 hours in vitro with or without ("mock") iNOP-7 delivery complexes of the present invention. "CM" designates chemically modified siRNA, while "UM" designates unmodified siRNA. Apo B mRNA levels in Figure 3OA and cell toxicity levels in Figure 3OB are expressed as a percent of an untransfected control. Each value represents the mean ±SD of duplicate cultures from two representative experiments. Figure 31 is a graphical depiction of liver apoB mRNA levels in mice treated in vivo with unmodified ("UM") or chemically modified ("CM") siRNA as compared to controls. ApoB mRNA levels were measured in liver 24 h after treating mice with 5 mg/kg of siRNA lacking associated nanotransporters. Figure 32A and B depict liver apoB mRNA levels in mice after targeted in vivo with exemplary iNOP7 delivery complexes of the present invention compared to control. Figure 32A depicts ApoB mRNA levels in liver 24 h after treating mice with 1.25mg/kg, 2.5mg/kg, or 5mg/kg of iNOP-7 containing either chemically modified siRNA ("CM") or its mismatch ("mm"). Values represent the mean ±SD of tissue samples from three liver regions (n=4 animals). Data are expressed as percent of control. Figure 32B is a Northern blot analysis of total RNA isolated from mice liver treated with unmodified ("UM") or chemically modified ("CM") siRNA with or without the nanotransporter NOP-7. Detection of miR-122 and tRNA was used as a control.

Figure 33 A and B graphically depicts liver apoB protein levels in plasma 24 hours after mice were injected with iNOP-7 containing siRNA. Figure 33 A depicts a Western blot of ApoB 100 and ApoB48 protein expression levels 24h after the final injection of 5mg/kg of iNOP-7 containing chemically modified ("CM") siRNA or its mismatch ("mm"). Total protein loading was confirmed by assessing plasma fibronectin levels. Figure 33B shows the results of densitometry analysis of all Western blot for plasma levels of ApoB 100 and ApoB48 in mice 24h after the final injection of iNOP-7. Data are expressed as percent of control (n=4 animals).

Figure 34 graphically depicts plasma cholesterol levels in mice treated with exemplary iNOP-7 delivery complexes of the present invention. Plasma cholesterol levels were determine 24h after the final injection of 5 mg/kg of iNOP-7. Figure 35 graphically depicts EFN-α levels in plasma 24 hours after mice were treated with 5 mg/kg of iNOP-7 delivery complexes containing chemically modified ("CM") siRNA or its mismatch ("mm") or with NOP-7 nanotransporters lacking siRNA ("mock"). As a positive control, one mouse was injected with 250 μg of Poly IC and plasma levels of IFN-α were assessed 6 hours later. Each value represents the mean ± SD of plasma samples from each treatment group.

Figures 36A-C are micrographs of histological liver sections stained with hematoxylin and eosin from mice treated with PBS control (Figure 36A), NOP-7 nanotransporter (Figure 30B), or iNOP-7 containing chemically modified apoB siRNA. Figures 37A and B depict exemplary charge controlling molecules ("R") of the invention (Figure 37B) and a generic structural formula for nanotransporters which comprise one or more lipids (where, "n" is the number of lipids) and or more charge controlling molecules (where, "m" is the number of charge controlling molecules). Figure 38 depicts modification of an exemplary nanotransporter (succinyl-

LDG3) with a charge controlling molecule (H-Lys(Boc)-OMe) to form SLDG3E which comprises 16 terminal carboxyls.

Figure 39 depicts the synthesis of an exemplary sulfur-containing nanoparticle comprising 16 terminal thiols using DeLDG4 as a starting material, Figure 40 depicts an exemplary nanoparticle (LDG5) comprising 64 terminal primary amines.

Figure 41 A and B depict an exemplary nanoparticle (SLDG4) comprising 32 terminal secondary amines (Figure 41B) and synthesis of said nanoparticle fromLDG4 (Figure 41A). Figure 42 depicts another exemplary nanoparticle (SLDG5) comprising 64 terminal secondary amines.

Figure 43 depicts an exemplary cholesterol-modified nanoparticle.

Figure 44 depicts an exemplary nanoparticle modified with cholesterol and oleoyl groups. Figure 45 depicts exemplary carbohydrate-containing nanotransporters HB-

M9LD and HB-MLD.

Figure 46 depicts an exemplary delivery complex comprising 7 oleoyl lipids and 5 Amantadine drug moieties.

Figure 47 depicts an exemplary nanotransporter comprising a Tat peptide and terminal primary amines, "m" designates the number of Tat peptides and "n" designates the number of primary amines.

Figure 48A and B depict exemplary delivery complexes comprising an LDG5 nanoparticle with 45 primary amines, 16 lipid groups, and 3 thiol-conjugated siRNAs (Figure 48A) and (ii) an LDG4 nanoparticle, 22 primary amines, 7 lipid groups, and 3 thiol conjugated siRNAs (Figure 48B).

Figure 49A and B depicts exemplary nanotransporters comprising (i) an O7P1 nanoparticle with 24 primary amines, 7 lipid groups, and 4 PEG groups (Figure 49A) and (ii) an O7C nanoparticle with 17 primary amines, 7 lipid groups, and 8 terminal carboxylates.

DETAILED DESCRIPTION OF THE INVENTION The present invention relates in part to the synthesis and formulation of novel nanotransporters for use as delivery agents of nucleic acid molecules, e.g, RNA silencing agents (e.g. siRNA), and/or for delivery of pharmaceutical agents. In exemplary aspects, the nanotransporters of the invention comprise a central core, wherein the core is a nanoparticle or a nanotube, with at least one functional surface group attached. A multitude of functional surface groups can be attached to the core.

The functional surface groups are chosen for their ability to increase the functionality of the nanotransporter, e.g., to increase cell targeting specificity, to increase delivery of the nanotransporter to the target cell, and/or to impart a precise biological function.

In other aspects, the present invention features nanotransporters which include at least one chemically modified RNA silencing agents (e.g., RNAi agents such small interfering RNA molecules (siRNA)) and methods (e.g., research and/or therapeutic methods) for using said RNA silencing agents. The present invention includes RNA silencing agents (e.g., RNAi agents) which have been chemically modified at both the 3' end and the 5' end of the sense strand, the antisense strand or both. Such RNA silencing agents, and nanotransporters which incorporate them, are useful, for example, in the treatment of metabolic disorders, e.g., high cholesterol, diabetes and obesity.

I. Definitions

So that the invention may be more readily understood, certain terms are first defined:

As used herein, the term "nanoparticle" refers to a particle with controlled dimensions on the order of nanometers, e.g., on the order of about 1 to about 500 nanometer, for example about 10 to about 100 nanometers. In certain embodiments, nanoparticles are dendrimers. As used herein, the term "dendrimer" refers to a highly branched polymer with a well-defined structure. The dendrimers of the invention include but are not limited to the following: polylysine dendrimers; Polyamidoamine (PAMAM) PAMAM: Amine terminated and/or PAMAM: Carboxylic Acid terminated (available, e.g., from Dendritech, Inc., Midland, MI); Diaminobutane (DAB) - DAB: Amine terminated and/or DAB: Carboxylic Acid terminated; PEGs: OH terminated (Frechet et al. JACS 123:5908 (2001)), among others.

The term "nanotube" as used herein, refers to a hollow cylindrical structure with an outside diameter of about 1 to about 5 nanometers. Exemplary nanotubes are carbon nanotubes. In certain embodiments, the nanotube is a single-walled nanotube, i.e., a single tube. In other embodiments, the nanotube is a multi-walled nanotube, i.e., a tube with at least one other tube embedded within it.

As used herein, the term "nanotransporter" refers to a multi-component complex with controlled dimensions, e.g., a diameter or. radius on the order of about 1 to about 1000 nanometers. In one embodiment, the nanotransporter is about 1 to about 100 nanometers in diameter. In another embodiment, the nanotransporter is about 1 to about 75 nanometers in diameter. In another embodiment, the nanotransporter is about 10, 20, 30, 40, 50, 60, 70, 80, 90, or 100 nanometers in diameter. In certain embodiments, nanotransporters comprise a nanoparticle, as defined herein, and at least one functional surface group as described herein. In one embodiment, the nanotransporters comprise about 1 to about 50 functional surface groups. In another embodiment, the nanotransporters comprise about 1 to about 25 functional surface groups. In another embodiment, the nanotransporters comprise about 1 to about 10 functional surface groups {e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 functional surface groups. In certain embodiments, the functional surface groups are the same. In other embodiments, different combinations of functional surface groups are used (e.g., 2, 3, 4, 5, or 6 types of functional surface groups are used, e.g., an oleoyl lipid and a cholesterol).

As used herein, the term "delivery complex" (also referred to as a interfering nanoparticle or "iNOP") refers to a complex formed by association of a nanotransporter and a nucleic acid (e.g., an RNA silencing agent) and/or pharmaceutical agent. Delivery complexes have two portions or subunits: (1) a nanotransporter (e.g., a core conjugated with at least one functional group); and (2) an RNA silencing agent (e.g., a chemically-modified or unmodified RNA silencing agent, e.g. a chemically modified or unmodified siRNA). Ia one embodiment, the delivery complex is about 1 to about 5000 nanometers in diameter. In another embodiment, the delivery complex is about 1 to about 1000 nanometers in diameter. In another embodiment, the delivery complex is about 100, 200, 300, 400, 500, 600, 700, 800, 900, or 1000 nanometers in diameter. As used herein, the term "RNA silencing" refers to a group of sequence-specific regulatory mechanisms (e.g. RNA interference (RNAi), transcriptional gene silencing (TGS), post-transcriptional gene silencing (PTGS), quelling, co-suppression, and translational repression) mediated by RNA molecules which result in the inhibition or "silencing" of the expression of a corresponding protein-coding gene. RNA silencing has been observed in many types of organisms, including plants, animals, and fungi.

The term "discriminatory RNA silencing" refers to the ability of an RNA molecule to substantially inhibit the expression of a "first" or "target" polynucleotide sequence while not substantially inhibiting the expression of a "second" or "non-target" polynucleotide sequence", e.g., when both polynucleotide sequences are present in the same cell. In certain embodiments, the target polynucleotide sequence corresponds to a target gene, while the non-target polynucleotide sequence corresponds to a non-target gene. In other embodiments, the target polynucleotide sequence corresponds to a target allele, while the non-target polynucleotide sequence corresponds to a non-target allele. In certain embodiments, the target polynucleotide sequence is the DNA sequence encoding the regulatory region (e.g. promoter or enhancer elements) of a target gene. In other embodiments, the target polynucleotide sequence is a target mRNA encoded by a target gene.

As used herein, the term "target gene" is a gene whose expression is to be substantially inhibited or "silenced." This silencing can be achieved by RNA silencing, e.g. by cleaving the mRNA of the target gene or translational repression of the target gene. The term "non-target gene" is a gene whose expression is not to be substantially inhibited. In one embodiment, the polynucleotide sequences of the target and non-target gene (e.g. mRNA encoded by the target and non-target genes) can differ by one or more nucleotides. In another embodiment, the target and non-target genes can differ by one or more polymorphisms. In another embodiment, the target and non-target genes can share less than 100% sequence identity. In another embodiment, the non-target gene may be a homolog (e.g. an ortholog or paralog) of the target gene.

A "target allele" is an allele whose expression is to be selectively inhibited or "silenced." This silencing can be achieved by RNA silencing, e.g. by cleaving the mRNA of the target gene or target allele by an siRNA. The term "non-target allele" is a allele whose expression is not to be substantially inhibited. In certain embodiments, the target and non-target alleles can correspond to the same target gene. In other embodiments, the target allele corresponds to a target gene, and the non-target allele corresponds to a non-target gene. In one embodiment, the polynucleotide sequences of the target and non-target alleles can differ by one or more nucleotides. In another embodiment, the target and non-target alleles can differ by one or more allelic polymorphisms. In another embodiment, the target and non-target alleles can share less than 100% sequence identity.

The term "polymorphism" as used herein, refers to a variation (e.g., a deletion, insertion, or substitution) in a gene sequence that is identified or detected when the same gene sequence from different sources or subjects (but from the same organism) are compared. For example, a polymorphism can be identified when the same gene sequence from different subjects (but from the same organism) are compared. Identification of such polymorphisms is routine in the art, the methodologies being similar to those used to detect, for example, breast cancer point mutations. Identification can be made, for example, from DNA extracted from a subject's lymphocytes, followed by amplification of polymorphic regions using specific primers to said polymorphic region. Alternatively, the polymorphism can be identified when two alleles of the same gene are compared.

A variation in sequence between two alleles of the same gene within an organism is referred to herein as an "allelic polymorphism". The polymorphism can be at a nucleotide within a coding region but, due to the degeneracy of the genetic code, no change in amino acid sequence is encoded. Alternatively, polymorphic sequences can encode a different amino acid at a particular position, but the change in the amino acid does not affect protein function. Polymorphic regions can also be found in non- encoding regions of the gene. As used herein, the term "RNA silencing agent" refers to an RNA which is capable of inhibiting or "silencing" the expression of a target gene. In certain embodiments, the RNA silencing agent is capable of preventing complete processing (e.g, the full translation and/or expression) of a mRNA molecule through a post- transcriptional silencing mechanism. RNA silencing agents include small (<50 b.p.), noncoding RNA molecules, for example RNA duplexes comprising paired strands, as well as precursor RNAs from which such small non-coding RNAs can be generated. Exemplary RNA silencing agents include siRNAs, miRNAs, siRNA-like duplexes, and dual-function oligonucleotides as well as precursors thereof. In one embodiment, the RNA silencing agent is capable of inducing RNA interference (RNAi). In another embodiment, the RNA silencing agent is capable of mediating translational repression.

The term "nucleoside" refers to a molecule having a purine or pyrimidine base covalently linked to a ribose or deoxyribose sugar. Exemplary nucleosides include adenosine, guanosine, cytidine, uridine and thymidine. Additional exemplary nucleosides include inosine, 1 -methyl inosine, pseudouridine, 5,6-dihydrouridine, ribothymidine, ²N-methylguanosine and ^2>2N,N-dimethylguanosine (also referred to as "rare" nucleosides). The term "nucleotide" refers to a nucleoside having one or more phosphate groups joined in ester linkages to the sugar moiety. Exemplary nucleotides include nucleoside monophosphates, diphosphates and triphosphates. The terms

"polynucleotide" and "nucleic acid molecule" are used interchangeably herein and refer to a polymer of nucleotides joined together by a phosphodiester linkage between 5' and 3' carbon atoms.

The term "RNA" or "RNA molecule" or "ribonucleic acid molecule" refers to a polymer of ribonucleotides. The term "DNA" or "DNA molecule" or deoxyribonucleic acid molecule" refers to a polymer of deoxyribo nucleotides. DNA and RNA can be synthesized naturally (e.g., by DNA replication or transcription of DNA, respectively). RNA can be post-transcriptionally modified. DNA and RNA can also be chemically synthesized. DNA and RNA can be single-stranded (i.e., ssRNA and ssDNA, respectively) or multi-stranded (e.g., double stranded, i.e., dsRNA and dsDNA, respectively). "mRNA" or "messenger RNA" is single-stranded RNA that specifies the amino acid sequence of one or more polypeptide chains. This information is translated during protein synthesis when ribosomes bind to the mRNA.

As used herein, the term "rare nucleotide" refers to a naturally occurring nucleotide that occurs infrequently, including naturally occurring deoxyribonucleotides or ribonucleotides that occur infrequently, e.g., a naturally occurring ribonucleotide that is not guanosine, adenosine, cytosine, or uridine. Examples of rare nucleotides include, but are not limited to, inosine, 1 -methyl inosine, pseudouridine, 5,6-dihydrouridine, ribothymidine, ²N-methylguanosine and ^ΛζiV'-dimethylguanosine. The term "nucleotide analog" or "altered nucleotide" or "modified nucleotide" refers to a non-standard nucleotide, including non-naturally occurring ribonucleotides or deoxyribonucleotides. Preferred nucleotide analogs are modified at any position so as to alter certain chemical properties of the nucleotide yet retain the ability of the nucleotide analog to perform its intended function. Examples of preferred modified nucleotides include, but are not limited to, 2-amino-guanosine, 2-amino -adenosine, 2,6-diamino- guanosine and 2,6-diamino-adenosine. Examples of positions of the nucleotide which may be derivitized include the 5 position, e.g., 5-(2-amino)propyl uridine, 5-bromo uridine, 5-propyne uridine, 5-propenyl uridine, etc.; the 6 position, e.g., 6-(2- amino)propyl uridine; the 8-position for adenosine and/or guanosines, e.g., 8-bromo guanosine, 8-chloro guanosine, 8-fluoroguanosine, etc. Nucleotide analogs also include deaza nucleotides, e.g., 7-deaza-adenosine; O- and N-modified (e.g., alkylated, e.g., N6- methyl adenosine, or as otherwise known in the art) nucleotides; and other heterocyclically modified nucleotide analogs such as those described in Herdewijn, Antisense Nucleic Acid Drug Dev., 2000 Aug. 10(4):297-310.

Nucleotide analogs may also comprise modifications to the sugar portion of the nucleotides. For example the 2' OH-group may be replaced by a group selected from H, OR, R, F, CI, Br, I, SH, SR, NH₂, NHR, NR₂, COOR, or OR, wherein R is substituted or unsubstituted Ci — C& alkyl, alkenyl, alkynyl, aryl, etc. Other possible modifications include those described in U.S. Patent Nos. 5,858,988, and 6,291,438.

The phosphate group of the nucleotide may also be modified, e.g., by substituting one or more of the oxygens of the phosphate group with sulfur (e.g., phosphorothioates), or by making other substitutions which allow the nucleotide to perform its intended function such as described in, for example, Eckstein, Antisense Nucleic Acid Drug Dev. 2000 Apr. 10(2): 117-21, Rusckowski et al. Antisense Nucleic Acid Drug Dev. 2000 Oct. 10(5):333-45, Stein, Antisense Nucleic Acid Drug Dev. 2001 Oct. 11(5): 317-25, Vorobjev et al. Antisense Nucleic Acid Drug Dev. 2001 Apr. 11(2):77-85, and U.S. Patent No. 5,684, 143. Certain of the above-referenced modifications (e.g., phosphate group modifications) preferably decrease the rate of hydrolysis of, for example, polynucleotides comprising said analogs in vivo or in vitro.

The term "oligonucleotide" refers to a short polymer of nucleotides and/or nucleotide analogs. The term "RNA analog" refers to a polynucleotide (e.g., a chemically synthesized polynucleotide) having at least one altered or modified nucleotide as compared to a corresponding unaltered or unmodified RNA but retaining the same or similar nature or function as the corresponding unaltered or unmodified RNA. The oligonucleotides may be linked with linkages which result in a lower rate of hydrolysis of the RNA analog as compared to an RNA molecule with phosphodiester linkages. For example, the nucleotides of the analog may comprise methylenediol, ethylene diol, oxymethylthio, oxyethylthio, oxycarbonyloxy, phosphorodiamidate, and/or phosphorothioate linkages. Exemplary RNA analogues include sugar- and/or backbone-modified ribonucleotides and/or deoxyribonucleotides. Such alterations or modifications can further include addition of non-nucleotide material, such as to the end(s) of the RNA or internally (at one or more nucleotides of the RNA). An RNA analog need only be sufficiently similar to natural RNA that it has the ability to mediate (mediates) RNA silencing (e.g. RNA interference). In an exemplary embodiment, oligonucleotides comprise Locked Nucleic Acids (LNAs) or Peptide Nucleic Acids (PNAs).

As used herein, the term "bond strength" or "base pair strength" refers to the strength of the interaction between pairs of nucleotides (or nucleotide analogs) on opposing strands of an oligonucleotide duplex (e.g., a duplex formed by a strand of a RNA silencing agent and a target mRNA sequence), due primarily to H-bonding, Van der Waals interactions, and the like between said nucleotides (or nucleotide analogs).

As used here, the term "melting temperature" or "Tm" refers to the temperature at which half of a population of double-stranded polynucleotide molecules becomes dissociated into single strands.

As used herein, the terms "sufficient complementarity" or "sufficient degree of complementarity" mean that the RNA silencing agent has a sequence (e.g. in the antisense strand, mRNA targeting moiety or miRNA recruiting moiety) which is sufficient to bind the desired target RNA, respectively, and to trigger the RNA silencing of the target mRNA.

As used herein, the term "RNA interference" ("RNAi") refers to a type of RNA silencing which results in the selective intracellular degradation of a target RNA. RNAi occurs in cells naturally to remove foreign RNAs (e.g., viral RNAs). Natural RNAi proceeds via fragments cleaved from free dsRNA which direct the degradative mechanism to other similar RNA sequences. Both RNAi and translational repression are mediated by RISC. Both RNAi and translational repression occur naturally or can be initiated by the hand of man, for example, to silence the expression of target genes.

As used herein, the term "translational repression" refers to a selective inhibition of mRNA translation. Natural translational repression proceeds via miRNAs cleaved from shRNA precursors. Both RNAi and translational repression are mediated by RISC. Both RNAi and translational repression occur naturally or can be initiated by the hand of man, for example, to silence the expression of target genes.

As used herein, the term "small interfering RNA" ("siRNA") (also referred to in the art as "short interfering RNAs") refers to an RNA (or RNA analog) comprising between about 5-60 nucleotides (or nucleotide analogs) which is capable of directing or mediating RNA silencing (e.g., RNA interference or translational repression). Preferably, a siRNA comprises between about 15-30 nucleotides or nucleotide analogs, more preferably between about 16-25 nucleotides (or nucleotide analogs), even more preferably between about 18-23 nucleotides (or nucleotide analogs), and even more preferably between about 19-22 nucleotides (or nucleotide analogs) (e.g., 19, 20, 21 or 22 nucleotides or nucleotide analogs). The term "short" siRNA refers to a siRNA comprising 5-23 nucleotides, preferably ~21 nucleotides (or nucleotide analogs), for example, 19, 20, 21 or 22 nucleotides. The term "long" siRNA refers to a siRNA comprising 24-60 nucleotides, preferably ~24-25 nucleotides, for example, 23, 24, 25 or 26 nucleotides. Short siRNAs may, in some instances, include fewer than 19 nucleotides, e.g., 16, 17 or 18 nucleotides, or as few as 5 nucleotides, provided that the shorter siRNA retains the ability to mediate RNAi. Likewise, long siRNAs may, in some instances, include more than 26 nucleotides, e.g., 27, 28, 29, 30, 35, 40, 45, 50, 55, or even 60 nucleotides, provided that the longer siRNA retains the ability to mediate RNAi or translational repression absent further processing, e.g., enzymatic processing, to a short siRNA.

As used herein, the term "microRNA" ("miRNA"), also referred to in the art as "small temporal RNAs" ("stRNAs"), refers to a small (10-50 nucleotide) RNA which are genetically encoded (e.g. by viral, mammalian, or plant genomes) and are capable of directing or mediating RNA silencing. An "miRNA disorder" shall refer to a disease or disorder characterized by an aberrant expression or activity of an miRNA.

As used herein, the term "antisense strand" of an RNA silencing agent, e.g. an siRNA or RNAi agent, refers to a strand that is substantially complementary to a section of about 10-50 nucleotides, e.g., about 15-30, 16-25, 18-23 or 19-22 nucleotides of the mRNA of the gene targeted for silencing. The antisense strand or first strand has sequence sufficiently complementary to the desired target mRNA sequence to direct target-specific silencing, e.g., complementarity sufficient to trigger the destruction of the desired target mRNA by the RNAi machinery or process (RNAi interference) or complementarity sufficient to trigger translational repression of the desired target mRNA.

The term "sense strand" or "second strand" of an RNA silencing agent, e.g. an siRNA or RNAi agent, refers to a strand that is complementary to the antisense strand or first strand. Antisense and sense strands can also be referred to as first or second strands, the first or second strand having complementarity to the target sequence and the respective second or first strand having complementarity to said first or second strand. miRNA duplex intermediates or siRNA-like duplexes include a miRNA strand having sufficient complementarity to a section of about 10-50 nucleotides of the mRNA of the gene targeted for silencing and a miRNA* strand having sufficient complementarity to form a duplex with the miRNA strand.

As used herein, the term "guide strand" refers to a strand of an RNAi agent, e.g., an antisense strand of an siRNA duplex or siRNA sequence, that enters into the RISC complex and directs cleavage of the target mRNA. The term "engineered," as in an engineered RNA precursor, or an engineered nucleic acid molecule, indicates that the precursor or molecule is not found in nature, in that all or a portion of the nucleic acid sequence of the precursor or molecule is created or selected by man. Once created or selected, the sequence can be replicated, translated, transcribed, or otherwise processed by mechanisms within a cell. Thus, an RNA precursor produced within a cell from a transgene that includes an engineered nucleic acid molecule is an engineered RNA precursor.

An "isolated nucleic acid molecule or sequence" is a nucleic acid molecule or sequence that is not immediately contiguous with both of the coding sequences with which it is immediately contiguous (one on the 5¹ end and one on the 3¹ end) in the naturally occurring genome of the organism from which it is derived. The term therefore includes, for example, a recombinant DNA or RNA that is incorporated into a vector; into an autonomously replicating plasmid or virus; or into the genomic DNA of a prokaryote or eukaryote, or which exists as a separate molecule (e.g., a cDNA or a genomic DNA fragment produced by PCR or restriction endonuclease treatment) independent of other sequences. It also includes a recombinant DNA that is part of a hybrid gene encoding an additional polypeptide sequence. As used herein, the term "isolated RNA" (e.g., "isolated shRNA", "isolated siRNA", "isolated siRNA-like duplex", "isolated miRNA", "isolated gene silencing agent", or "isolated RNAi agent") refers to RNA molecules which are substantially free of other cellular material, or culture medium when produced by recombinant techniques, or substantially free of chemical precursors or other chemicals when chemically synthesized.

As used herein, the term "transgene" refers to any nucleic acid molecule, which is inserted by artifice into a cell, and becomes part of the genome of the organism that develops from the cell. Such a transgene may include a gene that is partly or entirely heterologous (i.e., foreign) to the transgenic organism, or may represent a gene homologous to an endogenous gene of the organism. The term "transgene" also means a nucleic acid molecule that includes one or more selected nucleic acid sequences, e.g., DNAs, that encode one or more engineered RNA precursors, to be expressed in a transgenic organism, e.g., animal, which is partly or entirely heterologous, i.e., foreign, to the transgenic animal, or homologous to an endogenous gene of the transgenic animal, but which is designed to be inserted into the animal's genome at a location which differs from that of the natural gene. A transgene includes one or more promoters and any other DNA, such as introns, necessary for expression of the selected nucleic acid sequence, all operably linked to the selected sequence, and may include an enhancer sequence. A gene "involved" in a disease or disorder includes a gene, the normal or aberrant expression or function of which effects or causes the disease or disorder or at least one symptom of said disease or disorder.

"Allele specific inhibition of expression" refers to the ability to significantly inhibit expression of one allele of a gene over another, e.g., when both alleles are present in the same cell. For example, the alleles can differ by one, two, three or more nucleotides. In some cases, one allele is associated with disease causation, e.g., a disease correlated to a dominant gain-of-function mutation.

As used herein, the term "metabolic disorder", refers to any disease or disorder that affects how the body processes substances needed to carry out physiological functions. A number of metabolic disorders share certain characteristics, i.e. they are associated the insulin resistance, lack of ability to regulate blood sugar, weight gain, and increase in body mass index. Examples of metabolic disorders include diabetes and obesity, as well as increased serum cholesterol levels (e.g, hypercholesterolemia). The term "gain-of-fiinction mutation" as used herein, refers to any mutation in a gene in which the protein encoded by said gene (i.e., the mutant protein) acquires a function not normally associated with the protein (i.e., the wild type protein) causes or contributes to a disease or disorder. The gain-of-function mutation can be a deletion, addition, or substitution of a nucleotide or nucleotides in the gene which gives rise to the change in the function of the encoded protein. In one embodiment, the gain-of-function mutation changes the function of the mutant protein or causes interactions with other proteins. In another embodiment, the gain-of-function mutation causes a decrease in or removal of normal wild-type protein, for example, by interaction of the altered, mutant protein with said normal, wild-type protein.

The phrase "examining the function of a gene in a cell or organism" refers to examining or studying the expression, activity, function or phenotype arising therefrom.

Various methodologies of the instant invention include step that involves comparing a value, level, feature, characteristic, property, etc. to a "suitable control", referred to interchangeably herein as an "appropriate control". A "suitable control" or "appropriate control" is any control or standard familiar to one of ordinary skill in the art useful for comparison purposes. In one embodiment, a "suitable control" or "appropriate control" is a value, level, feature, characteristic, property, etc, determined prior to performing an RNAi methodology, as described herein. For example, a transcription rate, mRNA level, translation rate, protein level, biological activity, cellular characteristic or property, genotype, phenotype, etc. can be determined prior to introducing an RNAi agent of the invention into a cell or organism. In another embodiment, a "suitable control" or "appropriate control" is a value, level, feature, characteristic, property, etc. determined in a cell or organism, e.g., a control or normal cell or organism, exhibiting, for example, normal traits. In yet another embodiment, a "suitable control" or "appropriate control" is a predefined value, level, feature, characteristic, property, etc.

"Treatment", or "treating" as used herein, is defined as the application or administration of a therapeutic agent (e.g., a RNA silencing agent or a vector or transgene encoding same) to a patient, or application or administration of a therapeutic agent to an isolated tissue or cell line from a patient, who has a disorder with the purpose to cure, heal, alleviate, delay, relieve, alter, remedy, ameliorate, improve or affect the disease or disorder, or symptoms of the disease or disorder. The term "treatment" or "treating" is also used herein in the context of administering agents prophylactically. The term "effective dose" or "effective dosage" is defined as an amount sufficient to achieve or at least partially achieve the desired effect. The term "therapeutically effective dose" is defined as an amount sufficient to cure or at least partially arrest the disease and its complications in a patient already suffering from the disease. The term "patient" includes human and other mammalian subjects that receive either prophylactic or therapeutic treatment.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described below. AU publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.

Various aspects of the invention are described in further detail in the following subsections.

H. Nanotransporters

The present invention provides for compositions, e.g., pharmaceutical compositions, comprising nanotransporters wherein the nanotransporter comprises a core with various functional surface groups attached. Figure 1 is a schematic representation of the architecture of an exemplary nanotransporter of the invention. As can be seen from this figure, nucleic acid molecules, e.g., siRNA, can conjugate to the core of the nanotransporter. In some embodiments, the nucleic acid molecules, e.g., siRNA, are then delivered to the target site via the nanotransporter.

In another embodiment, pharmaceutical agents can be conjugate to the core of the nanotransporter. In some embodiments, pharmaceutical agents are then delivered to the target site via a nanotransporter.

a) Core of the Nanotransporter In exemplary embodiments, the core of the nanotransporter is a nanoparticle or a nanotube. Nanotubes may be single walled ("SWNTs") or multi-walled ("MWNTs"). See, e.g., S. Iijima et al., Nature, 363, 603 (1993); S. Iijima, Nature, 354, 56 (1991). A SWNT is a single tube that is about 1 nanometer in diameter and about 1 to about 100 microns in length. MWNTs are tubes with at least one other tube embedded within it.

In some embodiments, nanotubes can have one end capped with the hemisphere of a fullerene like structure. Nanotubes have attracted increasing attention because of their unique geometry and electronic, mechanical, chemical, and thermal properties. Nanotubes for use in the present invention may be single walled or multi-walled. In other embodiments, the nanotransporter core is a nanoparticle. Nanoparticles of the present invention include, but are not limited to dendrimers. Dendrimers are highly branched polymers with well-defined architecture. Dendrimers comprise several layers or "generations" of repeating units that all contain one or more branch points.

Dendrimers are generally prepared by condensation reactions of monomeric units having at least two reactive groups, for example by convergent or divergent synthesis.

Divergent synthesis of dendrimers routinely occurs in two steps: (1) activation of the end groups on the surface of the molecule, and (2) the addition of branching monomer units. The reaction starts at a core molecule, which contains several reactive sites. Monomer units react readily with the core molecule forming the first generation of the dendrimer. The end groups of the monomer are protected however, and must be activated before addition of another monomer unit. Thus, the passive end groups are removed by a secondary reaction, and additional monomer units are then added. The resulting dendrimer contains an ordered arrangement of layered branches.

Convergent synthesis of dendrimers involves a growth process that begins from what will become the surface of the dendrimer. Similar to divergent synthesis, convergent synthesis routinely involves two steps: (1) the attachment of the outermost groups to an inner generation and (2) the attachment of the inner generations to the core molecule. In one embodiment, dendrimers of the invention are synthesized by divergent synthesis. In another embodiment, dendrimers of the invention are synthesized by convergent synthesis.

Each dendrimer includes a core molecule or "core dendron," one or more layers of internal dendrons, and an outer layer of surface dendrons. As used herein, "dendrons" are the branched molecules used to construct a dendrimer generation. The dendrons can be the same or different in chemical structure and branching functionality. The branches of dendrons can contain either chemically reactive or passive functional groups. When the surface contains chemically reactive groups, those groups may be used for further extension of dendritic growth or for modification of dendritic molecular surfaces, for example by attachment of various functional surface groups. The chemically passive groups can be used to physically modify dendritic surfaces, such as to adjust the ratio of hydrophobic to hydrophilic terminals, or to improve the solubility of the dendrimer for a particular environment.

Dendrimers of the invention are described by reference to their "generation". As used herein, "generation" refers to the number of synthetic rounds that the dendrimer has undergone. For example, the starting or "core" dendron is generation zero. The first addition of dendrons onto the core dendron is the first generation. The second addition of dendrons onto the core dendron is the second generation, etc. Reference to the generation can provide information about the number of end groups available for conjugation with other moieties, for example with various functional surface groups. In other embodiments, the dendrimers comprise one or more (e.g. 2, 3, 4, 5, 6, 7, 8, 9, or 10) branches radially terminating from the core dendron.

In certain embodiments, the dendrimers of the invention comprise natural amino acids (e.g., histidine, lysine, etc.) or synthetic derivatives thereof. In one embodiment, the dendrimers of the invention comprise about 10 to about 100 amino acid subunits. In another embodiment, the dendrimers of the invention comprise about 10 to about 75 amino acid subunits. In another embodiment, the dendrimers of the invention comprise about 10 to about 50 amino acid subunits {e.g., 10, 11, 12, 13, 14,15, 16, 17, 18, 19, 20, 30, 40, or 50 subunits). In certain embodiments, the dendrimer is a sulfur-containing dendrimer Qe., comprises one or more sulfur atoms). For example, the sulfur-containing dendrimer may comprise branches which terminate at a terminal thiol group. In one embodiment, the dendrimer comprise one or more terminal thiols. Preferably, the dendrimer comprises 1-20 terminal thiols (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 terminal thiols). More preferably, the dendrimer comprises 16 terminal thiols. An exemplary sulfur-containing dendrimer is depicted in Figure 39. In other embodiments, the dendrimers comprise branches which terminate at a free amine group (e.g., a primary amine or secondary amine). In one embodiment, the dendrimer comprise one or more terminal primary amines. Preferably, the dendrimer comprises 1-20 terminal primary amines {e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, IS, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 40, 50, 60, 70, 80, 90, 100 or more terminal primary amines). More preferably, the dendrimer comprises 16 terminal primary amines. In another embodiment, the dendrimer comprises 60 or more terminal primary amines (see LDG5, Figure 40).

In another embodiment, the dendrimer comprise one or more terminal secondary amines. Preferably, the dendrimer comprises 1-20 terminal secondary amines (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 terminal secondary amines). In another embodiment, the dendrimer comprises 32 terminal secondary amines (see SLDG4, Figure 41). In another embodiment, the dendrimer comprises 64 terminal secondary amines (see SLDG5, Figure 42). In another embodiment, the dendrimer comprise one or more terminal carboxylates. Preferably, the dendrimer comprises 1-20 terminal carboxylates (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 terminal carboxylates). In another embodiment, the dendrimer comprises 8 terminal carboxylates. Many dendrimers are commercially available. The dendrimers of the invention include but are not limited to the following: polylysine dendrimers; Polyamido amine (PAMAM) PAMAM: Amine terminated and/or PAMAM: Carboxylic Acid terminated (available, e.g., from Dendriteck, Inc., Midland, MI); Diaminobutane (DAB) - DAB: Amine terminated and/or DAB: Carboxylic Acid terminated; PEGs: OH terminated (Frechet et al. JACS 123:5908 (2001)), among others. In one embodiment, polylysine dendrimers or a variant thereof are used.

In one embodiment, the core of the nanotransporter is a polylysine generation 1 ("LDGl"). An exemplary synthesis of LDGl is shown in Figure 4A. In another embodiment, the core of the nanotransporter is a polylysiαe generation 2 ("LDG2"). An exemplary synthesis of LDG2 is shown in Figure 4B. In yet other embodiments, the dendrimer is a high molecular weight dendrimer. For example, in another embodiment, the core of the nanotransporter is a polylysine generation 1 ("LDG3"). An exemplary synthesis of LDG3 is shown in Figure 4C. In yet another embodiment, the core of the nanotransporter is polylysine dendrimer generation 4 ("LDG4"). An exemplary synthesis of LDG4 is shown in Figure 4D.

In another embodiment, the core of the nanotransporter is a nanoparticle comprising a low molecular weight polylysine dendrimer. Figure 5 depicts an exemplary scheme of the synthesis of low molecular weight polylysine dendrimers.

b) Functional Surface Groups

In one aspect of the present invention, various functional surface groups can be conjugated to the core of the nanotransporter. As used herein, the term "functional surface group" refers to molecules that upon binding to the core increase the functionality of the nanotransporter, e.g., to increase cell targeting specificity, to increase delivery of the nanotransporter to the target cell, and/or to impart a precise biological function. Examples of functional surface groups of the invention include, but are not limited to, carbohydrates, lipids, fatty acids and derivatives, fluorescent and charge controlling molecules, and cell type specific targeting moieties. Figure 2 depicts a schematic of a nanotransporter delivery device with multiple functional surface groups attached. In the present invention, a single type of functional surface group or multiple types of functional surface groups may be present on the surface of the core of the nanotransporter. Moreover, multiple functional surface groups (e.g., lipids) of the same or different type may be present on the core of the nanotransporter (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 50, 60, 70, 80, 90, 100, or more functional surface groups). In preferred embodiments, 6 or 7 functional surface groups (e.g., 6 or 7 oleolyl lipids) are employed.

Q Lipid Functional Surface Groups

In one embodiment, the functional surface group is a lipid. Lipids are a major class of biomolecules that include fatty acids, waxes, glycerol and triacylglycerols, phospholipids and cholesterols. Without wishing to be bound by any particular theory, it is believed that the addition of a lipid to the core of the nanotransporter increases the ability of the nanotransporter to deliver the nucleic acid molecule or pharmaceutical agent to the target cell. In one embodiment, the lipid is a long chain fatty acid (e.g., an oleoyl derivative, see e.g. Figure 6A, or an oleolyic acid derivative, see e.g. Figure 7). In another embodiment, the lipid is a polyethylene glycol (PEG) derivative (e.g., see Figure 6B). In another embodiment, the lipid is a cholesterol derivative (e.g., Figure 6C) for use as a lipid functional surface group. For example, a nanotransporter of the invention may comprise 1, 2, 3, or 4 cholesterol groups (see eg. Figure 43) or 1, 2, 3, or 4 cholesterol groups combined with 1, 2, 3, 4, 5, 6, 7, or 8 lipid groups (see e.g., Figure 44). In another exemplary embodiment, a nanotransporter may comprise 1-10 PEG groups (e.g. 4 lipid groups) together with 1-10 (e.g., 7) lipids, and 1-50 (e.g.24) terminal primary amines (see Figure 49A). In another exemplary embodiment, a nanotransporter may comprise 1-10 lipid groups (e.g. 7 lipid groups) together with 1-10 (e.g., 8) terminal carboxylates, and 1-50 (e.g.17) terminal primary amines (see Figure 49B). The present invention is also directed to the synthesis of various lipid functional surface groups. Lipid functional surface groups of the invention can be prepared according to methods generally known in the art. In one embodiment, lipid functional surface groups are prepared according to the methods shown in Figure 6A-C. Figure 7 shows the synthesis of an oleoylic acid derivative, another lipid functional surface group for use in the present invention. In one embodiment, this chain is attached directly to the core of the nanotransporter. This chain may also be attached directly to a nucleic acid molecule or pharmaceutical agent.

The lipid functional surface group can be conjugated to a low molecular weight nanoparticle, e.g., a dendrimer. A non-limiting example of a lipid functional surface group conjugated to a low molecular weight nanoparticle can be seen in Figure 5.

It is understood that any lipid known in the art can be used to make lipid functional surface groups. For example, cationic lipids, neutral phospholipids or negatively charged lipids may be used. Suitable cationic lipid species which can be combined with the compounds of the invention include, but are not limited to, 1,2 bis(oleoyloxy)-3-(trimethylammonio)propane (DOTAP); N-[l,-(2,3-dioleoyloxy) propyl]-N,N,N-trimethyl ammonium chloride (DOTMA) or other N-(N₃N- 1-dialkoxy)- alkyl-N,N,N-trisubstituted ammonium surfactants; 1,2 dioleoyl-3-(4'-trimethyIammonio) butanoyl-sn-glycerol (DOBT) or cholesterol (4'-trimethylammonia) butanoate (ChOTB) where the trimethylammonium group is connected via a butanoyl spacer arm to either the double chain (for DOTB) or cholesterol group (for ChOTB); DORI (DL- 1,2- dioleoyl-3-dimethylaminopropyl-B-hydroxyethylammonium) or DORDE (DL-1,2-0- dioleoyl-3-dimethylaminopropyl-β-hydroxyethylammonium) (DORIE) or analogs thereof as disclosed in WO 93/03709; l,2-dioleoyl-3-succinyl-sn-glycerol choline ester (DOSC); cholesterol hemisuccinate ester (ChOSC); lipopolyamines such as doctadecylamidoglycylspermine (DOGS) and dipalmitoyl phosphatidyesthanolamidospermine (DPPES), or the cationic lipids disclosed in U.S. Pat. No. 5,283,185, cholesterol-Sβ-carboxyamido-ethylenetrimethylammonium iodide, l-dimethylaniino-S-trimetliylamraonio-DL-a-propyl-cholesterol carboxylate iodide, cholesterol-3 β-carboxyamidoethyleneamine, cholesterol-3 β- oxysuccinamidoethylenetrimethylammonium iodide, l-dimethylamino-3- trimethylamjnonio-DL-2-propyl-cholesterol-3 β-oxysuccinate iodide, 2-[(2- trimethylammonio)-ethylmethylamino] ethyl-cholestero 1-3 β-oxysuccinate iodide, 3β[N- (N',N'-dimethylaminoethane)-carbamoyl]-cholesterol (DC-chol), and 3β-[N- (polyethyleneimine)-carbamoyl]cholesterol.

Other exemplary cationic lipids include cholesterol-3β- carboxyamidoethylenetrimethylanimonium iodide, l-dimethylamino-3- trimethylaπunonio-DL-2-propyl-cholesterol carboxylate iodide, cholesterol-3 β- carboxyamidoethyleneamine, cholesterol-3 β-oxysuccin- amidoethylenetrimethylammonium iodide, 1 -dimethylamino-3-trimethylammonio-DL- 2-propyl-cholesterol-3 β-oxysuccinate iodide, 2-[(2- trimethylammonio)ethyknethylamino]-ethyl-cholesterol-3β-oxysuccinate iodide, 3β[N- (N^l,N'dimethyl-aminoethane)-carbamoyl]-cholesterol (DC-chol), and 3β[N-(N',N'- dimethylaminoethane)-carbamoyl]-cholesterol.

In addition to cationic lipids, other lipids may be employed. These lipids include, but are not limited to, lyso lipids of which lysophosphatidylcholine (1- oleoyllysophosphatidycholine) is an example, cholesterol, or neutral phospholipids including dioleoyl phosphatidyl ethanolamine (DOPE) or dioleoyl phosphatidylcholine (DOPC). Suitable negatively charged lipid species include, but are not limited to, phosphatidyl glycerol and phosphatide acid or a similar phospholipid analog.

ii> Dyes

In another embodiment of the invention, the functional surface group attached to the nanotransporter core is a dye. According to one embodiment, the dye acts as a label so as to provide for easy detection of the location at which the nanotransporter binds. Dyes for use in the present invention are generally known in the art. Preferred dyes include, but are not limited to, Fluorescein, Texas Red, Rhodamine Red, and Oregon Green 514, Examples of fluorescent dyes are found in the Molecular Probes Catalog, 6th Ed., Richard Haugland, Ed. The dyes of the invention may be conjugated to the core alone, or in combination with one or more other functional surface group.

In one embodiment, a lipid functional surface group and a dye are conjugated to the core of the nanotransporter. The lipid functional surface group and the dye can be conjugated to the core of the nanotransporter at the same time. In another embodiment, the lipid functional surface group and the dye are added to the core of the nanotransporter consecutively, e.g., either the lipid functional surface group or the dye is first conjugated, and then the other is conjugated to the core of the nanotransporter. Figure 9 shows an exemplary nanotransporter, wherein both a lipid functional surface group and a dye are conjugated to the nanoparticle core. Figure 10 shows two other exemplary nanotransporters comprising a nanoparticle core, a lipid functional surface group and a dye.

iv> Cell Type Specific Targeting Moieties

In another embodiment, the functional surface group is comprised of a cell type specific targeting moiety. Use of cell type specific targeting moieties allows the nanotransporter complex to discriminate among distinct cell types. The addition of a cell type specific targeting moiety to the nanotransporter therefore allows the nanotransporter to impart a precise biological function.

Numerous cell type specific targeting moieties are known in the art. The targeting moiety may be a protein, peptide, carbohydrate, glycoprotein, small molecule, metal, etc. The targeting moiety may be used to target specific cells or tissues. Examples of targeting moieties include, but are not limited to, lung carcinoma cell specific peptide TP H1299.1 (Zhao, X, et al., J. Am. Chem. Soc. 2004, 126, 15656), lung adenocarcinoma cell specific peptide TP H2009.1 (Oyama, T., et al., Cancer Lett, 2003, 202, 219), and endothelial cell targeting peptide CNGRC (Arap, et. al., Science 1998, 279:377). Such targeting moieties can be synthesized using methods known in the art, for example, as can be seen in Figure 12, by using a MBHA resin. The cell specific targeting moiety can then be conjugated directly with a nucleic acid molecule, e.g., siRNA, or a pharmaceutical agent. Figure 13 shows the conjugation of siRNA to lung cell specific peptide. Similarly, this method can be used to conjugate the peptide to the core of the nanotransporter. For example, as can be seen in Figure 11, a cyclic CNGRC can be conjugated to the core of the nanotransporter, e.g., LDG4. Additionally, a lipid functional group, e.g., an oleolyl derivative, is conjugated to the core of the nanotransporter. The nucleic acid molecule conjugates to the nanotransporter for delivery to the target cells, e.g., endothelial cells. The synthesis of this nanotransporter is shown in Figure 14. The nano transporters of the present invention further can be used to deliver nucleic acid molecules, e.g., siRNA, and/or pharmaceutical agents to cancer cells.

In one embodiment, the cell-type specific targeting moiety is specific for tumor cells or virally infected cells (e.g. Transportan, Penetratin, or Tat peptide). An exemplary nanotransporter of the invention comprising a LDG4 core functionalized with Tat peptide is shown in Figure 47.

v) Charge Controlling Molecules

In another embodiment, the functional surface group is comprised of a charge controlling molecule. A "charge controlling molecule," as used herein, refers to a molecule which contributes to the overall ionic environment or net charge of a nanotransporter. In one embodiment, the addition of a charge controlling molecule facilitates the association between the nanotransporter and a siRNA molecule and the formation of a delivery complex. In another embodiment, the addition of a charge controlling molecule facilitates improved cellular uptake of the delivery complex into the cell. In certain embodiments, charge controlling molecules can be attached to a nanotransporter as shown in Formula Ia of Figure 37A, thereby forming a modified nanotransporter of Formula Ib, wherein, n is the number of lipid groups attached to the surface of the nanotransporter, m is the number of charge controlling molecules or net charge of the nanotransporter and R is a charge controlling molecule. Exemplary charge controlling molecules for use with a nanotransporter of the present invention are shown in Figure 37B. In certain embodiments, the charge controlling molecules are the same chemical structure or class. In other embodiments where m is greater than 1, any combination of charge controlling molecules of different chemical structures or classes may be used. A preferred charge controlling molecule is H-Lys-OMe. Exemplary modification of a nanotransporter with H-Lys-OMe is depicted in Figure 38.

The net charge (m) and/or the number of lipid groups (n) of the modified nanotransporter may be varied depending on the tissue that is targeted. In one embodiment, m results in a positive net charge. In another embodiment, m is a positive negative charge. In other embodiment, m is a neutral net charge. In another embodiment, m is a positive integer less than 50 (e.g. 40, 30, 20, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1). In another embodiment, n is a positive integer less than 50 (e.g., (e.g. 40, 30, 20, 10, 9, 8, 1, 6, 5, 4, 3, 2, or 1). It is recognized that any combination of lipids described supra may be employed together with any combination of charge controlling molecules.

vi) Carbohydrates

In another embodiment, the functional surface group is comprised of carbohydrate. In one embodiment, the carbohydrate is a monosaccharide (e.g., an aldose, a ketose, a triose, a tetrose, a pentose, a hexose, a heptose, an aldohexose, a ketopentose, a allose, a glucose, a mannose, a galactose, a xylose, an erythrulose, a fructose, a glucoasamine, a ribose, a rhamnose, a galactosamine, N-acetylmuramic acid, N-acetylmuramic acid, fucose, and the like). In another embodiment, the carbohydrate is a polysaccharide (e.g., a homopolysaccharide (e.g., cellulose) or a heteropolysaccharide). In another embodiment, the carbohydrate is a disaccharide (e.g., sucrose, lactose, maltose, cellobiose, and the like). Any epimer or other stereoisomer (e.g., L or D isomer) of a monosaccharide may be employed. Synthesis of exemplary carbohydrate-containing nanotransporters may comprise 9 disaccharides (see e.g., HB- M9LD, Figure 44) or 26 disaccharides (see e.g., HB-MLD, Figure 44).

HL Nucleic Acid Molecules

In one embodiment nucleic acid molecules are delivered to a target cell via a nanotransporter. As used herein the term "nucleic acid molecule" refers to a polymer of nucleotides joined together by a phosphodiester linkage between 5' and 3' carbon atoms. Nucleic acid molecules are generally known in the art, and include, but are not limited to RNA silencing agents (e.g. siRNAs, chemically modified siRNAs, RNAi agents, miRNAs, and shRNAs), antisense molecules, ribozymes, and the like.

(a) RNA Silencing Agents

In certain embodiments, the present invention features RNA silencing agents (e.g., siRNA and shRNAs). The RNA silencing agents of the invention are duplex molecules (or molecules having duplex-like structure) comprising a sense strand and a complementary antisense strand (or portions thereof), wherein the antisense strand has sufficient complementary to a target sequence (e.g. target mKNf A) to mediate an RNA silencing mechanism (e.g. RNAi or translational repression).

i) Design of siRNA Molecules

An siRNA molecule is a duplex consisting of a sense strand and complementary antisense strand, the antisense strand having sufficient complementary to a target mRNA sequence to direct target-specific RNA interference (RNAi), as defined herein, i.e., the siRNA has a sequence sufficient to trigger the destruction of the target mRNA by the RNAi machinery or process. In alternative embodiments, the antisense strand of the siRNA has sufficient complementarity to a target mRNA sequence to direct translation repression of the target mRNA.

Preferably, the siRNA molecule has a length from about 5-60 (e.g., about 10-50) or more nucleotides, i.e., each strand comprises 5-60 (e.g., .10-50) nucleotides (or nucleotide analogs). More preferably, the siRNA molecule has a length from about 16 - 30, e.g., 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 nucleotides (or nucleotide analogs) in each strand, wherein one of the strands is sufficiently complementary to a target region. In other embodiments, siRNAs may have shorter or longer lengths. In one embodiment, the siRNA has a length of about 5-15 nucleotides or nucleotide analogs (e.g., 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 nucleotides) in each strand, wherein one of the strands is sufficiently complementary to a target region. In another embodiment, the siRNA has a length of about 30-60 nucleotides or nucleotide analogs (e.g., 35, 40, 45, 50, 55, or 60 nucleotides in each strand, wherein one of the strands is sufficiently complementary to a target region). Preferably, the strands are aligned such that there are at least 1, 2, or 3 bases (e.g., 1-5 bases) at the end of the strands which do not align (i.e., for which no complementary bases occur in the opposing strand) such that an overhang of 1, 2 or 3 residues occurs at one or both ends of the duplex when strands are annealed. In particularly preferred embodiments, at least one (preferably both) ends of the duplex comprise a 2 nucleotide overhands (e.g., dTdT overhangs).

Generally, siRNAs can be designed by using any method known in the art, for instance, by using the following protocol: 1. A target mRNA is selected and one or more target sites are identified within said target mRNA. Cleavage of mRNA at these sites results in mRNA degradation, preventing production of the corresponding protein. Polymorphisms from other regions of the mutant gene are also suitable for targeting. In preferred embodiments, the target sequence comprises AA dinucleotide sequences; each AA and the 3¹ adjacent 16 or more nucleotides are potential siRNA targets. In another preferred embodiment, the nucleic acid molecules are selected from a region of the target mRNA sequence beginning at least 50 to 100 nt downstream of the start codon, e.g., of the sequence of the target mRNA. Further, siRNAs with lower G/C content (35-55%) may be more active than those with G/C content higher than 55%. Thus in one embodiment, the invention includes target sequences having 35-55% G/C content, although the invention is not limited in this respect.

2. The sense strand of the siRNA is designed based on the sequence of the selected target site. Preferably the sense strand includes about 19 to 25 nucleotides, e.g., 19, 20, 21, 22, 23, 24 or 25 nucleotides. More preferably, the sense strand includes 21, 22 or 23 nucleotides. The skilled artisan will appreciate, however, that siRNAs having a length of less than 19 nucleotides or greater than 25 nucleotides can also function to mediate RNAi. Accordingly, siRNAs of such length are also within the scope of the instant invention provided that they retain the ability to mediate RNAi. Longer RNAi agents have been demonstrated to elicit an interferon or PKR response in certain mammalian cells which may be undesirable. Preferably the RNAi agents of the invention do not elicit a PKR response (i.e., are of a sufficiently short length). However, longer RNAi agents may be useful, for example, in cell types incapable of generating a PRK response or in situations where the PKR response has been downregulated or dampened by alternative means.

The siRNA molecules of the invention have sufficient complementarity with the target site such that the siRNA can mediate RNAi. In general, siRNA containing nucleotide sequences sufficiently identical to a portion of the target gene to effect RISC- mediated cleavage of the target gene are preferred. Accordingly, in a preferred embodiment, the sense strand of the siRNA is designed have to have a sequence sufficiently identical to a portion of the target. For example, the sense strand may have 100% identity to the target site. However, 100% identity is not required. Greater than 80% identity, e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or even 100% identity, between the sense strand and the target RNA sequence is preferred. The invention has the advantage of being able to tolerate certain sequence variations to enhance efficiency and specificity of RNAi. In one embodiment, the sense strand has 4, 3, 2, 1, or 0 mismatched nucleotide(s) with a target region, and the other strand is identical or substantially identical to the first strand. Moreover, siRNA sequences with small insertions or deletions of 1 or 2 nucleotides may also be effective for mediating RNAi. Alternatively, siRNA sequences with nucleotide analog substitutions or insertions can be effective for inhibition. Sequence identity may be determined by sequence comparison and alignment algorithms known in the art. To determine the percent identity of two nucleic acid sequences (or of two amino acid sequences), the sequences are aligned for optimal comparison purposes (e.g., gaps can be introduced in the first sequence or second sequence for optimal alignment). The nucleotides (or amino acid residues) at corresponding nucleotide (or amino acid) positions are then compared. When a position in the first sequence is occupied by the same residue as the corresponding position in the second sequence, then the molecules are identical at that position. The percent identity between the two sequences is a function of the number of identical positions shared by the sequences (i.e., % homology = # of identical positions/total # of positions x 100), optionally penalizing the score for the number of gaps introduced and/or length of gaps introduced.

The comparison of sequences and determination of percent identity between two sequences can be accomplished using a mathematical algorithm. In one embodiment, the alignment generated over a certain portion of the sequence aligned having sufficient identity but not over portions having low degree of identity (i.e., a local alignment). A preferred, non- limiting example of a local alignment algorithm utilized for the comparison of sequences is the algorithm of Karlin and Altschul (1990) Proc. Natl. Acad ScL USA 87:2264-68, modified as in Karlin and Altschul (1993) Proc. Natl. Acad. Sci. USA 90:5873-77. Such an algorithm is incorporated into the BLAST programs (version 2.0) of Altschul, et al. (1990) J. MoI Biol. 215:403- 10.

In another embodiment, the alignment is optimized by introducing appropriate gaps and percent identity is determined over the length of the aligned sequences (i.e., a gapped alignment). To obtain gapped alignments for comparison purposes, Gapped BLAST can be utilized as described in Altschul el al., (\ 997) Nucleic Acids Res. 25(17):3389-3402. In another embodiment, the alignment is optimized by introducing appropriate gaps and percent identity is determined over the entire length of the sequences aligned (i.e., a global alignment). A preferred, non-limiting example of a mathematical algorithm utilized for the global comparison of sequences is the algorithm of Myers and Miller, CABIOS (1989). Such an algorithm is incorporated into the ALIGN program (version 2.0) which is part of the GCG sequence alignment software package. When utilizing the ALIGN program for comparing amino acid sequences, a PAM120 weight residue table, a gap length penalty of 12, and a gap penalty of 4 can be used.

3. The anti sense strand sequence is designed such that nucleotides corresponding to the desired target cleavage site are essentially in the middle of the strand. For example, if a 21-nucleotide siRNA is chosen, nucleotides corresponding to the target cleavage site are at, for example, nucleotide 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 or 16 (i.e., 6, 1, 8, 9, 10, 11, 12, 13, 14, 15 or 16 nucleotides from the 5' end of the sense strand. For a 22-nucleotide siRNA, nucleotides corresponding to the target cleavage site are at, for example, nucleotide 7, 8, 9, 10, 11, 12, 13, 14, 15 or 16. For a 23-nucleotide siRNA, nucleotides corresponding to the target cleavage site are at, for example, 7, 8, 9, 10, 11, 12, 13, 14, 15 or 16. For a 24-nucleotide siRNA, nucleotides corresponding to the target cleavage site are at, for example, 9, 10, 11, 12, 13, 14 or 16. For a 25- nucleotide siRNA, nucleotides corresponding to the target cleavage site are at, for example, 9, 10, 11, 12, 13, 14, 15, 16 or 17. Moving nucleotides corresponding to an off-center position may, in some instances, reduce efficiency of cleavage by the siRNA. Such compositions, i.e., less efficient compositions, may be desirable for use if off- silencing of a second (non-target) mRNA is detected.

The sense strand is designed such that complementarity exists between the antisense strand of the siRNA and the sense strand. In exemplary embodiments, the siRNA is designed such that the strands have overhanging ends, e.g., overhangs of 1, 2, 3, 4, 5 or more nucleotide at one, or both, ends of the siRNA. Exemplary overhangs are deoxynucleotide overhangs, for example, a dTdT tail.

4. The antisense or guide strand of the siRNA is routinely the same length as the sense strand and includes complementary nucleotides. In one embodiment, the guide and sense strands are fully complementary, i.e., the strands are blunt-ended when aligned or annealed. In another embodiment, the strands of the siKNA can be paired in such a way as to have a 3' overhang of 1 to 4, e.g., 2, nucleotides. Overhangs can comprise (or consist of) nucleotides corresponding to the target gene sequence (or complement thereof). Alternatively, overhangs can comprise (or consist of) deoxyribonucleotides, for example dTs, or nucleotide analogs, or other suitable non- nucleotide material. Thus in another embodiment, the nucleic acid molecules may have a 3' overhang of 2 nucleotides, such as TT. The overhanging nucleotides may be either RNA or DNA.

5. Using any method known in the art, compare the potential targets to the appropriate genome database (human, mouse, rat, etc.) and eliminate from consideration any target sequences with significant homology to other coding sequences. One such method for such sequence homology searches is known as BLAST, which is available at National Center for Biotechnology Information website.

6. Select one or more sequences that meet your criteria for evaluation. Further general information about the design and use of siRNA may be found in

"The siRNA User Guide," available at The Max-Plank-Institut fur Biophysikalishe Chemie website.

Alternatively, the siRNA may be defined functionally as comprising an antisense or guide strand having a nucleotide sequence (or oligonucleotide sequence) that is capable of hybridizing with the target sequence (e.g., 400 mM NaCl, 40 mM PIPES pH 6.4, 1 mM EDTA, 50⁰C or 70⁰C hybridization for 12-16 hours; followed by washing). Additional preferred hybridization conditions include hybridization at 70⁰C in IxSSC or 50⁰C in IxSSC, 50% formamide followed by washing at 70⁰C in 0.3xSSC or hybridization at 70⁰C in 4xSSC or 50⁰C in 4xSSC, 50% formamide followed by washing at 67°C in IxSSC. The hybridization temperature for hybrids anticipated to be less than 50 base pairs in length should be 5-10⁰C less than the melting temperature (Tm) of the hybrid, where Tm is determined according to the following equations. For hybrids less than 18 base pairs in length, Tm(⁰C) = 2(# of A + T bases) + 4(# of G + C bases). For hybrids between 18 and 49 base pairs in length, Tm(⁰C) = 81.5 + 16.6(loglO[Na+]) + 0.41(%G+C) - (600/N), where N is the number of bases in the hybrid, and [Na+] is the concentration of sodium ions in the hybridization buffer ([Na+] for IxSSC = 0.165 M). Additional examples of stringency conditions for polynucleotide hybridization are provided in Sambrook, J., E.F. Fritsch, and T. Maniatis, 1989, Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY, chapters 9 and 11, and Current Protocols in Molecular Biology, 1995, F.M. Ausubel et al., eds., John Wiley & Sons, Inc., sections 2.10 and 6.3-6.4, incorporated herein by reference. Negative control siRNAs should have the same nucleotide composition as the selected siRNA, but without significant sequence complementarity to the appropriate genome. Such negative controls may be designed by randomly scrambling the nucleotide sequence of the selected siKNA; a homology search can be performed to ensure that the negative control lacks homology to any other gene in the appropriate genome. In addition, negative control siRNAs can be designed by introducing a significant number of base mismatches into the sequence.

7. To validate the effectiveness by which siRNAs destroy mutant mRNAs (e.g., mutant huntingtin mRNA), the siRNA may be incubated with mutant cDNA (e.g., mutant huntingtin cDNA) in a Drosophi la-based in vitro mRNA expression system. Radiolabeled with ³²P, newly synthesized mutant mRNAs (e.g., mutant huntingtin mRNA) are detected autoradiographically on an agarose gel. The presence of cleaved mutant mRNA indicates mRNA nuclease activity. Suitable controls include omission of siRNA. Alternatively, control siRNAs are as described above are utilized.

ϋ> miRNAs miRNAs are noncoding RNAs of approximately 22 nucleotides which can regulate gene expression at the post transcriptional or translational level during plant and animal development. One common feature of miRNAs is that they are all excised from an approximately 70 nucleotide precursor RNA stem-loop termed pre-miRNA, probably by Dicer, an RNase Hi-type enzyme, or a homolog thereof.

The miRNA sequence can be similar or identical to that of any naturally occurring miRNA (see e.g. The miRNA Registry; Grifϊiths-Jones S, Nuc. Acids Res., 2004). Over one thousand natural miRNAs have been identified to date and together they are thought to comprise ~1% of all predicted genes in the genome. Many natural miRNAs are clustered together in the introns of pre-mRNAs and can be identified in silico using homology-based searches (Pasquinelli et al., 2000; Lagos-Quintana et al., 2001; Lau et al., 2001; Lee and Ambros, 2001) or computer algorithms (e.g. MiRScan, MiRSeeker) that predict the capability of a candidate miRNA gene to form the stem loop structure of a pri-mRNA (Grad et al., MoI. Cell, 2003; Lim et al., Genes Dev._? 2003; Lim et al., Science, 2003; Lai EC et al., Genome Bio._} 2003). An online registry provides a searchable database of all published miRNA sequences (The miRNA Registry at the Sanger Institute website; Griffiths-Jones S, Nuc. Acids Res., 2004). Exemplary, natural miRNAs include lin-4, let-7, miR-10, mirR-15, miR-16, miR-168, miR-175, miR-196 and their homologs, as well as other natural miRNAs from humans and certain model organisms including Drosophila melemogaster, Caenorhabditis elegans, zebrafish, Arabidopsis thalania, mouse, and rat as described in International PCT Publication No. WO 03/029459. Naturally-occurring miRNAs are expressed by endogenous genes in vivo and are processed from a hairpin or stem-loop precursor (pre-miRNA or pri-miRNAs) by Dicer or other RNAses (Lagos-Quϊntana et al., Science, 2001; Lau et al., Science, 2001; Lee and Ambros, Science, 2001; Lagos-Quintana et al.,Curr. Biol., 2002; Mourelatos et al., Genes Dev., 2002; Reinhart et al., Science, 2002; Ambros et al., Curr. Biol., 2003; Brennecke et al., 2003; Lagos-Quintana et al., RNA, 2003; Lim et al., Genes Dev., 2003; Lim et al., Science, 2003). miRNAs can exist transiently in vivo as a double-stranded duplex but only one strand is taken up by the RISC complex to direct gene silencing. Certain miRNAs, e.g. plant miRNAs, have perfect or near-perfect complementarity to their target mRNAs and, hence, direct cleavage of the target mRNAs. Other miRNAs have less than perfect complementarity to their target mRNAs and, hence, direct translational repression of the target mRNAs. The degree of complementarity between an miRNA and its target mRNA is believed to determine its mechanism of action. For example, perfect or near-perfect complementarity between a miRNA and its target mRNA is predictive of a cleavage mechanism (Yekta et al., Science, 2004), whereas less than perfect complementarity is predictive of a translational repression mechanism. In particular embodiments, the miRNA sequence is that of a naturally-occurring miRNA sequence, the aberrant expression or activity of which is correlated with a miRNA disorder.

Naturally-occurring miRNA precursors (pre-miRNA) have a single strand that forms a duplex stem including two portions that are generally complementary, and a loop, that connects the two portions of the stem. In typical pre-miRNAs, the stem includes one or more bulges, e.g., extra nucleotides that create a single nucleotide "loop" in one portion of the stem, and/or one or more unpaired nucleotides that create a gap in the hybridization of the two portions of the stem to each other. Short hairpin RNAs, or engineered RNA precursors, of the invention are artificial constructs based on these naturally occurring pre-miENAs, but which are engineered to deliver desired RNAi agents (e.g., siRNAs of the invention). By substituting the stem sequences of the pre- miRNA with sequence complementary to the target rnRNA, a shRNA is formed. The shRNA is processed by the entire gene silencing pathway of the cell, thereby efficiently mediating RNAi.

In embodiments, where post-transcriptional gene silencing by translational repression of the target gene is desired, the miRNA sequence has partial complementarity with the target gene sequence. In certain embodiments, the miRNA sequence has partial complementarity with one or more short sequences (complementarity sites) dispersed within the target mRNA (e.g. within the 3'-UTR of the target mRNA) (Hutvagner and Zamore, Science, 2002; Zeng et al., MoL Cell, 2002; Zeng et al., RNA, 2003; Doench et al., Genes & Dev., 2003). Since the mechanism of translational repression is cooperative, multiple complementarity sites (e.g., 2, 3, 4, 5, or 6) may be targeted in certain embodiments. iii^"> siRNA-like molecules siRNA-like molecules of the invention have a sequence (i.e., have a strand having a sequence) that is "sufficiently complementary" to a target mRNA sequence to direct gene silencing either by RNAi or translational repression. siRNA-like molecules are designed in the same way as siRNA molecules, but the degree of sequence identity between the sense strand and target RNA approximates that observed between an miRNA and its target. In general, as the degree of sequence identity between a miRNA sequence and the corresponding target gene sequence is decreased, the tendency to mediate post-transcriptional gene silencing by translational repression rather than RNAi is increased.

The capacity of a siRNA-like duplex to mediate RNAi or translational repression may be predicted by the distribution of non-identical nucleotides between the target gene sequence and the nucleotide sequence of the silencing agent at the site of complementarity. In one embodiment, where gene silencing by translational repression is desired, at least one non-identical nucleotide is present in the central portion of the complementarity site so that duplex formed by the guide strand and the target mRNA contains a central "bulge" (Doench JG et al., Genes & Dev., 2003). In another embodiment 2, 3, 4, 5, or 6 contiguous or non-contiguous non-identicat nucleotides are introduced. The non-identical nucleotide may be selected such that it forms a wobble base pair {e.g., G:U) or a mismatched base pair (G:A, C:A, C:U, G:G, A.A, C:C, U:U). In a further preferred embodiment, the "bulge" is centered at nucleotide positions 12 and 13 from, the 5 'end of the siKNA-like molecule.

iv) Short hairpin RNA (shRNA) molecules

In certain featured embodiments, the instant invention provides shRNAs capable of mediating RNA silencing of a target sequence (e.g. target mRNA) with enhanced selectivity. In contrast to siRNAs, shRNAs mimic the natural precursors of micro RNAs (miRNAs) and enter at the top of the gene silencing pathway. For this reason, shRNAs are believed to mediate gene silencing more efficiently by being fed through the entire ' natural gene silencing pathway. The requisite elements of a shRNA molecule include a first portion and a second portion, having sufficient complementarity to anneal or hybridize to form a duplex or double-stranded stem portion. The two portions need not be folly or perfectly complementary. The first and second "stem" portions are connected by a portion having a sequence that, has insufficient sequence complementarity to anneal or hybridize to other portions of the shRNA. This latter portion is referred to as a "loop" portion in the shRNA molecule. The shRNA molecules are processed to generate siRNAs. shRNAs can also include one or more bulges, i.e., extra nucleotides that create a small nucleotide "loop" in a portion of the stem, for example a one-, two- or three- nucleotide loop. The stem portions can be the same length, or one portion can include an overhang of, for example, 1-5 nucleotides. The overhanging nucleotides can include, for example, uracils (Us), e.g., all Us. Such Us are notably encoded by thymidines (Ts) in the shRNA-encoding DNA which signal the termination of transcription.

In shRNAs of the instant invention, one portion of the duplex stem is a nucleic acid sequence that is complementary (or anti-sense) to the target mRNA. Preferably, one strand of the stem portion of the shRNA is sufficiently complementary (e.g., antisense) to a target RNA (e.g., mRNA) sequence to mediate degradation or cleavage of said target RNA via RNA interference (RNAi). Thus, shRNAs include a duplex stem with two portions and a loop connecting the two stem portions. The antisense portion can be on the 5' or 3' end of the stem. The stem portions of a shRNA are preferably about 15 to about 50 nucleotides in length. Preferably the two stem portions are about 18 or 19 to about 21, 22, 23, 24, 25, 30, 35, 37, 38, 39, or 40 or more nucleotides in length. In preferred embodiments, the length of the stem portions should be 21 nucleotides or greater. When used in mammalian cells, the length of the stem portions should be less than about 30 nucleotides to avoid provoking non-specific responses like the interferon pathway. In non-mammalian cells, the stem can be longer than 30 nucleotides. In fact, the stem can include much larger sections complementary to the target mRNA (up to, and including the entire mRNA). In fact, a stem portion can include much larger sections complementary to the target mRNA (up to, and including the entire mRNA).

The two portions of the duplex stem must be sufficiently complementary to hybridize to form the duplex stem. Thus, the two portions can be, but need not be, folly or perfectly complementary. In addition, the two stem portions can be the same length, or one portion can include an overhang of 1, 2, 3, or 4 nucleotides. The overhanging nucleotides can include, for example, uracils (Us), e.g., all Us. The loop in the shRNAs can be 2, 3, 4, 5, 6, 7, 8, 9, or more, e.g., 15 or 20, or more nucleotides in length.

A preferred loop consists of or comprises a "tetraloop" sequences. Exemplary tetraloop sequences include, but are not limited to, the sequences GNRA, where N is any nucleotide and R is a purine nucleotide, GGGG, and UUUU. In certain embodiments, shRNAs of the invention include the sequences of a desired siRNA molecule described supra. In other embodiments, the sequence of the antisense portion of a shRNA can be designed essentially as described above or generally by selecting an 18, 19, 20, 21 nucleotide, or longer, sequence from within the target RNA, for example, from a region 100 to 200 or 300 nucleotides upstream or downstream of the start of translation. In general, the sequence can be selected from any portion of the target RNA {e.g., mRNA) including the 5' UTR (untranslated region), coding sequence, or 3' UTR. This sequence can optionally follow immediately after a region of the target gene containing two adjacent AA nucleotides. The last two nucleotides of the nucleotide sequence can be selected to be UU. This 21 or so nucleotide sequence is used to create one portion of a duplex stem in. the shRNA. This sequence can replace a stem portion of a wild-type pre-miRNA sequence, e.g., enzymatically, or is included in a complete sequence that is synthesized. For example, one can synthesize DNA oligonucleotides that encode the entire stem-loop engineered RNA precursor, or that encode just the portion to be inserted into the duplex stem of the precursor, and using restriction enzymes to build the engineered RNA precursor construct, e.g., from a wild-type pre-miRNA.

Engineered RNA precursors include in the duplex stem the 21-22 or so nucleotide sequences of the siRNA, siRNA-like duplex, or miRNA desired to be produced in vivo. Thus, the stem portion of the engineered RNA precursor includes at least 18 or 19 nucleotide pairs corresponding to the sequence of an exonic portion of the gene whose expression is to be reduced or inhibited. The two 3' nucleotides flanking this region of the stem are chosen so as to maximize the production of the siRNA from the engineered RNA precursor and to maximize the efficacy of the resulting siRNA in targeting the corresponding mRNA for translational repression or destruction by RNAi in vivo and in vitro.

In certain embodiments, shRNAs of the invention include miRNA sequences, optionally end-modified miRNA sequences, to enhance entry into RISC. (v) Dual Functional Oligonucleotide Tethers

In other embodiments, the RNA silencing agents of the present invention include dual functional oligonucleotide tethers useful for the intercellular recruitment of a miRNA. Animal cells express a range of miRNAs, noncoding RNAs of approximately 22 nucleotides which can regulate gene expression at the post transcriptional or translational level. By binding a miRNA bound to RISC and recruiting it to a target mRNA, a dual functional oligonucleotide tether can repress the expression of genes involved e.g., in the arteriosclerotic process. The use of oligonucleotide tethers offers several advantages over existing techniques to repress the expression of a particular gene. First, the methods described herein allow an endogenous molecule (often present in abundance), an miRNA, to mediate RNA silencing; accordingly the methods described herein obviate the need to introduce foreign molecules {e.g., siRNAs) to mediate RNA silencing. Second, the RNA-silencing agents and, in particular, the linking moiety (e.g., oligonucleotides such as the 2'~O-m&ihyl oligonucleotide), can be made stable and resistant to nuclease activity. As a result, the tethers of the present invention can be designed for direct delivery, obviating the need for indirect delivery

(e.g. viral) of a precursor molecule or plasmid designed to make the desired agent within the cell. Third, tethers and their respective moieties, can be designed to conform to specific mRNA sites and specific miRNAs. The designs can be cell and gene product specific. Fourth, the methods disclosed herein leave the mRNA intact, allowing one skilled in the art to block protein synthesis in short pulses using the cell's own machinery. As a result, these methods of RNA silencing are highly regulatable.

The dual functional oligonucleotide tethers ("tethers") of the invention are designed such that they recruit miRNAs (e.g. , endogenous cellular miRNAs) to a target mRNA so as to induce the modulation of a gene of interest. In preferred embodiments, the tethers have the formula T -L -μ, wherein T is an mRNA targeting moiety, L is a linking moiety, and μ is an miRNA recruiting moiety. Any one or more moiety may be double stranded. Preferably, however, each moiety is single stranded. Moieties within the tethers can be arranged or linked (in the 5' to 3' direction) as depicted in the formula T-L-μ (i.e., the 3' end of the targeting moiety linked to the 5' end of the linking moiety and the 3¹ end of the linking moiety linked to the 5' end of the miRNA recruiting moiety). Alternatively, the moieties can be arranged or linked in the tether as follows: μ-T-L (i.e., the 3' end of the miRNA recruiting moiety linked to the 5' end of the linking moiety and the 3¹ end of the linking moiety linked to the 5¹ end of the targeting moiety).

The mRNA targeting moiety, as described above, is capable of capturing a specific target mRNA. According to the invention, expression of the target mRNA is undesirable, and, thus, translational repression of the mRNA is desired. The mRNA targeting moiety should be of sufficient size to effectively bind the target mRNA. The length of the targeting moiety will vary greatly depending, in part, on the length of the target mRNA and the degree of complementarity between the target mRNA and the targeting moiety. In various embodiments, the targeting moiety is less than about 200, 100, 50, 30, 25, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, or 5 nucleotides in length. In a particular embodiment, the targeting moiety is about 15 to about 25 nucleotides in length.

The miRNA recruiting moiety, as described above, is capable of associating with a miRNA. According to the invention, the miRNA may be any miRNA capable of repressing the target mRNA. Mammals are reported to have over 250 endogenous miRNAs (Lagos-Quintana et ail. (2002) Current Biol. 12:735-739; Lagos-Quintana et al (2001) Science 294:858-862; and Lim et al. (2003) Science 299: 1540). In various embodiments, the miRNA may be any art-recognized miRNA. The linking moiety is any agent capable of linking the targeting moieties such that the activity of the targeting moieties is maintained. Linking moieties are preferably oligonucleotide moieties comprising a sufficient number of nucleotides such that the targeting agents can sufficiently interact with their respective targets. Linking moieties have little or no sequence homology with cellular mRNA or miRNA sequences.

Exemplary linking moieties include one or more 2'-O- methylnucleotides , e.g., T-Q- methyladenosine, 2'-O-methylthymidine, 2'-O-methylguanosine or 2'-O-methyluridine.

(b) Discriminatory RNA Silencing Agents In other aspects, any of the RNA silencing agents described supra may be designed such that they are capable of discriminatory RNA silencing. For example, RNA silencing agents (e.g., siRNAs) which discriminate between RNAs of related sequences may be designed. Such agents are capable of silencing a target mRNA (e.g., an mRNA associated with a disease-associated allelic polymorphism) while failing to substantially silence a related non-target mRNA (e.g., an mRNA associated with a wild- type allele corresponding to the disease allele). In certain embodiments, RNA silencing agents capable of discriminatory RNA silencing may be designed by including a nucleotide which forms a Watson-Crick base pair with an allelic polymorphism in the target mRNA (e.g., a single-nucleotide polymorphism (SNP)) but which does not form a Watson-Crick base pair but a mismatched or wobble base pair with the corresponding nucleotide in the target mRNA (e.g., wild type). For example, the RNA silencing agent may be designed such that a mismatch (e.g., a purine:purine mismatch) or wobble exists between the siRNA and the non-target mRNA (e.g., wild type mRNA) at the single nucleotide. The purine:purine paring is selected, for example, from the group G: G, A:G, G:A and A: A pairing. Moreover, purine:pyrimidine pairing between the siRNA and the target mRNA (e.g. mutant mRNA) at the single nucleotide enhances single nucleotide specificity. The purine:pyrimidine paring is selected, for example, from the group G: C, C G, A:U, U: A, CrA, A:C, U:A and A:U pairing.

In other embodiments, the RNA silencing agents may be designed to discriminate between the non-target mRNA and the target mRNA by the introduction of a modified base positioned opposite the allelic polymorphism, such that the siRNA directs allele-specific cleavage of a mRNA comprising said polymorphism. Said methods are described in International PCT Publication No. WO 04/046324, which is incorporated herein by reference. In preferred embodiments, the modified base is selected from the group consisting of 5-bromo-uridine, 5-bromo-cytidine, 5-iodo- uridine, 5-iodo-cytidine, 2-am.ino-purine, 2-amino-allyl-purine, 6-amino-purine, 6- amino-allyl-purine, 2, 6-diaminopurine and 6-amino-8-bromo-purine. In an exemplary embodiment, the modified base is 5-bromo-uridine or 5-iodo-uridine and, e.g., the point mutation is an adenine. In another exemplary embodiment, the modified base is 2,6- diaminopurine and, e.g., the point mutation is a thymine.

(c) Chemically-Modified RNA Silencing Agents In certain aspects, the invention features novel RNA silencing agents, e.g., novel small interfering RNAs (siRNAs), that include a sense strand and an antisense strand, wherein the antisense strand has a sequence sufficiently complementary to a target mRNA sequence to direct target-specific RNA interference (RNAi) and wherein the sense strand and/or antisense strand is modified by the substitution of nucleotides with chemically modified nucleotides. In one embodiment, the sense strand and/or the antisense strand are modified with one or more internal chemical modifications. As defined herein, an "internal" nucleotide is one occurring at any position other than the 5' end or 3' end of nucleic acid molecule, polynucleotide or oligonucleotide. An internal nucleotide can be within a single-stranded molecule or within a strand of a duplex or double-stranded molecule. In one embodiment, the sense strand and/or the antisense strand are modified at the 5 'end and/or the 3' end. In one embodiment, the sense strand and/or the antisense strand are modified at both the 5 'end and the 3' end. As used herein, the term "modified at the end" when used in reference to the 5' or 3' ends, refers to any nucleotide within 10 nucleotides of the first and last nucleotide, for example any nucleotide within 7 nucleotides of the first and last nucleotide. In one embodiment, the sense strand and/or antisense strand is modified by the substitution of at least one internal nucleotide. In another embodiment, the sense strand and/or antisense strand is modified by the substitution of at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25 or more nucleotides. In another embodiment, the sense strand and/or antisense strand is modified by the substitution of at least 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or more of the nucleotides. In yet another embodiment, the sense strand and/or antisense strand is modified by the substitution of all of the nucleotides. Within the RNAi agents employed in the methods of the invention, as few as one and as many as all nucleotides of the oligonucleotide can be modified. In some embodiments, the RNAi agent will contain as few modified nucleotides as are necessary to achieve a desired level of in vivo stability, and/or bioaccessibility while maintaining cost effectiveness. Chemical modifications may lead to increased stability, e.g., increased or enhanced in vivo stability, compared to an unmodified RNAi agent or a label that can be used, e.g., to trace the RNAi agent, to purify an RNAi agent, or to purify the RNAi agent and cellular components with which it is associated. Such chemical modifications can also be used to stabilize the first (priming) strand of the siRNA for enhancing RISC activity / RNAi responsiveness in a cell (or cell extract or organism) and improve its intracellular half-life for subsequent receipt of the second strand wherein RNAi / gene silencing can now progress. Modifications can also enhance properties such as cellular uptake of the RNAi agents and/or stability of the RNAi agents, can stabilize interactions between base pairs, and can maintain the structural integrity of the antisense RNAi agent-target RNA duplex. RNAi agent modifications can also be designed such that properties important for in vivo applications, in particular, human therapeutic applications, are improved without compromising the RNAi activity of the RNAi agents e.g., modifications to increase resistance of, e.g., siRNA or miRNA molecules to nucleases. In certain embodiments, modified siRNA molecules of the invention can enhance the efficiency of target RNA inhibition as compared to a corresponding unmodified siRNA. In some embodiments, modified nucleotides do not affect the ability of the antisense strand to adopt A-form helix conformation when base-pairing with the target RNA sequence, e.g., an A-form helix conformation comprising a normal major groove when base-pairing with the target RNA sequence. Chemical modifications generally include end-, sugar-, base- and/or backbone- modifications to the ribonucleotides {i.e., include modifications to the phosphate-sugar backbone).

In one embodiment, the RNAi agent of the invention comprises one or more (e.g., about 1, 2, 3, or 4) end modifications. For example, modification at the 5' end of an siRNA molecule comprises, for example, a 5 '-propylamine group. Modifications of the 5' end may also include 5^* terminal phosphate groups, such as those described by Formula I:

wherein each X and Y is independently O, S, N, alkyl, substituted alkyl, or alkylhalo; wherein each Z and W is independently O, S, N, alkyl, substituted alkyl, O- alkyl, S-alkyl, alkaryl, aralkyl, alkylhalo, or acetyl. In some embodiments, W₇ X, Y and Z are not all O. Modifications to the 3^* OH terminus of an siRNA molecule can include, but are not limited to, 3 '-puromycin, 3'-biotin (e.g., a photocleavable biotin ), a peptide (e.g., a Tat peptide), a nanoparticle, a peptidomimetic, organic compounds (e.g., a dye such as a fluorescent dye), or a dendrimer. End modifications may be on the sense strand, on the antisense strand or both. Ia some embodiments, the 5' modifications are on the sense strand only.

In another embodiment, the RNAi agent of the invention may comprise one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more) sugar-modified nucleotides. Exemplary sugar modifications may include modifications represented by Formula II:

wherein each Rs, R4, Rs, Re, R7, Rs, Rio, Rn and Ri 2 is independently H, OH, alkyl, substituted alkyl, alkaryl or aralkyl, F, Cl, Br, CN, CF₃, OCF₃, OCN, O-alkyl, S-alkyl, N-alkyl, O-alkenyl, S-alkenyl, N-alkenyl, SO-alkyl, alkyl-OSH, alkyl-OH, O-alkyl-OH, O-alkyl-SH, S-alkyl-OH, S-alkyl-SH, alkyl-S-alkyl, alkyl-O-alkyl, ONO₂, NO₂, N₃, NH2, aminoalkyL, aminoacid, aminoacyl, ONH2, O-aminoalkyl, O-aminoacid, or O- aminoacyl, heterocyclo alkyl, heterocycloalkaryl, aminoalkylamino, polyalklylamino, substituted silyl; R₉ is O, S, CH₂, S=O, CHF, or CF₂, and B is a nucleosidic base. Sugar-modifed nucleotides include, but are not limited to: 2'-fluoro modified ribonucleotides, 2'-0Me modified ribonucleotides, 2'-deoxy ribonucleotides, 2'-amino modified ribonucleotides and 2'-thio modified ribonucleotides. The sugar-modified nucleotide can be, for example, 2'-fluoro-cytidine, 2'-fluoro-uridine, 2'-fiuoro-adenosine, 2^l-fluoro-guanosine_> 2'-amino-cytidine₅ 2'-amino-uridine, Z'-amino-adenosine, 2'-amino- guanosine or 2'-amino-butyryl-pyrene~uridine. In one embodiment, the sugar-modified nucleotide is a 2'-fluoro ribonucleotide. In some embodiments, when a 2'-deoxy ribonucleotide is present, it is upstream of the cleavage site referencing the antisense strand or downstream of the cleavage site referencing the antisense strand. The 2'- fluoro ribonucleotides can be in the sense and antisense strands. In some embodiments, the 2^*-fluoro ribonucleotides are every uridine and cytidine. In other embodiments, the 2'-fϊuoro ribonucleotides are only present at the 3' and 5' ends of the sense strand, the antisense strand or both. In another embodiment, the RNAi agent of the invention comprises one or more

(e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more) nucleobase-modified nucleotides. Nucleobase-modified nucleotides useful in the invention include, but are not limited to: . uridine and/or cytidine modified at the 5rposition (e.g., 5-bromo-uridine, 5-(2- amino)propyl uridine, 5-amino-allyl-uridine, 5-iodo-uridme, 5-methyl-cytidine, 5- fluoro-cytidine, and 5-fluoro-uridine), ribo-thymidine, 2-aminopurine, 2,6- diaminopurine, 4-thio-uridine, adenosine and/or guanosines modified at the 8 position (e.g., 8-bromo guanosine), deaza nucleotides (e.g., 7-deaza-adenosine), O- and N- alkylated nucleotides (e.g., N6-methyl adenosine) and non-nucleotide-type bases (e.g., deoxy-abasic, inosine, N3-methyl-uridine, N6, N6-dimethyl-adenosme, pseudouridine, purine ribonucleoside and ribavirin).

In another embodiment, the RNAi agent of the invention comprises one or more (e.g., about I, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more) backbone-modified nucleotides. For example, backbone modifications may include modifications represented by Formula III:

wherein each Rj and R₂ is independently any nucleotide as described herein, each X and Y is independently O, S, N, alkyl, or substituted alkyl, each Z and W is independently O, S, N, alkyl, substituted alkyl, O-alkyl, S-alkyl, alkaryl, aralkyl, or acetyl. In some embodiments, W, X, Y, and Z are not all O. Exemplary backbone- modified nucleotides contain a phosphorothioate group or a phosphorodithioate. In another embodiment, a backbone modification of the invention comprises a phosphonoacetate and/or thiophosphono acetate intemucleotide linkage (see for example Sheehan et al., 2003, Nucleic Acids Research, 31, 4109-4118). The backbone- modifications can be within the sense strand, antisense strand, or both the sense and antisense strands. In some embodiments, only a portion of the intemucleotide linkages are modified in one or both strands. In other embodiments, all of the intemucleotide linkages are modified in one or both strands. In one embodiment, the modified intemucleotide linkages are at the 3' and 5' ends of one or both strands.

In another embodiment, the siRNA molecule of the invention may comprise one or more {e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more) crosslinks, e.g., a crosslink wherein the sense strand is crosslinked to the antisense strand of the siRNA duplex. Crosslinkers useful in the invention are those commonly known in the art, e.g., psoralen, mitomycin C, cisplatin, chloroethylnitrosoureas and the like. In one embodiment, the . crosslink of the invention is a psoralen crosslink. Preferably, the crosslink is present i downstream of the cleavage site referencing the antisense strand, and more preferably, the crosslink is present at the 5' end of the sense strand.

In another embodiment, the RNAi agent of the invention comprises a sequence wherein the antisense strand and target mRNA sequences comprise one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more) mismatches. In some embodiments, the mismatch is downstream of the cleavage site referencing the antisense strand, e.g., within 1-6 nucleotides from the 3' end of the antisense strand. In another embodiment, the nucleic acid molecule, e.g., RNAi agent, of the invention is an siRNA molecule that comprises a bulge, e.g., one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more) unpaired bases in the duplex siRNA. In some embodiments, the bulge is in the sense strand.

It is to be understood that any of the above combinations can be used in any combination to provide the modified RNAi agent of the present invention. For example, in some embodiments, the invention includes an siRNA, wherein the sense strand includes one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more) phosphorothioate intemucleotide linkages, and/or one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more) 2'-deoxy, 2 -O-methyl, and/or 2'-fluoro sugar modifications, and/or one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more) base modified nucleotides, and/or an end- modification at the 3'-end, the 5'-end, or both the 3¹- and 5'-ends of the sense strand. In some embodiments, the invention includes an siRNA, wherein the antisense strand includes one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more) phosphorothioate internucleotide linkages, and/or one or more (e.g., about I₅ 2, 3. 4, 5, 6, 7, 8, 9, 10 or more) 2'-deoxy, 2-O-methyl, and/or 2-fϊuoro sugar modifications, and/or one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more) base modified nucleotides, and/or an end- modification at the 3'-end, the 5'-end, or both the 3¹- and 5'-ends of the antisense strand. In yet other embodiments, the invention includes an siRNA, wherein both the sense strand and the antisense strand include one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more) phosphorothioate internucleotide linkages, and/or one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more) 2'-deoxy, 2'-O-methyl, and/or 2'-fluoro sugar modifications, and/or one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more) base modified nucleotides, and/or an end-modification at the 3'-end, the 5'-end, or both the 3'- and 5'-ends of either or both the sense strand and/or the antisense strand.

Modified RNAi agents of the invention (i.e., duplex siRNA molecules) can be modified at the 5' end, 3' end, 5' and 3' end, and/or at internal residues, or any : combination thereof. RNAi agent modifications can be, for example, end modifications, sugar modifications, nucleobase modifications, backbone modifications, and can contain mismatches, bulges, or crosslinks. Also included are 3' end, 5' end, or 3' and 5' and/or internal modifications, wherein the modifications are, for example, cross linkers, heterofunctional cross linkers and the like. RNAi agents of the invention also may be modified with chemical moieties (e.g., cholesterol) that improve the in vivo pharmacological properties of the RNAi agents.

In certain aspects of the present invention, the chemically modified siRNAs of the present invention are "terminally-modified siRNAs". That is, the siRNAs are modified at one or both of the 3' end and the 5' end of the sense and/or antisense strand. In certain embodiments, the chemically modified siRNAs are modified at both the 3' end and the 5' end of both the sense antisense strand. In some embodiments, the 3 ' end and/or the 5' end of the sense and/or antisense strands are end-modified such that 2 or 3 or 4 modified nucleotides are incorporated per end (e.g., within the 5-7 terminal nucleotides, e.g., within the duplex). In some embodiments, the 3' end and/or the 5' end of the sense and/or antisense strands are end-modified such that 2 or 3 or 4 2'-fluoro nucleotides, e.g., T fluorocytidine and/or 2'fluorouracil, are incorporated per end (e.g., within the 5-7 terminal nucleotides, e.g., within the duplex). In some embodiments, the 3' end and/or the 5' end of the sense and/or antisense strands are end-modified such that 2 or 3 or 4 internucleotide Linkages are phosphorothioate linkages per end (e.g., between the 5-7 terminal nucleotides, e.g., within the duplex). In some embodiments, the modifications include any of the modifications described herein. In other embodiments, the modifications include phosphorothioate linkages. In still other embodiments, the modifications include 2'-sugar modifications. In still other embodiments, the modifications include 2'-fluoro nucleotide modifications. In yet other embodiments, the modifications include both phosphorothioate linkages and 2'-fluoro nucleotide modifications. Specific modifications include, but are not limited to, the siKNAs in Figure 21 which target ApoB and the siKNAs in Table 1 which Target SODl.

Table 1: Exemplary chemically modified siKNAs (target SODl)

5' P-U~2FC-A-2FC-A-2FU-2FU-GCCCAAG-2FU-2FC-2FU*2FC*2FC*U*U 3'

5' Cy3-G*G*A*GA-2FC-2FU-UGGGCAA-2FU-G-2FU*G*A*2FU*U 3'

5' Cy3-C*G*A*2FU-G-2FU-GUCUAUUGAAG*A-2FU*2FU*C 3'

5' P-A-2FU-2FC-2FU-UCAAUAGACA-2FC-A*2FU*2FC*G*G*C 3'

5' P-U-2FC-A-2FC-A-2FU-2FU-GCCCAAG-2FU-2FC-2FU*2FC*2FC*U*U 3'

5' Cy3-G*G*A*GA-2FC-2FU-UGGGCAA-2FU-G-2FU*G*A*2FU*U 3'

Modification key: 2'FU/FC = 2'fluorouricil/fluorocytidine * = phosphorothioate backbone linkage - = normal backbone linkage

In other aspects, RNA silencing agents may be modified according to methods described in the art (Amarzguioui et. al, Nuc.Λcids.Res., (2003) 31: 589-95; Chiu and Rana, RNA, (2003), 9: 1034-48; Chiu and Rana, MoLCeIl, (2002), 10: 549-61); Morrissey et al, Nat. Biotech., (2005), 23: 2002-7), each of which is incorporated by reference herein. In one embodiment, RNA silencing agent may be conjugated to cholesterol (see e.g:, Soutschek, et al, Nature, (2004), 432: 173-8). In some embodiments, the RNAi agent of the instant invention may also contain a nuclear localization/nuclear targeting signal(s). Such modifications may be made exclusive of, or in addition to, any combination of other modifications as described herein. Nuclear targeting signals include any art-recognized signal capable of effecting a nuclear localization to a molecule, including, for example, NLS signal sequence peptides. Oligonucleotide RNAi agents may be produced enzymatically or by partial/total organic synthesis. In one embodiment, an RNAi agent, e.g., siRNA, is prepared chemically. Methods of synthesizing RNA and DNA molecules are known in the art, in particular, the chemical synthesis methods as described in Verma and Eckstein (1998) Annul Rev. Biochem. 67:99-134. RNA can be purified from a mixture by extraction with a solvent or resin, precipitation, electrophoresis, chromatography, or a combination thereof. Alternatively, the RNA may be used with no or a minimum of purification to avoid losses due to sample processing. Alternatively, the RNA molecules, e.g., RNAi oligonucleotides, can also be prepared by enzymatic transcription from synthetic DNA templates or from DNA plasmids isolated from recombinant bacteria. Typically, phage RNA polymerases are used such as T7, T3 or SP6 RNA polymerase (Milligan and Uhlenbeck (1989) Methods Enzymol 180:51-62). The RNA may be dried for storage or dissolved in an aqueous solution. The solution may contain buffers or salts to inhibit annealing, and/or promote stabilization of the single strands. In one embodiment, siRNAs are synthesized either in vivo, in situ, or in vitro.

Endogenous RNA polymerase of the cell may mediate transcription in vivo or in situ, or cloned RNA polymerase can be used for transcription in vivo or in vitro. For transcription from a transgene in vivo or an expression construct, a regulatory region (e.g., promoter, enhancer, silencer, splice donor and acceptor, polyadenylation) may be used to transcribe the siRNA. Inhibition may be targeted by specific transcription in an organ, tissue, or cell type; stimulation of an environmental condition (e.g., infection, stress, temperature, chemical inducers); and/or engineering transcription at a developmental stage or age. A transgenic organism that expresses siRNA from a recombinant construct may be produced by introducing the construct into a zygote, an embryonic stem cell, or another multipotent cell derived from the appropriate organism.

Expression levels of target and any other surveyed RNAs and proteins may be assessed by any of a wide variety of well known methods for detecting expression of non-transcribed nucleic acid, and transcribed nucleic acid or protein. Non-limiting examples of such methods include RT-PCR of RNA followed by size separation of PCR products, nucleic acid hybridization methods e.g., Northern blots and/or use of nucleic acid arrays; nucleic acid amplification methods; immunological methods for detection of proteins; protein purification methods; and protein function or activity assays. RNA expression levels can be assessed by preparing mRNA/cDNA (i.e. a transcribed polynucleotide) from a cell, tissue or organism, and by hybridizing the mRNA/cDNA with a reference polynucleotide which is a complement of the assayed nucleic acid, or a fragment thereof. cDNA can, optionally, be amplified using any of a variety of polymerase chain reaction or in vitro transcription methods prior to hybridization with the complementary polynucleotide; preferably, it is not amplified. Expression of one or more transcripts can also be detected using quantitative PCR to assess the level of expression of the transcript(s).

(d) Other Nucleic Acid Molecules

In other embodiments, a nucleic acid molecule employed in a delivery complex of the invention is a nucleic acid molecule other than an RNA silencing agent. In certain embodiments, said nucleic acid molecules may comprise any of the chemical modifications discussed supra.

(i) Antisense Oligonucleotides

In one embodiment, a nucleic acid molecule employed in the invention is an antisense nucleic acid molecule that is complementary to a target mRNA or to a portion of said mRNA, or a recombinant expression vector encoding said antisense nucleic acid molecule. Antisense nucleic acid molecules are generally single-stranded DNA, RNA, or DNA/RNA molecules which may comprise one or more nucleotide analogs. The use of antisense nucleic acids to downregulate the expression of a particular protein in a cell is well known in the art (see e.g., Weintraub, H. et at, Antisense RNA as a molecular tool for genetic analysis, Reviews - Trends in Genetics, Vol. 1(1) 1986; Askari, F.K. and McDonnell, W.M. (1996) N. Eng. J. Med. 334:316-318; Bennett, M.R. and Schwartz, S.M. (1995) Circulation 92:1981-1993; Mercola, D. and Cohen, J.S. (1995) Cancer Gene Ther. 2:47-59; Rossi, JJ. (1995) Br. Med, BnIl. 51:217-225; Wagner, R. W. (1994) Nature 372:333-335). An antisense nucleic acid molecule comprises a nucleotide sequence that is complementary to the target mRNA sequence and accordingly is capable of hydrogen bonding to the mRNA. Antisense sequences complementary to a sequence of an mRNA can be complementary to a sequence found in the coding region of the mRNA, the 5' or 3¹ untranslated region of the mRNA or a region bridging the coding region and an untranslated region (e.g., at the junction of the 5' untranslated region and the coding region). Preferably, an antisense nucleic acid is designed so as to be complementary to a region preceding or spanning the initiation codon in the 3¹ untranslated region of an mRNA.

Given the known nucleotide sequence of a target mRNA, antisense nucleic acids of the invention can be designed according to the rules of Watson and Crick base pairing. The antisense nucleic acid molecule can be complementary to the entire coding region of an mRNA, but more preferably is antisense to only a portion of the coding or noncoding region of an mRNA. For example, the antisense oligonucleotide can be complementary to the region surrounding the translation start site of a target mRNA. An antisense oligonucleotide can be, for example, about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 100, 500, 1000 nucleotides or more in length. In some embodiments, the antisense oligonucleotide may be as long as, or longer than, the length of the mRNA that is targeted.

An antisense nucleic acid of the invention can be constructed using chemical synthesis and enzymatic ligation reactions using procedures known in the art. For example, an antisense nucleic acid (e.g., an antisense oligonucleotide) can be chemically synthesized using naturally occurring nucleotides or variously modified nucleotides designed to increase the biological stability of the molecules or to increase the physical stability of the duplex formed between the antisense and sense nucleic acids, e.g., phosphorothioate derivatives and acridine substituted nucleotides can be used.

Examples of modified nucleotides which can be used to generate the antisense nucleic acid include 5-fluorouracil, 5-bromouracil, 5-chlorouracil, 5-iodouracil, hypoxanthine, xanthine, 4-acetylcytosine, 5-(carboxyhydroxylmethyl) uracil, 5- carboxymethylaminomethyl-2-thiouridine, 5-carboxymethylaminomethyluracil, dihydrouracil, beta-D-galactosylqueosine, inosine, N6-isopentenyladenine, 1- methylguanine, 1-methy lino sine, 2,2-dimethylguanine, 2-methyladenine, 2- methylguanine, 3-methylcytosine, 5-methylcytosine, N6-adenine, 7-methylguanine, 5- methylaminomethyluracil, 5-methoxyaminomethyl-2-thiouracil, beta-D- mannosylqueosine, 5'-methoxycarboxymethyluracil, 5-methoxyuracil, 2-methylthio-N6- isopentenyladenine, uracil-5-oxyacetic acid (v), wybutoxosine, pseudouracil, queosine, 2-thiocytosine, 5-methyl-2-thiouracil, 2-thiouracil, 4-thiouracil, 5-methyluracil, uracil-5- oxyacetic acid methylester, uracil-5-oxyacetic acid (v), 5-methyl-2-thiouracil, 3-(3- amino-3-N-2-caτboxyρropyl) uracil, (acp3)w, and 2,6-diaminopurine. To inhibit expression in cells, one or more antisense oligonucleotides can be used.

Alternatively, an antisense nucleic acid can be produced biologically using an expression vector into which all or a portion of a cDNA has been subcloned in an antisense orientation (i.e., nucleic acid transcribed from the inserted nucleic acid will be of an antisense orientation to a target nucleic acid of interest). Regulatory sequences operatively linked to a nucleic acid cloned in the antisense orientation can be chosen which direct the expression of the antisense RNA molecule in a cell of interest, for instance promoters and/or enhancers or other regulatory sequences can be chosen which direct constitutive, tissue specific or inducible expression of antisense RNA. The antisense expression vector is prepared according to standard recombinant DNA methods for constructing recombinant expression vectors, except that the cDNA (or portion thereof) is cloned into the vector in the antisense orientation. The antisense expression vector can be in the form of, for example, a recombinant plasmid, phagemid or attenuated virus. The antisense expression vector can be introduced into cells using a standard transfection technique.

The antisense nucleic acid molecules of the invention are typically administered to a subject or generated in situ such that they hybridize with or bind to cellular mRNA and/or genomic DNA encoding a protein to thereby inhibit expression of the protein, e.g., by inhibiting transcription and/or translation. The hybridization can be by conventional nucleotide complementarity to form a stable duplex, or, for example, in the case of an antisense nucleic acid molecule which binds to DNA duplexes, through specific interactions in the major groove of the double helix. An example of a route of administration of an antisense nucleic acid molecule of the invention includes direct injection at a tissue site. Alternatively, an antisense nucleic acid molecule can be modified to target selected cells and then administered systemically. For example, for systemic administration, an antisense molecule can be modified such that it specifically binds to a receptor or an antigen expressed on a selected cell surface, e.g., by linking the antisense nucleic acid molecule to a peptide or an antibody which binds to a cell surface receptor or antigen. The antisense nucleic acid molecule can also be delivered to cells using the vectors described herein. To achieve sufficient intracellular concentrations of antisense molecules, vector constructs in which the antisense nucleic acid molecule is placed under the control of a strong pol II or pol IE promoter are preferred. (a) anti-RNA silencing agent oligonucleotides

In one particular embodiment, antisense oligonucleotides may be employed which are complementary to one or more of the RNA silencing agents (e.g., miRNA molecules) described supra. Said anti-miRNA oligonucleotides may be DNA or RNA oligonucleotides, or they may be comprised of both ribonucleotide and deoxyribonucleotides or analogs thereof. In preferred embodiments, said anti-miRNA oligonucleotides comprise one or more (e.g., substantially all) 2'O-methyl ribonucleotides. Such molecules are potent and irreversible inhibitors of miRNA- mediated silencing and are therefore useful for modulating RNA silencing both in vitro and in vivo. In vivo methodologies are useful for both general RNA silencing modulatory purposes as well as in therapeutic applications in which RNA silencing modulation (e.g., inhibition) is desirable. For example, insulin secretion has y been shown to be regulated by at least one miRNA (Poy et al. 2004), and a role for miRNAs has also been implicated in spinal muscular atrophy (SMA; Mourelatos et al. 2002).

(ii) α-anomeric nucleic acid molecules

In yet another embodiment, a nucleic acid molecule employed in the invention is an α-anomeric nucleic acid molecule. An α-anomeric nucleic acid molecule forms specific double-stranded hybrids with complementary RNA in which, contrary to the usual β-units, the strands run parallel to each other (Gaultier et al. (1987) Nucleic Acids. Res. 15:6625-6641). Such a nucleic acid molecule can also comprise a 2'-o- methylribonucleotide (Inoue et al. (1987) Nucleic Acids Res. 15:6131-6148) or a chimeric RNA-DNA analogue (Inoue et al. (1987) FEBS Lett. 215:327-330).

(iii) Ribozymes

In still another embodiment, an nucleic acid molecule employed in the invention is a ribozyme. Ribozymes are catalytic RNA molecules having extensive secondary structure and which intrinsically capable of cleaving a single-stranded nucleic acid, such as an mRNA, to which they have a complementary region. Thus, ribozymes (e.g., hammerhead ribozymes (described in Haselhoff and Gerlach (1988) Nature 334:585- 591)) can be used to catalytically cleave mRNA transcripts to thereby inhibit translation mRNAs. A ribozyme having specificity e.g., for a RCK (or a RCK ortholog or RCK interactor)-encoding nucleic acid can be designed based upon the nucleotide sequence of the cDNA. For example, a derivative of a Tetrahymena L-19 IVS RNA can be constructed in which the nucleotide sequence of the active site is complementary to the nucleotide sequence to be cleaved in a target mRNA. See, e.g., Cech et al. U.S. Patent No. 4,987,071 and Cech et al. U.S. Patent No. 5,116,742. Alternatively, a target mRNA can be used to select a catalytic RNA having a specific ribonuclease activity from a pool of RNA molecules. See, e.g., Bartel, D. and Szostak, J. W. (1993) Science 261 : 1411- 1418.

(iv) Triple Helix Molecules

Alternatively, gene expression can be inhibited by targeting nucleotide sequences complementary to the regulatory region of a target gene to form triple helical structures that prevent transcription of a gene in target cells. See generally, Helene, C. (1991) Anticancer Drug Des. 6(6):569-84; Helene, C. et al. (1992) Ann. N.Y. Acad. Sd. 660:27- 36; and Maher, LJ. (1992) Bioassays 14(12):807-15.

(v) Nucleic Acid Vectors

In other embodiments, a nucleic acid molecule of the invention is a vector, e.g., an expression vector containing a nucleic acid encoding a gene product (or portion thereof) or RNA silencing agent. As used herein, the term "vector" refers to a nucleic acid molecule capable of transporting another nucleic acid to which it has been linked. One type of vector is a "plasmid", which refers to a circular double stranded DNA loop into which additional DNA segments can be ligated. Another type of vector is a viral vector, wherein additional DNA segments can be ligated into the viral genome. Certain vectors are capable of autonomous replication in a host cell into which they are introduced (e.g., bacterial vectors having a bacterial origin of replication and episomal mammalian vectors). Other vectors (e.g., non-episomal mammalian vectors) are integrated into the genome of a host cell upon introduction into the host cell, and thereby are replicated along with the host genome. Moreover, certain vectors are capable of directing the expression of genes to which they are operatively linked. Such vectors are referred to herein as "expression vectors". In general, expression vectors of utility in recombinant DNA techniques are often in the form of plasmids. In the present specification, "plasmid" and "vector" can be used interchangeably as the plasmid is the most commonly used form of vector. However, the invention is intended to include such other forms of expression vectors, such as viral vectors (e.g., replication defective retroviruses, adenoviruses, adeno-associated viruses, retroviral vectors, and lentiviruses), which serve equivalent functions. In certain aspects, a vector of the invention encodes an RNA silencing agent described supra, e.g., small hairpin RNAs (shRNAs). Transcription of shRNAs is initiated at a polymerase III (pol III) promoter, and is thought to be terminated at position 2 of a 4-5-thymine transcription termination site. Upon expression, shRNAs are thought to fold into a stem-loop structure with 3' TJU-overhangs; subsequently, the ends of these shRNAs are processed, converting the shRNAs into siRNA-like molecules of about 21 nucleotides. Brummelkamp et al. (2002), Science, 296, 550-553; Lee et al, (2002). supra; Miyagishi and Taira (2002), Nature Biotechnol., 20, 497-500; Paddison et al. (2002), supra; Paul (2002), supra; Sui (2002) supra; Yu et al. (2002), supra. Such expression constructs may include one or more inducible promoters, RNA Pol III promoter systems such as U6 snRNA promoters or Hl RNA polymerase III promoters, or other promoters known in the art. The constructs can include one or both strands of the RNA silencing agent. Expression constructs expressing both strands can also include loop structures linking both strands, or each strand can be separately transcribed from separate promoters within the same construct. Each strand can also be transcribed from a separate expression construct, Tuschl (2002), supra.

IV. Pharmaceutical Agents

In one aspect, the present invention provides for the delivery of pharmaceutical agents via a nanotransporter to the desired target, e.g., a cell, or tissue. The term "pharmaceutical agent," as used herein, refers to compounds having pharmaceutical activity. Examples of pharmaceutical agents for use with the nanotransporters of the present invention include, but are not limited to polynucleotides, proteins, polypeptides, peptides, chemotherapeutic agents, antibiotics, etc. (a) Antibodies In certain embodiments, a pharmaceutical agent employed in a delivery complex of the invention is antibody. The term "antibody" as used herein refers to immunoglobulin molecules and immunologically active portions of immunoglobulin molecules, i.e., molecules that contain an antigen binding site which specifically binds (immunoreacts with) an antigen. Examples of immunologically active portions of immunoglobulin molecules include F(ab) and F(ab')2 fragments which can be generated by treating the antibody with an enzyme such as pepsin. Either polyclonal or monoclonal antibodies that bind target antigen may be employed in the methods of the invention.

The term "monoclonal antibody" or "monoclonal antibody composition", as used herein, refers to a population of antibody molecules that contain only one species of an antigen binding site capable of immuno reacting with a particular epitope of target antigen. A monoclonal antibody composition thus typically displays a single binding affinity for a particular target antigen with which it immunoreacts.

Polyclonal antibodies can be prepared by immunizing a suitable subject with a target antigen or immunogen, respectively. The antibody titer in the immunized subject can be monitored over time by standard techniques, such as with an enzyme linked immunosorbent assay (ELISA) using immobilized target antigen. If desired, the antibody molecules can be isolated from the mammal (e.g., from the blood) and further purified by well known techniques, such as protein A chromatography to obtain the IgG fraction. At an appropriate time after immunization, e.g., when the antibody titers are highest, antibody-producing cells can be obtained from the subject and used to prepare monoclonal antibodies by standard techniques, such as the hybridoma technique originally described by Kohler and Milstein (1975) Nature 256:495-497) (see also, Brown et al. (1981) J. Immunol. 127:539-46; Brown et al. (1980) J. Biol. Chem .255:4980-83; Yeh et al. (1976) PNAS 76:2927-31; and Yeh et al. (1982) Int. J. Cancer 29:269-75), the more recent human B cell hybridoma technique (Kozbor et al. (1983) Immunol Today 4:72), the EBV-hybridoma technique (Cole et al. (1985), Monoclonal Antibodies and Cancer Therapy, Alan R. Liss, Inc., pp. 77-96) or trioma techniques.

The technology for producing monoclonal antibody hybridomas is well known (see generally R. H. Kenneth, in Monoclonal Antibodies: A New Dimension In Biological Analyses, Plenum Publishing Corp., New York, New York (1980); E. A. Lerner (1981) Yale J. Biol. Med, 54:387-402; M. L. Gefter et al (1977) Somatic Cell Genet. 3:231-36). Briefly, an immortal cell line (typically a myeloma) is fused to lymphocytes (typically splenocytes) from a mammal immunized with a target antigen, and the culture supernatants of the resulting hybridoma cells are screened to identify a hybridoma producing a monoclonal antibody that binds target antigen. Any of the many well known protocols used for fusing lymphocytes and immortalized cell lines can be applied for the purpose of generating a monoclonal antibody (see, e.g., G. Galfre et al. (1977) Nature 266:55052; Gefter et al. Somatic Cell Genet., cited supra; Lerner, YaIe J. Biol. Med., cited supra; Kenneth, Monoclonal Antibodies, cited supra). Moreover, the ordinarily skilled worker will appreciate that there are many variations of such methods which also would be useful. Typically, the immortal cell line (e.g., a myeloma cell line) is derived from the same mammalian species as the lymphocytes. For example, murine hybridomas can be made by fusing lymphocytes from a mouse immunized with an immunogenic preparation of the present invention with an immortalized mouse cell line. Preferred immortal cell lines are mouse myeloma cell lines that are sensitive to culture medium containing hypoxanthine, aminopterin and thymidine ("HAT medium"). Any of a number of myeloma cell lines can be used as a fusion partner according to standard techniques, e.g., the P3-NSl/l-Ag4-l, P3-x63-Ag8.653 or Sp2/O- Ag 14 myeloma lines. These myeloma lines are available from ATCC. Typically, HAT-sensitive mouse myeloma cells are fused to mouse splenocytes using polyethylene glycol ("PEG"). Hybridoma cells resulting from the fusion are then selected using HAT medium, which kills unfused and unproductively fused myeloma cells (unfused splenocytes die after several days because they are not transformed). Hybridoma cells producing a monoclonal antibody of the invention are detected by screening the hybridoma culture supernatants for antibodies that bind target antigen, e.g., using a standard ELISA assay. Alternative to preparing monoclonal antibody-secreting hybridomas, a monoclonal antibody can be identified and isolated by screening a recombinant combinatorial immunoglobulin library (e.g., an antibody phage display library) with target antigen to thereby isolate immunoglobulin library members that bind target antigen, respectively. Kits for generating and screening phage display libraries are commercially available (e.g. , the Pharmacia Recombinant Phage Antibody System, Catalog No. 27-9400-01; and the Stratagene SurfZAP™ Phage Display Kit, Catalog No. 240612). Additionally, examples of methods and reagents particularly amenable for use in generating and screening antibody display library can be found in, for example, Ladner et al. U.S. Patent No. 5,223,409; Kang et at. PCT International Publication No. WO 92/18619; Dower et al. PCT International Publication No. WO 91/17271; Winter et al. PCT International Publication WO 92/20791; Markland et al PCT International Publication No. WO 92/15679; Breitling et al. PCT International Publication WO 93/01288; McCafferty et al. PCT International Publication No. WO 92/01047; Garrard et al. PCT International Publication No. WO 92/09690; Ladner et al. PCT International Publication No. WO 90/02809; Fuchs et al. (1991) Bio/Technology 9:1370-1372; Hay et al (1992) Hum. Antibod. Hy bridomas 3 :81-85; Uuse et al (1989) Science 246:1275-1281; Griffiths et al (1993) EMBO J 12:725- 734; Hawkins et al. (1992) J. MoI. Biol. 226:889-896; Clarkson et al (1991) Nature 352:624-628; Gram et al. (1992) PNAS 89:3576-3580; Garrad ef al. (1991) Bio/Technology 9:1373-1377; Hoogenboom et al. (1991) Nuc. Acid Res. 19:4133- 4137; Barbae et al (1991) PNAS 88:7978-7982; and McCafFerty et al. Nature (1990) 348:552-554.

fb) Drug Moeities

In certain embodiments, a pharmaceutical agent employed in a delivery complex of the invention is a drug moiety. The term "drug moiety" as used herein refers to small molecules or active portions thereof which have art-recognized therapeutic properties. Exemplary drug moieties include anti-inflammatory, anticancer, anti-infective (e.g., antifungal, antibacterial, anti-parasitic, anti-viral, etc.), and anesthetic therapeutic agents.

In one exemplary embodiment, the drug moiety is an anti-cancer agent. Exemplary anti-cancer agents include, but are not limited to, cytostatics, enzyme inhibitors, gene regulators, cytotoxic nucleosides, tubulin binding agents, hormones and hormone antagonists, anti-angiogenesis agents, and the like. Exemplary cytostatic anticancer agents include alkylating agents such as the anthracycline family of drugs (e.g. adriamycin, cyclosporin-A, chloroquine), DNA synthesis inhibitors (e.g., methotrexate, 5-fluorouracil, ganciclovir), DNArintercalators or cross-linkers (e.g., bleomycin, carbop latin, cyclophosphamide, cisplatin), DNA-RNA transcription regulators (e.g., actinomycin D). Exemplary cytotoxic nucleoside anti-cancer agents include, for example, adenosine arabinoside, cytarabine, cytosine arabinoside, 5-fluorouracil, fludarabine, floxuridine, ftorafur, and 6-mercaptopurine. Exemplary anti-cancer tubulin binding agents include taxoids (e.g. paclitaxel, docetaxel, taxane). Exemplary anti-cancer hormones and hormone antagonists, include corticosteroids (e.g. prednisone), progestins (e.g. hydroxyprogesterone or medroprogesterone), estrogens, (e.g. diethylstilbestrol), antiestrogens (e.g. tamoxifen), androgens (e.g. testosterone), aromatase inhibitors (e.g. aminogluthetimide), 17- (allylamino)-17-demethoxygeldanamycin, 4-amino-l,8-naphthalimide, apigenin, brefeldin A, cimetidine, dichloromethylene-diphosphonic acid, leuprolide (leuprorelin), luteinizing hormone-releasing hormone, pifithrin-α, rapamycin, sex hormone-binding globulin, and thapsigargin.

(c) Other Pharmaceutical Agents

As an alternative or in addition to the pharmaceutical agents described above, the delivery complexes of the invention may comprise therapeutic peptides (e.g., insulin), biological response modifiers, enzymes, or fragments thereof. Exemplary biological response modifiers include hormones, cytokines, chemokines, growth factors, and clotting factors. In fact delivery complexes may comprise any compound or composition, which, when present in an effective amount, reacts with and/or affects a tissue, living cell, and/or organism or traverses a biological space, e.g., a blood brain barrier, such that the therapeutic agent or pay load can have its mode of action. It is understood that depending on the nature of the active substance, the active substance can either be active in a biological space, at the cell surface, in the cell, or have its activity, such as with DNA, RNA, protein, or peptide after being introduced into the cell.

Examples of biologically active substances include, but are not limited to, nucleic acids such as DNA, cDNA, RNA (full length mRNA, ribozymes, antisense RNA, RNAi siRNA, miRNA, decoys), oligodeoxynucleotides (phosphodiesters, phosphothioates, phosphoramidites, and all other chemical modifications), oligonucleotide (phosphodiesters, etc.) or linear and closed circular plasmid DNA; carbohydrates, proteins and peptides (e.g., peptides for cellular delivery and transport, peptide for specific receptors, peptides that can cross the blood brain barrier, including recombinant proteins such as for example cytokines (e.g., NGF, G-CSF, GM-CSF), enzymes, vaccines (e.g., HBsAg, gpl20); vitamins, prostaglandins, drugs such as local anesthetics (e.g. procaine), antimalarial agents (e.g., chloroquine), compounds which need to cross the blood-brain barrier such as anti-parkinson agents (e.g., leva-DOPA), adrenergic receptor antagonists (e.g., propanolol), anti-neoplastic agents (e.g., doxorubicin), antihistamines, biogenic amines (e.g., dopamine), antidepressants (e.g., desipramine), anticholinergics (e.g., atropine), antiarrhythmics (e.g., quinidine), antiemetics (e.g., chloroprimamine) and analgesics (e.g., codeine, morphine) or small molecular weight drugs such as cisplatin which enhance transfection activity, or prolong the life time of DNA in and outside the cells. In one exemplary embodiment, the delivery complex comprises Amantadine (see e.g., Figure 46).

V. Delivery Complexes

(a> Nucleic Acid Molecule : Nanotransporter Delivery Complexes

Nucleic acid molecules, e.g., RNA silencing agents (e.g. novel chemically- modifed RNA Silencing agents of the invention), can be associated with (ie. operably linked to) a nanotransporter by any techniques and/or approaches known in the art, described herein, and/or as can be developed by one of skill in the art. In some embodiments, the association may involve covalent bonds, dipole interactions, electrostatic forces, hydrogen bonds, ionic bonds, van der Waals forces, and/or other bonds that can conjugate the nucleic acid to the nanotransporter.

In one embodiment, the nucleic acid molecule, e.g., an RNA silencing agent, e.g. an siRNA, is conjugated to the core of the nanotransporter, for example via a linker. Figure 14 shows an exemplary method for conjugating a nucleic acid molecule, e.g., siRNA, to a nanotransporter using a linking moiety. As can be seen in this figure, the nucleic acid molecule is conjugated to the nanotransporter using sulfosuccinimidyl-4-(p- maleimidophenyl)-butyrate Sulfosuccinimidyl-4-(P-Maleimidophenyl) Butyrate ("Sulfo- SMPB"). A "linking moiety" as used herein refers to any moiety capable of linking a nucleic acid molecule, e.g, siRNA, to a nanotransporter. Any linking moiety known in the art may be used in the present invention. A linking moiety useful in this invention may comprise any bi-fonctional compound, for example a bifunctional maleimide compound, e.g. sulfosuccinimidyl-4-(p-maleimidophenyl)-butyrate. The nucleic acid molecule may be associated or conjugated to the nanotransporter by generally known methods. In one embodiment, the nucleic acid molecule is associated with the nanotransporter by mixing the nucleic acid molecule with the nanotransporter. In another embodiment, the nucleic acid molecule is covalently bonded to the nanotransporter.

In some embodiments, the nucleic acid molecule is associated with the core via ionic bonds. In exemplary embodiments, the core of the nanotransporter is a low molecular weight polylysine dendrimer, to which dioleolyl can be also attached. Figure 3 shows the interaction of the above complex (DiOleoyl-LDG3) with siRNA. In one embodiment, this complex is formed by mixing the DiOleoyl-LDG3 with siRNA. In another embodiment, the siRNA is covalently conjugated to the DiOleoyl-LDG3 complex via the amino groups on the LDG3 branches. The core of the nanotransporter may be any molecule capable of association with a nucleic acid molecule, e.g., siRNA, and at least one functional surface group, for example the core may be DiOleoyl LDG3. In an exemplary embodiment, the core of the nanotransporter is a nanotube. Nanotube-siRNA conjugates can be formed in a similar manner as the methods described above. Figure 17 shows the synthesis of nanotube- siRNA conjugates .

In yet another embodiment, the nanotransporter of the invention is HBOLD. The structure of HBOLD can be seen, in Figure 18. Without wishing to be bound by any particular theory, it is believed that the nanotransporters of the invention, e.g., HBOLD, are non-toxic to cells. As can be seen in Figure 19, the HBOLD nanotransporter conjugated to siRNA has been found to be non-toxic in FL83B (mouse liver hepatocytes) cells.

The HBOLD constructs were also found to be as effective as standard transfection agents in the delivery of RNA silencing agents to target cells. In particular, as can be seen in Figure 20, the HBOLD constructs had a similar effectiveness as standard transfection agents in silencing expression of Apo B in hepatocytes.

(b) Pharmaceutical Agent : Nanotransporter Delivery Complexes In certain aspects, the present invention provides for the delivery of pharmaceutical agents via a nanotransporter of the invention to a desired target, e.g., a cell, or tissue. The term "pharmaceutical agent," as used herein, refers to compounds (e.g., compounds other than the nucleic acid molecules identified supra) having pharmaceutical activity. Examples of pharmaceutical agents for use with the nanotransporters of the present invention include, but are not limited to polynucleotides, proteins, polypeptides, peptides, chemotherapeutic agents, antibiotics, etc. Pharmaceutical agents can be conjugated to the nanotransporter by any techniques and/or approaches known in the art, described herein, and/or as can be developed by one of skill in the art. In some embodiments, the association may involve covalent bonds, dipole interactions, electrostatic forces, hydrogen bonds, ionic bonds, van der Waals forces, and/or other bonds that can conjugate the pharmaceutical agent to the nanotransporter.

VI. Target mRNAs

In one embodiment, the target mRNA of the invention specifies the amino acid sequence of a cellular protein (e.g., a nuclear, cytoplasmic, transmembrane, or membrane-associated protein). In another embodiment, the target mRNA of the invention specifies the amino acid sequence of an extracellular protein (e.g., an extracellular matrix protein or secreted protein). As used herein, the phrase "specifies the amino acid sequence" of a protein means that the mRNA sequence is translated into the amino acid sequence according to the rules of the genetic code. The following classes of proteins are listed for illustrative purposes: developmental proteins (e.g., adhesion molecules, cyclin kinase inhibitors, Wnt family members, Pax family members, Winged helix family members, Hox family members, cytokines/lymphokines and their receptors, growth/differentiation factors and their receptors, neurotransmitters and their receptors); oncogene-encoded proteins (e.g., ABLI, BCLI, BCL2, BCL6,

CBF A2, CBL, CSFIR, ERBA, ERBB, EBRB2, ETSI, ETSI, ETV6, FGR, FOS, FYN, HCR, HRAS, JUN, KRAS, LCK, LYN, MDM2, MLL, MYB, MYC, MYCLI, MYCN, NRAS, PDvI I, PML, RET, SRC, TALI, TCL3, and YES); tumor suppressor proteins (e.g., APC, BRCAl, BRCA2, MADH4, MCC, NF I, NF2, RB L TP53, and WTI); and enzymes (e.g., ACC synthases and oxidases, ACP desaturases and hydroxylases, ADP- glucose pyrophorylases, ATPases, alcohol dehydrogenases, amylases, amyloglucosidases, catalases, cellulases, chalcone synthases, chitinases, cyclooxygenases, decarboxylases, dextriinases, DNA and RNA polymerases, galactosidases, glucanases, glucose oxidases, granule-bound starch synthases, GTPases, helicases, hernicellulases, integrases, inulinases, invertases, isomerases, kinases, lactases, lipases, lipoxygenases, lysozymes, nopaϋne synthases, octopine synthases, pectinesterases, peroxidases, phosphatases, phospholipases, phosphorylases, phytases, plant growth regulator synthases, polygalacturonases, proteinases and peptidases, pullanases, recombinases, reverse transcriptases, RUBISCOs, topoisomerases, and xylanases).

In a preferred aspect of the invention, the target mRNA molecule of the invention specifies the amino acid sequence of a protein associated with a pathological condition. For example, the protein may be a pathogen-associated protein (e.g., a viral protein involved in immunosuppression of the host, replication of the pathogen, transmission of the pathogen, or maintenance of the infection), or a host protein which facilitates entry of the pathogen into the host, drug metabolism by the pathogen or host, replication or integration of the pathogen's genome, establishment or spread of infection in the host, or assembly of the next generation of pathogen. Alternatively, the protein may be a tumor-associated protein or an autoimmune disease-associated protein.

In one embodiment, the target mRNA molecule of the invention specifies the amino acid sequence of an endogenous protein (i.e., a protein present in the genome of a cell or organism). In another embodiment, the target mRNA molecule of the invention specified the amino acid sequence of a heterologous protein expressed in a recombinant cell or a genetically altered organism. In another embodiment, the target mRNA molecule of the invention specified the amino acid sequence of a protein encoded by a transgene (i.e., a gene construct inserted at an ectopic site in the genome of the cell). In yet another embodiment, the target mRNA molecule of the invention specifies the amino acid sequence of a protein encoded by a pathogen genome which is capable of infecting a cell or an organism from which the cell is derived.

By inhibiting the expression of such proteins, valuable information regarding the function of said proteins and therapeutic benefits which may be obtained from said inhibition may be obtained.

A) Metabolic Gene Targets

The nanotransporter, e.g., the HBOLD nanotransporter, of the invention may be used to target specific genes of interest, that is, genes associated with metabolic disorders including high cholesterol levels, obesity, and diabetes. In one embodiment, the HBOLD nanotransporter is associated with gene-specific siRNA molecule and is used to knock down or silence target genes associated with cholesterol production, including, but not limited to, apolipoprotein B (ApoB). ApoB is the main apolipoprotein of chylomicrons and low density lipoproteins (LDL). ApoB is found in the plasma in two main iso forms, apoB-48 and apoB-100, synthesized by the gut and the liver, respectively.

The intestinal (apoB-48) and hepatic (apoB-100) forms of apoB are coded by a single gene and by a single rnRNA transcript. The nucleotide and amino acid sequence of human ApoB can be found in GenBank record GI 4502152, the entire contents of which are incorporated by refenence herein. Nanotransporter s of the invention may be conjugated to siKNA corresponding to the RNA sequence of the apoB gene, including apoB-100, apoB-48, or both apoB-100 and apoB-48. The nucleotide sequence of apoB comprises the following sequence:

ATTCCCACCGGGACCTGCGGGGCTGAGTGCCCTTCTCGGTTGCTGCCGCTGAGGAGCCCGCCCA

ATGGACCCGCCGAGGCCCGCGCTGCTGGCGCTGCTGGCGCTGCCTGCGCTGCTGCTGCTGCTGC TGGCGGGCGCCAGGGCCGAAGAGGAAATGCTGGAAAATGTCAGCCTGGTCTGTCCAAAAGATGC GACCCGATTCAAGCACCTCCGGAAGTACACATACAACTATGAGGCTGAGAGTTCCAGTGGAGTC CCTGGGACTGCTGATTCAAGAAGTGCCACCAGGATCAACTGCAAGGTTGAGCTGGAGGTTCCCC AGCTCTGCAGCTTCATCCTGAAGACCAGCCAGTGCACCCTGAAAGAGGTGTATGGCTTCAACCC TGAGGGCAAAGCCTTGCTGAΆGΆAAACCAAGAACTCTGAGGAGTTTGCTGCAGCCATGTCCAGG TATGAGCTCAAGCTGGCCATTCCAGAAGGGAAGCAGGTTTTCCTTTACCCGGAGAAAGATGAAC TACTTACATCCTGAACATCAAGAGGGGCATCATTTCTGCCCTCCTGGTTCCCCCAGAGACAGAA

AGACGAGGAAGGGCAATGTGGCAACAGAAATATCCACTGAAAGAGACCTGGGGCAGTGTGATCG

CTTCAAGCCCATCCGCACAGGCATCAGCCCACTTGCTCTCATCAAAGGCATGACCCGCCCCTTG

TCAACTCTGATCAGCAGCAGCCAGTCCTGTCAGTACACACTGGACGCTAAGAGGAAGCATGTGG CAGAAGCCATCTGCAAGGAGCAACACCTCTTCCTGCCTTTCTCCTACAACAATAAGTATGGGAT

GGTGAAGGTACTAAGAAGATGGGCCTCGCATTTGAGAGCACCAAATCCACATCACCTCCAΆAGC AGGCCGAAGCTGTTTTGAAGACTCTCCAGGAACTGAAAAAACTAACCATCTCTGAGCAAAATAT CCAGAGAGCTAATCTCTTCAATAAGCTGGTTACTGAGCTGAGAGGCCTCAGTGATGAAGCAGTC ACATCTCTCTTGCCACAGCTGATTGAGGTGTCCAGCCCCATCACTTTACAAGCCTTGGTTCAGT GTGGACAGCCTCAGTGCTCCACTCACATCCTCCAGTGGCTGAAACGTGTGCATGCCAACCCCCT TCTGATAGATGTGGTCACCTACCTGGTGGCCCTGATCCCCGAGCCCTCAGCACAGCAGCTGCGA GAGATCTTCAACATGGCGAGGGATCAGCGCAGCCGAGCCACCTTGTATGCGCTGAGCCACGCGG TCAACAACTATCATAAGACAAACCCTACAGGGACCCAGGAGCTGCTGGACATTGCTAATTACCT GATGGAACAGATTCAAGATGACTGCACTGGGGATGAAGATTACACCTATTTGATTCTGCGGGTA TTGGAAATATGGGCCAAACCATGGAGCAGTTAACTCCAGAACTCAAGTCTTCAATCCTCAAATG TGTCCAAAGTACAAAGCCATCACTGATGATCCAGAAAGCTGCCATCCAGGCTCTGCGGAAAATG GAGCCTAAAGACAAGGACCAGGAGGTTCTTCTTCAGACTTTCCTTGATGATGCTTCTCCGGGAG ATAAGCGACTGGCTGCCTATCTTATGTTGATGAGGAGTCCTTCACAGGCAGATATTAACAAAAT TGTCCAAATTCTACCATGGGAACAGAATGAGCAAGTGAAGAACTTTGTGGCTTCCCATATTGCC AATATCTTGAACTCAGAAGAATTGGATATCCAAGATCTGAAAAAGTTAGTGAAAGAAGCTCTGA AAGAATCTCAACTTCCAACTGTCATGGACTTCAGAAAATTCTCTCGGAACTATCAACTCTACAA ATCTGTTTCTCTTCCATCACTTGACCCAGCCTCAGCCAAAATAGAAGGGAATCTTATATTTGAT CCAAATAACTACCTTCCTAAAGAAAGCATGCTGAAAACTACCCTCACTGCCTTTGGATTTGCTT CAGCTGACCTCATCGAGATTGGCTTGGAAGGAAAAGGCTTTGAGCCAACATTGGAAGCTCTTTT TGGGAAGCAAGGATTTTTCCCAGACAGTGTCAACAAAGCTTTGTACTGGGTTAATGGTCAAGTT CCTGATGGTGTCTCTAAGGTCTTAGTGGACCACTTTGGCTATACCAAΆGATGATAΆACATGAGC AGGATATGGTAAATGGAATAATGCTCAGTGTTGAGAAGCTGATTAAAGATTTGAAATCCAAAGA AGTCCCGGAΆGCCAGAGCCTACCTCCGCATCTTGGGAGAGGAGCTTGGTTTTGCCAGTCTCCAT GACCTCCAGCTCCTGGGAAAGCTGCTTCTGATGGGTGCCCGCACTCTGCAGGGGATCCCCCAGA TGATTGGAGAGGTCATCAGGAAGGGCTCAΆAGAΆTGACTTTTTTCTTCACTACATCTTCATGGA GAATGCCTTTGAACTCCCCACTGGAGCTGGATTACAGTTGCAAATATCTTCATCTGGAGTCATT GCTCCCGGAGCCAAGGCTGGAGTAAAACTGGAAGTAGCCAACATGCAGGCTGAACTGGTGGCAA AACCCTCCGTGTCTGTGGAGTTTGTGACAAATATGGGCATCATCATTCCGGACTTCGCTAGGAG TGGGGTCCAGATGAACACCAACTTCTTCCACGΆGTCGGGTCTGGAGGCTCATGTTGCCCTAAΆA GCTGGGAAGCTGAAGTTTATCATTCCTTCCCCAAAGAGACCAGTCAAGCTGCTCAGTGGAGGCA ACACATTACATTTGGTCTCTACCACCAAAACGGAGGTGATCCCACCTCTCATTGAGAACAGGCA GTCCTGGTCAGTTTGCAAGCAAGTCTTTCCTGGCCTGAATTACTGCACCTCAGGCGCTTACTCC AACGCCAGCTCCACAGACTCCGCCTCCTACTATCCGCTGACCGGGGACACCAGATTAGAGCTGG AACTGAGGCCTACAGGAGAGATTGAGCAGTATTCTGTCAGCGCAACCTATGAGCTCCAGAGAGA GGACAGAGCCTTGGTGGATACCCTGAAGTTTGTAACTCAAGCAGAAGGTGCGAAGCAGACTGAG GCTACCATGACATTCAΆATATAATCGGCAGAGTATGACCTTGTCCAGTGAΆGTCCAAATTCCGG ATTTTGATGTTGACCTCGGAACAATCCTCAGAGTTAATGATGAΆTCTACTGAGGGCAAAACGTC TTACAGACTCACCCTGGACATTCAGAACAAGAAAATTACTGAGGTCGCCCTCATGGGCCACCTA AGTTGTGACACAAAGGAAGAAAGAAAAATCAAGGGTGTTATTTCCATACCCCGTTTGCAAGCAG

TGCTACAGCTTATGGCTCCACAGTTTCCAAGAGGGTGGCATGGCATTATGATGAAGAGAAGATT GAATTTGAATGGAACACAGGCACCAATGTAGATACCAAAAAAATGACTTCCAATTTCCCTGTGG ATCTCTCCGATTATCCTAAGAGCTTGCATATGTATGCTAATAGACTCCTGGATCACAGAGTCCC TGAAACAGACATGACTTTCCGGCACGTGGGTTCCAAATTAATAGTTGCAATGAGCTCATGGCTT CAGAAGGCATCTGGGAGTCTTCCTTATACCCAGACTTTGCAAGACCACCTCAATAGCCTGAAGG

CGATGGCCGGGTCAAATATACCTTGAACAAGAACAGTTTGAAAATTGAGATTCCTTTGCCTTTT AGTCTGTGGGATTCCATCTGCCATCTCGAGAGTTCCAAGTCCCTACTTTTACCATTCCCAAGTT

TACAACTGGTCCGCCTCCTACAGTGGTGGCAACACCAGCACAGACCATTTCAGCCTTCGGGCTC GTTACCACATGAAGGCTGACTCTGTGGTTGACCTGCTTTCCTACAATGTGCAAGGATCTGGAGA AACAACATATGACCACAAGAATACGTTCACACTATCATGTGATGGGTCTCTACGCCACAAATTT CTAGATTCGAATATCAAATTCAGTCATGTAGAAAAACTTGGAAACAACCCAGTCTCAAAAGGTT TACTAATATTCGATGCATCTAGTTCCTGGGGACCACAGATGTCTGCTTCAGTTCATTTGGACTC CAAAAAGAAACAGCATTTGTTTGTCAAAGAAGTCAAGATTGATGGGCAGTTCAGAGTCTCTTCG TTCTATGCTAAAGGCACATATGGCCTGTCTTGTCAGAGGGATCCTAΆCACTGGCCGGCTCAATG GAGAGTCCAACCTGAGGTTTAACTCCTCCTACCTCCAAGGCACCAACCAGATAACAGGAAGATA TGAAGATGGAACCCTCTCCCTCACCTCCACCTCTGATCTGCAAΆGTGGCATCATTAAAAATACT GCTTCCCTAAAGTATGAGAACTACGAGCTGACTTTAAAATCTGACACCAATGGGAAGTATAAGA ACTTTGCCACTTCTAACAAGATGGATATGACCTTCTCTAAGCAAAATGCACTGCTGCGTTCTGA ATATCΆGGCTGATTACGAGTCATTGAGGTTCTTCAGCCTGCTTTCTGGATCACTAAATTCCCAT GGTCTTGAGTTAAATGCTGACATCTTAGGCACTGACAAAATTAATAGTGGTGCTCACAAGGCGA CACTAΆGGATTGGCCAAGATGGAATATCTACCAGTGCAACGACCAACTTGAAGTGTAGTCTCCT GGTGCTGGAGAATGAGCTGAATGCAGAGCTTGGCCTCTCTGGGGCATCTATGAAATTAACAACA AATGGCCGCTTCAGGGAACACAΆTGCAAAATTCAGTCTGGATGGGAAAGCCGCCCTCACAGAGC TATCACTGGGAAGTGCTTATCAGGCCATGATTCTGGGTGTCGACAGCAAAAACATTTTCAACTT CAAGGTCAGTCAAGAAGGACTTAAGCTCTCAAATGACATGATGGGCTCATATGCTGAAATGAAA TTTGACCACACAAACAGTCTGAACATTGCAGGCTTATCACTGGACTTCTCTTCAAAACTTGACA ACATTTACAGCTCTGACAAGTTTTATAAGCAAΆCTGTTAATTTACAGCTACAGCCCTATTCTCT GGTAACTACTTTAAACAGTGACCTGAAATACAATGCTCTGGATCTCACCAACAATGGGAAACTA CGGCTAGAACCCCTGAAGCTGCATGTGGCTGGTAACCTAAAAGGAGCCTACCAAAATAATGAAA TAAAACACATCTATGCCATCTCTTCTGCTGCCTTATCAGCAAGCTATAAAGCAGACACTGTTGC TAAGGTTCAGGGTGTGGAGTTTAGCCATCGGCTCAACACAGACATCGCTGGGCTGGCTTCAGCC ATTGACATGAGCACAAACTATAΆTTCAGACTCACTGCATTTCAGCAATGTCTTCCGTTCTGTAA TGGCCCCGTTTACCATGACCATCGATGCACATACAAATGGCAATGGGAAACTCGCTCTCTGGGG AGAACATACTGGGCAGCTGTATAGCAAATTCCTGTTGAAAGCAGAACCTCTGGCATTTACTTTC TCTCATGATTACAAAGGCTCCACAAGTCATCATCTCGTGTCTAGGAAAAGCATCAGTGCAGCTC TTGAACACAAAGTCAGTGCCCTGCTTACTCCAGCTGAGCAGACAGGCACCTGGAAACTCAAGAC CCAATTTAACAACAATGAATACAGCCAGGACTTGGATGCTTACAACACTAAAGATAAAATTGGC GTGGAGCTTACTGGACGAACTCTGGCTGACCTAACTCTACTAGACTCCCCAATTAAAGTGCCAC TTTTACTCAGTGAGCCCATCAATATCATTGATGCTTTAGAGATGAGAGATGCCGTTGAGAAGCC CCAAGAATTTACAATTGTTGCTTTTGTAAAGTATGATAAAAACCAAGATGTTCACTCCATTAAC CTCCCATTTTTTGAGACCTTGCAAGAATATTTTGAGAGGAATCGACAAACCATTATAGTTGTAG

TGGAΆAACGTACAGΆGAAΆCCTGAΆGCACATCAATATTGATCAATTTGTAAGAAAATACAGAGC AGCCCTGGGAAAACTCCCACAGCAAGCTAATGATTATCTGAATTCATTCAATTGGGAGAGACAA GTTTCACATGCCAAGGAGAAACTGACTGCTCTCACAAAAAAGTATAGAATTACAGAAAATGATA TACAAATTGCATTAGATGATGCCAAAATCAACTTTAATGAAAAACTATCTCAACTGCAGACATA TATGATACAATTTGATCAGTATATTAAAGATAGTTATGATTTACATGATTTGAAΆATAGCTATT GCTAATATTATTGATGAAATCATTGAAAAATTAAAAAGTCTTGATGAGCACTATCATATCCGTG TAΆATTTAGTAAAAACAATCCATGATCTACATTTGTTTATTGAAAATATTGATTTTAACAAAΆG TGGAAGTAGTACTGCATCCTGGATTCAAAATGTGGATACTAAGTACCAAATCAGAATCCAGATA CAAGAAAAACTGCAGCAGCTTAAGAGACACATACAGAATATAGACATCCAGCACCTAGCTGGAA AGTTAAAACAACACATTGAGGCTATTGATGTTAGAGTGCTTTTAGATCAATTGGGAΆCTACAAT TTCATTTGAAAGAATAAATGATGTTCTTGAGCATGTCAAACACTTTGTTATAAATCTTATTGGG GATTTTGAAGTAGCTGAGAAAATCAATGCCTTCAGAGCCAAAGTCCATGAGTTAΆTCGAGAGGT ATGAAGTAGACCAACAAATCCAGGTTTTAATGGATAAATTAGTAGAGTTGACCCACCAATACAA GTTGAAGGAGACTATTCAGAAGCTAAGCAATGTCCTACAACAAGTTAAGATAAAAGATTACTTT GAGAAATTGGTTGGATTTATTGATGATGCTGTGAAGAAGCTTAATGAATTATCTTTTAAAACAT

CCAGTTTGTAGATGAAACCAATGACAAAATCCGTGAGGTGACTCAGAGACTCAATGGTGAAATT CAGGCTCTGGAACTACCACAAAAAGCTGAAGCATTAAAACTGTTTTTAGAGGAAACCAΆGGCCA CAGTTGCAGTGTATCTGGAAAGCCTACAGGACACCAAAATAACCTTAATCATCAATTGGTTACA GGAGGCTTTAAGTTCAGCATCTTTGGCTCACATGAAGGCCAAATTCCGAGAGACTCTAGAAGAT ACACGAGACCGAATGTATCAAATGGACATTCAGCAGGAACTTCAACGATACCTGTCTCTGGTAG GCCAGGTTTATAGCACACTTGTCACCTACATTTCTGATTGGTGGACTCTTGCTGCTAAGAACCT TACTGACTTTGCAGAGCAATATTCTATCCAAGATTGGGCTAAACGTATGAAAGCATTGGTAGAG CAAGGGTTCACTGTTCCTGAAATCAAGACCATCCTTGGGACCATGCCTGCCTTTGAAGTCAGTC TTCAGGCTCTTCAGAAAGCTACCTTCCAGACACCTGATTTTATAGTCCCCCTAACAGATTTGAG GATTCCATCAGTTCAGATAAACTTCAAAGACTTAAAAAATATAAAAATCCCATCCAGGTTTTCC ACACCAGAATTTACCATCCTTAACACCTTCCACATTCCTTCCTTTACAATTGACTTTGTCGAAΆ TGAAAGTAAAGATCATCAGAACCATTGACCAGATGCAGAACAGTGAGCTGCAGTGGCCCGTTCC AGATATATATCTCAGGGATCTGAAGGTGGAGGACATTCCTCTAGCGAGAATCACCCTGCCAGAC

TTCCGTTTACCAGAAATCGCAATTCCAGAATTCATAATCCCAACTCTCAACCTTAATGATTTTC

AAGTTCCTGACCTTCACATACCAGAATTCCAGCTTCCCCACATCTCACACACAATTGAAGTACC TACTTTTGGCAAGCTATACAGTATTCTGAAAATCCAATCTCCTCTTTTCACATTAGATGCAAAT GCTGACATAGGGAATGGAACCACCTCAGCAAACGAAGCAGGTATCGCAGCTTCCATCACTGCCA AAGGAGAGTCCAAATTAGAAGTTCTCAATTTTGATTTTCAAGCAAATGCACAACTCTCAAACCC TAAGATTAATCCGCTGGCTCTGAΆGGAGTCAGTGAAGTTCTCCAGCAAGTACCTGAGAACGGAG CATGGGAGTGAAATGCTGTTTTTTGGAAATGCTATTGAGGGAAAΆTCAAACACAGTGGCAAGTT TACACACAGAAAAAAΆTACACTGGAGCTTAGTAΆTGGAGTGATTGTCAAGATAAACAΆTCAGCT TACCCTGGATAGCAACACTAAΆTACTTCCACAAATTGAACATCCCCAAΆCTGGACTTCTCTAGT CAGGCTGACCTGCGCAACGAGATCAAGACACTGTTGAAAGCTGGCCACATAGCATGGACTTCTT CTGGAAAAGGGTCATGGAAATGGGCCTGCCCCAGATTCTCAGATGAGGGAACACATGAΆTCACA AATTAGTTTCACCATAGAAGGACCCCTCACTTCCTTTGGACTGTCCAATAAGΆTCAΆTAGCAAA CACCTAAGAGTAAACCAAAACTTGGTTTATGAATCTGGCTCCCTCAACTTTTCTAAACTTGAAA TTCAATCACAAGTCGATTCCCAGCATGTGGGCCACAGTGTTCTAACTGCTAAAGGCATGGCACT GTTTGGAGAAGGGAAGGCAGAGTTTACTGGGAGGCATGATGCTCATTTAAATGGAAAGGTTATT GGAACTTTGAAAAATTCTCTTTTCTTTTCAGCCCAGCCATTTGAGATCACGGCATCCACAAACA ATGAAGGGAATTTGAAAGTTCGTTTTCCATTAAGGTTAACAGGGAAGATAGACTTCCTGAATAA CTATGCACTGTTTCTGAGTCCCAGTGCCCΆGCAAGCAAGTTGGCAAGTAAGTGCTAGGTTCAAT CAGTATAAGTACAACCAAAATTTCTCTGCTGGAAACAACGAGAACATTATGGAGGCCCATGTAG GAATAAATGGAGAAGCAAATCTGGATTTCTTAAACATTCCTTTAACAATTCCTGAAATGCGTCT ACCTTACACAATAATCACAACTCCTCCACTGAAAGATTTCTCTCTATGGGAAAAAACAGGCTTG AAGGAATTCTTGAAAACGACAAAGCAATCATTTGATTTAAGTGTAAAAGCTCAGTATAAGAAAA ACAAACACAGGCATTCCATCACAAATCCTTTGGCTGTGCTTTGTGAGTTTATCAGTCAGAGCAT CAAATCCTTTGACAGGCATTTTGAAAAAAACAGAAACAATGCATTAGATTTTGTCACCAAATCC TATAATGAAACAAAAATTAAGTTTGATAAGTACAAAGCTGAAAAATCTCACGACGAGCTCCCCA GGACCTTTCAAATTCCTGGATACACTGTTCCAGTTGTCAATGTTGAAGTGTCTCCATTCACCAT AGAGATGTCGGCATTCGGCTATGTGTTCCCAAAAGCAGTCΆGCATGCCTAGTTTCTCCATCCTA GGTTCTGACGTCCGTGTGCCTTCATACACATTAATCCTGCCATCATTAGAGCTGCCAGTCCTTC ATGTCCCTAGAAATCTCAAGCTTTCTCTTCCACATTTCAAGGAATTGTGTACCATAAGCCATAT TTTTATTCCTGCCATGGGCAATATTACCTATGATTTCTCCTTTAAATCAAGTGTCATCACACTG AATACCAATGCTGAACTTTTTAACCAGTCAGATATTGTTGCTCATCTCCTTTCTTCATCTTCAT

GAAGTTAGCCACAGCTCTGTCTCTGAGCAACAAATTTGTGGAGGGTAGTCATAACAGTACTGTG

AGCTTAACCACGAAAAATATGGAAGTGTCAGTGGCAAAAACCACAAAAGCCGAAATTCCAATTT TGAGAATGAATTTCAAGCAAGAACTTAATGGAAATACCAAGTCAAAACCTACTGTCTCTTCCTC

CATGGAATTTAAGTATGATTTCAATTCTTCAATGCTGTACTCTACCGCTAAAGGAGCAGTTGAC

GAATTCCAAGAGCACACGGTCTTCAGTGAAGCTGCAGGGCACTTCCAAAATTGATGATATCTGG

AGCACAGTACGAAAAACCACTTACAGCTAGAGGGCCTCTTTTTCACCAACGGAGAACATACAAG CAAAGCCACCCTGGAACTCTCTCCATGGCAAATGTCAGCTCTTGTTCAGGTCCATGCAAGTCAG

ACCAGAAGATCAGATGGAAAAATGAAGTCCGGATTCATTCTGGGTCTTTCCAGAGCCAGGTCGA

CCCCAATGGCTATTCATTCTCCATCCCTGTAAAAGTTTTGGCTGATAAATTCATTACTCCTGGG CTGAAACTAAATGATCTAAATTCAGTTCTTGTCATGCCTACGTTCCATGTCCCATTTACAGATC TTCAGGTTCCATCGTGCAAACTTGACTTCAGAGAAATACAAATCTATAAGAAGCTGAGAACTTC ATCATTTGCCCTCAACCTACCAACACTCCCCGAGGTAAAATTCCCTGAAGTTGATGTGTTAACA AAATATTCTCAACCAGAAGACTCCTTGATTCCCTTTTTTGAGATAACCGTGCCTGAATCTCAGT TAACTGTGTCCCAGTTCACGCTTCCAAAAAGTGTTTCAGATGGCATTGCTGCTTTGGATCTAAA TGCAGTAGCCAACAAGATCGCAGACTTTGAGTTGCCCACCATCATCGTGCCTGAGCAGACCATT

CTGCACGCTTTGAGGTAGACTCTCCCGTGTATAATGCCACTTGGAGTGCCAGTTTGAAAAACAA AGCAGATTATGTTGAAACAGTCCTGGATTCCACATGCAGCTCAACCGTACAGTTCCTAGAATAT GAACTAAATGTTTTGGGAACACACAAAATCGAAGATGGTACGTTAGCCTCTAAGACTAAAGGAA CACTTGCACACCGTGACTTCAGTGCAGAATATGAAGAAGATGGCAAATTTGAAGGACTTCAGGA ATGGGAAGGAAAAGCGCACCTCAATATCAAAAGCCCAGCGTTCACCGATCTCCATCTGCGCTAC CAGAAAGACAAGAAAGGCATCTCCACCTCAGCAGCCTCCCCAGCCGTAGGCACCGTGGGCATGG ATATGGATGAAGATGACGACTTTTCTAAATGGAΆCTTCTACTACAGCCCTCAGTCCTCTCCAGA TAAAAAACTCACCATATTCAAAACTGAGTTGAGGGTCCGGGAATCTGATGAGGAAACTCAGATC AAAGTTAATTGGGAAGAAGAGGCAGCTTCTGGCTTGCTAACCTCTCTGAAAGACAACGTGCCCA AGGCCACAGGGGTCCTTTATGATTATGTCAACAAGTACCACTGGGAACACACAGGGCTCACCCT GAGAGAAGTGTCTTCAAAGCTGAGAAGAAATCTGCAGAACAATGCTGAGTGGGTTTATCAAGGG GCCATTAGGCAAATTGATGATATCGACGTGAGGTTCCAGAAAGCAGCCAGTGGCACCACTGGGA CCTACCAAGAGTGGAAGGACAAGGCCCAGAATCTGTACCAGGAACTGTTGACTCAGGAAGGCCA AGCCAGTTTCCAGGGACTCAAGGATAACGTGTTTGATGGCTTGGTACGAGTTACTCAAAAATTC CATATGAAAGTCAAGCATCTGATTGACTCACTCATTGATTTTCTGAACTTCCCCAGATTCCAGT TTCCGGGGAAACCTGGGATATACACTAGGGAGGAACTTTGCACTATGTTCATAAGGGAGGTAGG GACGGTACTGTCCCAGGTATATTCGAAAGTCCATAATGGTTCAGAAATACTGTTTTCCTATTTC CAAGACCTAGTGATTACACTTCCTTTCGAGTTAAGGAAACATAAACTAATAGATGTAATCTCGA TGTATAGGGAACTGTTGAAAGATTTATCAAAAGAAGCCCAAGAGGTATTTAAAGCCATTCAGTC TCTCAAGACCACAGAGGTGCTACGTAATCTTCAGGACCTTTTACAATTCATTTTCCAACTAATA GAAGAT AACATTAAACAGCTGAAAGAGATGAAATTTACTTATCTTATTAATTATATCCAAGATG AGATCAACACAATCTTCAATGATTATATCCCATATGTTTTTAAATTGTTGAAAGAAAACCTATG CCTTAATCTTCATAAGTTCAATGAATTTATTCAAAACGAGCTTCAGGAAGCTTCTCAAGAGTTA CAGCAGATCCATCAATACATTATGGCCCTTCGTGAAGAATATTTTGATCCAAGTATAGTTGGCT GGACAGTGAAATATTATGAACTTGAAGAAAAGATAGTCAGTCTGATCAAGAACCTGTTAGTTGC TCTTAAGGACTTCCATTCTGAATATATTGTCAGTGCCTCTAACTTTACTTCCCAACTCTCAAGT CAAGTTGAGCAATTTCTGCACAGAAATATTCAGGAATATCTTAGCATCCTTACCGATCCAGATG GAAAAGGGAAAGAGAAGATTGCAGAGCTTTCTGCCACTGCTCAGGAAATAATTAAAAGCCAGGC CATTGCGACGAAGAAAΆTAATTTCTGATTACCACCAGCAGTTTAGATATAAACTGCAΆGATTTT TCAGACCAACTCTCTGATTACTATGAAAAATTTATTGCTGAATCCAAAAGATTGATTGACCTGT CCATTCAAAACTACCACACATTTCTGATATACATCACGGAGTTACTGAAAAAGCTGCAATCAAC CACAGTCATGAACCCCTACATGAAGCTTGCTCCAGGAGAACTTACTATCATCCTCTAATTTTTT AAAAGAAATCTTCATTTATTCTTCTTTTCCAATTGAACTTTCACATAGCACAGAAAAAATTCAA ACTGCCTATATTGATAAAACCATACAGTGAGCCAGCCTTGCAGTAGGCAGTAGACTATAAGCAG AAGCACATATGAACTGGACCTGCACCAAAGCTGGCACCAGGGCTCGGAAGGTCTCTGAACTCAG AΆGGATGGCATTTTTTGCAAGTTAAAGAAAATCAGGATCTGAGTTΆTTTTGCTAAACTTGGGGG AGGAGGAACAAATAAATGGAGTCTTTATTGTGTATCATA

The apoBlOO mature peptide is encoded by nucleotides 210 - 13817 of the above- mentioned sequence, and the apoB-48 mature peptide is encoded by nucleotides 210- 6665 of the above-mentioned sequence.

Silencing of the apoB gene may also be used to treat metabolic disorders associated with aberrant glucose transport (e.g., diabetes), obesity, increasing metabolism (e.g., fatty acid metabolism), and increasing brown fat. ApoB protein is a candidate target gene siRNA therapy for lipid-based diseases.

In another embodiment, the nanotransporter is associated with gene-specific siRNA and is used to treat metabolic disorders associated with aberrant glucose transport (e.g., diabetes) and obesity by knocking down or silencing nuclear receptor interacting protein 140 (RIP 140 or NRBPl for Nuclear Receptor-interacting Protein 1). RIP140 is a corepressor which can inhibit the transcriptional activity of a number of nuclear receptors. RIP 140 is a nuclear protein containing approximately 1158 amino acids, with a size of approximately 128 kDa. RJP140 binds to nuclear receptors via LXXLL motifs, wherein L is leucine and X is any amino acid (Heery et al., Nature, 387(6634):733-6, 1997). Ten LXXLL motifs are found in the RIP140 sequence. RIP140 also interacts with histone deacetylases and with C-terminal binding protein (CTBP) via a PXDLS motif found in the RIP 140 sequence. The nucleotide and amino acid sequence of human RTP140 can be found in GenBank record GI 57232745, the entire contents of which are incorporated by refenence herein. Nano transporters of the invention may be conjugated to siRNA molecules which target the RNA sequence of RJP 140. The sequence of RJP 140 comprises the following: AACACTGATATTTGCATTTAATGGGGAACAAAAGATGAAGAAGGAAAAGGAATATATTCACTAA GGATTCTATCTGCTTACTGCTACAGACCTATGTGTTAAGGAATTCTTCTCCTCCTCCTTGCGTA GAAGTTGATCAGCACTGTGGTCAGACTGCATTTATCTTGTCATTGCCAGAAGAAATCTTGGACA GAATGTAACAGTACGTCTCTCTCTGATTGCGATGGAAGGTGATAAACTGATACTCCTTTΆTTAΆ AGTTACATCGCACTCACCACAGAAAACCATTCTTTAAAGTGAATAGAAACCAAGCCCTTGTGAA CACTTCTATTGAACATGACTCATGGAGAAGAGCTTGGCTCTGATGTGCACCAGGATTCTATTGT TTTAACTTACCTAGAAGGATTACTAΆTGCATCAGGCAGCAGGGGGATCAGGTACTGCCGTTGAC AAAAAGTCTGCTGGGCATAATGAAGAGGATCAGAΆCTTTAACATTTCTGGCAGTGCΆTTTCCCA CCTGTCAAAGTAATGGTCCAGTTCTCAATACACATACATATCAGGGGTCTGGCATGCTGCACCT CAAAAAAGCCAGACTGTTGCAGTCTTCTGAGGACTGGAATGCAGCAΆAGCGGAAGAGGCTGTCT GATTCTATCATGAATTTAAACGTAAAGAAGGAAGCTTTGCTAGCTGGCATGGTTGACAGTGTGC CTAAAGGCAAACAGGATAGCACATTACTGGCCTCTTTGCTTCAGTCATTCAGCTCTAGGCTGCA GACTGTTGCTCTGTCACAACAAATCAGGCAGAGCCTCAAGGAGCAAGGATATGCCCTCAGTCAT GATTCTTTAAAAGTGGAGAAGGATTTAAGGTGCTATGGTGTTGCATCAAGTCACTTAAAAACTT TGTTGAAGAAAAGTAAAGTTAAAGATCAAAAGCCTGATACGAATCTTCCTGATGTGACTAAAAA CCTCATCAGAGATAGGTTTGCAGAGTCTCCTCATCATGTTGGACAAΆGTGGAACAAAGGTCATG AGTGAACCGTTGTCATGTGCTGCAAGATTACAGGCTGTTGCAAGCATGGTGGAAAAAAGGGCTA GTCCTGCCACCTCACCTAAACCTAGTGTTGCTTGTAGCCAGTTAGCATTACTTCTGTCAAGCGA AGCCCATTTGCAGCAGTATTCTCGAGAACACGCTTTAAAAACGCAAAATGCAAATCAAGCAGCA AGTGAAAGACTTGCTGCTATGGCCAGATTGCAAGAAAATGGCCAGAAGGATGTTGGCAGTTACC AGCTCCCAAAAGGAATGTCAAGCCATCTTAATGGTCAGGCAAGAACATCATCAAGCAAACTGAT GGCTAGCAAAAGTAGTGCTACAGTGTTTCAAAATCCAATGGGTATCATTCCTTCTTCCCCTAAA AATGCAGGTTATAAGAACTCACTGGAAAGAAACAATATAAAACAAGCTGCTAACAATAGTTTGC

AGTTTTACAGATGACAGCAGTGGTGATGAAAGTTCTTATTCCAACTGTGTTCCCATAGACTTGT CTTGCAAACACCGAACTGAAAAATCAGAATCTGACCAACCTGTTTCCCTGGATAACTTCACTCA ATCCTTGCTAAACACTTGGGATCCAΆAAGTCCCAGATGTAGATATCAAAGAAGATCAAGATACC TCAAAGAATTCTAAGCTAAACTCACACCAGAAAGTAACACTTCTTCAATTGCTACTTGGCCATA AGAATGAAGAAAATGTAGAAAAAAACACCAGCCCTCAGGGΆGTACACAATGATGTGAGCAAGTT CAATACACAAAATTATGCAAGGACTTCTGTGATAGAAAGCCCCAGTACAAATCGGACTACTCCA GTGAGCACTCCACCTTTACTTACATCAAGCAAAGCAGGGTCTCCCATCAATCTCTCTCAACACT CTCTGGTCATCAAATGGAATTCCCCACCATATGTCTGCAGTACTCAGTCTGAAAAGCTAACAAA

CAAAATGAAGGTGCACAGAACTCTGCAACGTTTAGTGCCAGTAAGCTGTTACAAAATTTAGCAC AATGTGGAATGCAGTCATCCATGTCAGTGGAAGAGCAGAGACCCAGCAAACAGCTGTTAACTGG AAACACAGATAAACCGATAGGTATGATTGATAGATTAAATAGCCCTTTGCTCTCAAATAAAACA AATGCAGTTGAAGAAAATAAAGCATTTAGTAGTCAACCAACAGGTCCTGAACCAGGGCTTTCTG GTTCTGAAATAGAAAATCTGCTTGAAAGACGTACTGTCCTCCAGTTGCTCCTGGGGAACCCCAA CAAAGGGAAGAGTGAAAAAAAAGAGAAAACTCCCTTAAGAGATGAAAGTACTCAGGAACACTCA GAGAGAGCTTTAAGTGAACAAATACTGATGGTGAAAΆTAAAATCTGAGCCTTGTGATGACTTAC AAATTCCTAACACAAATGTGCACTTGAGCCATGATGCTAAGAGTGCCCCATTCTTGGGTATGGC

TCCTGCTGTGCAGAGAAGCGCACCTGCCTTACCAGTGTCCGAAGACTTTAAATCGGAGCCTGTT TCACCTCAGGATTTTTCTTTCTCCAAGAATGGTCTGCTAAGTCGATTGCTAAGACAAAATCAAG

ATAGTTACCTGGCAGATGATTCAGACAGGAGTCACAGAAATAATGAAATGGCACTTCTAGAATC

AAAGAATcTTTGCATGGTcccTAAGΆAAAGGAAGCTTTATACTGAGCCATTAGAAAATCCATTT AAAAAGATGAAAAACAACATTGTTGATGCTGCAAACAATCACAGTGCCCCAGAAGTACTGTATG GGTCCTTGCTTAACCAGGAAGAGCTGAAATTTAGCAGAAATGATCTTGAATTTAAATATCCTGC TGGTCATGGCTCAGCCAGCGAAAGTGAACACAGGAGTTGGGCCAGAGAGAGCAAAAGCTTTAAT GTTCTGAAACAGCTGCTTCTCTCAGAAAACTGTGTGCGAGATTTGTCCCCGCACAGAAGTAACT CTGTGGCTGACAGTAAAAAGAAAGGACACAAAAΆTAATGTGACCAACAGCAAACCTGAATTTAG CATTTCTTCTTTAAATGGACTGATGTACAGTTCCACTCAGCCCAGCAGTTGCATGGATAACAGG ACATTTTCATACCCAGGTGTAGTAAAAACTCCTGTGAGTCCTACTTTCCCTGAGCACTTGGGCT GTGCAGGGTCTAGACCAGAATCTGGGCTTTTGAATGGGTGTTCCATGCCCAGTGAGAAAGGACC CATTAΆGTGGGTTATCACTGATGCGGAGAAGAATGAGTATGAAAAAGACTCTCCAAGATTGACC AAAACCAACCCAATACTATATTACATGCTTCAAAAAGGAGGCAATTCTGTTACCAGTCGAGAAA CACAAGACAAGGACATTTGGAGGGAGGCTTCATCTGCTGAAAGTGTCTCACAGGTCACAGCCAA AGAAGAGTTACTTCCTACTGCAGAAACGAAAGCTTCTTTCTTTAATTTAAGAAGCCCTTACAAT AGCCATATGGGAAATAATGCTTCTCGCCCACACAGCGCAAATGGAGAAGTTTATGGACTTCTGG GAAGCGTGCTAACGATAAAGAAAGAATCAGAATAAAATGTACCTGCCATCCAGTTTTGGATCTT TTTAAAACTAATGAGTATGAACTTGAGATCTGTATAAATAAGAGCATGATTTGAAAAAAAGCAT GGTATAATTGAAACTTTTTTCATTTTGAAAAGTATTGGTTACTGGTGATGTTGAAATATGCATA CTAATTTTTGCTTAACATTAGATGTCATGAGGAAACTACTGAACTAGCAATTGGTTGTTTAACA CTTCTGTATGCATCAGATAACAACTGTGAGTAGCCTATGAATGAAATTCTTTTATAAATATTAG GCATAAATTAAAATGTAAΆACTCCATTCATAGTGGATTAΆTGCATTTTGCTGCCTTTATTAGGG TACTTTATTTTGCTTTTCAGAAGTCAGCCTACATAACACATTTTTAAAGTCTAAACTGTTAAAC AΆCTCTTTAAAGGATAATTATCCAATAAAAAAAAACCTAGTGCTGATTCACAGCTTATTATCCA ATTCAAAAATAAATTAGAAAAATATATGCTTACATTTTTCACTTTTGCTAAAAAGAAAAAAAAA^' AGGTGTTTATTTTTAACTCTTGGAAGAGGTTTTGTGGTTCCCAATGTGTCTGTCCCACCCTGAT CCTTTTCAATATATATTTCTTTAAACCTTGTGCTACTTAGTAAAAATTGATTACAATTGAGGGA AGTTTGATAGATCCTTTAAAAAAAΆGGCAGATTTCCATTTTTTGTATTTTAACTACTTTACTAA ATTAATACTCCTCCTTTTACAGAΆTTAGAΆAAGTTAACATTTATCTTTAGGTGGTTTCCTGAAA AGTTGAATATTTAAGAAATTGTTTTTAACAGAAGCAAAATGGCTTTTCTTTGGACAGTTTTCAC

CTTAAACCTGAACTCAGACCACTTGCATTAGAACCATCTGGAGCACTTGTTTTAAAATGCAGAT TCATAGGCAGCATCTCAGATCTACAGAACAAGAATCTCTGCTAAGTGGACCTGGAΆTCTTCCAT

AGAACATGAGACTGTAAAΆCAAAAΆCAAAAAACTΆTGTGATGCCTCTATTTTCCCCAΆTACAGT GGTTCAGAACACTTTTTATGACAAAAATTGGGTGGAGGGGATAACTTTCATATCTGGCTCAACA

GATGGAAAAACAGGGCCACTTACCAAACTCAGGTGATTCCAGGATGGTTTGGAAACTTCTCCTG

AATGCATCCTTAACCTTTATTAAAACCATTGTCCTAAGAACAATGCCAACAAAGCTTACAACAT TTAGTTTAAACCCAAGAAGGGCACTAAACTCAGATTGACTAAATAAAAAGTACAAAGGGCACAT

GAAACAGGTCTGTTTTTATGTTCAGTTTGTACAATCCACAATTCATTCACCAGATATTTTGTTC TTAATTGTGAACCAGGTTAGCAAATGACCTATCAAAAATTATTCTATAATCACTACTAGTTAGG

ATTTCCTAATATGATCTAAAACCCTAAATGGTTATTTTTCCTCAGAATGATTTGTAAATAGCTA CTGGAAATATTATACAGTAATAGGAGTGGGTATTATGCAACATCATGGAGAAGTGAAGGCATAG GCTTATTCTGACATAAAATTCCACTGGCCAGTTGAATATATTCTATTCCATGTCCATACTATGA CAATCTTATTGTCAACACTATATAAATAAGCTTTTAAACAΆGTCATTTTTCTTGATCGTTGTGG AAGGTTTGGAGCCTTAGAGGTATGTCAGAAAAAATATGTTGGTATTCTCCCTTGGGTAGGGGGA AATGACCTTTTTACAAGAGAGTGAAATTTAGGTCAGGGAAAAGACCAAGGGCCAGCATTGCTAC TTTTGTGTGTGTGTGTGTGGGTTTTGTTTTGTTTTTTTGGTTGGCTGGTTGTTTTCGTTGTTGT TAACAAAGGAATGAGAATATGTAATACTTAAATAAACATGACCACGAAGAATGCTGTTCTGATT TACTAGAGAATGTTCCCAATTTGAATTTAGGGTGATTTTAAAGAACAGTGAGAAAGGGCATACA TCCACAGATTCACTTTGTTTATGCATATGTAGATACAAGGATGCACATATACACATTTTCAAGG ACTATTTTAGATATCTAGACAATTTCTTCTAATAAAGTCATTTGTGAAAGGGTACTACAGCTTA TTGACATCAGTAAGGTAGCATTCATTACCTGTTTATTCTCTGCTGCATCTTACAGAAGAGTAAA CTGGTGAGAGTATATATTTTATATATATATATATATATATATATATAATATGTATATATATATA TATTGACTTGTTACATGAAGATGTTAAAATCGGTTTTTAAAGGTGATGTAAATAGTGATTTCCT TAATGAAAAATACATATTTTGTATTGTTCTAATGCAACAGAAAAGCCTTTTAATCTCTTTGGTT CCTGTATATTCCATGTATAAGTGTAAATATAATCAGACAGGTTTAAAAGTTGTGCATGTATGTA

TACAGTTGCAΆGTCTGGACAAATGTATAGAATAAACCTTTTATTTAAGTTGTGATTACCTGCTG

CATGAAAAGTGCATGGGGGACCCTGTGCATCTGTGCATTTGGCAAAATGTCTTAACAAATCAGA

TCAGATGTTCATCCTAACATGACAGTATTCCATTTCTGGACATGACGTCTGTGGTTTAAGCTTT GTGAAAGAATGTGCTTTGATTCGAAGGGTCTTAAAGAATTTTTTTAATCGTCAACCACTTTTAA ACATAAAGAATTCACACAACTACTTTCATGAATTTTTTAATCCCATTGCAAACATTATTCCAAG AGTATCCCAGTATTAGCAATACTGGAATATAGGCACATTACCATTCATAGTAAGAATTCTGGTG TTTACACAACCAAATTTGATGCGATCTGCTCAGTAATATAATTTGCCATTTTTATTAGAAATTT AATTTCTTCATGTGATGTCATGAAACTGTACATACTGCAGTGTGAATTTTTTTGTTTTGTTTTT TAATCTTTTAGTGTTTACTTCCTGCAGTGAATTTGAATAAATGAGAΆAAAΆTGCATTGTC

The RDP140 mature peptide is encoded by nucleotides 335-381 lof the above-mentioned sequence, and the apoB-48 mature peptide is encoded by nucleotides 210-6665 of the above-mentioned sequence. Examples of other genes associated with metabolic diseases and disorders include, genes for dyslipidemia (e.g., liver X receptors (e.g., LXRα and LXRβ (Genback Accession No. NM.sub.— 007121)), farnesoid X receptors (FXR) (Genbank Accession No. NM.sub.--005123), sterol-regulatory element binding protein (SREBP), Site-1 protease (SlP), 3-hydroxy-3-methylglutary- 1 coenzyme-A reductase (HMG coenzyme- A reductase), Apolipoprotein (ApoB), and Apolipoprotein (ApoE)) and gene associated with diabetes (e.g., Glucose 6-phosphatase) (see, e.g., Forman et al., Cell 81:687 (1995); Seol et al., MoI. Endocrinol. 9:72 (1995), Zavacki et al., PNAS USA 94:7909 (1997); Sakai et al., Cell 85:1037-1046 (1996); Duncan et al., J. Biol. Chem. 272:12778-12785 (1997); Willy et al., Genes Dev. 9(9):1033-45 (1995); Lehmann et al., J. Biol. Chem. 272(6):3137-3140 (1997); Janowski et al., Nature 383 :728-731 (1996); Peet et al, CeU 93:693-704 (1998)).

Vπ. Methods of Treatment

The present invention provides for both prophylactic and therapeutic methods of treating a subject at risk of (or susceptible to) a disorder or having a disorder associated with aberrant or unwanted target gene expression or activity. "Treatment", or "treating" as used herein, is defined as the application or administration of a therapeutic agent (e.g., nucleic acid molecule, and/or a pharmaceutical agent) to a patient, or application or administration of a therapeutic agent to an isolated tissue or cell line from a patient, who has a disease or disorder, a symptom of disease or disorder or a predisposition toward a disease or disorder, with the purpose to cure, heal, alleviate, delay, relieve, alter, remedy, ameliorate, improve or affect the disease or disorder, the symptoms of the disease or disorder, or the predisposition toward disease.

With regards to both prophylactic and therapeutic methods of treatment, such treatments may be specifically tailored or modified, based on knowledge obtained from the field of pharmacogenomics. "Pharmacogenomics", as used herein, refers to the application of genomics technologies such as gene sequencing, statistical genetics, and gene expression analysis to drugs in clinical development and on the market. More specifically, the term refers the study of how a patient's genes determine his or her response to a drug (e.g., a patient's "drug response phenotype", or "drug response genotype"). Thus, another aspect of the invention provides methods for tailoring an individual's prophylactic or therapeutic treatment with the nucleic acid molecules and/or pharmaceutical agents of the present invention or target nucleic acid molecules and/or pharmaceutical agents according to that individual's drug response genotype. Pharmacogenomics allows a clinician or physician to target prophylactic or therapeutic treatments to patients who will most benefit from the treatment and to avoid treatment of patients who will experience toxic drug-related side effects.

a) Prophylactic Methods In one aspect, the invention provides a method for preventing in a subject, a disease or condition associated with an aberrant or unwanted target gene expression or activity, by administering to the subject a therapeutic agent (e.g., a nucleic acid molecule, and/or a pharmaceutical agent). Subjects at risk for a disease which is caused or contributed to by aberrant or unwanted target gene expression or activity can be identified by, for example, any or a combination of diagnostic or prognostic assays as described herein. Administration of a prophylactic agent can occur prior to the manifestation of symptoms characteristic of the target gene aberrancy, such that a disease or disorder is prevented or, alternatively, delayed in its progression. Depending on the type of target gene aberrancy, for example, a target gene, target gene agonist or target gene antagonist agent can be used for treating the subject. The appropriate agent can be determined based on screening assays described herein.

b) Therapeutic Methods

Another aspect of the invention pertains to methods of modulating target gene expression, protein expression or activity for therapeutic purposes. Accordingly, in an exemplary embodiment, the modulatory method of the invention involves contacting a cell capable of expressing the target gene with a therapeutic agent (e.g., a nucleic acid molecule and/or pharmaceutical agent) that is specific for the target gene or protein (e.g., is specific for the mRNA encoded by said gene or specifying the amino acid sequence of said protein) such that expression or one or more of the activities of target protein is modulated. These modulatory methods can be performed in vitro (e.g., by culturing the cell with the agent) or, alternatively, in vivo {e.g., by administering the agent to a subject). As such, the present invention provides methods of treating an individual afflicted with a disease or disorder characterized by aberrant or unwanted expression or activity of a target gene polypeptide or nucleic acid molecule. Inhibition of target gene activity is desirable in situations in which target gene is abnormally unregulated and/or in which decreased target gene activity is likely to have a beneficial effect.

c) Pharmacogenomics

The therapeutic agents (e.g., nucleic acid molecules and/or pharmaceutical agents) of the invention can be administered to individuals to treat (prophylactically or therapeutically) disorders associated with aberrant or unwanted target gene activity. In conjunction with such treatment, pharmacogenomics {i.e., the study of the relationship between an individual's genotype and that individual's response to a foreign compound or drug) may be considered. Differences in metabolism of therapeutics can lead to severe toxicity or therapeutic failure by altering the relation between dose and blood concentration of the pharmacologically active drug. Thus, a physician or clinician may consider applying knowledge obtained in relevant pharmacogenomics studies in determining whether to administer a therapeutic agent as well as tailoring the dosage and/or therapeutic regimen of treatment with a therapeutic agent.

Pharmacogenomics deals with clinically significant hereditary variations in the response to drugs due to altered drug disposition and abnormal action in affected persons. See, for example, Eichelbaum, M. et al. (1996) Clin. Exp. Pharmacol. Physiol. 23(10-11): 983-985 and Linder, M. W. et al. (1997) Clin. Chem. 43(2):254-266. In general, two types of pharmacogenetic conditions can be differentiated. Genetic conditions transmitted as a single factor altering the way drugs act on the body (altered drug action) or genetic conditions transmitted as single factors altering the way the body acts on drugs (altered drug metabolism). These pharmacogenetic conditions can occur either as rare genetic defects or as naturally-occurring polymorphisms. For example, glucose-6-phosphate dehydrogenase deficiency (G6PD) is a common inherited enzymopathy in which the main clinical complication is haemolysis after ingestion of oxidant drugs (anti-malarials, sulfonamides, analgesics, nitrofiirans) and consumption of fava beans.

One pharmacogenomics approach to identifying genes that predict drug response, known as "a genome-wide association", relies primarily on a high-resolution map of the human genome consisting of already known gene-related markers (e.g., a "bi- allelic" gene marker map which consists of 60,000-100,000 polymorphic or variable sites on the human genome, each of which has two variants.) Such a high-resolution genetic map can be compared to a map of the genome of each of a statistically significant number of patients taking part in a Phase II/HI drug trial to identify markers associated with a particular observed drug response or side effect. Alternatively, such a high resolution map can be generated from a combination of some ten-million known single nucleotide polymorphisms (SNPs) in the human genome. As used herein, a "SNP" is a common alteration that occurs in a single nucleotide base in a stretch of DNA. For example, a SNP may occur once per every 1000 bases of DNA. A SNP may be involved in a disease process, however, the vast majority may not be disease- associated. Given a genetic map based on the occurrence of such SNPs, individuals can be grouped into genetic categories depending on a particular pattern of SNPs in their individual genome. In such a manner, treatment regimens can be tailored to groups of genetically similar individuals, taking into account traits that may be common among such genetically similar individuals.

Alternatively, a method termed the "candidate gene approach", can be utilized to identify genes that predict drug response. According to this method, if a gene that encodes a drugs target is known (e.g., a target gene polypeptide of the present invention), all common, variants of that gene can be fairly easily identified in the population and it can be determined if having one version of the gene versus another is associated with a particular drug response.

As an illustrative embodiment, the activity of drug metabolizing enzymes is a major determinant of both the intensity and duration of drug action. The discovery of genetic polymorphisms of drug metabolizing enzymes (e.g., N-acetyltransferase 2 (NAT 2) and cytochrome P450 enzymes CYP2D6 and CYP2C19) has provided an explanation as to why some patients do not obtain the expected drug effects or show exaggerated drug response and serious toxicity after taking the standard and safe dose of a drug. These polymorphisms are expressed in two phenotypes in the population, the extensive metabolizer (EM) and poor metabolizer (PM). The prevalence of PM is different among different populations. For example, the gene coding for CYP2D6 is highly polymorphic and several mutations have been identified in PM, which all lead to the absence of functional CYP2D6. Poor metabolizers of CYP2D6 and CγP2C19 quite frequently experience exaggerated drug response and side effects when they receive standard doses. If a metabolite is the active therapeutic moiety, PM show no therapeutic response, as demonstrated for the analgesic effect of codeine mediated by its CYP2D6-formed metabolite morphine. The other extreme are the so called ultra-rapid metabolizers who do not respond to standard doses. Recently, the molecular basis of ultra-rapid metabolism has been identified to be due to CYP2D6 gene amplification.

Alternatively, a method termed the "gene expression profiling", can be utilized to identify genes that predict drug response. For example, the gene expression of an animal dosed with a therapeutic agent of the present invention can give an indication whether gene pathways related to toxicity have been turned on. Information generated from more than one of the above pharmacogenomics approaches can be used to determine appropriate dosage and treatment regimens for prophylactic or therapeutic treatment an individual. This knowledge, when applied to dosing or drug selection, can avoid adverse reactions or therapeutic failure and thus enhance therapeutic or prophylactic efficiency when treating a subject with a therapeutic agent, as described herein.

Therapeutic agents can be tested in an appropriate animal model. For example, an siRNA (or expression vector or transgene encoding same) as described herein can be used in an animal model to determine the efficacy, toxicity, or side effects of treatment with said agent. Alternatively, a therapeutic agent can be used in an animal model to determine the mechanism of action of such an agent. For example, an agent can be used in an animal model to determine the efficacy, toxicity, or side effects of treatment with such an agent. Alternatively, an agent can be used in an animal model to determine the mechanism of action of such an agent.

ά) Disease Indications

In certain aspects, the invention provides an improved method of treating diseases by providing a more effective means by which to deliver agents (e.g., RNA silencing agents) for treatment of such diseases. For example, the invention provides delivery complexes comprising an RNA silencing agent to treat a disorder by targeting relevant disease-associated target genes (e.g., a gain-of-function disorder target genes), such that expression of the target gene is silenced. The compositions of the invention can act as novel therapeutic agents for controlling one or more of neurologic disorders, cellular proliferative and/or difFerentiative disorders, disorders associated with bone metabolism, immune disorders, hematopoietic disorders, cardiovascular disorders, liver disorders, viral diseases, pain or metabolic disorders.

The delivery complexes of the invention are surprisingly effective when administered in low doses to a subject (e.g. a mammal, e.g., a human). In particular, the delivery complexes of the invention require only small amounts of RNA silencing agent in order to silence disease-related genes (e.g. endogenous disease-related genes) in a clinically acceptable and therapeutically affordable manner. In certain embodiments, delivery complexes are administered at a dose which provides an effective dose of about 1 to about 50 mg/kg of RNA silencing agent to the subject. In more preferred embodiments, the delivery complexes are administered at an effective dose that provides an effective dose of about 1 to about 10 mg/kg of RNA silencing agent to the subject. In particularly preferred embodiments, the delivery complexes are administered at an effective dose that provides about 1 to about 5 mg/kg of RNA silencing agent to the subject (e.g, 5 mg/kg, 4 mg/kg, 3 mg/kg, 2.5 mg/kg, 1.25 mg/kg, 1 mg/kg, or less). (ϊ) Cellular Proliferative/Differentiative Disorders

Examples of cellular proliferative and/or difFerentiative disorders include cancer, e.g., carcinoma, sarcoma, metastatic disorders or hematopoietic neoplastic disorders, e.g., leukemias. A metastatic tumor can arise from a multitude of primary tumor types, including but not limited to those of prostate, colon, lung, breast and liver origin. As used herein, the terms "cancer," "hyperproliferative," and "neoplastic" refer to cells having the capacity for autonomous growth, Le., an abnormal state or condition characterized by rapidly proliferating cell growth. Hyperproliferative and neoplastic disease states may be categorized as pathologic, Le., characterizing or constituting a disease state, or may be categorized as non-pathologic, i.e., a deviation from normal but not associated with a disease state. The term is meant to include all types of cancerous growths or oncogenic processes, metastatic tissues or malignantly transformed cells, tissues, or organs, irrespective of histopathologic type or stage of invasiveness. "Pathologic hyperproliferative" cells occur in disease states characterized by malignant tumor growth. Examples of non-pathologic hyperproliferative cells include proliferation of cells associated with wound repair.

The terms "cancer" or "neoplasms" include malignancies of the various organ systems, such as affecting lung, breast, thyroid, lymphoid, gastrointestinal, and genito- urinary tract, as well as adenocarcinomas which include malignancies such as most colon cancers, renal-cell carcinoma, prostate cancer and/or testicular tumors, non-small cell carcinoma of the lung, cancer of the small intestine and cancer of the esophagus.

The term "carcinoma" is art recognized and refers to malignancies of epithelial or endocrine tissues including respiratory system carcinomas, gastrointestinal system carcinomas, genitourinary system carcinomas, testicular carcinomas, breast carcinomas, prostatic carcinomas, endocrine system carcinomas, and melanomas. Exemplary carcinomas include those forming from tissue of the cervix, lung, prostate, breast, head and neck, colon and ovary. The term also includes carcinosarcomas, e.g., which include malignant tumors composed of carcinomatous and sarcomatous tissues. An "adenocarcinoma" refers to a carcinoma derived from glandular tissue or in which the tumor cells form recognizable glandular structures.

The term "sarcoma" is art recognized and refers to malignant tumors of mesenchymal derivation.

Additional examples of proliferative disorders include hematopoietic neoplastic disorders. As used herein, the term "hematopoietic neoplastic disorders" includes diseases involving hyperplastic/neoplastic cells of hematopoietic origin, e.g., arising from myeloid, lymphoid or erythroid lineages, or precursor cells thereof. Preferably, the diseases arise from poorly differentiated acute leukemias, e.g., erythroblastic leukemia and acute megakaryoblastic leukemia. Additional exemplary myeloid disorders include, but are not limited to, acute promyeloid leukemia (APML), acute myelogenous leukemia (AML) and chronic myelogenous leukemia (CML) (reviewed in Vaickus, L. (1991) Crit Rev. in OncoL/Hemotol. 11:267-97); lymphoid malignancies include, but are not limited to acute lymphoblastic leukemia (ALL) which includes B-lineage ALL and T-lineage ALL, chronic lymphocytic leukemia (CLL), prolymphocytic leukemia (PLL), hairy cell leukemia (HLL) and Waldenstrom's macroglobulinemia (WM). Additional forms of malignant lymphomas include, but are not limited to non-Hodgkin lymphoma and variants thereof, peripheral T cell lymphomas, adult T cell leukemia/lymphoma (ATL), cutaneous T-cell lymphoma (CTCL), large granular lymphocytic leukemia (LGF), Hodgkin's disease and Reed-Sternberg disease.

In general, the compositions of the invention are designed to target genes associated with particular proliferative disorders. Examples of such genes associated with proliferative disorders that can be targeted include activated ras, p53, BRCA-I , and BRCA-2.

(H) Neurologic Disorders

Other specific genes that can be targeted are those associated with amyotrophic lateral sclerosis (ALS; e.g., superoxide dismutase-1 (SODl)); Huntington's disease (e.g., huntingtin), Parkinson's disease (parkin), and genes associated with autosomal dominant disorders.

In certain embodiments, the neurological disorder is a polyglutamine disorder. The term "polyglutamine disorder" as used herein, refers to any disease or disorder characterized by an expanded of a (CAG)_n repeats at the 5' end of the coding region (thus encoding an expanded polyglutamine region in the encoded protein). In one embodiment, polyglutamine disorders are characterized by a progressive degeneration of nerve cells. Examples of polyglutamine disorders include but are not limited to: Huntington's disease, spino-cerebellar ataxia type \, spino-cerebellar ataxia type 2, spino-cerebellar ataxia type 3 (also know as Machado-Joseph disease), and spino- cerebellar ataxia type 6, spino-cerebellar ataxia type 7 and dentatoiubral-pallidoluysian atrophy.

(up Immune Disorders The compositions of the invention can be used to treat a variety of immune disorders, in particular those associated with overexpression of a gene or expression of a mutant gene. Examples of hematopoietic disorders or diseases include, but are not limited to, autoimmune diseases (including, for example, diabetes mellitus, arthritis (including rheumatoid arthritis, juvenile rheumatoid arthritis, osteoarthritis, psoriatic arthritis), multiple sclerosis, encephalomyelitis, myasthenia gravis, systemic lupus erythematosis, autoimmune thyroiditis, dermatitis (including atopic dermatitis and eczematous dermatitis), psoriasis, Sjogren's Syndrome, Crohn's disease, aphthous ulcer, iritis, conjunctivitis, keratoconjunctivitis, ulcerative colitis, asthma, allergic asthma, cutaneous lupus erythematosus, scleroderma, vaginitis, proctitis, drug eruptions, leprosy reversal reactions, erythema nodosum leprosum, autoimmune uveitis, allergic encephalomyelitis, acute necrotizing hemorrhagic encephalopathy, idiopathic bilateral progressive sensorineural hearing loss, aplastic anemia, pure red cell anemia, idiopathic thrombocytopenia, polychondritis, Wegener's granulomatosis, chronic active hepatitis, Stevens-Johnson syndrome, idiopathic sprue, lichen planus, Graves' disease, sarcoidosis, primary biliary cirrhosis, uveitis posterior, and interstitial lung fibrosis), graft-versus- host disease, cases of transplantation, and allergy such as, atopic allergy.

(iv) Cardiovascular Disorders

Examples of disorders involving the heart or "cardiovascular disorder" include, but are not limited to, a disease, disorder, or state involving the cardiovascular system, e.g., the heart, the blood vessels, and/or the blood. A cardiovascular disorder can be caused by an imbalance in arterial pressure, a malfunction of the heart, or an occlusion of a blood vessel, e.g., by a thrombus. Examples of such disorders include hypertension, atherosclerosis, coronary artery spasm, congestive heart failure, coronary artery disease, valvular disease, arrhythmias, and cardiomyopathies.

Disorders which may be treated by methods described herein include, but are not limited to, disorders associated with an accumulation in the liver of fibrous tissue, such as that resulting from an imbalance between production and degradation of the extracellular matrix accompanied by the collapse and condensation of preexisting fibers.

(v) Viral Disorders

Additionally, molecules of the invention can be used to treat viral diseases, including but not limited to hepatitis B, hepatitis C, herpes simplex virus (HSV), HIV- AIDS, poliovirus, and smallpox virus. Molecules of the invention are engineered as described herein to target expressed sequences of a virus, thus ameliorating viral activity and replication. The molecules can be used in the treatment and/or diagnosis of viral infected tissue. Also, such molecules can be used in the treatment of virus-associated carcinoma, such as hepatocellular cancer.

(vi) Metabolic Diseases and Disorders

Metabolic disorders affect how the body processes substances needed to carry out physiological functions. A number of metabolic disorders share certain characteristics, i.e. they are associated the insulin resistance, lack of ability to regulate blood sugar, weight gain, and increase in body mass index. Examples of metabolic disorders include diabetes and obesity, as well as increased serum cholesterol levels. Examples of diabetes include type 1 diabetes mellitus, type 2 diabetes mellitus, diabetic neuropathy, peripheral neuropathy, diabetic retinopathy, diabetic ulcerations, retinopathy ulcerations, diabetic macrovasculopathy, and obesity. Identification or selection of a subject in need of treatment can be accomplished by any skilled medical practitioner or researcher using art-recognized diagnostic skills or techniques.

In one embodiment, the invention includes a method of decreasing cholesterol levels by silencing a target gene associated with increased cholesterol, wherein the nanotransporter of the invention is conjugated to a RNA silencing agent (e.g., an siRNA) to form a delivery complex capable of efficiently targeting the target gene. In one embodiment the target gene is apoB. ApoB-100 participates in the transport and delivery of endogenous plasma cholesterol (Davidson and Shelness, Annu. Rev. Nutr., 2000, 20, 169-193). Elevated plasma levels of the ApoB-100-containing lipoprotein

Lp(a) are associated with increased risk for atherosclerosis and its manifestations, which may include hypercholesterolemia (Seed et al., N. Engl. J. Med., 1990, 322, 1494-1499). Furthermore, elevated plasma levels of the ApoB-100-containing lipoprotein Lp(a) are associated with increased risk for atherosclerosis and its manifestations, which may include hypercholesterolemia (Seed et al., N. Engl. J. Med., 1990, 322, 1494-1499). The invention provides a method of lowering serum cholesterol by administering an HBOLD conjugated siRNA to a subject having increased or high levels of cholesterol relative to those accepted as being physiologically normal.

In another embodiment, the invention includes a method of treating obesity by silencing a target gene associated with obesity. Obesity increases a person's risk of illness and death due to diabetes, stroke, coronary artery disease, hypertension, high cholesterol, and kidney and gallbladder disorders. Obesity may also increase the risk for some types of cancer, and may be a risk factor for the development of osteoarthritis and sleep apnea. Obesity can be treated with the siRNA conjgated nanotransporter of the invention alone or in combination with other metabolic disorders, including diabetes.

An obese subject is a subject, e.g., a human subject, who has been diagnosed as being obese (or would be diagnosed as being obese) by a skilled medical practitioner or researcher. Preferred tests utilized in obesity diagnosis include Body Mass Index (BMI)

- Sl - — Calculated by dividing your the subject's weight in kilograms by their height in meters squared. A BMI of 25 to 29.9 is considered overweight and 30 or higher is considered obese. (Source: Centers for Disease Control and Prevention and National Heart, Lung, and Blood Institute); Waist Circumference, Saggital Diameter, and Waist-To-Hip Ratio — Simple measurements that estimate the amount of fat deposited in the skin and inside the abdominal cavity. Waist circumferences that exceed 100 centimeters (39 inches) in men and 90 centimeters (35 inches) in women are associated with an increased risk of heart disease; Skinfold Caliper — Most fat is deposited beneath the skin. This test measures fat just beneath the skin, but cannot measure fat accumulated inside the abdomen; Water Displacement Tests — Fat is buoyant; other body tissues are not.

Determining how well the subject floats provides an estimated ratio of fat to body mass.

An example of a gene which might be targeted by a delivery complex (e.g. a delivery complex comprising an RNA silencing agent) for the treatment of obesity is RIP 140. As described in Leonardsson et al. (2004) PNAS 101 :8437, deletion of the RIP 140 gene in mice by genetic knockout resulted in the lack of fat accumulation even when mice were fed a high fat diet.

In another embodiment, the invention provides a method of treating diabetes, including diabetes type 2, by silencing a target gene associated with diabetes or insulin regulation. Diabetes includes the two most common types of the disorder, namely type I diabetes and type II diabetes, which both result from the body's inability to regulate insulin. Insulin is a hormone released by the pancreas in response to increased levels of blood sugar (glucose) in the blood.

The term "type 1 diabetes," as used herein, refers to a chronic disease that occurs when the pancreas produces too little insulin to regulate blood sugar levels appropriately. Type 1 diabetes is also referred to as insulin-dependent diabetes mellitus, IDMM, juvenile onset diabetes, and diabetes - type I. Type 1 diabetes represents is the result of a progressive autoimmune destruction of the pancreatic β-cells with subsequent insulin deficiency.

The term "type 2 diabetes," refers to a chronic disease that occurs when the pancreas does not make enough insulin to keep blood glucose levels normal, often because the body does not respond well to the insulin. Type 2 diabetes is also referred to as noninsulin-dependent diabetes mellitus, NDDM, and diabetes-type II Diabetes is can be diagnosed by the administration of a glucose tolerance test. Clinically, diabetes is often divided into several basic categories. Primary examples of these categories include, autoimmune diabetes mellitus, non-insulin-dependent diabetes mellitus (type 1 NDDM), insulin-dependant diabetes mellitus (type 2 DDDM), non- autoimmune diabetes mellitus, non-insulin-dependant diabetes mellitus (type 2

NIDDM), and maturity-onset diabetes of the young (MODY). A further category, often referred to as secondary, refers to diabetes brought about by some identifiable condition which causes or allows a diabetic syndrome to develop. Examples of secondary categories include, diabetes caused by pancreatic disease, hormonal abnormalities, drug- or chemical-induced diabetes, diabetes caused by insulin receptor abnormalities, diabetes associated with genetic syndromes, and diabetes of other causes, (see e.g., Harrison's (1996) 14^th ed., New York, McGraw-Hill).

Diabetes is afteπ treated with diet, insulin dosages, and various medications described herein. Accordingly, the siRNA associated nanotransporter of the invention may also be administered in combination with agents commonly used to treat metabolic disorders and pain commonly associated with diabetes.

A diabetic subject is a subject, e.g., a human subject, who has been diagnosed as having diabetes (or would be diagnosed as having diabetes) by a skilled medical practitioner or researcher. Preferred tests utilized in diabetes diagnosis include the fasting plasma glucose (FPG)test and the glucose tolerance test, e.g., the 75-g oral glucose tolerance test (OGTT). Exemplary criteria for the diagnosis of diabetes are set forth below.

Normoglycemia IFG or IGT* Diabetes* FPG < 110 mg/dl FPG > 110 and FPG > 126 mg/dl

< 126 mg/dl (IFG)

2-h PG^f < 140 mg/dl 2-h PG* > 140 and 2-h PG* > 200 mg/dl

<200 mg/dl (IGT)

Symptoms of diabetes and casual plasma glucose concentration > 200 mg/dl

* Midrange values indicating impaired glucose tolerance QQT), or impaired fasting glucose (IFG).

* A diagnosis of diabetes must be confirmed, on a subsequent day, by measurement of FPG, 2-h PG, or random plasma glucose (if symptoms are present). Fasting is defined as no caloric intake for at least 8 Ji. * This test requires the use of a glucose load containing the equivalent of 75 g anhydrous glucose dissolved in water. 2-h PG, 2-hpostload glucose.

An insulin resistant subject is a subject, e.g., a human subject, who has been diagnosed as being insulin resistant (or would be diagnosed as being insulin resistant) by a skilled medical practitioner or researcher. An insulin resistant subject can be identified, for example, by determining fasting glucose and/or insulin levels in said subject. In a preferred embodiment, an insulin resistant subject has a fasting glucose level of less than 110 mg/dX and has a fasting insulin level of greater that 30 mU/L. An example of a gene which to be targeted by a delivery complex of the invention (e.g., a nanotransporter associated with a target-specific siKNA) for the treatment of diabetes is RIP 140.

The invention also provides a method of treating metabolic disorders wherein the disorder is treated without immunostimulating the recipient subject. For example, by modifying an RNA silencing agent (e.g., an siRNA) with a HBOLD nanotransporter, an interferon response can be reduced or eliminated in a subject having a metabolic disorder undergoing treatment with said RNA silencing agent. Thus, the method of treating a metabolic disorder using the chemically modified RNA silencing agent of the invention provides an improvement over other therapies as it bypasses immunostimulation in the recipient.

VUU. Screening Assays

The methods of the invention are also suitable for use in methods to identify and/or characterize potential pharmacological agents, e.g. identifying new pharmacological agents from a collection of test substances and/or characterizing mechanisms of action and/or side effects of known pharmacological agents.

Thus, the present invention also relates to a system for identifying and/or characterizing pharmacological agents acting on at least one target protein comprising: (a) a eukaryotic cell or a eukaryotic non- human organism capable of expressing at least one endogenous target gene coding for said so target protein, (b) at least one composition (e.g. a RNA silencing agent or a delivery complex comprising same) of inhibiting the expression of said at least one endogenous target gene, and (c) a test substance or a collection of test substances wherein pharmacological properties of said test substance or said collection are to be identified and/or characterized. Further, the system as described above preferably comprises: (d) at least one exogenous target nucleic acid coding for the target protein or a variant or mutated form of the target protein wherein said exogenous target nucleic acid differs from the endogenous target gene on the nucleic acid level such that the expression of the exogenous target nucleic acid is substantially less inhibited by the composition than the expression of the endogenous target gene.

The test compounds of the present invention can be obtained using any of the numerous approaches in combinatorial library methods known in the art, including: biological libraries; spatially addressable parallel solid phase or solution phase libraries; synthetic library methods requiring deconvolution; the One-bead one-compound¹ library method; and synthetic library methods using affinity chromatography selection. The biological library approach is limited to peptide libraries, while the other four approaches are applicable to peptide, non-peptide oligomer or small molecule libraries of compounds (Lam, K.S. (1997) Anticancer Drug Des. 12:145). Examples of methods for the synthesis of molecular libraries can be found in the art, for example in: DeWitt et al. (1993) Proc. Natl. Acad. ScL U.S.A. 90:6909; Erb et al. (1994) Proc. Natl Acad. ScL USA 91:11422; Zuckermann et al (1994). J. Med Chem. 37:2678; Cho et al. (1993) Science 261 : 1303; ^'Canell et al. (1994)Angew. Chem. Int. Ed. Engl. 33:2059; Careli et al (1994) Angew. Chem. Int. Ed. Engl. 33:2061; and in Gallop et al (1994) J. Med. Chem. 37: 1233.

Libraries of compounds may be presented in solution (e.g., Houghten (1992) Biotechniques 13:412-421), or on beads (Lam (\99\) Nature 354:82-84), chips (Fodor (1993) Nature 364:555-556), bacteria (Ladner USP 5,223,409), spores (Ladner USP '409), plasmids (Cull et al. (1992) Proc Natl Acad Sci USA 89:1865-1869) or on phage (Scott and Smith (1990) Science 249:386-390); (Devlin (1990) Science 249:404-406); (Cwirla et al (1990) Proc. Natl Acad ScL 87:6378-6382); (Felici (1991) J. MoI Biol 222:301-310); (Ladner supra.)).

In a preferred embodiment, the library is a natural product library, e.g., a library produced by a bacterial, fungal, or yeast culture. In another preferred embodiment, the library is a synthetic compound library. IX. Knockout and/or Knockdown Cells or Organisms

A further preferred use for the siRNA molecules of the present invention (or vectors or transgenes encoding same) is a functional analysis to be carried out in eukaryotic cells, or eukaryotic non-human organisms, preferably mammalian cells or organisms and most preferably human cells, e.g. cell lines such as HeLa or 293 or rodents, e.g. rats and mice. By administering a suitable siRNA molecules which is sufficiently complementary to a target mKNA sequence to direct target-specific RNA interference, a specific knockout or knockdown phenotype can be obtained in a target cell, e.g. in cell culture or in a target organism. Thus, a further subject matter of the invention is a eukaryotic cell or a eukaryotic non-human organism exhibiting a target gene-specific knockout or knockdown phenotype comprising a folly or at least partially deficient expression of at least one endogenous target gene wherein said cell or organism is transfected with at least one vector comprising DNA encoding a siRNA molecule capable of inhibiting the expression of the target gene. It should be noted that the present invention allows a target-specific knockout or knockdown of several different endogenous genes due to the specificity of the RNA silencing agent.

Gene-specific knockout or knockdown phenotypes of cells or non-human organisms, particularly of human cells or non-human mammals may be used in analytic to procedures, e.g. in the functional and/or phenotypical analysis of complex physiological processes such as analysis of gene expression profiles and/or proteomes. Preferably the analysis is carried out by high throughput methods using oligonucleotide based chips.

X. Pharmaceutical Compositions

The invention pertains to uses of the any of the above-described nano transporters or RNA silencing agents for therapeutic treatments as described infra. Accordingly, the nano transporters of the present invention can be incorporated into pharmaceutical compositions suitable for administration. As used herein the language "pharmaceutically acceptable carrier" includes saline, solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, and the like, compatible with pharmaceutical administration. Supplementary active compounds can also be incorporated into the compositions. A pharmaceutical composition is formulated to be compatible with its intended route of administration. Examples of routes of administration include parenteral, e.g., intravenous, intradermal, subcutaneous, oral (e.g., inhalation), transdermal (topical), transmucosal, and rectal administration. Solutions or suspensions used for parenteral, intradermal, or subcutaneous application can include the following components: a sterile diluent such as water for .injection, saline solution, fixed oils, polyethylene glycols, glycerine, propylene glycol or other synthetic solvents; antibacterial agents such as benzyl alcohol or methyl parabens; antioxidants such as ascorbic acid or sodium bisulfite; chelating agents such as ethylenediaminetetraacetic acid; buffers such as acetates, citrates or phosphates and agents for the adjustment of tonicity such as sodium chloride or dextrose. pH can be adjusted with acids or bases, such as hydrochloric acid or sodium hydroxide. The parenteral preparation can be enclosed in ampoules, disposable syringes or multiple dose vials made of glass or plastic.

Pharmaceutical compositions suitable for injectable use include sterile aqueous solutions (where water soluble) or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersion. For intravenous administration, suitable carriers include physiological saline, bacteriostatic water, Cremophor EL™ (BASF, Parsippany, NJ) or phosphate buffered saline (PBS). In all cases, the composition must be sterile and should be fluid to the extent that easy syringability exists. It should be stable under the conditions of manufacture and storage and must be preserved against the contaminating action of microorganisms such as bacteria and fungi. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (for example, glycerol, propylene glycol, and liquid polyetheylene glycol, and the like), and suitable mixtures thereof. The proper fluidity can be maintained, for example, by the use of a coating such as lecithin, by the maintenance of the required particle size in the case of dispersion and by the use of surfactants. Prevention of the action of microorganisms can be achieved by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, ascorbic acid, tbimerosal, and the like. In many cases, it will be preferable to include isotonic agents, for example, sugars, polyalcohols such as manitol, sorbitol, sodium chloride in the composition. Prolonged absorption of the injectable compositions can be brought about by including in the composition an agent which delays absorption, for example, aluminum monostearate and gelatin. Sterile injectable solutions can be prepared by incorporating the active compound in the required amount in an appropriate solvent with one or a combination of ingredients enumerated above, as required, followed by filtered sterilization. Generally, dispersions are prepared by incorporating the active compound into a sterile vehicle, which contains a basic dispersion medium and the required other ingredients from those enumerated above. In the case of sterile powders for the preparation of sterile injectable solutions, the preferred methods of preparation are vacuum drying and freeze-drying which yields a powder of the active ingredient plus any additional desired ingredient from a previously sterile-filtered solution thereof. Oral compositions generally include an inert diluent or an edible carrier. For the purpose of oral therapeutic administration, the active compound can be incorporated with excipients and used in the form of tablets, troches, or capsules, e.g., gelatin capsules. Oral compositions can also be prepared using a fluid carrier for use as a mouthwash. Pharmaceutically compatible binding agents, and/or adjuvant materials can be included as part of the composition. The tablets, pills, capsules, troches and the like can contain any of the following ingredients, or compounds of a similar nature: a binder such as microcrystalline cellulose, gum tragacanth or gelatin; an excipient such as starch or lactose, a disintegrating agent such as alginic acid, Primogel, or com starch; a lubricant such as magnesium stearate or Sterotes; a glidant such as colloidal silicon dioxide; a sweetening agent such as sucrose or saccharin; or a flavoring agent such as peppermint, methyl salicylate, or orange flavoring.

For administration by inhalation, the compounds are delivered in the form of an aerosol spray from pressured container or dispenser which contains a suitable propellant, e.g., a gas such as carbon dioxide, or a nebulizer. Such methods include those described in U.S. Patent No. 6,468,798.

Systemic administration can also be by transmucosal or transdermal means. For transmucosal or transdermal administration, penetrants appropriate to the barrier to be permeated are used in the formulation. Such penetrants are generally known in the art, and include, for example, for transmucosal administration, detergents, bile salts, and fusidic acid derivatives. Transmucosal administration can be accomplished through the use of nasal sprays or suppositories. For transdermal administration, the active compounds are formulated into ointments, salves, gels, or creams as generally known in the art. The compounds can also be prepared in the form of suppositories (e.g., with conventional suppository bases such as cocoa butter and other glycerides) or retention enemas for rectal delivery.

The compounds can also be administered by transfection or infection using methods known in the art, including but not limited to the methods described in

McCaffrey et al. (2002), Nature, 418(6893), 38-9 (hydrodynamic transfection); Xia et al. (2002), Nature Biotechnol., 20(10), 1006-10 (viral-mediated delivery); or Putnam (1996), Am. J. Health Syst. Pharm. 53(2), 151-160, erratum at Am. J. Health Syst. Pharm. 53(3), 325 (1996). The compounds can also be administered by any method suitable for administration of nucleic acid agents, such as a DNA vaccine. These methods include gene guns, bio injectors, and skin patches as well as needle-free methods such as the micro-particle DNA vaccine technology disclosed in U.S. Patent No. 6,194,389, and the mammalian transdermal needle-free vaccination with powder-form vaccine as disclosed in U.S. Patent No. 6,168,587. Additionally, intranasal delivery is possible, as described in, inter alia, Hamajύna et al. (1998), Clin. Immunol. Immunopathol., 88(2), 205-10. Liposomes (e.g., as described in U.S. Patent No. 6,472,375) and microencapsulation can also be used. Biodegradable targetable microparticle delivery systems can also be used (e.g., as described in U.S. Patent No. 6,471,996). In one embodiment, the active compounds are prepared with carriers that will protect the compound against rapid elimination from the body, such as a controlled release formulation, including implants and microencapsulated delivery systems. Biodegradable, biocompatible polymers can be used, such as ethylene vinyl acetate, polyanhydrides, polyglycolic acid, collagen, polyorthoesters, and polylactic acid. Such formulations can be prepared using standard techniques. The materials can also be obtained commercially from Alza Corporation and Nova Pharmaceuticals, Inc. Liposomal suspensions (including liposomes targeted to infected cells with monoclonal antibodies to viral antigens) can also be used as pharmaceutically acceptable carriers. These can be prepared according to methods known to those skilled in the art, for example, as described in U.S. Patent No. 4,522,811.

Toxicity and therapeutic efficacy of such compounds can be determined by standard pharmaceutical procedures in cell cultures or experimental animals, e.g., for determining the LD50 (the dose lethal to 50% of the population) and the ED50 (the dose therapeutically effective in 50% of the population). The dose ratio between toxic and therapeutic effects is the therapeutic index and it can be expressed as the ratio LD50/ED50. Compounds which exhibit high therapeutic indices are preferred. While compounds that exhibit toxic side effects may be used, care should be taken to design a delivery system that targets such compounds to the site of affected tissue in order to minimize potential damage to uninfected cells and, thereby, reduce side effects.

A therapeutically effective amount of a composition containing a compound of the invention (e.g., a siRNA, candidate siRNA derivative, modified siRNA, etc.) (i.e., an effective dosage) is an amount that inhibits expression of the polypeptide encoded by the target gene by at least 30 percent. Higher percentages of inhibition, e.g., 45, 50, 75, 85, 90 percent or higher may be preferred in certain embodiments. Exemplary doses include milligram or microgram amounts of the molecule per kilogram of subject or sample weight (e.g., about 1 microgram per kilogram to about 500 milligrams per kilogram, about 100 micrograms per kilogram to about 5 milligrams per kilogram, or about 1 microgram per kilogram to about 50 micrograms per kilogram. The compositions can be administered one time per week for between about 1 to 10 weeks, e.g., between 2 to 8 weeks, or between about 3 to 7 weeks, or for about 4, 5, or 6 weeks. The skilled artisan will appreciate that certain factors may influence the dosage and timing required to effectively treat a subject, including but not limited to the severity of the disease or disorder, previous treatments, the general health and/or age of the subject, and other diseases present. Moreover, treatment of a subject with a therapeutically effective amount of a composition can include a single treatment or a series of treatments.

It is furthermore understood that appropriate doses of a composition depend upon the potency of composition with respect to the expression or activity to be modulated. When one or more of these molecules is to be administered to an animal (e.g., a human) to modulate expression or activity of a polypeptide or nucleic acid of the invention, a physician, veterinarian, or researcher may, for example, prescribe a relatively low dose at first, subsequently increasing the dose until an appropriate response is obtained. In addition, it is understood that the specific dose level for any particular subject will depend upon a variety of factors including the activity of the specific compound employed, the age, body weight, general health, gender, and diet of the subject, the time of administration, the route of administration, the rate of excretion, any drug combination, and the degree of expression or activity to be modulated.

The data obtained from the cell culture assays and animal studies can be used in formulating a range of dosage for use in humans. The dosage of such compounds lies preferably within a range of circulating concentrations that include the ED50 with little or no toxicity. The dosage may vary within this range depending upon the dosage form employed and the route of administration utilized. For any compound used in the method of the invention, the therapeutically effective dose can be estimated initially from cell culture assays. A dose may be formulated in animal models to achieve a circulating plasma concentration range that includes the IC50 (/. e., the concentration of the test compound which achieves a half-maximal inhibition of symptoms) as determined in cell culture. Such information can be used to more accurately determine useful doses in humans. Levels in plasma may be measured, for example, by high performance liquid chromatography. The pharmaceutical compositions can be included in a container, pack, or dispenser together with instructions for administration.

XL Methods of Administration

Physical methods of introducing the compositions (e.g., nanotransporters, RNA silencing agents, or delivery complexes) of the present invention include injection of a solution containing the composition, bombardment by particles covered by the composition, or electroporation of cell membranes in the presence of the composition. Where the composition comprises a nucleic acid molecule, a viral construct packaged into a viral particle would accomplish both efficient introduction of an expression construct into the cell and transcription of a nucleic acid molecule encoded by the expression construct. Other methods known in the art for introducing nucleic acids to cells may be used, such as lipid-mediated carrier transport, chemical- mediated transport, such as calcium phosphate, and the like. Thus the nucleic acid (e.g. RNA silencing agent) may be introduced along with components that perform one or more of the following activities: enhance nucleic acid uptake by the cell, inhibit annealing of strands, stabilize the strands, or other-wise increase inhibition of the target gene.

Compositions may be directly introduced into the cell (i.e., intracellularly); or introduced extracellularly into a cavity, interstitial space, into the circulation of an organism. Vascular or extravascular circulation, the blood or lymph system, and the cerebrospinal fluid are sites where the compositions may be introduced.

The cell with the target gene may be derived from or contained in any organism, including animals. Preferred are vertebrate animals. Examples of vertebrate animals include, but are not limited to, fish, mammal, cattle, goat, pig, sheep, rodent, hamster, mouse, rat, primate, and human. The agents of the instant invention are especially suited for use in humans.

Depending on the particular target gene and the dose of composition delivered, this process may provide partial or complete loss of function for the target gene. A reduction or loss of gene expression in at least 50%, 60%, 70%, 80%, 90%, 95% or 99% or more of targeted cells is exemplary. Inhibition of gene expression refers to the absence (or observable decrease) in the level of protein and/or mRNA product from a target gene. Specificity refers to the ability to inhibit the target gene without manifest effects on other genes of the cell. The consequences of inhibition can be confirmed by examination of the outward properties of the cell or organism (as presented below in the examples) or by biochemical techniques such as RNA solution hybridization, nuclease protection, Northern hybridization, reverse transcription, gene expression monitoring with a microarray, antibody binding, enzyme linked immunosorbent assay (ELISA), Western blotting, radioimmunoassay (RIA), other immunoassays, and fluorescence activated cell analysis (FACS).

Quantitation of the amount of gene expression allows one to determine a degree of inhibition which is greater than 10%, 33%, 50%, 90%, 95% or 99% as compared to a cell or organism not treated according to the present invention. Lower doses of injected material and longer times after administration of the composition may result in inhibition in a smaller percentage of inhibition {e.g., at least 10%, 20%, 50%, 75%, 90%, or 95% inhibition). Quantitation of gene expression may show similar amounts of inhibition at the level of accumulation of target mRNA or translation of target protein. As an example, the efficiency of inhibition may be determined by assessing the amount of gene product, for example in a cell or sample derived from a treated organism; mRNA may be detected with a hybridization probe having a nucleotide sequence outside the region used for the inhibitory double-stranded RNA, or translated polypeptide may be detected with an antibody raised against the polypeptide sequence of that region. The composition may be introduced in an amount which allows delivery of at least one molecule {e.g. at least one copy of RNA) per cell. Higher doses {e.g., at least 5, 10, 100, 500 or 1000 copies per cell) of material may yield more effective inhibition; lower doses may also be useful for specific applications.

EXAMPLES

The following materials, methods and examples are meant to be illustrative only and are not intended to be limiting.

Example 1. Synthesis of Exemplary Nanoparticles

Various nanoparticles (e.g. dendrimers) can be synthesized for use in a nanotransporter of the invention. Synthesis of exemplary high mo lecular weight or low molecular weight dendrimers is set forth below.

a. Synthesis of High Molecular Weight Poly lysine Dendrimers

Tert-butyl 5-(methoxycarbonyl)-5-aminopentylcarbamate and tert-butyl 2- (carboxy)-ethylcarbamate are reacted with BOP, and DIEA in DMF at room temperature for 24 hours. The resulting product is the dendron that is used for creation of further generations. The dendron is reacted with 1. OM NaOH and 1,4,-Dioxane methanol. The product of that reaction is then reacted with 1,5-diamine, BOP₇ and DIEA, in DMF at room temperature for 24 hours. The resulting complex is polylysine dendrimer generation 1 ("LDGl") depicted in Figure 4 A.

LDGl is then reacted with TFA at room temperature for 30 minutes. The resulting product is reacted with the dendron, BOP, and DIEA in DMF at room temperature for 24 hours. The resulting product of this reaction is polylysine dendrimer generation 2 ("LDG2") depicted in Figure 4B. The above two reaction steps are repeated once, to form to form a 3^rd generation dendrimer ("LDG3", see Figure 4C), or twice to form to form a 4^th generation dendrimer ("LDG4", Figure 4D).

b. Synthesis of Low Molecular Weight Polylysine Dendrimers

In the first step of the reaction Fmoc-β-Ala-OH is reacted with HOBt and DIC at room temperature for 6 hours. The product of this first step is then reacted with Fmoc- Cys(Trt)-OH and HBTU/HOBt at room temperature for 2 hours. The resulting product is further reacted with Fmoc-Lys(Fmoc)-OH and HBTU/HOBt at room temperature for 2 hours. This final step is repeated twice more. The resulting product is shown in Figure 5. The MBHA resin is then removed using a solution comprising 94% TF A, 2.5% water, 2.5% EDC and 1% TIS.

Example 2. Synthesis of Exemplary Functional Surface Groups

Various functional surface groups {e.g., lipid functional surface groups) can be synthesized for use in a nanotransporter of the invention. Synthesis of exemplary lipid functional surface groups is set forth below.

As can be seen in Figure 6A, an oleoyl derivative can be synthesized. Oleoyl chloride is reacted with hydroxy pyrrolidine-2,5-dione in EtaN, DMAP, and THF/CH2CI2. The resulting oleoylic derivative can be used as a lipid functional surface group.

Alternatively, as can be seen in Figure 6B, an PEG (polyethylene glycol) derivative can be synthesized for use with the present invention. PEG is reacted with dihydrofurane-2,5-dione in CH2CI2 to yield the PEG derivative. The PEG derivative can be used as a lipid functional surface group. In other embodiments, a cholesterol derivative can be synthesized for use with the present invention (see Figure 6C). Cholesterol is reacted with dihydrofurane-2,5- dione in CH2CI2. The product of that reaction is further reacted with hydroxy pyrrolidine-2,5-dione in DCC and CH2CI2 to yield a cholesterol derivative which is capable of use in the present invention as a lipid functional surface group. In yet other embodiments, an oleolylic acid derivative can be synthesized for use with present invention (see Figure 7). Propane- 1, 2,3 -triol is reacted with Tr-Cl, Et3N and DMAP. The product of this reaction is then reacted with oleoyl chloride. The triphenylmethyl protecting group is then removed using 85% HCOOH and Et₂θ. The resulting product is then reacted with 3-(2,5-dioxo-2H-pyrrol-l (5H)-yl)proρanoic ^a°id *ⁿ EDC to yield the desired oleoylic acid derivative.

Example 3. Synthesis of Exemplary Nanotransporters In certain embodiments, a nanotransporter of the invention can be synthesized by combining a functional surface group (e.g., a lipid) with a core particle (e.g., a nanoparticle, e.g., low-molecular weight dendrimer) (see Figure 8). Synthesis of exemplary nanotransporters is set forth below.

a. Synthesis of Fluorescein Labeled Oleoyl-Polylysine Dendrimer Generation Four

In one exemplary embodiment, a nanotransporter is synthesized by linking a lipid {e.g., an oleoyl derivative) and a fluorescent group (e.g._Λ fluorescein) to a nanoparticle (e.g., a high molecular weight dendrimer). For example, as can be seen in Figure 9, LDG4 may be combined with an oleoyl derivative in a ratio of 1 :8 parts LDG4 to oleoyl derivative, and 6-fluorescein NHS ester in a ratio of 1 :4 parts LDG4 to 6- fluorescein NHS ester in triethyl amine, and DMF at room temperature for 24 hours. The product of this reaction is purified by washing, re-precipitation and dialysis.

b. Synthesis of Nanotransporters comprising an LDG4 core, an oleoyl derivative lipid functional surface group, and a cyclic cell type specific targeting moiety.

In one exemplary embodiment, a nanotransporter is synthesized by linking a lipid and a cell type specific targeting moiety to a nanoparticle. For example, a nanotransporter may comprise an oleoyl derivative and a cyclic CNGRC endothelial-cell specific peptide linked to a high molecular weight dendrimer (see Figure 11). As can be seen in the first two steps of the reaction shown in Figure 12, the cyclic peptide CNGRC is first made cyclic in accordance with standard practice. The cyclic moiety is then reacted with a nanotransporter (e.g., an HBOLD nanotransporter) in BOP, and DIEA. The complex is then washed with TFA to remove the protecting groups, yielding the final product. Exemplary synthesis of alternative nanotransporter which employs the CKGGRAKDC cell type specific targeting moiety is depicted in Figure 13.

C; Synthesis of NOP7 Nanotransporter

In another exemplary embodiment, an exemplary nanotransporter (herein "NOP- 7", see Figure 26) used in the invention is a generation-4 lysine dendrimer, which was chemically synthesized, labeled with oleoyl lipids, purified and characterized by NMR and mass spectrometry (see Figures 27 and 28). Dynamic light scattering experiments showed that the average diameter of NOP-7 was 15 nm (Figure 29A). US2007/002210

Example 4. Synthesis of Exemplary Nanotransporter: KNA silencing agent Delivery Complexes

In certain exemplary embodiments, a delivery complex of the invention can be synthesized by conjugating an RNA silencing agent (e.g., an siRNA) to a to a functional surface group (e.g., a cell-specific targeting peptide, e.g. a lung specific peptide) employed in the nanotransporter using a bifunctional linker (see Figure 14).

In one exemplary embodiment, a siRNA is conjugated to the multiple, cross- linked, lung specific peptides depicted Figure 15. The siRNA may be reacted with Sulfosuccinimidyl-4-(P-Maleimidophenyl) Butyrate (Sulfo-SMPB) so that it is reactive with the thiol group of the cysteine in cross-linker moiety of the modified lung cell specific peptide (see Figure 16).

In another exemplary embodiment, an siRNA is conjugated to a nanotube. A carbon nanotube is refluxed in 2.5 M HNO3 for 36 hours. The reaction mixture is then sonicated for 30 minutes and refluxed again for an additional 36 hours. The reaction mixture is then filtered on a polycarbonate filter (pore size lOOnm), rinsed, and re-suspended in water. The mixture is then centrifuged at 7000 RPM for 5 minutes. The product is then reacted with EDC, 5-(5-aminopentyl)thioureidyl fluorescein, and phosphate buffer. The resulting product is further reacted with EDC, N3-5'-ssRNA and phosphate buffer. The product of this reaction can further be reacted with a lipid functional surface group. Examples of suitable lipid functional surface groups include but are not limited to oleoyl amine (seen in step C of the reaction of Figure 17) and cholesterol (seen in step D of the reaction of Figure 17). Lipid functional surface groups are attached to the nanotube in EDC. N3-3'-antisense RNA and EDC are added to the product from the above reaction. Finally, sense-RNA is added to the resulting product, yielding the final carbon nanotube-siRNA conjugate.

In another exemplary embodiment, a delivery complex comprises (i) an LDG5 nanoparticle with 45 primary amines; (ii) 16 lipid functional surface groups, and (iϋ) 3 thiol-conjugated siRNAs (Figure 48 A). In another exemplary embodiment, a delivery complex comprises (i) an LDG4 nanoparticle with 22 primary amines; 7 lipid functional surface groups, and 3 thiol conjugated siRNAs (Figure 48B). (a) JNOP7 Delivery Complex

In another exemplary embodiment, the NOP -7 nanotransporter described above is combined with siRNA to form a delivery complex termed "iNOP-y". Exemplary iNOP7 delivery complexes were prepared by mixing the siRNAs and the NOP-7 nanotransporter at a ratio of 1 :2 (w/w) in Hepes saline or Opti-MEM culture medium (Invitrogen) and incubating at room temperature for 20 min. Dynamic light scattering experiments showed that the average diameter of the complex was increased to ~200 nm when siRNA was added to NOP-7 (Figure 29B).

The ApoB siRNAs used (see Table 2) were chemically synthesized using silyl ethers to protect 5'-hydroxyls and acid-labile orthoesters to protect 2'-hydroxyls (2'- ACE) (Dharmacon, Lafayette, CO, USA). After deprotection and purification, siRNA strands were annealed as described ( Chiu and Rana. RNA, (2003), RNA, 9:1034-48.). AU Apo B siRNAs target ORP position 10049-10071. .

Table 2: Apo-B siRNAs

NOTE: Superscript letters F and S represent nucleotide analogs having 2'-O-Fluoro (F) and phosphorthioate backbone modifications (SH) respectively. t Example 5: In vitro silencing of apoB gene expression by Delivery Complexes a) In vitro silencing ofapoB gene expression using a delivery complex comprising HBOLD and siRNA

ApoB mRNA silencing in FL83B (mouse liver hepatocytes) cells was tested using an exemplary delivery complex comprising the HBOLD nanotransporter associated with siRNA. The amounts of HBOLD construct used in the transcriptional assay included 0.25μM HBOLD = 1.4μg and lμM HBOLD = 5.8 μg. In addition, 1.4μg was used for TNX and L2K was used at a concentration of 2μg/mL. As shown in Figure 20, apoB targeted HBOLD nanotransporter was effective at decreasing transcription apoB in mouse liver cells.

b) In vitro silencing ofapoB gene expression using a delivery complex comprising NOP- 7 and siRNA ("iNOP-7")

ApoB mRNA silencing in FL83B (mouse liver hepatocytes) cells was tested using the exemplary iNOP-7 delivery complex described above.

FL83B (mouse hepatocytes) cells were maintained at 37°C with 5% CO₂ in F12 Khangians modified culture medium (ATCC, USA) supplemented with 10% fetal bovine serum (FBS), 100U/ml penicillin and 100 μg/ml streptomycin. Cells were regularly passaged and plated in 96-well and 6 well-culture plates 16 h before transfection at 70% confluency. Cells were transfected with 1 ml/well of iNOP-7 complex for 2.5 h at 37°C. Medium was removed and replaced with full growth medium without antibiotics and incubated for an additional 24 h. Cell viability was assessed using a CellTiter 96^® AQueous One Solution cell proliferation assay by colorimetric analysis of the MTS tetrazolium compound according to the manufacturer's instructions (Promega, USA). Total RNA was extracted using RNeasy mini spin columns and treated with DNase I (Qiagen, USA) before quantitation. To assess levels ofapoB mRNA, real time quantitative PCR (qPCR) was performed using SYBR Green (Qiagen USA) with forward (5'-TTCCAGCCATGGGCAACTTTACCT-S') and reverse (5'- TACTGC AGGGCGTCAGTGACAAAT-S') apoB primers. ApoB mRNA levels were then normalized against the housekeeping gene GAPDH using forward (5'- ATCAAGAAGGTGGTGAAGCAGGCA-S') and reverse (5'- TGGAAGAGTGGGAGTTGCTGTTGA-3') GAPDH primers. As can be seen in Figure 30A an exemplary delivery complex containing NOP-7 and unmodified apoB siRNA almost completely silenced apoB mRNA expression (>90%) in FL83B cells when compared to controls or cells treated with a delivery agent containing mismatched siRNA and the NOP-7 nanotransporter. The efficiency of apoB mRNA silencing using the delivery agent as an siRNA transporter was similar to that of cells transfected with Lipofectamine 2000 complexed to unmodified siRNA. An exemplary delivery complex comprising NOP-7 and chemically modified siRNA directed against apoB was more efficient in silencing apoB mRNA than an exemplary delivery agent comprising NOP-7 and an unmodified apoB siRNA (Figure 30A). These results show that the exemplary delivery complexes comprising NPO-7 and siRNA, did not negatively influence RNAi activity.

The reduced levels of apoB mRNA levels in FL83B cells were not due to delivery complex induced cell toxicity as confirmed by phase contrast microscopy (results not shown) and by a modified MTS cell viability assay (Figure 30B). Taken together, these results demonstrate that the exemplary delivery complex was non-toxic and efficiently transported siRNA into cells.

Example 6: In vivo decrease of cholesterol using apoB siRNA Delivery Complexes

(a) In vivo silencing ofapoBgene expression using a delivery complex comprising HBOLD and siRNA

An exemplary delivery complex of the invention, i.e., HBOLD conjugated to siRNA, was tested for in vivo efficacy in silencing the apoB gene and decreasing cholesterol levels. Constructs used for testing in vivo efficacy of apoB specific siRNA conjugated to HBOLD are depicted in Figure 21.

In vivo administration of the HBOLD / apoB-specific siRNA (ApoBJHBOLD) resulted in decreased apoB protein expression (as shown in Figure 22), as well as an overall decrease in plasma cholesterol levels (as shown in Figure 23). As described in Figure 23, the ApoBJHBOLD was able to decrease plasma cholesterol levels 34.4% relative to the control and mismatched ApoBmm_HBOLD control. The decrease in cholesterol levels resulted from silencing of the apoB gene, as shown in Figure 24.

Importantly, administration of the FJBOLD constructs, including ApoBmm_HBOLD and ApoBJHBOLD, did not induce an in vivo immunostimulation in the recipient, as shown in Figure 25. Thus, not only was ApoBJHBOLD effective at silencing apoB expression and decreasing cholesterol levels in the recipient, it was safe as it did not act as an immunostimulant.

(b) In vivo silencing ofapoB gene expression using an iNOP-7 delivery complex In another exemplary embodiment, the delivery complex iNOP7 was tested for in vivo efficacy in silencing the apoB gene and decreasing cholesterol levels. Delivery complexes comprising NOP-7 and either chemically modified (CM) apoB siRNA or its mismatched (MM) siRNA were prepared as described above.

Six- to eight-week-old male C57BL/6 mice (Charles River laboratories, USA) were maintained under a 12 hour/dark cycle in a pathogen-free animal facility. Mice were injected on three consecutive days via the lateral tail vein with phosphate buffered saline pH 7.4 (PBS) or exemplary delivery agent complexes, i.e., NOP-7 complexes of chemically modified (CM) apoB siRNA or its mismatched (mm) siRNA. Daily dosages of 1.25 mg/kg, 2.5mg/kg, or 5mg/kg delivery complex were delivered in a final volume of 0.15ml. Twenty-four hours after the final injection, liver tissue levels of apoB mRNA, plasma levels of apoB protein, and total plasma cholesterol were measured. Plasma cholesterol was measured by a commercial enzyme assay according to the manufacturer's instructions (Biodesign International, USA).

To determine apoB mRNA levels in liver tissue after treatment with a delivery complex, small uniform tissue samples were collected from three regions of the liver. Total RNA was extracted with Trizol and treated with DNase I before quantification. ApoB mRNA levels were determined by qPCR as described above. ApoB protein levels were determined by western blot using a polyclonal goat anti-apoB 100/48 antibody (Santa Cruz, USA). ApoB protein levels were then detected by enhanced chemiluminescence (PerkinElmer Life Sciences, USA). As a control, fibronectin was visualized by immunoblot using a polyclonal rabbit anti-fϊbronectin antibody (Sigma, USA). ApoB mRNA was significantly lower in liver tissue from mice treated with 1.25 mg/kg, 2.5 mg/kg, or 5 mg/kg delivery complexes containing chemically modified siRNA (51 ± 3%, 51 ± 3%, and 47 ± 3% respectively, n = 3-4 animals) than in livers from control mice and mice treated with delivery complexes containing mismatched siRNA (Figure 32A). The presence of the guide strand of ApoB siRNA in mice liver was determined by performing northern blot analysis of total RNA isolated from mice liver treated with an exemplary delivery complex. The guide strand was still present in the liver of animals after 24 hours of final delivery complex injections (Fig 32B). A strong signal for the guide strand was observed when the delivery complex contained the chemically modified siRNA as compared with a delivery complex assembled with unmodified siRNA (Fig 32B). These results correlate with the findings that unmodified siRNA did not efficiently silence apoB mRNA in vivo ( Soutschek, J., et al., (2004). Nature 432, 173-8.). No detectable amount of siRNA was found in mice liver when unmodified or chemically modified siRNA duplexes were injected without the nanotransporter NOP-7. Consistent with the siRNA guide strand northern results, significant knockdown of apoB mRNA in mice liver was not obtained when unmodified or chemically modified siRNAs were injected without nanoparticles (Figure 31). These results collectively indicate that the delivery complex , i.e., chemically stabilized RNA and NOP-7, was essential for efficient delivery of siRNA in vivo.

To determine if silencing of apoB mRNA correlated with reduced plasma levels of apoB protein, apoBlOO and apoB48 levels were measured by immunoblot. Injecting 1.25-5 mg/kg delivery complex containing chemically modified siRNA and NOP-7 decreased both apoBlOO and apoB48 serum levels to >70% of control (Figures 33 A and B), while fibronectin levels were unaffected. These results show that delivery complexes containing NOP-7 complexed to chemically modified siRNA efficiently silenced apoB expression in vivo. These delivery complex mediated silencing activities required only 1.25 mg/kg siRNA, a clinically feasible dose for RNAi therapeutic applications.

To investigate the physiological effects of apoB mRNA silencing on cholesterol metabolism, total plasma cholesterol levels were measured in mice 24 hours after the final injection of the delivery complex. As shown in Figure 34, delivery complex- mediated silencing of apoB expression in liver and plasma samples was correlated with a reduction of total cholesterol (34.4 ± 7%). Cholesterol levels were unchanged in mice receiving control treatments or treated with an exemplary delivery complex containing chemically modified, mismatched siRNA and NOP-7 (Figure 34). Together, these findings demonstrate that delivery complex-mediated targeting of apoB could provide a clinically significant new approach to reducing cholesterol levels in patients with hypercholesterolemia.

Example 7. Nanotransporters and Delivery Complexes are non-toxic to cells (a) HBOLD Nanotransporters are Non-toxic

An exemplary HBOLD nanotransporter (see Figure 18) was tested for cell toxicity in an in vitro assay using FL83B cells (mouse liver hepatocytes). Cell viability was measured as a percentage of the control cell viability. HBOLD was assayed in three different concentrations as to whether or not it was toxic to the cells. The amounts included 0.25μM HBOLD = 1.4μg; lμM HBOLD = 5.8 μg; and 3 μM HBOLD = 17.4μg. In addition, 1.4μg was used for TNX and L2K was used at a concentration of 2μg/mL. As shown in Figure 19, the HBOLD nanotransporter was not toxic to cells, as it did not affect cell viability at concentrations of 0.25 μM and lμM. (b) iNOP- 7 is Non-toxic to cells

To assess for any nonspecific immune response to injected delivery complexes comprising NOP -7 and siRNA, mouse liver tissue was assessed for expression of the interferon (IFN)-inducible genes, EFN-induced protein with tetratricopeptide repeats 1 (IFITl) and signal transducer and activator of transcription 1 (STAT 1). Liver tissue was obtained from mice treated with PBS (control), delivery complexes comprising NOP-7 and modified apoB siRNA, or delivery complexes comprising NOP-7 and modified apoB siRNA mismatch. Expression of IFITl and STATl were measured by qPCR as described above using the following primers:

IFITl forward: 5'-AAACCCTGAGTACAACGCTGGCTA-S ' ^' IFITl reverse: 5'-AAACCCTGAGTACAACGCTGGCTA-S';

STAT 1: forward: 5'-CAGCTGCAAAGCTGGTTCACCATT-S' STAT 1 reverse: 5'-AGGTTCGATCTGACAACACCTGCT-S'. IFITl and STAT 1 mRNA levels were normalized against the housekeeping gene GAPDH. In addition, plasma IFN-α levels were quantified 24 hours after the final injection using sandwich ELISA according to the manufacturer's instructions (PBL biomedical Laboratories, USA). As a positive control for both assays, C57BL/6 mice were injected via the lateral tail vein with 250 μg polyinosinic-polycytidylic acid (Poly IC, total volume 0.125 ml). Six hours after the injection, liver and plasma samples were collected.

Injecting mice with a delivery complex comprising NOP-7 alone or a delivery complex comprising chemically modified siRNA and NOP-7 did not alter the expression of EFLTl and STAT 1 genes in the liver, nor did it induce the release of IFN-α in plasma relative to controls (Figure 35). To address concerns about delivery complex toxicity, all mice were monitored daily for overall health, food intake and weight changes. At the end of treatment with the exemplary delivery complexes, mice were sacrificed and necropsied. Histological sections of liver, the target tissue for apoB silencing, were prepared and independently examined for toxic effects by a board-certified animal pathologist. No histological differences were noted between tissues from no treatment (Figure 36A) or NOP-7 only (Figure 36B) mice and from those treated with delivery complexes comprising chemically modified siRNA and NOP-7 (Fig 36C). These results demonstrate that treatment with an exemplary delivery complex did not induce an immune response in animals and caused no apparent toxic effects.

OTHER EMBODIMENTS

It is to be understood that while the invention has been described in conjunction with the detailed description thereof, the foregoing description is intended to illustrate, and not limit the scope of the invention, which is defined by the scope of the appended claims. Other aspects, advantages, and modifications are within the scope of the following claims.

In addition, the contents of all references, patents, and patent applications cited throughout this application are hereby incorporated by reference.

Claims

Claims:

I . A αanotransporter comprising a core conjugated with at least one functional surface group.

2. The nano transporter of claim 1, wherein the core is a nanoparticle,

3. The nano transporter of claim 2, wherein the nanoparticle is a dendrimer.

4. The nanotransporter of claim 3, wherein the dendrimer is a polylysine dendrimer.

5. The nanotransporter of claim 1, wherein the core is a nano tube.

6. The nanotransporter of claim 5, wherein the nanotube is a single walled nanotube.

7. The nanotransporter of claim 5, wherein the nanotube is a multi- walled nanotube.

8. The nanotransporter of claim I, wherein the functional surface group is at least one of a lipid, a cell type specific targeting moiety, a fluorescent molecule, and a charge controlling molecule.

9. The nanotransporter of claim 8, wherein the targeting moiety is a tissue-selective peptide.

10. The nanotransporter of claim 8, wherein the lipid is an oleoyl lipid or derivative thereof.

I I. The nanotransporter of claim I₅ which is NOP-7 or HBOLD.

12. A delivery complex comprising the nanotransporter of claim 1, wherein the nanotransporter is conjugated or associated with a nucleic acid molecule or pharmaceutical agent.

13. The delivery complex of claim 12, wherein the nucleic acid molecule is selected from the group consisting of an RNA silencing agent, an antisense molecule, a plasmid, and a ribozyme.

14. The delivery complex of claim 13, wherein the RNA silencing agent is selected from the group consisting of an sϊRNA, a miRNA, a dual-functional oligonucleotide, and a shRNA.

15. The delivery complex of claim 13, wherein the antisense molecule is an anti- RNA silencing oligonucleotide.

16. The delivery complex of claim 15, wherein the oligonucleotide is an anti-miRNA oligonucleotide.

17. The delivery complex of claim 12, wherein the nanotransporter is conjugated or associated with a pharmaceutical agent.

18. The delivery complex of claim 17, wherein the pharmaceutical agent is at least one of a polynucleotide, a protein, an antibody, a polypeptide, a peptide, a chemotherapeutic agent, and an antibiotic.

19. A method for delivering a nucleic acid molecule or pharmaceutical agent to a cell in vitro, the method comprising, contacting the cell with the delivery complex of claim 12, thereby delivering the nucleic acid molecule to the cell.

20. The method of claim 12, wherein the cell contacted is a human cell.

21. The method of claim 19, wherein the nucleic acid molecule is an RNA silencing agent.

22. A method for delivering a nucleic acid molecule or pharmaceutical agent to a cell in vivo, the method comprising contacting the cell with the delivery complex of claim 12, thereby delivering the pharmaceutical agent to the cell.

23. The method of claim 21, wherein the cell contacted is a human cell.

24. The method of claim 21, wherein the nucleic acid molecule is an KNA silencing agent.

25. The method of claim 21, wherein the RNA silencing agent is delivered at a effective dose of about 1 to about 10 mg/kg.

26. An RNA silencing agent, comprising a sense strand and an antisense strand, wherein

(a) the antisense strand has a sequence sufficiently complementary to a target mRNA sequence to direct target-specific RNA interference (RNAi);

(b) the strands are modified at both ends with more than one chemically modified nucleotides such that in vivo stability is enhanced as compared to a corresponding unmodified siRNA; and

(c) wherein the target mRNA is associated with a metabolic disorder.

27. The agent of claim 26, wherein the antisense strand retains the ability to form an

A-form helix when in association with a target RNA 28. The RNA silencing agent of claim 26, wherein at least 4-5 of the 5' and 3 ' terminal nucleotides of the strands are modified.

29. The RNA silencing agent of claim 26, wherein the modified nucleotides are selected from the group consisting of 2'-fluoro modified ribonucleotide, 2'- amino modified ribonucleotide, 2' alkyl modified ribonucleotide, 2'-O-methyl ribonucleotide, and backbone-modified nucleotides.

30. The RNA silencing agent of claim 29, wherein the 2'-fluoro modified ribonucleotides are 2'-fluoro uridine and 2'-fluoro cytidine.

31. The RNA silencing agent of claim 26, wherein the backbone-modified nucleotides contain a phosphorothioate group.

32. The RNA silencing agent of claim 26, wherein the antisense strand comprises at least one mismatch with a non-target mRNA.

33. The RNA silencing agent of claim 26, which is an siRNA, wherein the strands of the siRNA are have lengths selected from the group consisting of between about

5 and 60 nucleotides in length, between about 5 and 18 nucleotides in length, between about 25 and 60 nucleotides in length, and between about 18 and 25 residues in length.

34. The siRNA of claim 33, wherein the strands are about 21-23 residues in length.

35. The RNA silencing agent of claim 26, where the target mRNA is ApoB mRNA or RIP- 140 mRNA.

36. The agent of claim 35, which targets ApoB mRNA in a region capable of encoding a ApoB mutation.

37. The agent of claim 36, wherein the siRNA targets ApoB mRNA and wild type ApoB mRNA.

38. The agent of claim 35, which targets RIP-140 mRNA in a region capable of encoding a RIP-140 mutation.

39. The agent of claim 35, wherein the siRNA targets RIP-140 mRNA and wild type RIP-140 mRNA.

40. A delivery complex comprising the RNA silencing agent of claim 26 which is conjugated or associated with a nanotransporter comprising a core conjugated with at least one functional surface group.

41. A method of activating RNA silencing in a cell in vitro comprising contacting said cell with the RNA silencing agent of claim 26, said agent being introduced in an amount sufficient for RNA silencing of the target mRNA to occur, thereby activating RNA silencing in the cell.

42. The method of claim 41, wherein the RNA silencing agent is introduced into the cell by contacting the cell with a delivery complex comprising the siRNA which is conjugated or associated with a nanotransporter comprising a core conjugated with at least one functional surface group.

43. A method of activating RNA silencing in an organism comprising administering to said organism the RNA silencing agent of claim 23, said agent is administered in an amount sufficient for degradation of the target mRNA to occur, thereby activating RNA silencing in the organism.

44. The method of claim 43, wherein the RNA silencing agent is administered in association with a delivery complex comprising the siRNA which is conjugated or associated with a nanotransporter comprising a core conjugated with at least one functional surface group.

45. The method of claim 43, wherein the RNA silencing agent is administered by an intravenous or intraperitoneal route.

46. The method of claim 43, wherein the metabolic disease or disorder is at least one metabolic disease or disorder selected from the group consisting of obesity, diabetes and high cholesterol.

47. The method of claim 43, wherein degradation of the target mRNA is such that the protein specified by said target mRNA is decreased by at least 10%.

48. A method of treating a metabolic disease or disorder associated with the activity of a protein specified by a target mRNA in a subject, comprising administering to said subject the RNA silencing agent of claim 24, said RNA silencing agent being administered in an amount sufficient for degradation of the target mRNA or suppression of protein expression to occur, thereby treating the metabolic disease or disorder associated with the protein.

49. The method of claim 48, wherein the disease or disorder is at least one metabolic disease or disorder selected from the group consisting of: obesity, diabetes and high cholesterol.

50. The method of claim 48, wherein the metabolic disease or disorder is obesity, and wherein the weight of the subject decreases by at least 5% as compared to the weight of the subject before administration of the composition.

51. The method of claim 48, wherein the metabolic disease or disorder is diabetes and wherein the glucose level of the subject is lowered by at least about 5% as compared to the glucose level of the subject before administration of the composition

52. The method of claim 48, wherein the metabolic disease or disorder is high cholesterol and wherein the cholesterol level of the subject decreases by at least 5% as compared to the cholesterol level of the subject before administration of the composition.

53. A method of treating a metabolic disease or disorder associated with the activity of a protein specified by a target mRNA in a subject, comprising administering to said subject the delivery complex of claim 36, said delivery complex being administered in an amount sufficient for degradation of the target mRNA to occur, thereby treating the metabolic disease or disorder associated with the protein.

54. The method of claim 53, wherein the disease or disorder is at least one metabolic disease or disorder selected from the group consisting of: obesity, diabetes and high cholesterol.

55. The method of claim 53, wherein the metabolic disease or disorder is obesity and wherein the weight of the subject decreases by at least 5% as compared to the weight of the subject before administration of the composition.

56. The method of claim 53, wherein the metabolic disease or disorder is diabetes and wherein the glucose level of the subject is lowered by at least about 5% as compared to the glucose level of the subject before administration of the composition

57. The method of claim 53, wherein the metabolic disease or disorder is high cholesterol and wherein the cholesterol level of the subject decreases by at least 5% as compared to the cholesterol level of the subject before administration of the composition.