WO2018170290A1 - Compositions and methods for increasing fmr1 expression - Google Patents

Abstract

The disclosure relates to methods and compositions for reactivating a silenced FMR1 gene. In some aspects, methods described by the disclosure are useful for treating a FMR1-inactivation-associated disorder (e.g., fragile X syndrome).

Description

COMPOSITIONS AND METHODS FOR INCREASING FMR1 EXPRESSION

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No.

62/471 ,919, filed March 15, 2017, and U.S. Provisional Application No. 62/578, 138, filed October 27, 2017, the contents of which are each incorporated herein by reference in their entireties.

REFERENCE TO SEQUENCE FILE SUBMITTED HEREWITH

[0002] The contents of the text file submitted electronically herewith are incorporated herein by reference in their entirety: A computer readable format copy of the Sequence Listing (filename: FULC_002_01WO_SeqList_ST25.txt, date recorded: March 15, 2018, file size 1.3 kilobytes).

FIELD OF THE DISCLOSURE

[0003] The present invention relates to methods for increasing gene expression of FMR1.

BACKGROUND OF THE INVENTION

[0004] Fragile X Syndrome (FXS) is a genetic condition that causes a range of developmental problems including learning disabilities and cognitive impairment. FXS is the most common genetic form of mental retardation, and occurs in approximately 1 in 4,000 males and 1 in 8,000 females. Usually, males are more severely affected by this disorder than females. Most males with FXS have intellectual disability, while about one-third of affected females are intellectually disabled. FXS is caused by the expansion (>200 repeats) of a poly morphic CGG sequence within the 5' untranslated region (UTR) of the X-linked FMR1 gene. The FMR1 gene containing the expanded CGG repeat becomes transcriptionally silenced, causing a lack of expression of Fragile X mental retardation protein (FMRP) (reviewed in Brasa et al. Clinical Epigenetics (2016)). FMRP is an RNA-binding protein and a translational repressor that modulates the translation of numerous synaptic proteins, expression of axonal guidance genes, and plays an important role in synaptic plasticity. Thus, the symptoms of fragile X syndrome are a result of synaptic changes caused by lack of proper expression of FMRP. [0005] Several therapeutic agents that target the synaptic dysfunction in FXS have been investigated, but do not address the transcriptional silencing that occurs by the genetic mutation. These investigational treatments have demonstrated efficacy in the FMR1 knockout mouse model. However, none have advanced to the clinic. No disease-modifying treatment for FXS is available and current treatments are only directed to improve behavioral symptoms.

SUMMARY OF THE INVENTION

[0006] As described above, there is an urgent need for a new disease-modifying treatment for FXS, and such a treatment may arise from correcting the underlying transcriptional silencing of FMR1 . In some aspects, the disclosure relates to epigenetic modulators which are useful for the treatment of diseases associated with FMR1 -inactivation- associated disorders (e.g. , FXS). In some embodiments, epigenetic modulators disclosed herein are useful because they induce a more permissive chromatin state in the epigeneticaily-silenced FMR1 gene or improve access to the promoter of FMR1 , which promotes a transcriptionally active state. In some embodiments, induction of a more permissive chromatin state in the epigeneticaily-silenced FMR1 gene of subjects having FMR1 inactivation-associated disorders (e.g., FXS) results in increased FMR1 gene expression and a decrease disease symptoms.

[0007] In some aspects, the disclosure provides a method for reactivating a transcriptionally inactive FMR1 gene in a cell, the method comprising: contacting the cell with an effective amount of one or more epigenetic modulator of FMR1 , wherein the one or more epigenetic modulator of FMR1 comprises an inhibitor of a chromatin modifier, and wherein the one or more epigenetic modulator reactivates FMR1 in the cell.

[0008] In some aspects, the disclosure provides a composition for reactivating a transcriptionally inactive FMR1 gene in a cell, comprising (i) one or more epigenetic modulator of FMR1 , wherein the one or more epigenetic modulator of FMR1 comprises an inhibitor of a chromatin modifier; and (ii) a pharmaceutically acceptable carrier.

[0009] In some embodiments, the chromatin modifier is Embryonic Ectoderm

Development (EED).

[0010] In certain embodiments, EED regulates a transcription complex. In other embodiments, the transcription complex is Poly comb Repressive Complex 1 (PRO), In some embodiments, PRC1 comprises EED, B lymphoma Mo-MLV insertion region 1 (BMI1), RING 1 A (RINGl ), and RING I B (RING2 or RNF2). In further embodiments, the one or more epigenetic modulator inhibits PRC 1 function. In some embodiments, EED regulates the activity of a histone methyltransferase.

[0012] In some embodiments, EED is a core component of Polycomb

Repressive Complex 2 (PRC2). In certain embodiments, the histone methyltransferase is part of PRC2. in further embodiments, PRC2 further comprises Enhancer of Zeste Homolog 1 or 2 (EZHl or 2) and Suppressor of Zeste 12 (SUZ12). In some embodiments, the one or more epigenetic modulator inhibits PRC2 function. In certain embodiments, PRC2 regulates methylation nucleation. In other embodiments, PRC2 regulates methylation spreading.

[0013] In some embodiments of the methods disclosed herein, the one or more epigenetic modulator is Compound 1 :

, a derivative or a pharmaceutically acceptable salt thereof.

In some embodiments, the inhibitor of EED is a nucleic acid, polypeptide, or small molecule. In an exemplary embodiment, the inhibitor of EED is a nucleic acid. In some embodiments, the nucleic acid is an interfering nucleic acid selected from the group consisting of: double stranded RNA (dsRNA), siRNA, shRNA, miRNA, gRNA (directing a Cas9 protein) and antisense oligonucleotide (ASO). In an exemplary embodiment, the inhibitor of EED is a polypeptide. In certain embodiments, the polypeptide is an antibody. In an exemplar)' embodiment, the inhibitor of EED is a small molecule. In certain embodiments, the small molecule is Compound 1.

[0015] In some embodiments of the methods disclosed, the cell is a neuronal cell or an induced pluripotent stem cell (iPSC). In some embodiments, the cell is in vitro, in vivo, or ex vivo. In certain embodiments, the transcriptionally inactive FMR1 gene comprises at least one epigenetic mark associated with silenced FMR1 gene. In some embodiments, the at least one epigenetic mark is selected from the group consisting of DNA methylation (DNAme), histone H3 lysine 27 tnmethylation (H3K27me3), histone H3 lysine 9 trimethylation (H3K9me3), histone H4 lysine 20 tnmethylation (H4K20me3), hisione H2A ubiquitination (H2Aub), histone H2A acetylation, histone H2B acetvlation, histone H3 acetvlation, histone H4 acetylation, and histone H3 lysine 4 trimethylation (H3K4me3). In some embodiments, the cell comprises an expansion of a polymorphic CGG repeat within the 5'UTR of the FMR1 gene. In some embodiments, the expansion comprises between about 55 CGG repeats and about 200 CGG repeats. In further embodiments, the expansion comprises more than 200 CGG repeats.

[0016] In some embodiments, the one or more epigenetic modulator inhibits formation of an R-loop between the FMR1 and an mRNA encoding FMR1.

[0017] In some embodiments, wherein prior to contacting the cell with an effective amount of one or more epigenetic modulator of FMR1 , the transcriptionally inactive FMR1 gene is associated with silenced FMR1 gene.

[0018] In some aspects, the disclosure provides a method for reactivating a transcriptionally repressed or inactive FMR1 gene in a cell, the method comprising: contacting the cell with an effective amount of an epigenetic modulator of FMR1, wherein the epigenetic modulator reactivates FMR1 in the cell.

[0019] In another aspect, the disclosure provides a method for treating a

FMR1 -inacti vation or reduction associated disorder in a subject in need thereof, the method comprising: administering to the subject a therapeutically effective amount of one or more epigenetic modulator of FMR1 , wherein the one or more epigenetic modulator of FMR1 comprises an inhibitor of a chromatin modifier, and wherein the one or more epigenetic modulator reactivates FMR1 in the subject.

[0020] In some embodiments, the subject is identified as being in need thereof based upon the presence of a transcriptionally inactive FMR1 gene. In some embodiments, the subject is identified as being in need thereof based upon the presence of expansion of a polymorphic CGG repeat within the 5'UTR of the FMR1 gene. In certain embodiments, the expansion comprises between about 55 CGG repeats and about 200 CGG repeats. In other embodiments, the expansion comprises more than 200 CGG repeats.

[0021] In some embodiments, the FMR1 -inactivati on-associated disorder is fragile X syndrome, fragile X-associated tremor/ataxia syndrome, premature ovarian aging, or polycystic ovarian syndrome. In certain embodiments, the FMR1 -inactivation-associated disorder is fragile X syndrome. In some embodiments, the FMR1 -inactivation-associated disorder is autism spectrum disorder, a major depression disorder, bipolar disease, schizophrenia, neurodegeneration associated wdth TDP-43 pathology, a neurodegenerative disorder associated with axonal and/or dendritic functional processes that regulate effective synaptic plasticity, a tenopathy, and/or a synucleinopathy. In certain embodiments, the TDP- 43 pathology is frontal temporal dementia In some embodiments, the FMR1 -inactivation- associated disorder is Amyotrophic Lateral Sclerosis (ALS). In further embodiments, the tenopathy is frontal temporal dementia with parkinsonism- 17 (FTDP-17), progressive supranuclear palsy (PSP), corticobasal degeneration (CBD) or Alzheimer's disease. In some embodiments, the synucleinopathy is Parkinson's disease, multiple systems atrophy (MSA) or lewybody dementia (LBD).

[0022] In some embodiments, reactivation of FMR1 in the subject comprises an increase in fragile X menial retardation protein (FMRP) expression compared to a control subject not having a reactivation of FMR1.

[0023] In some embodiments of a method for treating a FMR1 -inactivation or reduction associated disorder, the therapeutically effective amount is delivered to the CNS of the subject. In some embodiments, the therapeutically effective amount is delivered to neuronal ceils. In certain embodiments, the neuronal cells are differentiated neuronal cells.

[0024] In some embodiments, a method for treating a FMR1 -inactivation or reduction associated disorder in a subject in need thereof further comprises assessing the FMR1 epigenetic profile of the subject before and/or after the administering, wherein a change in the FMR1 epigenetic profile indicates effectiveness of the treatment.

[0025] In some embodiments, a method for treating a FMR1 -inactivation or reduction associated disorder in a subject in need thereof further comprises assessing the FMR1 transcriptional regulatory profile of the subject before and'' or after the administering, wherein a change in the FMR1 transcriptional profile indicates effectiveness of the treatment.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG. 1 shows a model of Poly comb Repressive Complex 1 (PRC1) and

Poly comb Repressive Complex 2 (PRC2) (from Onodera, A., & Nakayama, T. (2015). Trends in molecular medicine, 21(5): 330-340).

[0027] FIG. 2 illustrates Compound 1 : (N-((5-fIuoro-2,3-dihyclrobenzofuran-4-

amine).

[0028] FIG. 3 shows reactivation of FMR1 mRNA expression in FXS-induced

NGN2 glutamatergic neurons by Quantigene View. FMR1 expression in the wild type healthy control NGN2- directed neurons (derived from iPSC 194) (Zhang et al , 2013) was at normal levels and FMR1 was not detectable in untreated FX neurons (derived from iPSC 135). FMR1 expression was increased after treatment with 3.3 μΜ Compound 1. FMR1 expression is indicated in the two left panels by arrows. FMR1 quantigene probes were hybridized by in situ (described in Quantigene View assay protocol; Thermo). FMR l imaging and analysis was conducted using the CX7 and neuronal profiling algorithm and defined as % FMR1 positive cells over the beta tubulin 3 mask. FMR1 expression was analyzed following treatment of either WT or FXS cells with DMSO, or 3.3 μΜ Compound 1.

[0029] FIG. 4A-F1G. 4B shows the activity of Compound 1 on inhibition of the binding of EED to H3K27me blocks the activity of the PRC2 complex. EED activity was inhibited by Compound 1 , N-((5-fluoro-2,3-dihydrobenzofuran-4-yl)methyl)-8-(l-isopropyl- 3-methyl-1H-pyrazol-4-yl)-[l,2,4]triazolo[4,3-c]pyrimidin-5-amine. Inhibition was measured biochemically by monitoring the transfer of a ³H methyl group from ³H S-adenosylmethionine (1 μΜ) to chicken core hi stones (at 0.05 mg/mL) catalyzed by recombinant, human PRC2 complex (13 nM) containing either EZH1 (FIG. 4A) or EZH2 (FIG. 4B). (Reaction Biology, www. reactionbiology.com,''webapps/site/HMTProfiling.aspx; or Vaswani, R., et al J Med Chem, 2016, 59 (21): 9928-9941 ). Reaction conditions were conducted in a buffer containing 50 mM Tris-HCl, pH 8.0; 50 mM NaCl, 1 mM EDTA, 1 mM DTT, 1 mM PMSF.

[0030] FIG. 5 shows activity of Compound 1 on H3K27me blocking the activity of PRC2 complex in HEK293 cells by quantitative immunofluorescence on CX7. 3 μΜ Compound 1 was diluted ½ log to the lowest concentration of 0.09 nM. Cells were fixed in 4% paraformaldehyde, permeabilized Phosphate Buffered Saline, pH 7.4 plus 3% Bovine Serum Albumin and 0.1% Triton X-100 for one hour at room temperature, and primary or secondary antibodies as follows: Hoechst 1 :2000, Cell Signaling H3K27me3 rabbit (Cat# CS9733) at 1 :200 dilution, 1 :2000 anti-rabbit Alexa-fluor 488 and 1 :5000 Cell Mask Deep Red (Cell Signaling). Quantitation was conducted by image acquisition and analysis on the CX7 using a 20X objective and compartmental analysis for H3K27me3 average intensity in the nucleus. Data are expressed as mean ± S.D. EED inhibition of H3K27me3 in cells by immunocytochemistry produced an IC50 of 36 nM.

[0031] FIG. 6 shows sustained reactivation of FMR1 transcript following treatment of FXS neurons with Compound 1. Expression of FMR1 mRNA was monitored by qRT-PCR analysis in iPSC -derived, NGN2 doxycycline-induced WT 194 or FXS 135 neurons (Zhang et al , 2013) treated with either DMSO or 3 μΜ Compound 1 for 1, 2, or 3 weeks, as indicated. RNA was collected using the Norgen Single-Cell RNA Purification Kit; Norgen P/N 51800. cDNA was generated using the Qiagen QuantiTech Reverse Transcription Kit (Qiagen 205313) according to the manufacturer's protocol. qRT-PCR was conducted by TaqMan using the GAPDH-VIC primer (Applied Biosystems P/N 4448489 Hs0 2780024_ gl ), FMR1 -F AM (Applied Biosystems P/N 4331 182 Hs00924547_ml). Expression data were converted to copy number normalized to the GAPDH copy number per well, averaged, and the median

DMSO control value was determined for each week and then used to determine the fold of gene induction as compared to the DMSO control within the week (Intra- week). FMR1 levels were increased ~20X compared to the DMSO control FXS neurons and highest in the WT neurons, and the level of induction of FMR1 was sustained through the 3 week timepoint. FMR1 expression was normalized to that obtained upon treatment with the FXS vehicle DMSO, which was set to 1. *P<0.05.

[0032] FIG. 7 shows FMRP regulates an important downstream neuronal network that represses REST (Repressor Element- 1 Silencing Transcription factor). REST is an important transcriptional regulator of axonal guidance genes (reviewed in Halevy et al, 2015). In FXS, where there is a l ack of FMRP, the neuronal miR-382 is limiting leading to an accumulation of REST and silencing of axonal guidance genes. Synaptic failure in FXS is, in part, due to the failure of appropriate regulation of REST because of the insufficient lev els of FMRP.

[0033] FIG. 8 shows sustained reduction of REST transcript following treatment of FXS neurons with Compound 1 for two weeks. Expression of REST mRNA was monitored by qRT-PCR in iPSC-derived NGN2 doxycycline-induced WT 194 or FXS 135 neurons (Zhang et al , 2013) treated with either DMSO or 3 μΜ Compound 1 for 1 , 2, or 3 weeks, as indicated. RNA was collected using the Norgen Single-Cell RNA Purification Kit; Norgen P/N 51800. cDNA was generated using the Qiagen QuantiTech Reverse Transcription Kit (Qiagen 205313) per the manufacturer's protocol. qRT-PCR was conducted by TaqMan using the GAPDH-VIC primer (Applied Biosystems P/N 4448489 Hs02786624__gl), REST- FAM (Applied Biosystems P/N 4331182 Hs00958503_ml). Expression data were converted to copy number

normalized to the GAPDH copy number per well, averaged, and the median DMSO control value was determined for each week and then used to determine the fold of gene induction as compared to the DMSO control within the week (Intra-week). REST levels were decreased compared to the DMSO control FXS neurons and lowest in the WT neurons, and the level of reduction of REST mRNA was sustained through the 3 week time- point. REST expression was normalized to that obtained upon treatment with the FXS vehicle DMSO, which was set to 1. *P<0.05.

[0034] FIG. 9 shows CRISPR/Cas9-mediated reduction of EED leads to an increase in FMR1 mRNA expression in FXS NGN2 induced neurons. EED- and EZH2-specific gRNAs (EED-1 and -2 and EZH2-1 and -2) were transduced using lentiviral infection into FXS NGN2 induced neurons expressing inducible Cas9. EED specific gRNAs (EED-1 and -2 and EZH2-1 and -2) increased FMR1 mRNA expression in NGN2 induced neurons when compared to non-targeting control gRNA (NTC).

[0035] FIG. 10 shows FXS neuron MEA network reduction caused by

Compound 1. Quantification of the spikes per minute were recorded on the Multielectrode Array (MEA) from Axion Systems using methods described by the manufacturer. Both FXS neuronal cultures and the isogenic controls neurons activity is shown. Data represented as mean

DETAILED DESCRIPTION

[0036] In some aspects, the present invention provides compositions and methods for reactivating an inactivated FMR1 gene by inducing a more permissive chromatin state, modulating transcriptional complexes that regulate FMR1 gene expression, and/or inhibiting enzymes that are part of signaling complexes regulating transcriptional machinery. In some embodiments, methods of reactivating FMR1 are useful in the treatment of subjects suffering from an FMR1 -inactivation-associated disorder, such as fragile X syndrome (FXS). For example, in some embodiments, methods of reactivation of FMR1 in a subject in need thereof result in increased expression of FMR1 and decreased or reversed disease symptoms, for example by modifying axonai guidance genes or synaptic activity. In some embodiments, the present invention provides inhibitors of epigenetic silencers of the FMR1 gene and methods of using said inhibitors in the reactivation of FMR1 and/or in the treatment of a subject suffering from an FMR1 -inactivati on-associated disorder. In some embodiments, the inhibitors of epigenetic silencers of the FMR1 gene are small molecule inhibitors or antisense oligonucleotides. In other embodiments, methods of inhibiting epigenetic silencers of the FMR1 gene comprise antisense oligonucleotide (ASO)-mediated knockdown of the epigenetic silencer.

[0037] In some aspects, the disclosure provides a method for treating an FMR1 - inactivation or FMR11 -reduction- associated disorder in a subject in need thereof, the method comprising: administering to the subject a therapeutically effective amount of an epigenetic modulator of FMR1 , wherein said modulator reactivates the FMR1 gene in the subject.

[0038] In some embodiments, the disclosure provides a method for treating a FMR1 -inactivation or FMR l -reduction-associated disorder in a subject in need thereof, the method comprising: administering to the subject a therapeutically effective amount of one or more epigenetic modulator of the FMR1 gene, wherein the one or more epigenetic modulator of the FMR1 gene comprises an inhibitor of a chromatin modifi er, and wherein the one or more epigenetic modulator reactivates expression of the FMR1 gene in the subject.

FMR 1 -inactivation

[0039] In some embodiments, the present invention provides compositions and methods for the reactivation of an inactivated FMR1 gene. Herein, an "inactivated FMR1 gene" refers an FMR1 gene that is transcriptionally inactive such that the expression of the FMRl gene is reduced or inhibited compared to an activated or reactivated FMR1 gene. Expression of the FMR1 gene may refer to the level of an encoded FMR1 mRNA transcript and/or the level of the encoded fragile X mental retardation protein (FMRP) protein. In some embodiments, an inactivated FMR1 gene may be referred to as a "transcriptionally inactive FMR1 gene ' or a "silenced FMR1 gene." In particular embodiments, the expression of the inactivated FMR1 gene is reduced or inhibited by at least 25% as compared to an activated or reactivated FMR1 gene.

[0040] Herein, a "reactivated FMR1 gene" refers to a change in the state of an FMR1 gene from a transcriptionally inactive (e.g., silenced) state to a transcriptionally active (e.g., expressed) state. Reactivation of an FMR1 gene can be measured as the expression level of FMR1 in a sample (e.g., a cell or a subject) after treatment with an epigenetic, transcriptional, or signaling modulator of FMR1 relative to the expression level of FMR1 in the sample prior to treatment with the modulator or in a control sample. "Expression of FMR1 " refers to the level of an FMR1 mRNA transcript and/or the level of the FMRP protein. For example, in some embodiments, reacti vation of the FMR1 gene results in increased expression of FMR1 mRNA and/or increased expression of the FMRP protein. In particular embodiments, the increase in expression is at least 2-fold, at least 5-fold, at least 10-fold, at least 100-fold, or at least 1000- fold. Expression of an FMR1 gene can be measured by any suitable method known in the art, for example by hybridization-based assay (e.g. , RT-PCR, qRT-PCR, Northern Blot, Quantigene), protein-based methods (e.g., Western blot, chemiluminescence, ELISA, Quanterix), spectroscopic methods (e.g. , mass spectrometry), and cell-based methods (e.g. , flow cytometry, fluorescence activated cell sorting (FACS), immunofluorescence, and FMR1 reporter, or in situ hybridization).

[0041] In some embodiments, inactivation of an FMR1 gene is a result of epigenetic silencing. In such embodiments, the inactivated FMR1 gene may comprise an altered pattern of epigenetic marks compared to an activated or reactivated FMRI gene. As used herein, the term "epigenetic mark" refers to a feature or characteristic of a gene that is not directly governed by the genetic code, for example methylation of DNA and covalent modification of histone proteins. Generally, epigenetic marks influence the expression of a gene by the modifying chromatin state and can be activating marks (e.g., promoting expression of the gene) or repressive marks (e.g. , inhibiting expression of the gene). Exemplar}' activating marks include but are not limited to, histone (H2A/2B/3/4) acetylation and histone H3 lysine 4 trimethylation (H3K4me3). Exemplary repressive marks include but are not limited to, DNA methylation, histone H3 lysine 27 trimethylation (H3K27me3), histone H3 lysine 9 trimethylation (H3K9me3), and histone H4 lysine 20 trimethylation (H4K20me3). Epigenetic marks associated with inactivation of the FMRI gene are known in the art (See e.g.. Warren 2007). For example, reciprocal changes in DNA methylation and hydroxymethylation as well as a broad repressive epigenetic switch characterize inactivated FMRI genes in particular FMRI -maetivati on-associated disorders, such as fragile X syndrome (FXS).

[0042] In some aspects, an inacti vated FMRI gene comprises an increase in one or more repressive marks compared to an active or reactivated FMRI gene. In some aspects, an inactivated FMRI gene comprises a decrease in activating marks compared to an active or reactivated FMRI gene.

[0043] In some embodiments, an inactivated FMRI gene comprises an expansion of a polymorphic CGG sequence within the 5' untranslated region (5'UTR) of the FMRI gene. Without wishing to be bound by any specific theory, it is thought that the FMRI gene comprising expanded CGG repeats may become transcriptionally silenced due to (i) the presence of repressive epigenetic marks (e.g., histone modifications and/or DNA hypermethylation) within these repeats, therefore resulting in decreased FMRP protein expression or (ii) the formation of an mRNA-DNA duplex (e.g. , an "R- loop") between the expanded CGG repeat of the FMRI mRNA transcript and the complementary CGG repeat of the FMRI gene (See Groh el al , 20 4). l

[0044] The number of CGG repeats in an expansion present in an inactivated

FMRI gene can vary. In some embodiments, the number of CGG repeats in the expansion comprises from about 55 to about 500 repeats. In some embodiments, the number of CGG repeats in the expansion comprises from about 201 to about 500 repeats. In some embodiments, the number of CGG repeats in the expansion is greater than 500 repeats. In some embodiments, severity of an FMR1 -inactivation-associated disorder can be classified by the number of polymorphic CGG repeats present in the 5'UTR of a subject's FMRI gene. In some embodiments, a subject's FMR1 gene comprises about 55 CGG repeats to about 200 CGG repeats. In such embodiments, the subject is referred to as a "permutation subject." In some embodiments, a subject's FMR1 gene comprises greater than 200 CGG repeats. In such embodiments, the subject is referred to as a "full mutation subject."

Epigenetic modulators of FMRl

[0045] In some embodiments, the present invention provides agents and methods for reactivation of an inactivated FMR1 gene by inhibition of certain epigenetic modulators. As used herein, the term "epigenetic modulator of FMR1 " refers to an agent that alters the transcriptional activation of FMR1 through modulation of one or more epigenetic marks. In some embodiments, an epigenetic modifier directly alters the transcriptional activation of the FMR1 gene by modulating the epigenetic marks on the FMR1 gene itself. In some embodiments, an epigenetic modifier indirectly alters the transcriptional activation of the FMR1 gene by modulating the epigenetic marks on a modulator of the FMR1 gene. For example, in some embodiments, an epigenetic modulator of FMR1 alters the expression level or activity (e.g. , function) of another protein that modulates the transcriptional activity of FMR1 . Similarly, in some embodiments, an inactivated FMR1 gene has increased DNA methylation and an epigenetic modifier of FMR1 may inhibits the activity or expression of a DNA methylation enzyme. In some embodiments, an epigenetic modifier of FMR1 can be a nucleic acid, polypeptide, small molecule, or any combination of the foregoing.

[0046] In some embodiments, the inactivated FMR1 gene comprises at least one epigenetic mark associated with a silenced FMR1 gene. In some embodiments, at least one epigenetic mark is selected from the group consisting of DNA methylation (DNAme) and histone H3 lysine 27 trimethylation (H3K27me3).

[0047] In some embodiments, an epigenetic modifier of FMR1 may change the chromatin state of FMR1 to increase the transcription of the FMR1 gene. The chromatin state (e.g. , packaging of DNA with histone and non-histone proteins) of a cell has significant effects on gene expression. In some embodiments, the disclosure relates compositions and methods for reactivating an inactivated FMR1 gene by knocking down or inhibiting one or more chromatin modifiers. In some embodiments, an epigenetic modulator of FMR1 inhibits a chromatin modifier. As used herein, the term "chromatin modifier" refers to a protein that modifies DNA (e.g., by methylation) or post-translationally modifies histone proteins (for example by phosphorylation, acetylation, methylation or ubiquitination), resulting in alteration of chromatin structure and thus modified gene expression. In some embodiments, the chromatin modifiers described herein include components of the PRC2 complex, described below. In certain embodiments, the chromatin modifier is EED. In some embodiments, the chromatin modifiers can include, but are not limited to, DNA methyltransferases, histone methyitransferases, histone ubiquitin ligases, and hisione acetyltransferases.

[0048] In some embodiments, the epigenetic modulator inhibits the expression or function of a protein. In some embodiments, the epigenetic modulator inhibits the expression or function of a protein and prevents the formation of a protein complex comprising that protein. For example, the Poly comb Repressive Complexes (PRC), namely PRC2 and PRCl, are known to modulate the transcriptional activation of the FMR1 gene. PRC 2 acts through the H3K27me3 histone modification, and PRC l acts through the H2AK119 mono-ubiquitination histone modification (FIG. 1). The major core components of human PRC2 include the histone methy transferase, Enhancer of Zeste Homolog 1 or 2 (EZH1 or 2), and its known binding partners, Embryonic Ectoderm Development (EED) and Suppressor of Zeste 12 (SUZ12) (Cao et. al., 2014). The human PRCl complex comprises B lymphoma Mo-MLV insertion region 1 (BMI1 ), RING 1 A (also known as RING I ), and RING IB (also known as RING2 or RNF2) (FIG, 1).

[0049] In some embodiments, the epigenetic modulator is an inhibitor of EED.

In some embodiments, the epigenetic modulator inhibits the interaction of EED interaction with other proteins comprised in the PRCl or PRC2 complexes. Inhibition of EED plays a distinct mechanistic role in regulation of spreading of di-and trimethylation of lysine 27 of histone 3 (H3K27me3 marks) at key regulator regions of many genes. In some embodiments, EED binds and recognizes the H3K27Me3 mark, which allosterically activates the EZH1 or EZH2 catalytic component in the PRC2 complex. This recognition and activation of the complex leads to regul ation of spreading of H3K27me3 marks at key regulator regions of many genes, but is exemplified here in the regulation of FMR1 expression. In some embodiments, EED functions also to recruit PRC l to H3K27me3 loci and enhances PRC l mediated H2A ubiquitin E3 ligase activity. Taken together, this suggests an integral role for EED as an epigenetic exchange factor coordinating the activities of PRC 2 (reviewed in Cao et al. , 2014).

[0050] In some embodiments, the epigenetic modulator of FMR1 is an inhibitor of EED within the PRC2 complex and inhibits the catalyzation of tri-methylation of histone H3 at lysine 27 (H3K27me3) within chromatin. This is distinct from a mechanism whereby, PRC2 is recruited to a limited number of "nucleation sites" that are enriched for local CpG islands (CGIs), distinguished from other CGIs by the presence of JARID2 binding motifs. Thereby discrete from these nucleation sites found in close 3-dimensional proximity, forming polycomb foci within the nucleus. Rather this EED inhibitory mechanism acts to effect PRC2 spreading both locally and distally via long-range contacts to form H3K27me3-chromatin domains (UedaT, et al. 2016; Margueron, R. et al. 2009). These mechanistic insights into the establishment and maintenance of poly comb-repressive domains across the genome point to the centrality of the spatial nature of chromatin structure and regulation.

[0051] Thus, in some embodiments, selective inhibition of EED inhibits the repressive function of PRCl and PRC2 on the FMR1 gene, resulting in reactivation of the inactivated FMR1. In some embodiments, inhibitors of EED are useful for treating FMR1- inactivation-associated disorders, such as fragile X syndrome (FXS).

[0052] In some embodiments, the epigenetic modulator is an inhibitor of EED.

In some embodiments, the inhibition of EED is measured as a function of FMR1 expression. For example, in some embodiments, inhibition of EED results in an increased production of the FMR1 mRNA transcript compared to the level of the FM R1 mRNA transcript produced in the absence of the EED inhibitor. In some embodiments, inhibition of EED results in an increased production of the FMRP protein compared to the level of the FMRP protein produced in the absence of the EED inhibitor. In some embodiments, inhibition of EED is measure as a change in one or more epigenetic marks on the FMRL1 gene. For example, in some embodiments, EED inhibition results in an increase in activating epigenetic marks and/or a decrease in repressive genetic marks. Unexpectedly, the inventors have found that selective inhibition of an EED protein interaction with the PRC2 complex plays a distinct mechanistic role in regulation of spreading of H3K27me3 marks at key regulator regions of FMR1, thereby regulating FMR1 expression. An example of small molecule inhibitors of EED proteins and antisense molecules that reduce expression of EED are shown in FIG. 2.

[0053] In some embodiments, the epigenetic modulator selectively inhibits an

EED protein, resulting in lowered activity of the repressive PRC1 or PRC2 complexes. In some embodiments, the epigenetic modulator is Compound 1, a derivative thereof, or a pharmaceutically acceptable salt thereof.

[0054] In some embodiments, an epigenetic modulator of FMR1 is a selective inhibitor. As used herein, a "selective inhibitor" or an inhibitor that is said to "selectively inhibit" refers to an inhibitor that preferentially inhibits activity or expression of a target molecule of a particular class compared with other molecules of the same class. In some embodiments, a selective inhibitor of a target molecule of a particular class has half maximal inhibitory concentration (IC50) for the target molecule that is at least 2-fold, at least 4-fold, at least 8-fold, at least 10-fold, at least 20-fold, at least 30-fold, at least 40-fold, or at least 50-fold lower than the IC50 for one or more other members of the class. In some embodiments, a selective inhibitor can be an inhibitor of a chromatin modifier (e.g. , an EED protein),

[0055] In some embodiments, a selective inhibitor selectively inhibits a chromatin modifier. In some embodiments, a selective inhibitor of EED, which is a chromatin modifier, has half maximal inhibitory concentration (IC50) for EED that is at least 2-fold, at least 4-fold, at least 8-fold, at least 10-fold, at least 20-fold, at least 30-fold, at least 40-fold, or at least 50-fold lower than the IC50 for one or more other chromatin modifiers.

[0056] In some embodiments, the epigenetic modulator of FMR1 is a nucleic acid, polypeptide, or small molecule. In some embodiments, the epigenetic modulator of FMR1 is a polypeptide, for example an antibody. In some embodiments, the epigenetic modulator of FMR1 is a small molecule, for example a small molecule shown in Fig. 2.

[0057] In some embodiments, an epigenetic modulator of FMR1 is an interfering RNA. Examples of interfering RNA include, but are not limited to, double stranded RNA (dsRNA), siRNA, shRNA, miilNA, gRNA (directing a Cas9 protein) and antisense oligonucleotide (ASO). Inhibitory oligonucleotides may interfere with gene expression, transcription and/or translation. Generally, inhibitory oligonucleotides bind to a target polynucleotide via a region of complementarity. For example, binding of an inhibitor}' oligonucleotide to a target polynucleotide can trigger RNAi pathway-mediated degradation of the target polynucleotide (in the case of dsRNA, siRNA, shRNA, etc.), or can block the translational machinery (e.g., antisense oligonucleotides). In some embodiments, inhibitory oligonucleotides can be single-stranded or double-stranded. In some embodiments, inliibitor oligonucleotides are DNA or RNA. In some embodiments, the inhibitory oligonucleotide is selected from the group consisting of: antisense oligonucleotide, siRNA, shRNA, gRNA (directed by Cas9) and miRNA. In some embodiments, inhibitory oligonucleotides are modified nucleic acids.

[0058] The term "nucleotide analog" or "altered nucleotide" or "modified nucleotide" refers to a non-standard nucleotide, including non-naturally occurring ribonucleotides or deoxyribonucleotides. In some embodiments, 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 fimction. Examples of positions of the nucleotide which may be derivatized include the 5 position, e.g. , 5-(2-amino)propyl uridine, 5-bromo uridine, 5-propyne undine, 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-adenosme; O- and N-modified (e.g. , alkylated, e.g. , N6-methyl adenosine, or as otherwise known in the art) nucleotides; and other heterocy clically modified nucleotide analogs such as those described in Herdewijn, Antisense Nucleic Acid Drug Dev., 2000 Aug, 10(4): 297-310.

[0059] 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, 1, SH, SR, NH2, NHR, NR2, COOR, or OR, wherein R is substituted or unsubstituted C₁-C₆ alkyl, alkenyl, alkynyl, aryl, etc. Other possible modifications include those described in U.S. Pat. Nos. 5,858,988, and 6,291 ,438. A locked nucleic acid (LNA), often referred to as inaccessible RNA, is a modified RNA nucleotide. The ribose moiety of an LN A nucleotide is modified with an extra bridge connecting the 2' oxygen and 4' carbon.

[0060] 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): 1 17-21 , 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. Pat. 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. In some embodiments, the inhibitory oligonucleotide is a modified inhibitory oligonucleotide. In some embodiments, the modified inhibitory oligonucleotide comprises a locked nucleic acid (LNA), phosphorothioate backbone, and/or a 2'-OMe modification.

Methods for Reactivating FMRl

[0061] In some aspects, the disclosure provides a method for reactivating a transcriptionally inactive FMR1 gene in a cell, the method comprising: contacting the cell with an effective amount of one or more epigenetic modulator of FMR1 , wherein the one or more epigenetic modulator of FMR1 comprises an inhibitor of a chromatin modifier, and wherein the one or more epigenetic modulator reactivates FMR1 in the cell. In some embodiments, the cell is in vitro, in vivo, or ex vivo. The neural precursor cell could also be engineered to either impact the FMR1 expression using a sequence specific demethvlation approach, wherein one uses dCAS TET (demethylase) or a neural precursor cell stably expresses FMR1 or a genomic tool targeting genomic reduction of EED (antisense or shRNA mechanism). This neural precursor cell could be delivered via the cerebrospinal fluid intrathecally or surgically implanted intraventricularly.

[0062] In some embodiments, the cell contacted with the effective amount of one or more epigenetic modulator of FMR1 can be any cell that has a transcriptionally inactive FMR1 gene. For example, the cell can be a brain cell, a testicular cell, an ovarian cell, a spleen cell, a thymus cell, or an ocular cell. In some embodiments, the cell is an induced pluripotent stem cell (iPSC). In some embodiments, a ceil having a transcriptionally inactive FMR1 gene bears one or more epigenetic marks indicative of having a transcriptionally inactive (e.g. , epigenetically silenced) FMR l gene. Epigenetic marks can be activating marks, repressive marks, or activating marks and repressive marks. Examples of epigenetic marks associated with transcriptionally inactive FMR1 gene include DNA methylation (DNAme), histone H3 ly sine 27 trimethylation (H3K27me3), histone H3 lysine 9 trimethylation (H3K9me3), histone 4 lysine 20 trimethylation (H4K20me3), hisione H2A ubiquitination (H2Aub), histone H2A acetylation, histone H2B acetylation, histone H3 aeetylation, histone H4 acetylation, and histone H3 lysine 4 trimethylation (H3K4me3).In some embodiments, a ceil having a transcriptionally inactive FMR1 gene can also comprise an expansion of a polymorphic CGG repeat within the 5'UTR of the FMR1 gene. The number of repeats in the expansion can vary. In some embodiments, the number of CGG repeats in the expansion ranges from about 55 to about 500 repeats. In some embodiments, the number of CGG repeats ranges from about 55 repeats to about 200 repeats. In some embodiments, the number of CGG repeats ranges from about 100 to about 500 repeats. In some embodiments, the number of CGG repeats is greater than 200 repeats. In some embodiments, the number of CGG repeats is greater than 500 repeats.

[0063] In some embodiments, an effective amount of an epigenetic modulator of FMR1 is delivered to an induced pluripotent stem cell (iPSC). In some embodiments, the ceil (e.g., neuronal cell, iPSC) is in vitro. In some embodiments, neurogenin 2 (NGN2) is delivered to the iPSC packaged in a ientivirus and induced using doxycycline to generate glutamatergic neurons. In some embodiments, the neuronal cell or iPSC comprises an expansion of a polymorphic CGG repeat within the 5'UTR of the FMR1 gene, for example an expansion that comprises between about 55 and about 200 CGG repeats. In some embodiments, the cell comprises an expansion that comprises more than 200 CGG repeats.

[0064] In some embodiments, the present invention provides methods of reactivating an epigenetically -silenced FMR1 gene in a subject comprising administering to the subject an epigenetic modulator, wherein the epigenetic modulator is EED. In some embodiments, the subject suffers from FXS. [0065] In some aspects, the disclosure provides methods for treating a subject having an FMR1 -inactivation-associated disorder. The terms "FMR1 -inactivation-associated disorder" and "FMR1 - reduction-associated disorder" are used interchangeably herein and refer to a disease or disorder that results from transcriptional inactivation or reduced expression of the FMR1 gene. Generally, inactivation of the FMR1 gene results in the loss of production of fragile X mental retardation protein (FMRP). FMRP is an RNA binding protein (RNABP) involved in a range of developmental problems including learning disabilities and cognitive impairment, moderate to severe mental retardation, ataxia (e.g., loss of coordination), tremor, memory loss, loss of sensation in the lower extremities (e.g. , peripheral neuropathy), mental and behavioral changes, and polycystic ovarian syndrome. In some embodiments, loss of function in the FMRP protein causes FXS (Verkerk et al, 1991), the most common inherited form of intellectual disability, which is further characterized by autistic behaviors, childhood seizures, and abnormal dendritic spines (Hagerman and Hagerman, 2002; Hernandez et al , 2009). Fragile X syndrome (FXS) was the first genetic disorder to link RNA regulation to human cognitive function. In some embodiments, an FMR1 -inactivation-associated disorder is fragile X syndrome (FXS).

[0066] FMR1 /FMRP expression has been shown to be reduced in o ther neuropsychiatric disorders including, but not limited to autism spectrum disorders (ASD), depression, bipolar disease, schizophrenia (Velmeshev et al Molecular Autism 2013, 4:32; Darnell, et al , Cell 2011; Neelroop et al , 2013; Fatemi and Folsom Molecular Autism 2011 ; Foisom, et al , Schizophr Res. 2015; Fatemi et al, Schizophr Res. 2010). FMRI/FMRP decreases may also be associated with TDP-43 pathology in neurodegenerative disorders as well as neurodegenerative disorders that impact axonal and dendritic functional processes that regulate effective synaptic plasticity (Yu et al , 2012 JBC VOL, 287, NO. 27, pp. 22560 - 22572; Wang 2015 Front in Cell Neuro). Neurodegenerative diseases impacted include tauopathies (e.g., frontal temporal dementia with parkinsonism- 17 (FTDP-17), progressive supranuclear palsy (PSP), cortical basal degeneration (CBD), and Alzheimer's disease (AD)), synucieinopathies (e.g. , Parkinson's disease (PD), multiple systems atrophy (MSA), lewybody dementia (LBD)), and TDPopathies (e.g. , frontal temporal dementia, Amyotrophic lateral sclerosis (ALS), Alzheimer's disease, and Parkinson's disease, etc. ) (Yu et al, 2012 JBC VOL. 287, NO, 27, pp. 22560 -22572; Wang 2015 Front in Cell Neuro). In some embodiments, an FMR1 -reduction-associated disorder can be autism, seizure, schizophrenia, bipolar disorder or major depression disorder. In some embodiments, an FMR1 -reduction-associated disorder is associated with TDP-43 pathology in neurodegenerative disorders as well as neurodegenerative disorders that impact axonal and dendritic functional processes that regulate effective synaptic plasticity. In some embodiments, an FMR1 -reduction-associated disorder is associated with neurodegenerative diseases that include tenopathies (e.g. FTDP-17, PSP, CBD, and Alzheimer's disease), synucleinopathies (e.g. Parkinson's disease, MSA, and LBD), and TDPopathies (e.g. frontal temporal dementia, ALS, Alzheimer's disease, and Parkinson's disease). In some embodiments, the FMR1 -inactivati on-associated disorder is fragile X syndrome.

[0067] In some aspects, the disclosure provides a method for treating an FMR1 - inactivati on-associated disorder in a subject in need thereof, the method comprising: administering to the subject a therapeutically effective amount of an epigenetic modulator of FMR1 , wherein the epigenetic modulator reactivates FMR1 in the subject. For example, transcriptional inactivation of the FMR1 gene may lead to FXS in a subject. As used herein, a "subject" is interchangeable with a "subject in need thereof, both of which may refer to a subject having an FMR1 -inactivati on-associated disorder, or a subject having an increased risk of developing such a disorder relative to the population at large. A subject can be a human, non-human primate, rat, mouse, cat, dog, or other mammal. The method may be used to treat any of the FMR1 -inactivation-associated disorders disclosed herein, including but not limited to FXS.

[0068] In particular embodiments, the disclosure provides a method for treating an FMR1 -inactivation-associated disorder, e.g., FXS, in a subject in need thereof, the method comprising: administering to the subject a therapeutically effective amount of an inhibitor of EED, wherein the inhibitor of EED reactivates FMR1 in the subject. In certain embodiments, the inhibitor of EED is Compound 1 or a derivative or pharmaceutically acceptable salt thereof.

[0069] A subject in need thereof may be a subject having an inactive FMR1 gene. In some embodiments, any of the methods described herein further comprises determining the presence of an inacti vated FMR1 gene in a subject. In such embodiments, the presence of an inactivated FMR1 gene may be determined by analyzing a sample obtained from the subject comprising one or more cells by DNA sequencing, Western blot, qPCR, immunohistochemistiy, chromatin immunoprecipitation, an/or bisulfite sequencing. In some embodiments, the presence of an inactivated FMR1 gene is determined by the presence one or more repressive epigenetic marks on an FMR1 gene; the reduction or absence of one or more activating epigenetic marks on an FMR1 gene compared to a control sample; the presence of CGG repeats in the 5' UTR of the FMR1 gene; decreased levels of FMR1 mRNA compared to a control sample; decreased levels of FMRP protein expression compared to a control sample. In some embodiments, the presence of an inacti vated FMR1 gene in a subject is determined by reviewing the results of an analysis performed on a sample or cells obtained from the subject. In some embodiments, subjects determined to have an inactivated FMR1 gene are selected for treatment by one of the agents described herein (e.g., an epigenetic modulator of FMR1 , such as Compound I ). In certain embodiments, the subject is treated if it is determined that the subject has an inactivated FMR1 gene.

[0070] In some embodiments, severity of an FMR1 -inactivati on-associated disorder can be classified by the number of polymorphic CGG repeats present in the 5'UTR of a subject's FMR1 gene. For example, a subject comprising about 55 CGG repeats to about 200 CGG repeats in the FMR1 gene is referred to as a permutation subject and a subject comprising greater than 200 CGG repeats in the FMR1 gene is referred to as a full mutation subject. In some embodiments, a full mutation subject is determined to have, or is diagnosed with an FMRI -inactivation-associated disorder. For example, in some embodiments, a full mutation subject has FXS. In some embodiments, the number of CGG repeats in a full mutation subject having FXS ranges from about 201 to about 500 repeats. In some embodiments, the number of CGG repeats in a full mutation subject having FXS is greater than 500 repeats. In some embodiments, pre-mutation subjects (e.g. subjects having between 6 and 54 CGG repeats) are susceptible to conversion to full mutation status and are thus at increased risk of developing an FMR1 -inactivation-associated disorder (e.g., FXS) compared to subjects having normal levels of CGG repeats in the FMRI gene.

[0071] As used herein, the terms "treatment ", "treating ", and "therapy" refer to therapeutic treatment and prophylactic or preventative manipulations. The terms further include ameliorating existing symptoms, preventing additional symptoms, ameliorating or preventing the underlying causes of symptoms, preventing or reversing causes of symptoms, for example, symptoms associated with a FMRI -inactivation-associated disorder. Thus, the terms denote that a beneficial result has been conferred on a subject with a disorder (e.g. , an FMRI -inactivation-associated disorder), or with the potential to develop such a disorder. Furthermore, the term "treatment" is defined as the application or administration of an agent (e.g., therapeutic agent or a therapeutic composition) to a subject, or an isolated tissue or cell line from a subject, who may have a disease, a symptom of disease or a predisposition toward a disease, with the purpose to cure, heal, alleviate, relieve, alter, remedy, ameliorate, improve or affect the disease, the symptoms of disease or the predisposition toward disease.

[0072] Therapeutic agents or therapeutic compositions may include an agent in a pharmaceutically acceptable form that prevents and/or reduces the symptoms of a particular disease (e.g., a FMR1 -inactivation-associated disorder). For example a therapeutic composition may be a pharmaceutical composition that prevents and/or reduces the symptoms of a FMR1 - inactivation-associated disorder. It is contemplated that the therapeutic composition of the present disclosure will be provided in any suitable form. The form of the therapeutic composition will depend on a number of factors, including the mode of administration as described herein. The therapeutic composition may contain diluents, adjuvants and excipients, among other ingredients as described herein.

Pharmaceutical Compositions

[0073] In some aspects, the disclosure relates to pharmaceutical compositions comprising an epigenetic modulator of FMR1 , e.g., an inhibitor of BED (e.g. , Compound 1). In some embodiments, the composition comprises an epigenetic modulator of FMR1 , e.g., an inhibitor of EED (e.g.. Compound 1) and a pharmaceutically acceptable carrier. In some embodiments, the disclosure relates to a composition for reactivating a transcriptionally inactive FMR1 gene in a cell, comprising: one or more epigenetic modulator of FMR1 , wherein the one or more epigenetic modulator of FMR1 comprises an inhibitor of a chromatin modifier; and a pharmaceutically acceptable carrier.

[0074] As used herein the term "pharmaceutically acceptable earner" is intended to include any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, and the like, compatible with pharmaceutical administration. The use of such media and agents for pharmaceutically active substances is well known in the ait. Except insofar as any conventional media or agent is incompatible with the active agent, use thereof in the compositions is contemplated. Supplementary active agents can also be incorporated into the compositions. Pharmaceutical compositions can be prepared as described below. The active ingredients may be admixed or compounded with any conventional, pharmaceutically acceptable carrier or excipient. The compositions may be sterile.

[0075] Typically, pharmaceutical compositions are formulated for delivering an effective amount of an agent (e.g. , an epigenetic modulator of FMR1 such as Compound 1). In general, an "effective amount" of an active agent refers to an amount sufficient to elicit the desired biological response (e.g. , reactivation of the inactive FMR1 gene). An effective amount of an agent may vary depending on such factors as the desired biological endpoint, the pharmacokinetics of the agent, the disease being treated (e.g. , a FMR1 -inactivation-associated disorder), the mode of administration, and the patient. [0076] A composition is said to be a "pharmaceutically acceptable carrier" if its administration can be tolerated by a recipient patient. Sterile phosphate-buffered saline is one example of a pharmaceutically acceptable carrier. Other suitable carriers are well-known in the art. See, for example, REMINGTON'S PHARMACEUTICAL SCIENCES, 18th Ed. (1990), It will be understood by those skilled in the art that any mode of administration, vehicle or carrier conventionally employed and which is inert with respect to the active agent may be utilized for preparing and administering the pharmaceutical compositions of the present disclosure. Illustrative of such methods, vehicles and carriers are those described, for example, in Remington's Pharmaceutical Sciences, 4th ed. ( 1970), the disclosure of which is incorporated herein by reference in its entirety. Those skilled in the art, having been exposed to the principles of the disclosure, will experience no difficulty in determining suitable and appropriate vehicles, excipients and carriers or in compounding the active ingredients therewith to form the pharmaceutical compositions of the disclosure,

[0077] In some embodiments, an "effective amount" or a "therapeutically effective amount" of an epigenetic modulator of FMR1 (e.g., Compound 1 ) is an amount of an agent sufficient to ameliorate at least one adverse effect associated with inactivation (e.g. , transcriptional inactivation), or reduced expression, of the FMR1 gene in a cell or in an individual in need of such modulation. In some embodiments, an effective amount of an agent is an amount sufficient to reacti vate FMR1 gene in a cell or in an individual in need of FMR1 reactivation. The therapeutically effective amount to be included in pharmaceutical compositions depends, in each case, upon several factors, e.g. , the type, size and condition of the patient to be treated, the intended mode of administration, the capacity of the patient to incorporate the intended dosage form, etc. Generally, an amount of active agent is included in each dosage form to provide from about 0.1 to about 250 mg/kg, and preferably from about 0.1 to about 100 mg/kg. One of ordinary skill in the art would be able to determine empirically an appropriate therapeutically effective amount.

[0078] Combined with the teachings provided herein, by choosing among the various active agents and weighing factors such as potency, relative bioavailability, patient body weight, severity of adverse side-effects and selected mode of administration, an effective prophylactic or therapeutic treatment regimen can be planned which does not cause substantial toxicity and yet is entirely effective to treat the particular subject. The effective amount of an agent for any particular application can vary depending on such factors as the disease or condition being treated, the particular therapeutic agent being administered, the size of the subject, or the severity of the disease or condition. One of ordinary skill in the art can empirically determine the effective amount of a particular nucleic acid and/or other therapeutic agent without necessitating undue experimentation,

[0079] In some cases, agents of the disclosure are prepared in a colloidal dispersion system. Colloidal dispersion systems include lipid-based systems including oil-in- water emulsions, micelles, mixed micelles, and liposomes. In some embodiments, a colloidal system of the disclosure is a liposome. Liposomes are artificial membrane vessels which are useful as a delivery vector in vivo or in vitro. It has been shown that large unilamellar vesicles (LUVs), which range in size from 0.2 - 4.0 μηι can encapsulate large macromolecules. RNA, DNA and intact virions can be encapsulated within the aqueous interior and be delivered to cells in a biologically active form. Fraley et al. (1981) Trends Biochem Sci 6:77.

[0080] Liposomes may be targeted to a particular tissue by coupling the liposome to a specific ligand such as a monoclonal antibody, sugar, glycolipid, or protein. Ligands which may be useful for targeting a liposome to, for example, a neuronal cell include, but are not limited to: intact or fragments of molecules which interact with neuronal cell specific receptors and molecules, such as antibodies, which interact with the cell surface markers of neuronal cells. Such ligands may easily be identified by binding assays well known to those of skill in the art. In still other embodiments, the liposome may be targeted to a tissue by coupling it to an antibody known in the art.

[0081] Lipid formulations for transfection are commercially available from

QIAGEN, for example, as EFFECTENE™ (a non-Iiposomal lipid with a special DNA condensing enhancer) and SL1PERFECT™ (a novel acting dendrimenc technology).

[0082] Liposomes are commercially available from Gibco BRL, for example, as LIPOFECTIN™ and LIPOFECTACE™, which are formed of cationic lipids such as N-[l- (2, 3 dioleyloxy)-propyl]-N, N, N-trimethyl ammonium chloride (DOTMA) and dimethyl dioctadecylammonium bromide (DDAB). Methods for making liposomes are well known in the art and have been described in many publications. Liposomes also have been reviewed by Gregonadis G (1985) Trends Biotechnol 3:235-241.

[0083] Certain cationic lipids, including in particular N-[ l-(2, 3 dioleoyloxy)- propyl]-N,N,Ntrimethylammonium methyl-sulfate (DOTAP), may be advantageous when combined with the epigenetic modulators of FMR1(e.g. , interfering RNA) of the disclosure.

[0084] In some aspects of the disclosure, the use of compaction agents may also be desirable. Compaction agents also can be used alone, or in combination with, a biological or chemical/physical vector. A "compaction agent", as used herein, refers to an agent, such as a hi stone, that neutralizes the negative charges on the nucleic acid and thereby permits compaction of the nucleic acid into a fine granule. Compaction of the nucleic acid facilitates the uptake of the nucleic acid by the target cell. The compaction agents can be used alone, e.g. , to deliver an epigenetic modulator of FMR1 in a form that is more efficiently taken up by the cell or, in combination with one or more of the above-described carriers.

[0085] Other exemplay compositions that can be used to facilitate uptake of an epigenetic modulator of FMR1 include calcium phosphate and other chemical mediators of intracellular transport, microinjection compositions, electroporation and homologous recombination compositions (e.g., for integrating a nucleic acid into a preselected location within the target cell chromosome).

[0086] The agents described herein (e.g. , an epigenetic modulator of FMR1) may be administered alone (e.g., in saline or buffer) or using any delivery vehicle known in the art. For instance the following delivery vehicles have been described: cochleates; Emulsomes; ISCOMs; liposomes; live bacterial vectors (e.g. , Salmonella, Escherichia coli, Bacillus Calmette-Guerin, Shigella, Lactobacillus); live viral vectors (e.g.. Vaccinia, adenovirus, Herpes Simplex); microspheres; nucleic acid vaccines; polymers (e.g., carboxymethylcellulose, chitosan); polymer rings; proteosomes; sodium fluoride; transgenic plants; virosomes: and, virus-like particles.

[0087] The formulations of the disclosure are administered in pharmaceutically acceptable solutions, which may routinely contain pharmaceutically acceptable concentrations of salt, buffering agents, preservatives, compatible carriers, adjuvants, and optionally other therapeutic ingredients.

[0088] The term pharmaceutically-acceptable carrier means one or more compatible solid or liquid filler, diluents or encapsulating substances which are suitable for administration to a human or other vertebrate animal. The term carrier denotes an organic or inorganic ingredient, natural or synthetic, with which the active ingredient is combined to facilitate the application. The components of the pharmaceutical compositions also are capable of being commingled with the agentss of the present disclosure, and with each other, in a manner such that there is no interaction which would substantially impair the desired pharmaceutical efficiency.

[0089] Dragee cores are provided with suitable coatings. For this purpose, concentrated sugar solutions may be used, which may optionally contain gum arable, talc, polyvinyl pyrrolidone, carbopol gel, polyethylene glycol, and/or titanium dioxide, lacquer solutions, and suitable organic solvents or solvent mixtures. Dyestuffs or pigments may be added to the tablets or dragee coatings for identification or to characterize different combinations of active agent doses.

[0090] In addition to the formulations described herein, the agents may also be formulated as a depot preparation. Such long-acting formulations may be formulated with suitable polymeric or hydrophobic materials (for example, as an emulsion in an acceptable oil) or ion exchange resins, or as sparingly soluble derivatives, for example, as a sparingly soluble salt.

[0091] The pharmaceutical compositions also may comprise suitable solid or gel phase carriers or excipients. Examples of such carriers or excipients include but are not limited to calcium carbonate, calcium phosphate, various sugars, starches, cellulose derivatives, gelatin, and polymers such as polyethylene glycols.

[0092] Suitable liquid or solid pharmaceutical preparation forms are, for example, aqueous or saline solutions for inhalation, microencapsulated, encochleated, coated onto microscopic gold particles, contained in liposomes, nebulized, aerosols, pellets for implantation into the skin, or dried onto a sharp object to be scratched into the skin. The pharmaceutical compositions also include granules, powders, tablets, coated tablets, (micro)capsules, suppositories, syrups, emulsions, suspensions, creams, drops or preparations with protracted release of active agents, in whose preparation excipients and additives and/or auxiliaries such as disintegrants, binders, coating agents, swelling agents, lubricants, flavorings, sweeteners or solubilizers are customarily used as described above. The pharmaceutical compositions are suitable for use in a variety of drug delivery systems. For a brief review of methods for drug delivery, see Langer R (1990) Science 249: 1527-1533, which is incorporated herein by reference in its entirety.

[0093] The agents may be administered per se (neat) or in the form of a pharmaceutically acceptable salt. When used in medicine the salts should be pharmaceutically acceptable, but non-pharmaceutically acceptable salts may conveniently be used to prepare pharmaceutically acceptable salts thereof. Such salts include, but are not limited to, those prepared from the following acids: hydrochloric, hydrobromic, sulphuric, nitric, phosphoric, maleic, acetic, salicylic, p-toiuene sulphonic, tartaric, citric, methane sulphonic, formic, raalonic, succinic, naphthalene-2-sulphonic, and benzene sulphonic. Also, such salts can be prepared as alkaline metal or alkaline earth salts, such as sodium, potassium or calcium salts of the carboxylic acid group.

[0094] Suitable buffering agents include: acetic acid and a salt (1-2% w/v); citric acid and a salt (1-3% w/v); boric acid and a salt (0.5-2.5% w/v); and phosphoric acid and a salt (0.8-2% w/v). Suitable preservatives include benzalkonium chloride (0.003-0.03% w/v); chlorobutanol (0.3-0.9% w/v); parabens (0.01-0,25% w/v) and thimerosal (0,004-0.02% w/v).

[0095] The compositions may conveniently be presented in unit dosage form and may be prepared by any of the methods well known in the art of pharmacy. All methods include the step of bringing the agents into association with a carrier which constitutes one or more accessor}' ingredients. In general, the compositions are prepared by uniformly and intimately bringing the agents into association with a liquid carrier, a finely divided solid carrier, or both, and then, if necessary, shaping the product. Liquid dose units are vials or ampoules. Solid dose units are tablets, capsules and suppositories.

Modes of Administration

[0096] In some embodiments, the pharmaceutical compositions of the present disclosure preferably contain a pharmaceutically acceptable carrier or excipient suitable for rendering the agent or mixture administrable orally as a tablet, capsule or pill, or parenterally, intravenously, intradermally, intramuscularly or subcutaneously, or transdermall}' .

[0097] In some embodiments, a therapeutically effective amount of an epigenetic modulator of FMR1 is delivered to a target tissue or a target cell. Generally, FMR l is widely expressed in human embryos. Thus, in some embodiments, a therapeutically effective amount of an epigenetic modulator of FMR1 is delivered to the brain, testes, ovaries, esophagus, epithelium, thymus, eye and/or spleen of a subject. In some embodiments, an effective amount of epigenetic modulator of FMR1 is delivered to the central nervous system (CNS) of a subject. In some embodiments, an effective amount of epigenetic modulator of FMR1 is delivered to a neuronal cell of a subject, for example a differentiated neuronal cell. Examples of differentiated neuronal cells include, but are not limited to, motor neurons, sensory neurons, peripheral neurons, interneurons, Purkinje cells, Granule cells, tripolar neurons, pyramidal cells. Chandelier cells, spindle neurons, stellate ceils, basket cells, ganglion cells, and hair cells,

[0098] The pharmaceutical compositions containing an epigenetic modulator of FMR1 and/or other agents can be administered by any suitable route for administering medications. A variety of administration routes are available. The particular mode selected will depend, of course, upon the particular agent or agents selected, the particular condition being treated, and the dosage required for therapeutic efficacy. The methods of this disclosure, generally speaking, may be practiced using any mode of administration that is medically acceptable, meaning any mode that produces therapeutic effect without causing clinically unacceptable adverse effects. Various modes of administration are discussed herein. For use in therapy, an effective amount of the epigenetic modulator of FMR1 and/or other therapeutic agent can be administered to a subject by any mode that delivers the agent to the desired surface, e.g. , mucosal, systemic.

[0099] Administering the pharmaceutical composition of the present disclosure may be accomplished by any means known to the skilled artisan. Routes of administration include, but are not limited to oral, parenteral, intravenous, intramuscular, intraperitoneal, intranasal, sublingual, intratracheal, inhalation, subcutaneous, ocular, vaginal, and rectal. Systemic routes include oral and parenteral . Several types of devices are regularly used for administration by inhalation. These types of devices include metered dose inhalers (MDI), breath-actuated MDI, dry powder inhaler (DPI), spacer/holding chambers in combination with MDI, and nebulizers.

[00100] For oral administration, the agents can be formulated readily by combining the active agent(s) with pharmaceutically acceptable carriers well known in the art. Such carriers enable the agents of the disclosure to be formulated as tablets, pills, dragees, capsules, liquids, gels, syrups, slurries, suspensions and the like, for oral ingestion by a subject to be treated. Pharmaceutical preparations for oral use can be obtained as solid excipient, optionally grinding a resulting mixture, and processing the mixture of granules, after adding suitable auxiliaries, if desired, to obtain tablets or dragee cores. Suitable excipients are, in particular, fillers such as sugars, including lactose, sucrose, mannitol, or sorbitol; cellulose preparations such as, for example, maize starch, wheat starch, nee starch, potato starch, gelatin, gum tragacanth, methyl cellulose, hydroxypropylmethyl-cellulose, sodium carboxymethylcellulose, and/or polyvinylpyrrolidone (PVP). If desired, disintegrating agents may be added, such as the cross-linked polyvinyl pyrrolidone, agar, or alginic acid or a salt thereof such as sodium alginate. Optionally the oral formulations may also be formulated in saline or buffers for neutralizing internal acid conditions or may be administered without any carriers.

[00101] Pharmaceutical preparations which can be used orally include push-fit capsules made of gelatin, as well as soft, sealed capsules made of gelatin and a plasticizer, such as glycerol or sorbitol . The push-fit capsules can contain the active ingredients in admixture with filler such as lactose, binders such as starches, and/or lubricants such as talc or magnesium stearate and, optionally, stabilizers. In soft capsules, the active agents may be dissolved or suspended in suitable liquids, such as fatty oils, liquid paraffin, or liquid polyethylene glycols. In addition, stabilizers may be added. Microspheres formulated for oral administration may also be used.

[00102] Such microspheres have been well defined in the art. All formulations for oral administration should be in dosages suitable for such administration.

[00103] For buccal administration, the compositions may take the form of tablets or lozenges formulated in conventional manner.

[00104] For administration by inhalation, the agents for use according to the present disclosure may be conveniently delivered in the form of an aerosol spray presentation from pressurized packs or a nebulizer, with the use of a suitable propellant, e.g. , dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide or other suitable gas. In the case of a pressurized aerosol the dosage unit may be determined by providing a valve to deliver a metered amount. Capsules and cartridges of e.g., gelatin for use in an inhaler or insufflator may be formulated containing a powder mix of the agent and a suitable powder base such as lactose or starch.

[00105] The agents, when it is desirable to deliver them systemically, may be formulated for parenteral administration by injection, e.g. , by bolus injection or continuous infusion. Formulations for injection may be presented in unit dosage form, e.g. , in ampoules or in multidose containers, with an added preservative. The compositions may take such forms as suspensions, solutions or emulsions in oily or aqueous vehicles, and may contain formulatory agents such as suspending, stabilizing and/or dispersing agents.

[00106] Pharmaceutical formulations for parenteral administration include aqueous solutions of the active agents in water-soluble form. Additionally, suspensions of the active agents may be prepared as appropriate oily injection suspensions. Suitable lipophilic solvents or vehicles include fatty oils such as sesame oil, or synthetic fatty acid esters, such as ethyl oleate or triglycerides, or liposomes. Aqueous injection suspensions may contain substances which increase the viscosity of the suspension, such as sodium carboxymethyl cellulose, sorbitol, or dextran. Optionally, the suspension may also contain suitable stabilizers or agents which increase the solubility of the agents to allow for the preparation of highly concentrated solutions.

[00107] Alternatively, the active agents may be in powder form for constitution with a suitable vehicle, e.g., sterile pyrogen-free water, before use.

[00108] The agents may also be formulated in rectal or vaginal compositions such as suppositories or retention enemas, e.g., containing conventional suppository bases such as cocoa butter or other glycerides. [00109] Other delivery systems can include time-release, delayed release or sustained release delivery systems. Such systems can avoid repeated administrations of the agents, increasing convenience to the subject and the physician. Many types of release deliver}' systems are available and known to those of ordinary skill in the art. They include polymer base systems such as poly(lactide-glycolide), copoly oxalates, polycaprolactones, polyesteramides, polyorthoesters, polyhydroxybutyric acid, and polyanhydrides. Microcapsules of the foregoing polymers containing drugs are described in, for example, U.S. Pat. No. 5,075,109. Delivery systems also include non-polymer systems that are: lipids including sterols such as cholesterol, cholesterol esters and fatty acids or neutral fats such as mono-, di~, and tri-glycerides; hydrogel release systems; silastic systems; peptide-based systems; wax coatings; compressed tablets using conventional binders and excipients; partially fused implants; and the like. Specific examples include, but are not limited to: (a) erosional systems in which an agent of the disclosure is contained in a form within a matrix such as those described in U.S. Pat. Nos. 4,452,775, 4,675,189, and 5,736,152, and (b) diffusionai systems in which an active component permeates at a controlled rate from a polymer such as described in U.S. Pat, Nos. 3,854,480, 5,133,974 and 5,407,686. In addition, pump-based hardware deliver}' systems can be used, some of which are adapted for implantation.

[00110] In some embodiments, an inhibitory oligonucleotide (e.g. , interfering

RNA) can be delivered to the cells via an expression vector engineered to express the inhibitor oligonucleotide. An expression vector is one into which a desired sequence may be inserted, e.g. , by restriction and ligation, such that it is operably joined to regulatory sequences and may be expressed as an RNA transcript. An expression vector typically contains an insert that is a coding sequence for a protein or for an inhibitory oligonucleotide such as an shRNA, a miRNA, a gRNA (directed by Cas9) or an miRNA. Vectors may further contain one or more marker sequences suitable for use in the identification of cells that have or have not been transformed or transfected with the vector. Markers include, for example, genes encoding proteins that increase or decrease either resistance or sensitivity to antibiotics or other agents, genes that encode enzymes whose activities are detectable by standard assays or fluorescent proteins, etc.

[00111] As used herein, a coding sequence (e.g. , protein coding sequence, miRNA sequence, shRNA sequence) and regulatory sequences are said to be "operably" joined when they are covaiently linked in such a way as to place the expression or transcription of the coding sequence under the influence or control of the regulator}- sequences. If it is desired that the coding sequences be translated into a functional protein, two DNA sequences are said to be operably joined if induction of a promoter in the 5' regulatory sequences results in the transcription of the coding sequence and if the nature of the linkage between the two DNA sequences does not (1) result in the introduction of a frame-shift mutation, (2) interfere with the ability of the promoter region to direct the transcription of the coding sequences, or (3) interfere with the ability of the corresponding RNA transcript to be translated into a protein. Thus, a promoter region would be operably joined to a coding sequence if the promoter region were capable of effecting transcription of that DNA sequence such that the resulting transcript might be translated into the desired protein or polypeptide. It will be appreciated that a coding sequence may encode an miRNA, shRNA, gRNA or miRNA.

[00112] The precise nature of the regulatory sequences needed for gene expression may vary between species or cell types, but shall in general include, as necessary, 5' non-transcribed and 5' non-translated sequences involved with the initiation of transcription and translation, respectively, such as a TATA box, capping sequence, CAAT sequence, and the like. Such 5' non-transcribed regulatory sequences will include a promoter region that includes a promoter sequence for transcriptional control of the operably joined gene. Regulatory sequences may also include enhancer sequences or upstream activator sequences as desired. The vectors of the disclosure may optionally include 5' leader or signal sequences.

[00113] In some embodiments, a virus vector for delivering a nucleic acid molecule is selected from the group consisting of adenoviruses, adeno-associated viruses, poxviruses including vaccinia viruses and attenuated poxviruses, Semliki Forest virus, Venezuelan equine encephalitis virus, retroviruses, Sindbis virus, and Ty virus-like particle. Examples of viruses and virus-like particles which have been used to deliver exogenous nucleic acids include: replication -defective adenoviruses, a modified retrovirus, a nonreplicating retrovirus, a replication defective Semliki Forest vims, canarypox virus and highly attenuated vaccinia virus derivative, non-replicative vaccinia virus, replicative vaccinia virus, Venzuelan equine encephalitis viras, Sindbis virus, lentiviral vectors and Ty virus-like particle. Another virus useful for certain applications is the adeno-associated virus. The adeno-associated virus is capable of infecting a wide range of cell types and species and can be engineered to be replication-deficient. It further has advantages, such as heat and lipid solvent stability, high transduction frequencies in cells of diverse lineages, including hematopoietic cells, and lack of superinfection inhibition thus allowing multiple series of transductions. The adeno-associated viras can integrate into human cellular DNA in a site-specific manner, thereby minimizing the possibility of msertional mutagenesis and variability of inserted gene expression. In addition, wild-type adeno-associated virus infections have been followed in tissue culture for greater than 100 passages in the absence of selective pressure, implying that the adeno-associated virus genomic integration is a relatively stable event. The adeno-associated virus can also function in an extrachromosomal fashion,

[00114] In general, other useful viral vectors are based on non-cytopathic eukaryotic viruses in which non-essential genes have been replaced with the gene of interest. Non-cytopathic viruses include certain retroviruses, the life cycle of which involves reverse transcription of genomic viral RNA into DNA with subsequent proviral integration into host cellular DNA. In general, the retroviruses are replication-deficient (e.g. , capable of directing synthesis of the desired transcripts, but incapable of manufacturing an infectious particle). Such genetically altered retroviral expression vectors have general utility for the high-efficiency transduction of genes in vivo. Standard protocols for producing replication-deficient retroviruses (including the steps of incorporation of exogenous genetic material into a plasmid, transfection of a packaging cell line with plasmid, production of recombinant retroviruses by the packaging cell line, collection of viral particles from tissue culture media, and infection of the target cells with viral particles) are provided in Kriegler, M., "Gene Transfer and Expression, A Laboratory Manual," W.H. Freeman Co., New York (1990) and Murry, E.J. Ed. "Methods in Molecular Biology," vol. 7, Humana Press, Inc., Clifton, New Jersey (1991 ).

[00115] Various techniques may be employed for introducing nucleic acid molecules of the disclosure into cells, depending on whether the nucleic acid molecules are introduced in vitro or in vivo in a host. Such techniques include transfection of nucleic acid molecule-calcium phosphaie precipitates, transfection of nucleic acid molecules associated with DEAE, transfection or infection with the foregoing viruses including the nucleic acid molecule of interest, liposome-mediated transfection, and the like. Other examples include: N- TER™ Nanoparti cle Transfection System by Sigma- Aldrich, FectoFly™ transfection reagents for insect cells by Polypius Transfection, Polyethyleiurnine "Max" by Polysciences, Inc. , Unique, Non- Viral Transfection Tool by Cosmo Bio Co., Ltd., Lipofeetamine™ LTX Transfection Reagent by Invitrogen, SatisFection™ Transfection Reagent by Stratagene, Lipofectamine™ Transfection Reagent by Invitrogen, FuGENE® HD Transfection Reagent by Roche Applied Science, GMP compliant in vivo-) etPEI™ transfection reagent by Polypius Transfection, and Insect Gene Juice® Transfection Reagent by Novagen.

Screening Methods

[00116] In some aspects, the disclosure provides a method for identifying epi genetic modulators of FMR1, the method comprising: contacting a cell comprising an inactivated FMR1 gene with a candidate agent; detecting expression level of FMR1 in the cell; and, identifying the candidate agent as an epigenetic modulator of FMR1 when the expression level of FMR1 increases relative to a control cell after contact with the candidate agent.

[00117] In some embodiments, the method is performed in vitro, for example in a cell (e.g., neuronal cell or iPSC). In some embodiments, the ceil has an epigenetically silenced FMR.1 gene. In some embodiments, the cell contains an expansion of a polymorphic CGG repeat within the 5'UTR of the FMR1 gene, for example an expansion that comprises between about 55 and about 200 CGG repeats. In some embodiments, the cell contains an expansion that comprises more than 200 CGG repeats. The ceil contains, in some embodiments, at least one epigenetic mark associated with silenced FMR.1 gene.

[00118] In some embodiments, the method is performed in vitro, for example in a ceil (e.g. , neuronal cell or iPSC). In some embodiments, the ceil has a transcriptionally silenced FMR1 gene. In some embodiments, the cell contains an expansion of a polymorphic CGG repeat within the 5'UTR of the FMR1 gene, for example an expansion that comprises between about 55 and about 200 CGG repeats. In some embodiments, the cell contains an expansion that comprises more than 200 CGG repeats. The cell contains, in some embodiments, at least one transcriptional complex that is associated with a silenced FMR1 gene.

[00119] In some embodiments, the candidate agent is selected from a compound library. In some embodiments, the library comprises PRC 2 complex inhibitors. In some embodiments, the library comprises EED inhibitors. In some embodiments, the PRC2 inhibitors are EED inhibitors.

[00120] In some embodiments, the detection is performed by hybridization- based assay (e. Quantigene plex or view), Western blot, immunofluorescence (ICC), flow cytometry, quantitative real-time polymerase chain reaction (qRT-PCR), chromatin immunoprecipitation (ChIP), or FACS.

[00121] As used herein, the term "candidate agent" refers to any agent (e.g. , Compound I) wherein the characterization of the agent's ability to reactivate silenced FMR1 gene is desirable. Exemplary candidate agents include, but are not limited to small molecules, antibodies, antibody conj ugates, peptides, proteins, and/or antisense molecules (e.g. , interfering RNAs). In some embodiments, methods described by the disclosure are useful for screening large libraries of candidate compounds (e.g. , compound libraries) to identify new epigenetic modulators of FMR1 . In some embodiments, compound libraries consist of candidate agents specific for a particular target, for example an activating mark or a repressive mark. Compound libraries may also consist of candidate agents that are specific for a particular protein target, such as a chromatin modifier. In some embodiments, candidate agents are inhibitors of a chromatin modifier.

[00122] The skilled artisan recognizes several methods for contacting the cell having an inactivated FMR1 gene with the candidate agent. For example, automated liquid handling systems are generally utilized for high throughput drug screening. Automated liquid handling systems utilize arrays of liquid dispensing vessels, controlled by a robotic arm, to distribute fixed volumes of liquid to the wells of an assay plate. Generally, the arrays comprise 96, 384 or 1536 liquid dispensing tips. Non-limiting examples of automated liquid handling systems include digital dispensers (e.g., HP D300 Digital Dispenser) and pinning machines (e.g., MULTI-BLOT™ Replicator System, CyBio, Perkin Elmer Janus). Non-automated methods are also contemplated by the disclosure, and include but are not limited to a manual digital repeat multichannel pipette.

[00123] In some embodiments, screening methods described by the disclosure are carried out in a high throughput mode. In some embodiments, high-throughput screening is carried out in a multi-well cell culture plate. In some embodiments, the multi-well plate is plastic or glass. In some embodiments, the multi-well plate comprises an array of 6, 24, 96, 384 or 1536 wells. However, the skilled artisan recognizes that multi-well plates may be constructed into a variety of other acceptable configurations, such as a multi-well plate having a number of wells that is a multiple of 6, 24, 96, 384 or 1536. For example, in some embodiments, the multi-well plate comprises an array of 3072 wells (which is a multiple of 1536).

[00124] The expression level of FMR1 in the ceil can be measured by any suitable means known in the art. For example, expression level of FMR1 in a cell can be measured by a hybridization-based method. Examples of hybridization-based assays include reverse transcription polymerase chain reaction (RT-PCR), quantitative RT-PCR (qRT-PCR), Northern blot, and Southern blot. In some embodiments, the expression level of FMR1 in the cell is measured by a protein-based method. Examples of protein-based assays include, but are not limited to, Western blot, Bradford assay, Lowry protein assay, and spectroscopic methods (e.g. , mass spectrometry, high pressure liquid chromatography, etc.). In some embodiments, expression level of FMR1 in the cell is determined by a cell-based method. Examples of cell- based assays include flow cytometry, fluorescent activated cell sorting (FACS), magnetic activated cell sorting (MACS). In some embodiments, cells are modified such that FMR1 activation is operably linked to expression of a resistance gene, and thus reactivation of silenced FMRI allows growth and selection of cells in the presence of a selection media. Additional methods of quantifying expression level of FMR1 in the cell will be readily apparent to those skilled in the art.

[00125] In some embodiments, a candidate agent can be identified as an epigenetic modulator of FMR1 if the amount of FMR1 expressed in the presence of the candidate agent is increased compared to the amount expressed in the absence of the candidate agent. In some embodiments, the amount of FMR1 expressed in the presence of an epigenetic modulator of FMR1 can range from about 2 -fold more to about 500-fold more, 5-fold more to about 250-fold more, 10-fold more to about 150-fold more, or about 20-fold more to about 100-fold more, than the amount of FMR1 expressed in the absence of the epigenetic modulator of FMR1 . In some embodiments, the amount of FMR1 expressed in the presence of an epigenetic modulator of FMR1 can range from about 1 % to about 1000% more, about 10% to about 500%) more, about 20% to about 250%) more, about 50% to about 500% more, about 100% to about 750% more than the amount of FMR1 expressed in the absence of the epigenetic modulator of FMR1 . In some embodiments, FMR1 is expressed in the presence of an epigenetic modulator of FMR1 and is not expressed (e.g. , transcriptionally inactive or silenced) in the absence of an epigenetic modulator of FMR1 .

[00126] In some embodiments, a candidate agent can be identified as an epigenetic modulator of FMR1 if the agent is sufficient to modify the hyperactive network activity of FXS human neurons compared to the network activity in healthy normal controls. In some embodiments, the amount of change in network activity modulation by an epigenetic modulator in FXS can range from 1% to 100% of a healthy normal neuron, about 10% to about 100% of healthy control, about 20% to about 100% of healthy control, about 50% to about 100% of healthy control. In some embodiments, the epigenetic modulator is an EED inhibitor and the change in network activity is dependent on FMR1 upregulation or result from a gene expression change that impacts other signal transduction pathways in the presence of the epigenetic modulator of FMR1 .

EXAMPLES

Example 1

[00127] Factors responsible for depositing repressive marks or for removing activating marks are potential targets to reactivate the epigenetically silenced FMR1 gene. De- repressing or enhancing the FMR1 gene represents a novel therapeutic approach by which to reverse FXS symptoms. A number of targets for discovery of biological or small molecule inhibitors that will reactivate the silenced FMR l gene have been identified. In addition, previously described small molecule inhibitors, including chaetocin and azacytidine, have been described to have a biological role in de-repressing expression of the FMR1 gene. These two molecules are known to be toxic when presented to cells. New targets and chemical entities that inhibit these target activities have been identified that are not toxic when presented to FXS neurons and cells to reactivate the silenced FMR1 allele.

[00128] FIG. 2 shows the structure of a small molecule inhibitor of BED that inhibits the EED-induced spread and/or and maintenance of epigenetic marks that maintain the silenced FMR1 gene.

[00129] Table 1 shows activity of the small molecule EED inhibitor, Compound

1 , which reactivates FMR1 mRNA expression in FXS induced NGN2 glutamatergic neurons derived from iPSCs as measured by Quantigene View (FIG. 3). The quantitative image analysis where FMR1 expression was normalized to that obtained in the wild type healthy control neurogenin (NGN2) directed neurons (as described in Zhang et al., 2013) and set to 100% (derived from iPSC 194) and the FXS neurons were treated with the indicated compounds (derived from iPSC 135). FMR1 quantigene probes were hybridized by in situ (described in Quantigene View assay protocol ; Thermo). FMR1 imaging and analysis was conducted using the CX7 and neuronal profiling algorithm and defined as % FMR1 positive ceils over the beta tubulin 3 mask. FMR1 expression was analyzed following treatment with either WT or FXS treated with DMSO or 3.3 μΜ Compound 1 (EED inhibitor).

Example 2

[00130] CRISPR/Cas9-mediated reduction of EED or EZH2 lead to an increase in FMR1 mRNA expression in FXS NGN2 induced neurons. EED- and EZH2-specific gRNAs (EED-1 and -2, EZH2-1 and -2) were transduced using lenti viral infection into FXS NGN2- induced neurons expressing inducible CAS9. Briefly, patient-derived FXS iPSCs (SC-135cl) were infected with NGN 2 and rrTA lentivirus at MOI=5. On day 1, medium was changed to induction medium (DMEM/F12 + N2 + Giutamax + Glucose + P/S + Dox + Puromycin + Blasiicidin). On day 4, cells were re-plated in a 96 well plate coated with PDL-laminin at density of 50k cells/well in neuronal medium (NB + Glutamax + NEAA + Glucose + B27 + P/S + Dox + Puromycin + Blasticidin + BDNF + GDNF). Cas9 lentivirus (MOI=3) and sgRNAs targeting EED (MOI=T) were added to the resuspended cells and Protamine (Sigma) was added at final concentration of 2 pg/mL. The plate was then immediately spun at 1 000 rpm for 1 hr and then incubated at 37" C overnight. On day 5, medium was changed remove the virus particles. On day 12, cells were lysed and qPCR was performed using Cells-to-CT 1 step TaqMan Kit. EED, EZH2, and NTC sgRNA sequences are as follows:

[00131] EED-specific and EZH2-specific gRNAs increased FMR1 mRNA expression in NGN2 -induced neurons when compared to non-targeting control gRNAs (NTC) (FIG. 9).

[00132] An agent that inhibits the EED target was added to neurons and reactivation of FMR1 was observed by FMR1 quantigene view (FMR1 is indicated by the red probe hybridization) shown in FIG. 3. FIG. 3 shows reactivation of FMR1 mRNA expression in FXS induced NGN2 glutamatergic neurons by Quantigene View (FMR1 probe in red and beta tubulin in green). FMR1 expression in the w ild type healthy control neurogenin (NGN2) directed neurons (as described in Zhang el al , 2013) is at normal levels (derived from iPSC 194) and in FX neurons (derived from iPSC 135) FMR1 was not detectable. FMR1 quantigene probes were hybridized by in situ (described in Quantigene View assay protocol; Thermo). FMR1 imaging and analysis was conducted using the CX7 and neuronal profiling algorithm and defined as % FMR1 positive cells over the beta tubulin 3 mask. FMR1 expression was analyzed following treatment with either WT or FXS cells treated with DMSO or 3.3 μΜ Compound 1 (EED inhibitor).

Example 3

[00133] Factors responsible for depositing repressive marks, such as EED, are potential targets to reactivate the epigenetically silenced FMR1 gene. Compound 1, an EED inhibitor, was assessed for inhibition of the binding of EED to methylated Lysine 27 of histone 3 to block the acti v ity of the PRC2 complex and the data are shown in FIG. 4A-FIG. 4B. EED activity was inhibited by Compound l, N-((5-fluoro-2,3-dihydrobenzofuran-4-yl)methy])-8-(l- isopropyl-3-methyl-lH-pyrazol-4-yl)-[l,2,4]tri Inhibition is measured biochemically by monitoring the transfer of a ³H methyl group from ¾ S- adenosylmethionine (1 μΜ) to chicken core hisiones (at 0.05 mg/mL) catalyzed by recombinant, human PRC2 complex (13 nM) containing either ΕΖΗ1 (FIG. 4A) or ΕΖΗ2 (FIG. 4B). Compound 1 inhibits the action of the ΕΖΗ1 -containing PRC 2 complex with an EC50 = 10 nM. Compound 1 inhibits the action of the EZH2-containing PRC2 complex with an EC50 = 10 nM.

Example 4

[00134] Factors responsible for depositing repressive marks, such as EED, are potential targets to reactivate the epigenetically silenced FMR1 gene. FIG. 5 shows activity of Compound 1 on methylated lysine 27 of histone 3 blocking the activity of PRC2 complex in HEK293 cells by quantitative immunofluorescence on CX7. 3 μΜ Compound 1 was diluted ½ log to the lowest concentration of 0,09 nM. EED inhibition of H3K27me3 in cells by immunocytochemistiy produced an ICso of 36 nM.

Example 5

[00135] Targets responsible for depositing repressive marks, such as EED, are potential targets for small molecule modulators to reactivate the epigenetically silenced FMR1 gene. FIG. 6 shows sustained reactivation of FMR1 transcript following treatment of FXS neurons with Compound 1. qRT-PCR analysis monitoring expression of FMR1 in iPSC derived NGN2 doxycycline induced neurons, WT 194 or FXS 135 (as described in Zhang et al. , 2013) treated with either DMSO or 3 μΜ Compound 1 for 1, 2, or 3 weeks, as indicated. FMR1 levels were increased ~20X compared to the DMSO control FXS neurons and highest in the WT neurons and the level of induction of FMR1 was sustained through the 3 week timepoint.

Example 6

[00136] Targets responsible for depositing repressive marks, such as EED and are targets for small molecule modulators to reactivate the epigenetically silenced FMR1 gene shown in FIG. 6. Restoring FMR1 mRNA expression in FXS neurons will lead to increased FMRP expression. FMRP regulates an important downstream neuronal microRNA, miR-382, that represses REST (Repressor Element-1 Silencing Transcription factor) shown diagrammaticall}' in FIG. 7. REST is an important transcriptional regulator of axonal guidance genes (reviewed in Halevy el al, 2015). In FXS, where there is a lack of FMRP, neuronal miR- 382 is limiting leading to an accumulation of REST and silencing of axonal guidance genes. Synaptic failure in FXS, is in part, due to the failure of appropriate regulation of REST because of the insufficient levels of FMRP.

[00137] Following treatment of FXS neurons induced from IPSCs with

Compound 1, an EED inhibitor, reduction of REST transcript was observed and sustained three weeks after treatment. qRT-PCR analysis monitoring expression of REST in iPSC derived NGN2 doxycycline induced neurons, WT 1 94 or FXS 135 (as described in Zhang et al., 2013) treated with either DMSO or 3 μΜ Compound 1 for 1, 2, or 3 weeks. REST levels were decreased compared to the DMSO control FXS neurons and lowest in the WT neurons and the level of reduction of REST mRNA was sustained through the 3 week timepoint. REST expression was normalized to that obtained upon treatment with the FXS vehicle DMSO, which was set to 1. *P<0.05. These data show that 10-20% FMR1 mRNA expression compared to baseline FXS is sufficient to rescue FMRP dependent phenotypes like REST expression and downstream axonal genes (FIG. 8).

Example 7

[00138] A second modality was used to show reactivation of FMR1 mRNA following treatment of FXS neurons with CRISPR gRNAs against EED in a stable neuron environ (FIG. 9). qRT-PCR analysis monitoring expression of FMR1 in iPSC derived NGN2 doxycycline induced neurons, WT 194 or FXS 135 (as described in Zhang et al., 2013) treated with either non-targeting or EED targeting gRNAs, as indicated. Expression data were converted to copy number normalized to the GAPDH copy number per well, averaged,

and the median vehicle control value was determined for each week and then used to determine the fold of gene induction. FMR1 expression was normalized to that obtained upon treatment with the FXS vehicle, which was set to 1. *P<0.05.

Example 8

[00139] EED inhibition reduces network hyperactivity in FXS 135 neurons. As shown in FIG. 10, treatment with the EED inhibitor (Compound 1) for 2 weeks resulted in a reduction of the network hyperactivity in FXS 135 neurons compared to the isogenic control neurons (FIG. 10). Quantification of the spikes per minute were recorded on the Muitielectrode Array (MEA) from Axion Systems using methods described by the manufacturer. Both Fragile X neuronal cultures and the isogemc controls neurons activity is shown. Data represented as mean +/- SEM. These data support the notion that the EED inhibitor induces epi genetic gene expression modulation sufficient to rescue functional phenotypes in FXS neurons.

[00140] The foregoing detailed description has been given for clearness of understanding only and no unnecessary limitations should be understood therefrom as modifications will be obvious to those skilled in the art.

[00141] While the disclosure has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice withm the art to which the disclosure pertains and as may be applied to the essential features hereinbefore set forth and as follows in the scope of the appended claims.

[00142] The disclosures, including the claims, figures and/or drawings, of each and every patent, patent application, and publication cited herein are hereby incorporated herein by reference in their entireties.

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Claims

WHAT IS CLAIMED IS;

1 . A method for reactivating a transcriptionally inactive FMR1 gene in a cell, the method comprising: contacting the cell with an effective amount of one or more epigenetic modulator of FMR1 wherein the one or more epigenetic modulator of FMR1 comprises an inhibitor of a chromatin modifier, and wherein the one or more epigenetic modulator reactivates FMR1 in the cell.

2. The method of claim 1, wherein the chromatin modifier is an Embryonic Ectoderm Development (EFT)) protein.

3. The method of claim 2, wherein the EED protein regulates a histone methy 1 transf eras e.

4. The method of claim 2, wherein the EED protein regulates a transcription complex.

5. The method of claim 4, wherein the transcription complex is a Poly comb Repressive Complex 1 (PRC1) complex.

6. The method of claim 5, wherein the PRC1 complex comprises an EED protein, B lymphoma Mo-MLV insertion region 1 (BMT1), RINGl A (RINGl), and RINGIB (RING2 or RNF2).

7. The method of claim 4 or 5, wherein the one or more epigenetic modulator inhibits the function of the PRC l complex.

8. The method of claim 2, wherein the EED protein is a core component of a Poly comb Repressive Complex 2 (PRC2) complex.

9. The method of claim 3, wherein the histone methyltransferase is part of the PRC2 complex.

10. The method of claim 8 or 9, wherein the PRC2 complex further comprises Enhancer of Zeste Homolog 1 or 2 (EZH1 or 2) and Suppressor of Zeste 12 (SUZ12).

11. The method of any one of claims 8-10, wherein the one or more epi genetic modulator inhibits a function of the PRC2 complex.

12. The method of any one of claims 8-1 1, wherein the PRC2 complex regulates methylation nucleation.

13. The method of any one of claims 8-1 1 , wherein the PRC2 complex regulates methylation spreading.

14. The method of claim 1 , wherein the one or more epigenetic modulator is Compound 1 :

a derivative thereof, or a pharmaceutically acceptable salt thereof.

15. The method of claim 2, wherein the inhibitor of the EED protein is a nucleic acid, polypeptide, or small molecule.

16. The method of claim 15, wherein the inhibitor of the EED protein is a nucleic acid.

17. The method of claim 16, wherein the nucleic acid is an interfering nucleic acid selected from the group consisting of: double stranded RNA (dsRNA), siRNA, shRNA, miRNA, gRNA (directed by CAS9) and antisense oligonucleotide (ASO).

18. The method of claim 15, wherein the inhibitor of the EED protein is a polypeptide.

19. The method of claim 18, wherein the polypeptide is an antibody

20. The method of claim 2, wherein the inhibitor of the EED protein is Compound

1.

21. The method of any one of claims 1 to 20, wherein the cell is a neuronal cell or an induced pluripotent stem cell (iPSC).

22. The method of any one of claim 20, wherein the inhibitor of the EED protein is a derivative of Compound 1 or a pharmaceutically acceptable salt of Compound 1.

23. The method of any one of claims 1 to 22, wherein the transcriptionally inactive FMR1 gene comprises at least one epigenetic mark associated with silenced FMR1 gene.

24. The method of claim 23, wherein the at least one epigenetic mark is selected from the group consisting of DNA methylation (DNAme), histone H3 lysine 27 trimethylation (H3K27me3), histone H3 lysine 9 trimethylation (H3K9me3), histone H4 lysine 20 trimethylation (H4K20me3), histone H2A ubiquitination (H2Aub), histone H2A acetylation, histone H2B acetylation, histone H3 acetylation, histone H4 acetylation, and histone H3 lysine 4 trimethylation (H3K4me3).

25. The method of any one of claims 1 to 24, wherein the cell comprises an expansion of a polymorphic CGG repeat within the 5'UTR of the FMR1 gene.

26. The method of claim 25, wherein the expansion comprises between about 55 CGG repeats and about 200 CGG repeats.

27. The method of claim 25, where tihne expansion comprises more than 200 CGG repeats.

28. The method of claim 1, wherein the one or more epigenetic modulator inhibits formation of an R-loop between the FMR1 and an mRN A encoding FMR1 .

29. The method of claim 1 , wherein prior to contacting the cell with an effective amount of one or more epigenetic modulator of FMR1 , the transcriptionally inactive FMR1 gene is associated with silenced FMR1 gene.

30. A composition for reactivating a transcriptionally inactive FMR1 gene in a cell, comprising:

one or more epigenetic modulator of FMR1 , wherein the one or more epigenetic modulator of FMR1 comprises an inhibitor of a chromatin modifier; and

a pharmaceutically acceptable carrier.

31. The composition of claim 30, wherein the chromatin modifier is an Embryonic Ectoderm Development (BED) protein.

32. The composition of claim 31, wherein the EED protein regulates a histone methyltransferase.

33. The composition of claim 31, wherein the EED protein regulates a transcription complex.

34. The composition of claim 33, wherein the transcription complex is a Poly comb Repressive Complex 1 (PRCl ) complex.

35. The composition of claim 34, wherein the PRC comlplex comprises an EED protein, B lymphoma Mo-MLV insertion region 1 (BMll), RINGl A (RINGl), and RINGl B (RJNG2 or RNF2).

36. The composition of claim 34 or 35, wherein the one or more epigenetic modulator inhibits the function of the PRC1 complex.

37. The composition of claim 31, where tihne EED protein is a core component of a Polycomb Repressive Complex 2 (PRC2).

38. The composition of claim 32, wherein the histone methyltransferase is part of Polycomb Repressive Complex 2 (PRC2) complex.

39. The composition of claim 37 or 38, wherein PRC2 further comprises Enhancer of Zeste Homolog 1 or 2 (EZH1 or 2) and Suppressor of Zeste 12 (SUZ12),

40. The composition of any one of claims 37-39, wherein the one or more epigenetic modul ator inhibits the function of the PRC2 complex.

41. The composition of any one of claims 37-40, wherein the PRC2 complex regulates methylation nucleation.

42. The composition of any one of claims 37-40, wherein the PRC2 complex regulates methylation spreading.

43. The composition of claim 30, wherein the one or more epigenetic modulator is Compound 1 :

derivative thereof, or a pharmaceutically acceptable salt thereof.

44. The composition of claim 31, wherein the inhibitor of the EED protein is a nucleic acid, polypeptide, or small molecule.

45. The composition of claim 44, wherein the inhibitor of the EED protein is a nucleic acid.

46. The composition of claim 45, wherein the nucleic acid is an interfering nucleic acid selected from the group consisting of: double stranded RNA (dsRNA), siRNA, shRNA, miRNA, gRNA (directed by CAS9) and antisense oligonucleotide (ASO).

47. The composition of claim 44, wherein the inhibitor of the EED protein is a polypeptide.

48. The composition of claim 47, wherein the polypeptide is an antibody .

49. The composition of claim 31, wherein the inhibitor of the EED protein is Compound 1, a derivative thereof, or a pharmaceutically acceptable salt thereof.

50. The composition of any one of claims 30 to 49, wherein the cell is a neuronal stem cell or an induced pluripotent stem cell (iPSC).

51. The composition of any one of claims 30 to 50, wherein the cell is in vitro.

52. The composition of any one of claims 30 to 51 , wherein the transcriptionally inactive FMR1 gene comprises at least one epigenetic mark associated with silenced FMR1 gene.

53. The composition of claim 52, wherein the at least one epigenetic mark is selected from the group consisting of DNA methylation (DNAme), histone H3 lysine 27 tnmethylation (H3K27me3), histone H3 lysine 9 trimethylation (H3K9me3), histone H4 lysine 20 tnmethylation (H4K20me3), histone H2A ubiquitination (H2Aub), histone H2A acetylation, histone H2B acetylation, histone H3 acetylation, histone H4 acetylation, and histone H3 lysine 4 trimethylation (H3K4me3).

54. The composition of any one of claims 30 to 53, wherein the cell comprises an expansion of a polymorphic CGG repeat within the 5' UTR of the FMR1 gene.

55. The composition of claim 54, wherein the expansion comprises between about 55 CGG repeats and about 200 CGG repeats.

56. The composition of claim 54, wherein the expansion comprises more than 200 CGG repeats.

57. The composition of claim 30, wherein the one or more epigenetic modulator inhibits formation of an R-loop between the FMR1 and an mRNA encoding FMR1 .

58. The composition of claim 30, wherein the transcriptionally inactive FMR1 geneciated with silenced FMR1 gene.