CN101186930B

CN101186930B - Replication defect type recombination adenovirus

Info

Publication number: CN101186930B
Application number: CN2007101643145A
Authority: CN
Inventors: 王东; 向德兵; 陈正堂; 谢家印; 李梦侠; 仲召阳
Original assignee: Third Affiliated Hospital of TMMU
Current assignee: Third Military Medical University TMMU; Third Affiliated Hospital of TMMU
Priority date: 2007-10-09
Filing date: 2007-10-09
Publication date: 2010-06-02
Anticipated expiration: 2027-10-09
Also published as: CN101186930A

Abstract

The invention relates to plication-deficient recombinant adenovirus which contains the expression sequence of siGNA of the gene APE1 of human being. The sequence of siGNA of the gene APE1 of human being at which the two ends are provided with restriction site is chemically synthesized and inserted under the prompter U6 of the shuttle plasmid of adenovirus after restriction enzyme, then shuttle plasmid pDC316-EGFP-U6-APE1siRNA is constructed, and then shuttle plasmid pDC316-EGFP-U6-APE1siRNA and the bone plasmid of adenovirus pBHG-fiber5/35 are simultaneously cotransfected into cell 293, consequently the recombinant adenovirus Ad5/F35-APE1siRNA with the expression sequence of siGNA of the gene APE1 of human being is achieved through the fixed-point recombination produced by the system function of Cre/loxP. The recombinant adenovirus is capable of effectively preventing the expression of the gene APE1 and effectively strengthening the sensibility of radiotheraphy and chemotherapy of tumour cell.

Description

A kind of duplicate deficit type recombinant adenovirus

Technical field

The present invention relates to field of biomedicine technology, be specifically related to the duplicate deficit type recombinant adenovirus that contains exogenous dna fragment that a kind of Ad5/F35 of use adenovirus carrier and AdMax adenovirus packaging system make up, this recombinant adenovirus can effectively suppress tumour cell APE1 expression of gene, can effectively strengthen the susceptibility to the tumour cell radiation and chemotherapy.

Background technology

The dna damage repair system is resisted the molecular basis of various damages as body, and for safeguarding genomic stable and the complete crucial effects that plays, yet for by the putting of damage dna kill cancer cell, chemotherapy, this process has weakened result of treatment undoubtedly.Therefore repairing gene with dna damage is that the gene therapy of target spot is expected effectively to strengthen the susceptibility of tumour cell self to radiotherapy and cellulotoxic chemotherapeutics.

APE1 is the model of structure and functional characteristics of signing an undertaking most in the biomacromolecule of finding so far, and it is repaired by DNA and two relatively independent functional zone of redox constitute.APE1 is that (base excision repair, BER) the crucial rate-limiting enzyme of approach are repaired in the excision of DNA base ^[1], be the important reparative factor that cell radiation injury and genotoxicity medicine alkylating agent are caused injury, in the tumor chemoradiotherapy opposing, play a significant role.

APE1 also has the redox function, so be called the redox factor (redox factor again, ref-1), regulate the dna binding activity and the downstream expression of target gene of multiple transcription factor by redox mechanism, and participate in the cell response of multiple keys such as oxidative stress, cell cycle regulating and apoptosis.Controlled transcription factor comprises important factor relevant with cell proliferation, differentiation, conversion and apoptosis such as NF-κ B, AP-1, Egr-1, p53, PEBP2, Myb, HIF-1 α and Pax5,8 etc. ^[2], and these transcription factors and tumor chemoradiotherapy opposing are closely related.Therefore APE1 is by all too many levels of endonuclease and difunctional direct influence of redox and decision radiation and chemotherapy susceptibility, is the chemicotherapy susceptibility that the gene therapy of target spot is expected effectively to strengthen tumour cell with APE1.How effectively suppressing the APE1 expression of gene will be the key of decision clinical application.

(RNA interference RNAi) is a kind of gene silencing that is brought out by double-stranded RNA (gene silencing) in the RNA interference.In this process, there is the messenger RNA(mRNA) (mRNA) of homologous sequence to be degraded with double-stranded RNA, thereby suppressed this expression of gene.RNAi has become the important tool in the genome research field at present, is applied to field of tumor gene therapy just gradually.Gene import system (gene delivery system) becomes gene therapy and RNAi technology key in application.Virus vector is important function of gene importing means because of the natural infectivity of its pair cell forms.The virus vector that can be used for importing siRNA has adenovirus carrier, retroviral vector and AAV carrier etc.

Adenovirus carrier has bale capacity bigger, easy to prepare and easy purifying and concentrated, characteristics such as host range is wide, efficiency of infection is high, no DNA integration, is one of most widely used virus vector in present gene therapy research and the clinical trial ^[3]Be applied to the 2 and 5 serotype adenovirus that gene therapy adenovirus carrier thumping majority adopts the C kind at present, the infection of its pair cell mainly is by the trifle on the cilium and cell surface receptor-change of coxsackie b virus and adenovirus receptor (Coxsackie Bvirus-adenovirus receptor, CAR) combination, adenovirus depends primarily on the expression level of organizing CAR to the infection of tissue.In human body, the CAR wide expression is in various epithelium, and has CAR downward modulation or disappearance in various degree in tumor tissues, and the adenovirus of system applies often is trapped within normal epithelium cell, especially the virus quantity that liver cell, so tumour cell infects significantly reduces.Therefore, the inventor is seeking the adenovirus carrier that can further improve the tumour cell efficiency of infection always.

The Ad5/F35 adenovirus carrier is the adenovirus chimeric vector (Chimericadenovirus) of a kind of " changing shell ", promptly substitutes the cilium trifle of first-generation adenovirus 5 type adenovirus with the cilium trifle of Ad35.Ad35 belongs to adenovirus B kind, and most cells of people are had good efficiency of infection, because its acceptor CD46 almost is present in all human cell surfaces, and many tumour cell high expression level CD46.Therefore the Ad5/F35 adenovirus carrier becomes the gene importing carrier that tumour cell is fit to.

Summary of the invention

Play an important role in tumor radiotherapy and chemotherapy opposing based on the APE1 gene, effectively suppress the APE1 expression of gene, carrying out with the APE1 gene is the radiation and chemotherapy susceptibility that the gene therapy of target spot is expected effectively to strengthen tumour cell, improves the result of treatment of clinical tumor radiation and chemotherapy.Just be based on above-mentioned design, the contriver proposes to import carrier with the Ad5/F35 adenovirus carrier as the gene that tumour cell is fit to, the encoding sequence of the siRNA of APE1 gene inserted make up a kind of recombinant adenovirus in the adenovirus carrier, it can be expressed in tumour cell, utilize RNAi can effectively suppress APE1 genetic expression, reach the purpose of enhancing the susceptibility of tumour cell radiation and chemotherapy.

The purpose of this invention is to provide a kind of duplicate deficit type recombinant adenovirus, this duplicate deficit type recombinant adenovirus serves as the treatment target spot with DNA-repair gene APE1, utilizes the RNAi technology effectively to suppress APE1 genetic expression, strengthens tumour cell chemicotherapy susceptibility.

Technical scheme of the present invention is as follows:

A kind of duplicate deficit type recombinant adenovirus, it contains the expressed sequence of people APE1 gene siRNA, its sequence such as sequence table sequence 1.

Described expressed sequence contain the specific target sequence of people APE1 gene siRNA positive-sense strand sequence, antisense strand sequence, connect the Loop ring sequence and the terminal terminator sequence of 9 bases of positive-sense strand and antisense strand.

The specific target sequence of the siRNA of described APE1 gene is that gene is numbered the 867-885 base sequence in the people APE1 gene cDNA encoding sequence of NM_001641, and its sequence is CTGGTACGACTGGAGTACC.

Described recombinant adenovirus is the Ad5/F35 recombinant adenovirus, and the shuttle plasmid of recombinant adenovirus is pDC316-EGFP-U6, and skeleton plasmid is pBHG-fiber5/35, and the packing cell of recombinant adenovirus is 293 cells.

The expressed sequence of described people APE1 gene siRNA is connected under the U6 promotor of adenovirus shuttle plasmid.

The construction process of duplicate deficit type recombinant adenovirus of the present invention comprises the steps:

1, analyze design system with Ambion siRNA target sequence, the scanning gene is numbered the cDNA encoding sequence of the people APE1 gene of NM_001641, select principle of design according to the siRNA target sequence, behind the BLAST sequence homology analysis, choose the specific siRNA target sequence (867-885 of people APE1 gene, 19nt), the expressed sequence of designer APE1 gene siRNA, promptly between the positive-sense strand sequence of selecting target sequence and antisense strand sequence, add the Loop ring sequence and the terminal terminator TTTTTT of 9 bases respectively, as follows by 5 '-3 ' this sequence: CTGGTACGACTGGAGTACCTTCAAGAGAGGTACTCCAGTCGTACCAGACTTTTTT, the restriction enzyme site cohesive end is introduced at two ends in above-mentioned sequence respectively, chemosynthesis has the single stranded DNA fragment and the complementary single-stranded dna fragment thereof of restriction enzyme site cohesive end, is the double-stranded expression template of people APE1 gene siRNA with the above-mentioned complementary strand annealing product that obtains annealing;

2, above-mentioned annealing product is that the double-stranded expression template of people APE1 gene siRNA is connected after enzyme is cut with the pDC316-EGFP-U6 adenovirus shuttle plasmid, obtains the pDC316-EGFP-U6-APE1siRNA adenovirus shuttle plasmid;

3, with the pDC316-EGFP-U6-APE1siRNA adenovirus shuttle plasmid and adenovirus skeleton plasmid pBHG-fiber5/35 cotransfection 293 cells that obtain, the pBHG-fiber5/35 skeleton plasmid can cooperate with the shuttle plasmid that has the loxP site, utilize acting on of Cre/loxP system that the fixed point reorganization takes place in 293 cells, generation has the Ad5/F35-APE1siRNA recombinant adenovirus of people APE1 gene siRNA expressed sequence, called after Ad5/F35-APE1siRNA.

Ad5/F35-APE1siRNA recombinant adenovirus of the present invention can be made liquid preparation such as injection liquid, be used for malignant tumour radiotherapy and/hypersitization medicine of chemotherapy.

Describe in detail in the following examples: the building process of (1) recombinant adenovirus Ad5/F35-APE1siRNA; (2) observe recombinant adenovirus Ad5/F35-APE1siRNA and can effectively enter tumour cell; (3) having observed recombinant adenovirus Ad5/F35-APE1siRNA suppresses the APE1 expression of gene; (4) observe recombinant adenovirus Ad5/F35-APE1siRNA and significantly strengthened susceptibility to tumor radiotherapy; (5) observe recombinant adenovirus Ad5/F35-APE1siRNA and significantly strengthened susceptibility to chemotherapy of tumors.

Because the APE1 gene plays a significant role in the opposing of malignant tumour radiation and chemotherapy, if recombinant adenovirus of the present invention is played a role, not only the treatment for malignant tumour provides a kind of new therapeutic strategy, and has clinical value widely.

Description of drawings

The structural representation of Fig. 1 adenovirus shuttle plasmid pDC316-EGFP-U6.

Fig. 2 pDC316-EGFP-U6-APElsiRNA shuttle plasmid double digestion is identified figure.Wherein swimming lane 1 is 20bp DNA marker;

Swimming lane

2,3 is 2 positive colonies.

Fig. 3 pDC316-EGFP-U6-APE1siRNA shuttle plasmid sequencer map.

Fig. 4 recombinant adenovirus Ad5/F35-APE1siRNA packs (structure) schema.

The PCR of Fig. 5 recombinant adenovirus Ad5/F35-APE1siRNA identifies figure.Wherein swimming lane 1 is DL2000Marker; Swimming lane 2 is an Ad5/F35-APE1siRNA recombinant adenovirus stoste; Swimming lane 3 is 10 times of Ad5/F35-APE1siRNA recombinant adenovirus dilutions; Swimming lane 4 is 100 times of Ad5/F35-APE1siRNA recombinant adenovirus dilutions; 50 times of swimming lane 5 positive contrasts (pDC316-EGFP-U6-APE1-siRNA) dilutions; 100 times of swimming lane 6 positive contrasts (pDC316-EGFP-U6-APE1-siRNA) dilutions; Swimming lane 7 negative contrasts.

The recombinant adenovirus Infection in Vitro colorectal cancer cells strain LOVO 24h postoperative infection efficient of the different MOI of Fig. 6.

Annotate: *, compare with Ad5-EGFP P＜0.01.

Fluorescent microscope was observed EGFP expression (* 100) down after Fig. 7 recombinant adenovirus infected colorectal cancer cells strain LOVO transplanted tumor in nude mice 3d.

Western blotting detected the APE1 protein expression after Fig. 8 Ad5/F35-APE1siRNA recombinant adenovirus and contrast adenovirus Ad5/F35-EGFP infected LOVO cell 48h.

Fig. 9 Showed by immune group result Ad5/F35-APE1siRNA recombinant adenovirus suppresses LOVO cell transplanted tumor in nude mice and organizes APE1 protein expression (SP * 100).

LOVO cell survival curve behind Figure 10 various dose roentgen radiation x.

LOVO apoptosis behind Figure 11 TUNEL method detection roentgen radiation x.

Figure 12 tumor growth curve shows that Ad5/F35-APE1siRNA recombinant adenovirus combination radiotherapy group tumor growth significantly suppresses.

Respectively organize transplanted tumor histocyte apoptosis rate behind Figure 13 roentgen radiation x.

Figure 14 various dose 5-FU handles back LOVO cell survival curve.

Figure 155-FU respectively organizes the LOVO apoptosis rate after handling.

Embodiment

Materials and methods

DMEM substratum, foetal calf serum and RPMI1640 (Hyclone company), Lipofectamine2000 (Invitrogen company); Hind III, BamH I, T4 dna ligase (TaKaRa company); PDC316-EGFP-U6, pBHG-fiber5/35 plasmid (this yuan Zhenyang company); Mouse β-actin monoclonal antibody (Sigma company), mouse APE1 monoclonal antibody (NovusBiologicals company).The goat-anti mouse two anti-(Pierce company) of HRP mark.Colorectal cancer cells LOVO is available from U.S. ATCC, and 293 cells are available from this yuan Zhenyang company.Contrast recombinant adenoviral vector Ad5/F35-EGFP and Ad5-EGFP are presented by this yuan Zhenyang company.

Embodiment 1pDC316-EGFP-U6-APE1siRNA adenovirus shuttle plasmid makes up and identifies

According to us ^[4]The effective people APE1 siRNA sequence of design, analyze design system with Ambion siRNA target sequence, the scanning gene is numbered the people APE1 gene cDNA encoding sequence of NM_001641, select principle of design according to the siRNA target sequence, behind the BLAST sequence homology analysis, choose the specific siRNA target sequence of the common 19nt of 867-885 in the people APE1 gene cDNA encoding sequence, the expressed sequence of designer APE1 gene siRNA, this expressed sequence contains the positive-sense strand sequence of the specific target sequence of APE1 gene siRNA, the antisense strand sequence, the Loop ring sequence and the terminal terminator sequence that connect 9 bases of positive-sense strand and antisense strand, sequence 1 in this sequence such as the sequence table, introduce BamH I respectively at serial 1 two ends, HindIII restriction enzyme site cohesive end, following two the complementary strands of chemosynthesis:

Top strand：

5′-GATCCGCTGGTACGACTGGAGTACCTTCAAGAGAGGTACTCCAGTCGTACCAGACTTTTTTGGAAA-3′；

Bottom strand：

5′-AGCTTTTCCAAAAAAGTCTGGTACGACTGGAGTACCTCTCTTGAAGGTACTCCAGTCGTACCAG CG-3′

95 ℃ of annealing of above-mentioned complementary strand 5min naturally cools to room temperature, and the product that obtains annealing is the double-stranded expression template of people APE1 gene siRNA.BamH I, HindIII double digestion adenovirus shuttle plasmid pDC316-EGFP-U6 (Fig. 1) and annealing product, enzyme is cut product and is connected, promptly make up adenovirus shuttle plasmid pDC316-EGFP-U6-APE1siRNA, transformed into escherichia coli DH5 α, ammonia benzyl plate screening is selected positive colony, extracts plasmid DNA, enzyme cut and check order identify correct (Fig. 2, Fig. 3).

Embodiment 2Ad5/F35-APE1siRNA recombinant adenovirus packing, amplification and purifying

2.1Ad5/F35-APE1siRNA recombinant adenovirus packing

Packing principle and schema: adopt the adenovirus Ad5/F35MaxTM packaging system of this yuan Zhenyang company to make up recombinant adenovirus.The shuttle plasmid pDC316-EGFP-U6-APE1siRNA and adenovirus skeleton plasmid pBHG-fiber5/35 cotransfection 293 cells that will have people APE1 gene siRNA expressed sequence, the pBHG-fiber5/35 skeleton plasmid can cooperate with the shuttle plasmid that has the loxP site, utilize acting on of Cre/loxP system that the fixed point reorganization takes place in 293 cells, produce the Ad5/F35-APE1siRNA recombinant adenovirus that has people APE1 gene siRNA expressed sequence.The recombinant virus that obtains like this is the replication-defective adenoviral of E1 disappearance, and virus can only realize expression of exogenous gene in the cell that the E1 district can not be provided and itself does not possess multiplication capacity.The native system flow package is seen Fig. 4.

Transfection the day before yesterday, with 293 cell inoculations in six orifice plates, every hole 5 * 10 ⁵Individual cell, substratum is the DMEM+10% foetal calf serum, puts overnight incubation in 37 ℃ of incubators that contain 5%CO2.With adenovirus skeleton plasmid pBHG-fiber5/35 and shuttle plasmid pDC316-EGFP-U6-APE1siRNA cotransfection 293 cells, homologous recombination produces recombinant adenovirus Ad5/F35-APE1siRNA with the Lipofectamine2000 liposome.Under fluorescent microscope, observe EGFP respectively at different time after the transfection and express situation, understand the adenovirus wrapping process.293 cells become the big circle that becomes about 10d, are botryoidalis, and begin to occur obvious plaque.Treat the most of pathology of cell and come off to receive poison from the bottom.The Tissue Culture Flask that will go out poison is placed in-70 ℃ of refrigerators and the 37 ℃ of water-baths multigelation earlier 3 times, and virus is fully discharged from sick cell.With the centrifugal 5min of freeze thawing liquid 3000rpm, collect the supernatant liquor that contains virus, abandon precipitation.This supernatant is first-generation seed culture of viruses (P1), as the seed culture of viruses of a large amount of virus amplification subsequently.

2.2 seed culture of viruses evaluation, amplification and purifying

Seed culture of viruses is identified: identify the viral product that has siRNA according to a pair of primer of shuttle plasmid pDC316-EGFP-U6-APE1siRNA sequences Design.Upstream primer combines with the sequence specific of the inner inclined to one side 3 ' end of EGFP gene, and downstream primer combines with the sequence specific of U6 promotor inside.The fragment of amplification is about and is 500bp, comprises the part of a part, siRNA encoding sequence and the U6 promotor of EGFP gene.

Upstream primer (RNAi-ID-f): 5 '-TGTAGAGGTTTTACTTGCTT-3 '

Downstream primer (RNAi-ID-r): 5 '-CATATACGATACAAGGCTG-3 '

Ad5/F35-EGFP-U6-APE1 adenovirus template is handled: get the 50ul adenovirus and add 2ulProtein K (10mg/mL), 56 ℃ 1 hour, boiled ice-water bath, ddH 10 minutes ₂The O dilution.

PCR condition: 94 ℃ of 5min; 94 ℃ of 30s, 55 ℃ of 30s, 72 ℃ of 40s, 72 ℃ of 5min, 30Cycles altogether.

Ad5/F35-APE1siRNA adenovirus dilution can be expanded for 100 times and the goal gene band, and size is about 500bp, and PCR identifies correct (Fig. 5).

Adenovirus amplification and purifying: first-generation seed culture of viruses through PCR identify correct after again repeated infection 293 cells increase.Collecting cell ,-70 ℃ and 3 cracking cells of 37 ℃ of multigelations, fully the supernatant that contains virus is collected in vibration and centrifugal back.After the DNase enzymic digestion, the membrane filtration with 0.45um carries out column purification then.Carry out ion-exchange purification with SOURSE 15Q, and then be further purified with molecular sieve, the virus behind the purifying is stored in adenovirus preserves in the liquid, after handling, desalination filters out bacterium with the 0.22UM disposable filter, thereby with obtaining aseptic purified virus, packing is stored in-70 ℃ of refrigerators.

The titer determination of purified virus: with 10 * employing virus cracking liquid cracking purified virus sample, the OD260 of mensuration and OD280 value are according to formula: VP/ml=OD260 * 1.1 * 10 ¹², calculate the virion number (V.P./ML) in every ml goods.Measure the titre of adenovirus with the TCID50 method.Titer determination result after the amplification purification: Ad5/F35-EGFP-U6-APE1siRNA physics titre 3.8 * 10 ¹¹VP/mL, infection titer 1.6 * 10 ¹⁰TCID50/mL; Ad5/F35-EGFP physics titre 5.8 * 10 ¹¹VP/mL, infection titer 2.6 * 10 ¹⁰TCID50/mL.

Recombinant adenovirus TCID50 measurement operation rules:

1) cultivate 293 cells, when treating that the cell stand density is about 80-90%, peptic cell and counting cells quantity.

2) with the DMEM inoculum preparation cell suspension that contains 5%FBS, it is 1 * 10 that every plate needs 11ml concentration ⁵The cell suspension of/ml.

3) by every hole 100 μ l (promptly 1 * 10 ⁴Individual cell) adds 2 96 orifice plates.

4) sample is infected in preparation: first group of dilution, 10 are carried out in aseptic technique ⁶Begin continuous 8 dilution gradients;

Carry out second group of dilution again, careful operation is in order to avoid obscure two groups of sample diluting liquids.

5) inoculation sample: 11,12 liang of row in 96 orifice plates are respectively added the DMEM of 100 μ l 5%FBS, do negative control.Add the A-H row in 96 orifice plates successively, respectively add the sample solution that 100 μ l are labeled as 8 each continuous gradient dilution.Cover first plate and at 37 ℃ of CO ₂Cultivate in the incubator.Second block of plate of same step operation.Cover second plate and at 37 ℃ of CO ₂Cultivate in the incubator.

The structure of culture plate is as follows in the experiment:

	1	2	3	4	5	6	7	8	9	10	11	12
	1	2	3	4	5	6	7	8	9	10	11	12	A	1× 10 ⁴	1× 10 ⁴	1× 10 ⁴	1× 10 ⁴	1× 10 ⁴	1× 10 ⁴	1× 10 ⁴	1× 10 ⁴	1× 10 ⁴	1× 10 ⁴	Negative control	Negative control
B	1× 10 ⁵	1× 10 ⁵	1× 10 ⁵	1× 10 ⁵	1× 10 ⁵	1× 10 ⁵	1× 10 ⁵	1× 10 ⁵	1× 10 ⁵	1× 10 ⁵	Negative control	Negative control	A	1× 10 ⁴	1× 10 ⁴	1× 10 ⁴	1× 10 ⁴	1× 10 ⁴	1× 10 ⁴	1× 10 ⁴	1× 10 ⁴	1× 10 ⁴	1× 10 ⁴	Negative control	Negative control
B	1× 10 ⁵	1× 10 ⁵	1× 10 ⁵	1× 10 ⁵	1× 10 ⁵	1× 10 ⁵	1× 10 ⁵	1× 10 ⁵	1× 10 ⁵	1× 10 ⁵	Negative control	Negative control	C	1× 10 ⁶	1× 10 ⁶	1× 10 ⁶	1× 10 ⁶	1× 10 ⁶	1× 10 ⁶	1× 10 ⁶	1× 10 ⁶	1× 10 ⁶	1× 10 ⁶	Negative control	Negative control
D	1× 10 ⁷	1× 10 ⁷	1× 10 ⁷	1× 10 ⁷	1× 10 ⁷	1× 10 ⁷	1× 10 ⁷	1× 10 ⁷	1× 10 ⁷	1× 10 ⁷	Negative control	Negative control	C	1× 10 ⁶	1× 10 ⁶	1× 10 ⁶	1× 10 ⁶	1× 10 ⁶	1× 10 ⁶	1× 10 ⁶	1× 10 ⁶	1× 10 ⁶	1× 10 ⁶	Negative control	Negative control
D	1× 10 ⁷	1× 10 ⁷	1× 10 ⁷	1× 10 ⁷	1× 10 ⁷	1× 10 ⁷	1× 10 ⁷	1× 10 ⁷	1× 10 ⁷	1× 10 ⁷	Negative control	Negative control	E	1× 10 ⁸	1× 10 ⁸	1× 10 ⁸	1× 10 ⁸	1× 10 ⁸	1× 10 ⁸	1× 10 ⁸	1× 10 ⁸	1× 10 ⁸	1× 10 ⁸	Negative control	Negative control
F	1× 10 ⁹	1× 10 ⁹	1× 10 ⁹	1× 10 ⁹	1× 10 ⁹	1× 10 ⁹	1× 10 ⁹	1× 10 ⁹	1× 10 ⁹	1× 10 ⁹	Negative control	Negative control	E	1× 10 ⁸	1× 10 ⁸	1× 10 ⁸	1× 10 ⁸	1× 10 ⁸	1× 10 ⁸	1× 10 ⁸	1× 10 ⁸	1× 10 ⁸	1× 10 ⁸	Negative control	Negative control
F	1× 10 ⁹	1× 10 ⁹	1× 10 ⁹	1× 10 ⁹	1× 10 ⁹	1× 10 ⁹	1× 10 ⁹	1× 10 ⁹	1× 10 ⁹	1× 10 ⁹	Negative control	Negative control	G	1× 10 ¹⁰	1× 10 ¹⁰	1× 10 ¹⁰	1× 10 ¹⁰	1× 10 ¹⁰	1× 10 ¹⁰	1× 10 ¹⁰	1× 10 ¹⁰	1× 10 ¹⁰	1× 10 ¹⁰	Negative control	Negative control
H	1×	1×	1×	1×	1×	1×	1×	1×	1×	1×	Negative right	Negative	G	1× 10 ¹⁰	1× 10 ¹⁰	1× 10 ¹⁰	1× 10 ¹⁰	1× 10 ¹⁰	1× 10 ¹⁰	1× 10 ¹⁰	1× 10 ¹⁰	1× 10 ¹⁰	1× 10 ¹⁰	Negative control	Negative control
H	1×	1×	1×	1×	1×	1×	1×	1×	1×	1×	Negative right	Negative		10 ¹¹	10 ¹¹	10 ¹¹	10 ¹¹	10 ¹¹	10 ¹¹	10 ¹¹	10 ¹¹	10 ¹¹	10 ¹¹	According to	Contrast

6) 96 orifice plates are placed 37 ℃ of CO ₂Cultivated 10 days in the incubator.The observation of cell situation from the 3rd day to the 10th day.

7) analysis in the 10th day, record CPE result: CPE should occur within 10 days.Examined under a microscope every hole CPE situation on the 10th day, and arrange contrast, write down the positive hole count (contaminated if any a plate, experiment must be reformed) of every stock layout product with one of negative control.

8) at the 10th day, meet the following conditions and can carry out calculating as a result: it all is tangible (a) having sample diluting liquid CPE in 12 holes at least; (b) has the rarest 3 but in no more than 9 holes tangible CPE is arranged of sample diluting liquid at least; (c) having a sample diluting liquid at least all is obviously not have CPE in 12 holes.

The virus titer calculation formula:

For 100 μ l samples, titre T=10 ^{1+d (s-0.5)}D=log ₁₀Extent of dilution=1 (for 10 times extent of dilution); The positive ratio sum (counting) of s=from first 10 times of extent of dilution.The titre value that twice repeated experiments obtains should differ≤and 10 ^0.7

Embodiment 3Ad5/F35-APE1siRNA recombinant adenovirus is to the efficiency of infection of colorectal cancer cells

3.1 Infection in Vitro efficient detects

The LOVO cell places 37 ℃ of incubators that contain 5%C02 to cultivate, and nutrient solution RPMI1640 contains 10%FCS, and 1.0 * 10 ⁵U/L penicillin and Streptomycin sulphate.Adenovirus infection the day before yesterday, with the LOVO cell inoculation in six orifice plates, every hole 5 * 10 ⁵Individual cell.Respectively with 0～20 infection multiplicity (multiplicity of infection, MOI) adenovirus Ad5/F35-APE1siRNA or contrast adenovirus Ad5/F35-EGFP and Ad5-EGFP infect LOVO cell 90min, inhale then and abandon nutrient solution, change perfect medium, observe LOVO cell EGFP down in the fluorescence inverted microscope behind the 24h and express and shooting.0.25% trypsin digestion cell, the centrifugal 5min of 500g room temperature inhales and abandons supernatant, 0.01M PBS re-suspended cell, the centrifugal 5min of 500g room temperature, collecting cell send the youngster of children's hospital of Medical University Of Chongqing to grind institute, Flow cytometry EGFP positive cell ratio.

The adenovirus Ad5/F35-APE1siRNA of 0～20MOI or contrast adenovirus Ad5/F35-EGFP and Ad5-EGFP observe LOVO cell EGFP expression down in the fluorescence inverted microscope after infecting LOVO cell 24h, excite down at blue-fluorescence, the visible part cell sends the green fluorescence that intensity does not wait, along with the increase of MOI, green fluorescence strengthens gradually; The LOVO cell green fluorescence intensity of Ad5/F35-APE1siRNA and Ad5/F35-EGFP adenovirus infection under the same MOI situation is suitable, but obviously is better than the Ad5-EGFP adenovirus.Detect EGFP positive cell ratio through flow cytometer and find that Ad5/F35-APE1siRNA and Ad5/F35-EGFP adenovirus are suitable to the efficiency of infection of LOVO cell, but are significantly higher than Ad5-EGFP adenovirus (Fig. 6).

3.2 efficiency of infection detects in the body

The transplanted tumor in nude mice model: the LOVO cell is at 37 ℃, and 5%CO2 contains in the substratum of RPMI-1640 of 10% foetal calf serum and cultivates, and will be in cell 0.25% tryptic digestion of logarithmic phase, makes 2.5 * 10 with aseptic PBS liquid is resuspended ⁷The single cell suspension of/ml, every 4～5 week BALB/c nu/nu nude mouse right side oxter subcutaneous vaccination in age 0.2ml (5 * 10 ⁶/ ml) cell suspension.

The subcutaneous visible obviously lump of BALB/c nu/nu nude mouse behind inoculation LOVO cell 5～6d.After the subcutaneous vaccination the 11st day, when gross tumor volume reaches about 100mm ³The time, nude mice is divided into four groups at random: normal control group, Ad5-EGFP control group, Ad5/F35-EGFP control group, Ad5/F35-APE1siRNA group.Every group of 5 nude mices.The PBS and 5 * 10 of local injection 50 μ l in the difference knurl ⁸The Ad5-EGFP of IU, Ad5/F35-EGFP, Ad5/F35-APE1siRNA adenovirus.Put to death nude mice behind the injection 3d, get the tumor tissues frozen section immediately, thick 20 μ m, glycerine mounting, fluorescent microscope are observed the EGFP expression down.The result shows PBS control group redgreen fluorescence, the visible a small amount of EGFP positive cell of Ad5-EGFP adenovirus group, and the visible a large amount of EGFP positive cells of Ad5/F35-EGFP and Ad5/F35-APE1siRNA adenovirus group, EGFP is the diffusivity strong positive and expresses (Fig. 7).

Embodiment 4Ad5/F35-APE1siRNA recombinant adenovirus is to the restraining effect of colorectal cancer cells APE1 protein expression

4.1Western it is external to the proteic restraining effect of colorectal cancer cells APE1 that blot analyzes recombinant adenovirus Ad5/F35-APE1siRNA

The LOVO cell places 37 ℃ of incubators that contain 5%CO2 to cultivate, and nutrient solution RPMI1640 contains 10% foetal calf serum, 1.0 * 10 ⁵U/L penicillin and Streptomycin sulphate.Adenovirus infection the day before yesterday, with the LOVO cell inoculation in six orifice plates, every hole 5 * 10 ⁵Individual cell.Infect LOVO cell 90min with 0～20MOI adenovirus Ad5/F35-EGFP-U6-APE1siRNA or contrast spring virus of A d5/F35-EGFP, inhale then and abandon nutrient solution, change perfect medium, collecting cell behind the 48h, the conventional total protein of cell that extracts.Get the equal protein sample and carry out SDS-PAGE electrophoresis (resolving gel concentration is 10%, and spacer gel concentration is 5%).Be transferred to pvdf membrane behind the electrophoresis, after the sealing of 5% skim-milk, adding APE1 or β-actin one are anti-, and 4 ℃ of shaking table overnight incubation are hatched 1h for 37 ℃, and the goat-anti mouse two that adds the HRP mark is anti-, and shaking table is hatched 1h under the room temperature.With the colour developing of ECL test kit, the X-ray sheet exposes in the darkroom, conventional development, photographic fixing.

After 1～20MOI adenovirus Ad5/F35-APE1siRNA infected LOVO cell 48h, cell APE1 protein expression all had decline in various degree.Along with increasing of MOI, the APE1 protein expression descends gradually; Contrast adenovirus Ad5/F35-EGFP does not have obvious influence (Fig. 8) to LOVO cell APE1 protein expression.

4.2 immunohistochemical analysis recombinant adenovirus Ad5/F35-APE1siRNA body is interior to the proteic restraining effect of colorectal cancer cells APE1

The PBS and 5 * 10 of local injection 50 μ l in the transplanted tumor in nude mice knurl ⁸The Ad5/F35-EGFP of IU, Ad5/F35-APE1siRNA recombinant adenovirus.Get tumor tissues behind the 3d, neutral formalin is 24h fixedly, conventional embedded section, and immunohistochemical staining is observed APE1 and is expressed.The result shows that PBS and Ad5/F35-EGFP control group A PE1 albumen are karyon and the kytoplasm strong positive is expressed, and mainly is positioned karyon.Ad5/F35-APE1siRNA adenovirus group APE1 protein expression obviously weakens (Fig. 9).

Embodiment 5 estimates the influence of Ad5/F35-APE1siRNA recombinant adenovirus to the large bowel cancer radiation sensitivity

5.1 the clone forms the external radiation sensitivity of analyzing and testing colorectal cancer cells

5.1.1 adenovirus infection: adenovirus infection the day before yesterday, with the LOVO cell inoculation of logarithmic phase in six orifice plates, every hole 5 * 10 ⁵Individual cell.With 10, the adenovirus Ad5/F35-APE1siRNA of 20MOI or the contrast adenovirus Ad5/F35-EGFP of 20MOI infect LOVO cell 90min, inhales then and abandon nutrient solution, changes perfect medium, continues to cultivate 48h.

5.1.2 radiotherapy: with 0,2,4,6, dose irradiation cell that 8Gy is different;

5.1.3 inoculating cell: clean twice with PBS immediately after the irradiation,, make single cell suspension through 0.25% trysinization.Inoculate 500,1000,2000,10000,100000 cells respectively in the 60mm culture dish according to the irradiation dose size, each dose point is established 3 parallel sample.

5.1.4 the culture dish cell places 37 ℃, saturated humidity contains 5%CO ₂Incubator in conventional the cultivation, nutrient solution is the RPMI-1640 that contains 10%FCS and 100U/ml penicillin and Streptomycin sulphate, changes liquid once in per 2～3 days, cultivates altogether 10 days.

5.1.5 cell is cleaned twice with PBS, after methyl alcohol is fixing, dye with 0.1% Viola crystallina (crystalviolet), make clone's counting (each clone can not be less than 50 cells), calculate cell clone rate of formation and surviving fraction (surviving fraction, SF), irradiating cell cloning efficiency not, promptly inoculate efficient (plating efficincy, PE) calculate according to following formula:

PE=is the clone's number/inoculating cell number of irradiating cell formation not

The plastidogenetic clone's number in SF=irradiation back/(the inoculating cell number * PE)

5.1.6 obtain corresponding a series of SF according to different radiotherapy dosage, use the survivorship curve of one-hit multitarget mathematical model (Single-hit multitarget model) match cell at last, and obtain mean lethal dose (D ₀) value and quasi-field dosage (quasithreshould dose, D _q) value.

One-hit multitarget mathematical model formula: SF=1-(1-e ^-kD) ^NOr SF=1-(1-e ^-D/D0) ^N

D ₀It is the inverse of the straight line portion slope (k) of dosage survivorship curve, respectively make a line that parallels with X-coordinate and curve intersection from survivorship curve logarithmic coordinates 0.1 and 0.037, make vertical line and dosage axle respectively from these two intersection points and intersect, the difference of joining dosage is D ₀Value is promptly reduced to 0.037 required dosage to SF from 0.1 at the straight line portion of dose effect curve.D _qBe that the straight line portion of survivorship curve extends upward and the dosage that equals 1 transverse axis joining by SF, promptly overcome the required dosage in shoulder district, the ability of reflection cell accumulation sublethal damage, relevant with injury repairing.The numerical value of extrapolation of survivorship curve straight line portion and ordinate zou joining is extrapolation N value (extrapolation number), represents the number or the required number of times that hits target of target in the cell.

With GraphPad Prism 4.0 software match cell survival curves, obtain D ₀, N and k value, according to formula Dq=D ₀Log _eN obtains the Dq value.

Calculate radiation sensitization than (sensitive enhancement ratio, SER), SER (D ₀)=contrast D ₀/ irradiation back D ₀SER (D _q)=contrast D _q/ irradiation back D _q

The LOVO cell that infects Ad5/F35-APE1siRNA recombinant adenovirus and contrast Ad5/F35-EGFP adenovirus is subjected to the roentgen radiation x of 0～8Gy, cultivate the typical cells clone of all as seen differing in size behind the 10d, clone with classics forms analytical method detection cell proliferation and radiosensitivity, adopts the multi-hit mathematical model of single target [SF=1-(1-e ^-D/D0) ^N], through the survivorship curve of GraphPad Prism4.0 software match LOVO cell, see Figure 10 (semilog plot).The radiosensitivity parameter of different groups sees Table 1.

Table 1Ad5/F35-APE1siRNA recombinant adenovirus to LOVO cellular radiosensitivity parameter relatively

By survivorship curve as can be seen Ad5/F35-EGFP control group LOVO cell one significantly " shoulder breadth " arranged, and " shoulder breadth " of Ad5/F35-APE1siRNA group LOVO cell obviously dwindles and narrows down, and the survival umber at each dose point all is starkly lower than the Ad5/F35-EGFP control group, the radiosensitivity that shows Ad5/F35-APE1siRNA group LOVO cell is than the control group height, and 20MOI is than 10MOI Ad5/F35-APE1siRNA group radiosensitivity height.Its enhanced sensitivity ratio sees Table 1, and different enhanced sensitivities are than asking method to reflect different enhanced sensitivity mechanism, D ₀Value has been than having reflected ray required dosage ratio (height of mean lethal dose is relatively) when causing identical biological effect, reflection be the sensitivitys of different cells to ray.D _qValue is than having reflected the comparison of cell to ray sublethal damage repair ability height.This research shows that with the multi-hit model analysis result of single target APE1 siRNA imports the radiosensitivity that is increased behind the LOVO cell, mainly realizes by suppressing the sublethal damage reparation.

5.2TUNEL method detects apoptosis

Adopt the TUNEL method to detect LOVO cell in-situ apoptosis.TUNEL original position apoptosis test kit is a U.S. Roche company product.The LOVO cell inoculation of logarithmic phase growth in six orifice plates on the cover glass, every hole 1 * 10 ⁵Individual cell.After the recombinant adenovirus Ad5/F35-APE1siRNA of 20MOI or contrast adenovirus Ad5/F35-EGFP infect LOVO cell 48h, give 0,5Gy radiotherapy dosage irradiating cell, 24h is continued to cultivate in the irradiation back, the TUNEL method detects LOVO cell in-situ apoptosis.Cover glass 4% Paraformaldehyde 96 room temperature is 30min fixedly, PBS flushing 2 times, 0.5%Triton X-100 room temperature 10min, PBS flushing 2 times, drip TUNEL reaction solution 20 μ l (TUNEL reaction solution matching while using, terminal nucleotidyl transferase TdT: fluorescein-labelled dUTP=1: 9, negative control does not add the TdT enzyme.), wet box sealing is hatched 1h for 37 ℃.PBS flushing 2 times, anti-fluorescein antibody (POD) the 20 μ l of dropping horseradish peroxidase-labeled, wet box sealing is hatched 30min for 37 ℃.PBS flushing 2 times adds 50 μ l DAB substrate solutions, incubated at room 10min.Hematorylin is redyed 15-30s, gradient alcohol dehydration, and dimethylbenzene is transparent, the DPX mounting.

Experiment is divided into four groups: the Ad5/F35-EGFP group; The Ad5/F35-APE1siRNA group; C:Ad5/F35-EGFP combined radiotherapy group, i.e. Ad5/F35-EGFP+IR group; Ad5/F35-APE1siRNA combined radiotherapy group, i.e. Ad5/F35-APE1siRNA+IR group.The result shows: the accidental apoptotic cell of Ad5/F35-EGFP control group, Ad5/F35-APE1siRNA group apoptotic cell increases (P＜0.01).The Ad5/F35-APE1siRNA+IR group significantly increases (P＜0.01) (Figure 11) than Ad5/F35-EGFP+IR group apoptosis cell.

5.3 transplanted tumor in nude mice experiment in the body

1. transplanted tumor in nude mice model

With embodiment 3.The subcutaneous visible obviously lump of BALB/c nu/nu nude mouse behind inoculation LOVO cell 5～6d.After the subcutaneous vaccination the 11st day, when gross tumor volume reaches about 100mm ³The time, the following experiment of beginning.

2. infect and radiotherapy in the virosome

Nude mice is divided into four groups at random: the Ad5/F35-EGFP group; The Ad5/F35-APE1siRNA group; C:Ad5/F35-EGFP combined radiotherapy group, i.e. Ad5/F35-EGFP+IR group; Ad5/F35-APE1siRNA combined radiotherapy group, i.e. Ad5/F35-APE1siRNA+IR group.Every group of 5 nude mices.

Infect in the recombinant adenovirus body: local injection 5 * 10 in the corresponding group knurl ⁸The Ad5/F35-APE1siRNA virus of IU (50 μ l) or contrast Ad5/F35-EGFP virus.Adopt Sweden's medical courses in general to reach (ELEKTA) precise linear accelerator behind the injection 3d, ource-skin Distance 100cm, exposure dose rate 3Gy/min, in the radiotherapy of transplanted tumor in nude mice topical administration 6Gy 6MV X ray once.

3. tumor growth detects

Every day is with major diameter (a) of vernier caliper measurement knurl body and minor axis (b), according to formula V (mm after the radiotherapy ³)=ab ²/ 2 calculate tumor size, draw growth curve, calculate tumour inhibiting rate.Put to death nude mice behind the 2W, it is heavy to measure tumour final volume and knurl.Measured the nude mice body weight once in per 3 days after the radiotherapy.

Each is organized formation curve and sees Figure 12.Experimental result shows that Ad5/F35-APE1siRNA+IR group tumor growth obviously is suppressed than the Ad5/F35-EGFP+IR group, shows that Ad5/F35-APE1siRNA significantly strengthens LOVO cell radiation sensitivity in the body.Simple Ad5/F35-APE1siRNA group tumor control rate is 15.06% behind the 2W, and Ad5/F35-EGFP+IR group tumor control rate is 41.41%, and the knurl inhibiting rate is 70.90% in the Ad5/F35-APE1siRNA+IR group.

4.TUNEL dyeing detects apoptosis

TUNEL original position apoptosis test kit is a U.S. Roche company product.Use fixedly 24h of new 4% Paraformaldehyde 96 of preparing after tumor specimen takes off immediately, the dehydration of gradient alcohol series is cut into slices behind the paraffin embedding, the conventional aquation that dewaxes of cutting into slices.The later same method of each step " (four) apoptosis detects (TUNEL method) ".Be pale brown look or brown is the apoptosis positive staining with nucleus.Apoptotic cell shared ratio in whole cancer cells is calculated in 5 visuals field of picked at random under 400 times of high power fields.Apoptotic index (apoptosis index, AI)=(apoptosis cell/cancer cells sum) * 100%.

Experiment is divided into four groups: the Ad5/F35-EGFP group; The Ad5/F35-APE1siRNA group; C:Ad5/F35-EGFP combined radiotherapy group, i.e. Ad5/F35-EGFP+IR group; Ad5/F35-APE1siRNA combined radiotherapy group, i.e. Ad5/F35-APE1siRNA+IR group.LOVO Transplanted cells tumor tissue TUNEL method detected result shows: the accidental apoptotic cell of Ad5/F35-EGFP control group, Ad5/F35-APE1siRNA group apoptotic cell increases (P＜0.01).The Ad5/F35-APE1siRNA+IR group significantly increases (P＜0.01) (Figure 13) than Ad5/F35-EGFP+IR group apoptosis cell.

Embodiment 6 estimates the influence of Ad5/F35-APE1siRNA recombinant adenovirus to large bowel cancer 5-FU chemosensitivity

6.1MTT method detects cell survival rate

1. adenovirus infection: adenovirus infection the day before yesterday, with the LOVO cell inoculation of logarithmic phase in six orifice plates, every hole 5 * 10 ⁵Individual cell.Adenovirus Ad5/F35-APE1siRNA or contrast adenovirus Ad5/F35-EGFP with 20MOI infect LOVO cell 90min, inhale then and abandon nutrient solution, change perfect medium, continue to cultivate 48h.

2.MTT method detects cell survival rate

The LOVO cell of adenovirus infection is with 4 * 10 ³/ hole is inoculated in 96 well culture plates and cultivates, and absorbs original fluid behind the 24h, more renews the RPMI1640 nutrient solution, and with the 5-FU processing cell of 0～100 μ M, other establishes and only adds nutrient solution, does not add the blank group that is of cell and medicine.Every group 3 multiple holes.Behind each group cell continuation cultivation 72h, carry out the MTT experiment, every hole adds MTT solution (5g/L) 20 μ L, continues to cultivate 4h, stops cultivating, the careful suction abandoned culture supernatant in the hole, every hole adds DMSO150 μ L, and vibration 10min fully dissolves crystallization, measure the absorbance A value (A490) in each hole at 490nm wavelength place with microplate reader, calculate inhibitory rate of cell growth by following formula:

Inhibitory rate of cell growth (IR)=[1-(the blank group of A experimental group-A)/(the blank group of A control group-A)] * 100%.And the half-inhibition concentration IC50 of calculating 5-FU.

The survivorship curve figure (Figure 14) of LOVO cell as seen behind the 5-FU effect 72h, increase along with 5-FU concentration, the LOVO cell survival rate descends gradually, compare with the Ad5/F35-EGFP group, the Ad5/F35-APE1siRNA group descends more obvious, and each dose point of 5-FU all has highly significant significant difference (P＜0.01).The IC50 of Ad5/F35-EGFP and Ad5/F35-APE1siRNA group is respectively 7.04 μ M and 1.69 μ M.

6.2 apoptosis detects (TUNEL method)

Adopt the TUNEL method to detect LOVO cell in-situ apoptosis.The LOVO cell inoculation of logarithmic phase growth in six orifice plates on the cover glass, every hole 1 * 10 ⁵Individual cell.After the adenovirus Ad5/F35-APE1siRNA of 20MOI or contrast adenovirus Ad5/F35-EGFP infected LOVO cell 48h, the 5-FU that gives 0,10 μ M handled cell, continues to cultivate 24h, and the TUNEL method detects LOVO cell in-situ apoptosis.The same third part of concrete steps.

Experiment is divided into four groups: the Ad5/F35-EGFP group; The Ad5/F35-APE1siRNA group; C:Ad5/F35-EGFP associating 5-FU group, i.e. Ad5/F35-EGFP+5-FU group; Ad5/F35-APE1siRNA associating 5-FU group, i.e. Ad5/F35-APE1siRNA+5-FU group.TUNEL method detected result shows: the accidental apoptotic cell of Ad5/F35-EGFP control group, Ad5/F35-APE1siRNA organizes apoptotic cell reinforcement (P＜0.01).The Ad5/F35-APE1siRNA+5-FU group significantly increases (P＜0.01) (Figure 15) than Ad5/F35-EGFP+5-FU group apoptosis cell.

Reference

1.Shen JC，Loeb LA.Mutations in the alpha8 loop of human APE1 alterbinding and cleavage of DNA containing an abasic site.J BiolChem，2003，278(47)：46994-47001.

2.Tel1 G，Pines A，Paron I，et al.Redox effector factor-1regulates the activity of thyroid transcription factor 1 bycontrolling the redox state of the N transcriptional activationdomain.J Biol Chem，2002，277(17)：14564-14574.

3.Volpers C，Kochanek S.Adenoviral vectors for gene transfer andtherapy.J Gene Med，2004，Suppl 1：S164-71.

4.Wang D，Luo M，Kelley MR.Human apurinic endonuclease 1(APE1)expression and prognostic significance in osteosarcoma：enhanced sensitivity of osteosarcoma to DNA damaging agentsusing silencing RNA APE1 expression inhibition.Mol Cancer Ther，2004，3(6)：679-686.

Sequence table

<160>1

<170>Patent Inversion 3.3

<210>1

<211>55

<212>DNA

＜213〉artificial sequence

<220>

＜223〉be numbered APE1 in the people APE1 gene cDNA encoding sequence of NM_001641 according to gene

The target sequence of gene siRNA is selected principle of design and is designed

<400>1

ctggtacgac tggagtacct tcaagagagg tactccagtc gtaccagact ttttt 55

Claims

1. duplicate deficit type recombinant adenovirus is characterized in that it contains the expressed sequence of people APE1 gene siRNA, and described expressed sequence is shown in the sequence in the sequence table 1.

2. recombinant adenovirus as claimed in claim 1, the specific target sequence that it is characterized in that described APE1 gene siRNA are that gene is numbered the 867-885 base sequence in the people APE1 gene cDNA encoding sequence of NM_001641.

3. as each described recombinant adenovirus of claim 1-2, it is characterized in that making up the used shuttle plasmid of described recombinant adenovirus is pDC316-EGFP-U6.

4. recombinant adenovirus as claimed in claim 3 is characterized in that described people APE1 gene siRNA expressed sequence is connected under the U6 promotor of pDC316-EGFP-U6 adenovirus shuttle plasmid.

5. recombinant adenovirus as claimed in claim 3, it is characterized in that making up the used skeleton plasmid of described recombinant adenovirus is pBHG-fiber5/35.

6. recombinant adenovirus as claimed in claim 4, it is characterized in that making up the used packing cell of described recombinant adenovirus is 293 cells.