Construction of adenovirus-mediated anti-sense RNA targeting K-ras exon 1 in SW1990 cell line

Objective:To construct an adenovirus-mediated anti-sense RNA targeting K-ras exon 1 of SW1990 cell line and observe its effect on ceil proliferation and apoptosis after transferred into SW1990 cell line.Methods:K-ras exon 1 cDNA was cloned into shuttle vector pShuttle-CMV and the resultant plasmid was confirmed by enzyme digestion and PCR.Clones with inverted insertion were selected and co-transferred into E.coli BJ5183 with an adenoviral backbone plasmid pAdEasy-1 to produce recombinant plasmid by homologous recombination.Recombinants were then selected and transfected into 293 cell line to produce recombinant adenovirus.Recombinant adenovirus production was confirmed by PCR analysis and was amplified and purified;the virus titer was determined.Ad-LacZ was used to infect SW1990 cells and the infection efficiency was observed by X-gal staining.SW1990 cells was infected with the recombinant adenovirus and their proliferation and apoptosis were determined by MTT and annexin V/PI FCM assay.Results:A 282 bp target gene fragment was acquired by PCR;the titer of recombinant adenovirus was 7.6×10~8 pfu/ml before purification by CsCl_2 gradient centrifugation and 5.0×10~(10)pfu/ml after CsCl_2 gradient centrifugation.When the recombinant adenovirus was at 100 MOI,the infection efficiency of SW1990 cells nearly reached 100%.The transfection of recombinant adenovirus significantly inhibited SW1990 cell proliferation(P0.05),with a maximal inhibitory rate of 40.5% 4-5 days after infection;it also significantly increased SW1990 cell apoptosis,with the apoptotic rate being(22.54±5.38)% 72 hours after infection.Conclusion:We have successfully constructed an anti-sense RNA adenovirus vector targeting K-ras exon 1 of SW1990 cell line,paving a way for the anti-sense K-ras gene therapy of pancreatic carcinoma.