The selective killing effect of adenoviral mediated HSV-tk/GCV suicide gene system controlled by hTERT promoter on bladder cancer cells

To investigate the selective killing effect of adenoviral mediated herpes simplex virus-thymidine kinase/ganciclovir (HSV-tk/GCV) suicide gene system controlled by human telomerase reverse transcriptase (hTERT) promoter on bladder cancer cells in vitro.Methods Bladder cancer cell line 253J and human fibroblast cell line MRC-5 were transfected by the recombinant adenovirus of different multiplicities of infection (MOI),and the infection rate was measured by observing the expression of enhanced green fluorescent protein (EGFP) under the fluorescent microscopy.Ad-hTERT-HSV/tk and Ad-CMV-SHV/tk were transduced into 253J and MRC-5,followed by GCV treatment.The relative survival rate of cells in presence of prodrug GCV was measured with MTT method.Results Recombinant adenovirus Ad-hTERT-EGFP could selectively infect 253J cells,with the infection rate associated with the increasing MOI of recombinant adenovirus (P<0.01).When MOI was 1,the infection rate was 8.3%;when MOI was 1000,the infection rate was 100.0%.GCV significantly inhibited the growth of both cell lines (253J and MRC-5) infected with Ad-CMV-HSV/tk and the growth of only 253J infected with Ad-hTERT-HSV/tk (P<0.001).The survival rate of 253J was correlated with the concentration of both the prodrugs and MOI of recombinant adenovirus (P<0.01).When MOI was 1,with 1 μmol/L GCV,the survival rate of 253J was 95.4%;when MOI was 100,with 1000 μmol/L GCV,the survival rate of 253J was 6.1%.Conclusion Recombinant adenovirus vector containing EGFP can report the transfection rate accurately and easily.Adenoviral vector containing hTERT promoter for the HSV/tk plus GCV treatment appears to be highly selective in killing bladder cancer cell line in vitro.7 refs.2 tabs.