(1.Central Laboratory，Wuxi Hospital for Maternaland Child Health Care Affiliated to Nanjing Medical University，Wuxi214002，China;2.Center of Radioimmunology，Medical School of Southeast University，Nanjing210009，China;3.Department of Clinical Laboratory，Wuxi No.1Hospital，Wuxi214042，China;

    4.Department of Clinical Laboratory，Shanghai Sanitarium of East of China，Wuxi214042，China)

    [Abstract] Objective To study in vitro and in vivo killing effect and the bystander effect of HSV.TK.GCV suicide gene system on cervix cancer cell line Hela.Methods GINaTK retroviral vector containing HSV.TK gene was transduced into PA317packaging cell by lipofectin.Cervix cancer cell line Hela was infected by high titer viral supernatant.Hela.TK cells and Hela cells were used in in vitro and in vivo study.In in vitro study，sensitivity of Hela.TK cells to GCV and bystander effect were observed by MTT test.In in vivo study，Hela.TK cells and Hela cells were injected s.c.into flanking BALB.C mice，GCV was administrated i.p.，RT-PCR was applied to detect the expression of HSV.TK gene.Statistical analysis of the data was performed by using the ANOVA(analysis of variance).Re-sults The Hela cells transfered with GINaTK gene displayed a higher antitumor effect than parent cells.In in vitro study ......