Objective To investigate the effect of herpes simplex virus thymidine kinase/ganciclovir (HSV-TK/GGV)system driven by human alpha fetoprotein(AFP)enhancer on hepatocellular carcinoma(HCC)cells in vitro and in vivo.Methods HCC-specific eukarotypic expression vector carrying suicide gene driven by AFP enhancer(pAFP-cDNA3.1-TK)was constructed.The plasmid was trasfected to AFP-positive HepG2 cells and AFP-negative SMMC7721 cells by liposomes.Protein and mRNA expressions of TK were detected by RT-PCR or Western blot.The survival rates of HCC cells were detected by methyl thiazolyl tetrazolium assay.The effects of GGV on the in vitro proliferation,survival and apoptosis of HCC cells were observed,and the inhibitive effect of GGV on the survival of HCC cells in vivo was also detected.All data were analyzed by using the t test.Results The pAFP-cDNA3.1-TK was successfully constructed and transfected to the HCC cells.The protein and mRNA expressions of TK were detected in AFP-positive HepG2 cells.GGV dose-and time-dependently inhibited the growth and induced the apoptosis of HepG2 cells in vitro,but it had no effect on SMMC7721 cells.No protein or mRNA expression of TK was detected in the SMMC7721 cells.There was a significant difference on the inhibitory effects of GGV on HepG2 cells and SMMC7721 cells(t =2.58,2.73,3.12,P ＜0.05).GGV specifically inhibited the growth of AFP-positive HepG2 cells,and the inhibition rate was 46%;the growth of AFP-negative SMMC7721 cells was not influenced by GGV.There was a significant difference in the inhibitive effect of GGV on the growth of HepG2 cells and SMMC7721 cells(t = 3.36,P ＜ 0.05).Conclusion HSV-TK/GGV systemdriven by human APF enhancer kills APF-positive HCC cells and inhibits the growth of HCC cells.