OBJECTIVE To investigate apoptosis induced by Bax in hepatocellular carcinoma cells and to examine the results of 2 different routes for in vivo gene delivery.METHODS The anti-hepatocellular carcinoma activity of the Bax gene transferred to the human hepatocellular carcinoma QGY7703 cell line was examined. In addition the Bax gene was transferred in vivo in mice via the caudal vein or hepatic artery to investigate the differences in target organ and non-target organ transfection.RESULTS 1)The Bax gene mediated by a binary adenoviral vector system induced apoptosis in the human hepatic carcinoma QFY7703 cell line. The cell apoptotic rate in the experimental group (Bax) was 50.2± 6.9% but only 32.1 ± 9.7% in the Ad/CMV-p53 group, showing that the Bax-apoptotic rate was significantly higher than the control group. 2) LacZ expression was higher in the target organ (liver) when given through the hepatic artery than through the tail vein. In contrast, LacZ expression in the nontarget organs was higher if given through the tail vein compared to the hepatic artery.CONCLUSION Superselective hepatic artery delivery with Bax gene therapy is safe, specific, effective and has low toxicity. This study provided the basis for Bex-gene therapy via the hepatic artery in vivo.