The Inhibition of Apoptosis of Hepatoma Cells Induced by HBx Is Mediated by Up-regulation of Survivin Expression

To investigate the effect of HBx on expression of survivin in hepatoma cells and mechanisms of inhibition of apoptosis on hepatoma cells induced by HBx, the expression plasmid pHA HBx encoding full length of HBx was transfected into HepG2 cells and the transformed cells were identified by RT PCR. The expression of survivin both in HepG2 cells and HBx transfected cells was examined with RT PCR. The nude mice model of hepatoma was established by injecting HepG2 cells and HBx transfected cells into the flank of nude mice subcutaneously. The expression level of survivin both in HepG2 formed tumors and HBx transfected cell formed tumors in nude mice was examined with Western blot. The TUNEL assay was used to detect the apoptotic cells of tumor tissues in nude mice after intraabdominal chemotherapy with adriamycin. The results indicated that the amplification of survivin in HBx transfected HepG2 cells was up regulated when compared with that in non transfected cells. Western blot showed that the tumor cells expressing HBx in nude mice had a positive band of survivin expression and the tumor cells without HBx expression had no positive band. The result of TUNEL assay showed that there were less apoptotic cells in tumor tissues expressing HBx than that in control group cells. It was concluded that HBx could up regulate the expression of survivin in hepatic carcinoma cells, which can inhibit apoptosis of hepatic carcinoma cells induced by adriamycin.