乙型肝炎病毒X基因对肝细胞系细胞凋亡及端粒酶活性的影响

目的探讨乙型肝炎病毒x基因对肝细胞恶性变的作用机制.方法将带C基因、S基因的载体电转染导入HepG2细胞,筛选表达细胞克隆,复苏带X基因的HepG2细胞.PCR-ELISA检测各株细胞的端粒酶活性.用反义寡核苷酸诱导细胞凋亡,流式细胞仪观测转染了x基因、C基因、S基因细胞的凋亡情况.结果表达细胞克隆经同步化处理,39.50%转染X基因的细胞进入细胞S周期,其端粒酶活性指数395±0.07明显高于其它各组细胞.反义寡核苷酸诱导后,转染X基因细胞凋亡峰明显减小,凋亡率仅1.75%;其细胞活性与反义寡核苷酸浓度成反比.结论乙型肝炎病毒X基因上调肝源细胞端粒酶活性,抑制细胞凋亡,这可能是诱导肝细胞恶性变的又一机制.

Effects of hepatitis B virus X gene on apoptosis and the activity of telomerase in HepG2 cells

OBJECTIVE: To observe the effects of hepatitis B virus X gene on hepatic carcinoma. METHODS: The expression vectors of HBs gene and HBc gene (pCEP4-S and pCEP4-C) were transfected into HepG(2) cells by electroporation technique, and the cells, HepG(2) cells which contained the expression vectors of HBs (pCEP4-X) were recovered and cultured stably. The activity index of telomerase and the apoptosis rates in three cell lines were determined by PCR-ELISA and flow cytometry. RESULTS: The 39.50% of cells expressed HBx gene came into S-phase of cell cycle, and the activity index of telomerase was higher in the cell line (3.95 +/- 0.07) than in other cell lines and control (F=20.85, P<0.01; d'=2.15, P<0.05) after synchronized culture. Induced by antisense oligonucleotides against telomerase the apoptosis of cell line expressed HBx gene reduced (apoptosis rate: 1.75%). The activity of cells also reduced with the dose increase of the antisense oligonucleotides and it showed a dose-response relationship. CONCLUSION: The activity of HepG(2) cell can be increased and the cell apoptosis can be reduced by HBx gene. It may be another malignant process of hepatocytes.