Influence of hepatitis B virus X gene on apoptosis of hepatic cells mediated by Fas

Abstract

Objective: To investigate the influence of hepatitis B virus X gene (HBx) on apoptosis of hepatic cells mediated by Fas in HePG2 cells. Methods: HBx eukaryotic vector pcDNA3.1(+)-X was transfected into HEPG2 cells with lipofectamine, and the null vector pcDNA3.1(+) and untransfected HEPG2 were used as normal controls. The cells were collected 72 h after transfection, and the expression of HBx mRNA and protein was determined using RT-PCR and Western blot, respectively. The mRNA expression of apoptosis-related genes Bcl-2 and Bax mRNA was also determined using RT-PCR. Cytotoxicity and apoptosis were evaluated using CCK-8 and flow cytometry, respectively, after HepG2-HBx and HepG2-3.1 cells were treated with stimulatory monoclonal antibody anti-Fas CH11. The t test was used for pairwise comparison. Results: The cell line HepG2-HBx was successfully established, as confirmed by RT-PCR and Western blot, and RT-PCR results showed that HepG2-HBx cells had significantly higher expression of Bcl-2 mRNA than HepG2-3.1 and HepG2 cells (P < 0.05), but had significantly lower expression of Bax mRNA than HepG2-3.1 and HepG2 cells (P < 0.05); CCK-8 and flow cytometry showed that anti-Fas CH11 had a lower cytotoxicity to HepG2-HBx cells and allowed for a lower apoptosis rate of HepG2-HBx cells compared with HepG2-3.1 and HepG2 cells. Conclusions: HBx can inhibit apoptosis of hepatic cells mediated by the Fas pathway.