Apoptosis and its pathway in X gene-transfected HepG(2) cells.

摘要

AIM: To investigate the effect of hepatitis B virus (HBV) X gene on apoptosis and expressions of apoptosis factors in X gene-transfected HepG(2) cells. METHODS: The HBV X gene eukaryon expression vector pcDNA(3)-X was transiently transfected into HepG(2) cells by lipid-media transfection. Untransfected HepG(2) and HepG(2) transfected with pcDNA(3) were used as controls. Expression of HBx in HepG(2) was identified by RT-PCR. MTT and TUNEL were employed to measure proliferation and apoptosis of cells in three groups. Semi-quantified RT-PCR was used to evaluate the expression levels of Fas/FasL, Bax/Bcl-xL, and c-myc in each group. RESULTS: HBV X gene was transfected into HepG(2) cells successfully. RT-PCR showed that HBx was only expressed in HepG(2)/pcDNA(3)-X cells, but not expressed in HepG(2) and HepG(2)/pcDNA(3) cells. Analyzed by MTT, cell proliferation capacity was obviously lower in HepG(2)/pcDNA(3)-X cells (0.08910+/-0.003164) than in HepG(2) (0.14410+/-0.004927) and HepG(2)/pcDNA(3) cells (0.12150+/-0.007159) (P<0.05 and P<0.01). Analyzed by TUNEL, cell apoptosis was much more in HepG(2)/pcDNA(3)-X cells (980/2 000) than HepG(2) (420/2 000), HepG(2)/pcDNA(3) cells (520/2 000) (P<0.05 and P<0.01). Evaluated by semi-quantified RT-PCR, the expression level of Fas/FasL was significantly higher in HepG(2) cells transfected with HBx than in HepG(2) and HepG(2)/pcDNA(3) cells (P<0.05 and P<0.01). Bax/Bcl-xL expression level was also elevated in HepG(2)/pcDNA(3)-X cells (P<0.05 and P<0.01). Expression of c-myc was markedly higher in HepG(2)/pcDNA(3)-X cells than in HepG(2) and HepG(2)/pcDNA(3) cells (P<0.05 and P<0.01). CONCLUSION: HBV X gene can impair cell proliferation capacity, improve cell apoptosis, and upregulate expression of apoptosis factors. The intervention of HBV X gene on the expression of apoptosis factors may be a possible mechanism responsible for the change in cell apoptosis and proliferation.