Effects of hepatitis B virus X protein on cell proliferation and GSK3β expression of human liver cell line L02 / 肿瘤

ABSTRACT

Objective: To investigate the effects of hepatitis B virus (HBV) X protein (HBx) on cell proliferation, cell cycle and the glycogen synthase kinase 3β (GSK3β) expression of human liver cell line LO2, and discuss the mechanism of carcinogenesis of HBV-associated hepatocellular carcinoma (HCC). Methods: The human liver cell line L02 was infected with Ad-GFP or Ad-HBx. The expressions of HBx and GSK3β mRNAs were identified by RT-PCR. MTT method and flow cytometry were used to detect the cell proliferation and cell cycle distribution, respectively. The expression levels of HBx, total-GSK3β (t-GSK3β),phospho-GSK3β (p-GSK3β), β-catenin and cyclin D1 proteins were examined by Western blotting. Results: The positive expressions of HBX mRNA and protein in L02 cells were detected after infection with Ad-HBx. The cell proliferation rate was elevated in a time-dependant manner. The percentage of Ad-HBx-infected cells at G1 period was lower than that in the control group, while the percentages of Ad-HBx-infected cells at S and G2 periods were both higher than those in the control group (P<0.05). The expression levels of t-GSK3β mRNA and protein in Ad-HBx-infected cells had no significant changes, and the expression levels of p-GSK3β, β-catenin and cyclin D1 proteins were increased compared with those in the control group (P<0.05). Conclusion: HBx may participate in the activation of downstream Wnt/β-catenin signal pathway through promoting the phosphorylation of GSK3β in L02 cells, and eventually increase the cell proliferation ability.