OBJECTIVETo study the effect of hepatitis C virus core protein (HCV-C) on human normal biliary epithelial cells (BEC) transformation and tumor development.

METHODSBEC cells were transfected with plasmid pcDNA HCV-C (expressing HCV-C) by lipofectamine and selected in G418. The expression of HCV-C gene and protein was determined by PCR and immunohistochemical staining, respectively. Biological effect of transfected cells was observed through cell proliferation assay, anchor independent growth, and tumor development in nude mice. The expression of HCV-C protein in the induced tumor was evaluated by immunohistochemistry.

RESULTSHCV-C was strongly expressed in BEC cells transfected with plasmid pcDNA HCV-C and the positive signal was located in cytoplasm. The HCV-C expression protein in the induced cytoplasm. Cell proliferation assay showed that the population doubling time in the pcDNA HCV-C transfected cells was much shorter than that in the pcDNA3 and non-transfected cells (14 h, 28 h, 30 h respectively). The cloning efficiencies of transfected cells with pcDNA HCV-C, pcDNA3 and non-transfected cells were 36%, 2.5% and 1.5%, respectively (P < 0.01). Tumor developed in nude mice inoculated with pcDNA HCV-C transfected cells after the inoculation. HE staining showed bile duct carcinoma character and immunohistochemistry confirmed HCV-C expression in the tumor tissue. The positive control group also showed tumor development, while no tumor mass obtained in the nude mice inoculated with pcDNA3 and non-transfected cells even 36 days after the injection.

CONCLUSIONHCV-C protein showed human normal biliary epithelial cells transformation and tumorigenic features.