Abstract: AIM: To establish an expression model of HCV NS3 protein and explore the differences of telomerase activities among different hepatitis C virus genotypes.METHODS: Screening of different HCV genotypes through PCR array. HCV NS3 gene fragments (HCV 1b NS3 and HCV 2a NS3) were amplified and cloned into eukaryotic protein expression vector pBK-CMV. Followed by the introduction of recombinant plasmids (pBK-HCV1b NS3 and pBK-HCV2a NS3) and control vector into hepatoma cell lines HepG2, respectively. Telomerase activities of HepG2 cells were detected by telomeric repeat amplification protocol (TRAP) assay.RESULTS: The popular genotype of HCV in our region was HCV 1b, second was HCV 2a. Telomerase activities in HepG2 cells transfected with pBK-HCV NS3 significantly increased, compared with control. Furthermore, telomerase activities of HepG2 cells transfected with recombinant pBK-HCV1b NS3 were higher as compare with the cells transfected with pBK-HCV2a NS3 distinctly.CONCLUSION: HCV NS3 protein may activate telomerase through the same pathway. Different genotypes of HCV NS3 protein have different effects on the malignant transformation of HepG2 cells.

Key words: HCV NS3 protein, genotype, telomerase