丙型肝炎病毒NS3蛋白促进人源肝细胞的增殖及其相关机制研究

The Mechanisms for HCV NS3 Protein Upregulating Cell Proliferation in Human Hepatocytes

丙型肝炎病毒(HCV)NS3蛋白与肝癌细胞(HCC)的发生密切相关,但其机制尚不清楚.既往体外研究极少采用HCV的自然宿主细胞——人肝细胞作为研究体系,故所获研究结果有待进一步探讨和证实.构建了表达HCVNS3蛋白的真核质粒,通过稳定转染人源永生化肝细胞系QSG7701,建立了稳定表达HCVNS3蛋白的人源永生化肝细胞系QSG7701/NS3,以此为实验平台,检测了细胞增殖的变化,丝裂原蛋白激酶(MAPK)通路激酶磷酸化水平的改变及转录因子AP-1、NF-κB和STAT3的活性变化.结果表明:HCVNS3蛋白可促进人源永生化肝细胞QSG7701的增殖,HCVNS3蛋白激活ERKs/AP-1可能是其促进细胞增殖的重要机制,并通过上调转录因子NF-κB和STAT3的活性,诱导宿主细胞急性炎症损伤.

HCV NS3 protein plays an important role in the carcinogenesis of HCV related HCC. But the mechanism remains to be determined. The cell lines and transgenic mice used in previous studies were rarely based on HCV natural infection process, so the results acquired may need to be further evaluated. Under such background, the eukaryotic plasmid expressing HCV NS3 protein （pcDNA3.1/NS3） was constructed. Through transfecting the human hepatocyte line QSG7701 with pcDNA3.1/NS3, the research system expressing HCV NS3 protein was constructed successfully. On this basis, the effects of HCV NS3 on cell proliferation, the phosphorylation of MAP kinases and activity of transcription factors AP-1, NF-κB and STAT3 were investigated. The results showed that HCV NS3 protein could enhance proliferation, up-regulate phosphorylation of Erks and the activity of transcription factors AP-1, NF-κB and STAT3 in human hepatocytes. It is speculated that, HCV NS3 protein up-regulates ERKs/AP-1 activities is an important mechanism by which HCV NS3 protein enhances cell proliferation, its up-regulation of activity of transcription factors NF-κB and STAT3 might be relevant to the acute hepatitis associated with HCV infection.