乙型肝炎病毒preS/S蛋白对人PCNA基因启动子激活作用的研究

Activating effect of hepatitis B virus preS/S protein on proliferating cell nuclear antigen gene promoter

目的 研究乙型肝炎病毒preS S蛋白对人增殖细胞核抗原 (PCNA)基因启动子的激活作用。方法 利用荧光素酶报告基因 ,用共转染方法研究该整合片段对人PCNA启动子的作用。用免疫组织化学法确定preS S蛋白在细胞中的定位。结果 在人肝细胞L0 2中 ,含有上述HBV整合片段的质粒pKSH7C HpaⅠ能以剂量依赖方式激活PCNA启动子 ,使PCNA启动子活性提高 0 .5倍 ;免疫组化分析表明 ,其蛋白定位于细胞质中。结论 preS S蛋白对PCNA启动子有激活作用 ,但作用并非直接 。

Objective PreS/S gene was derived from hepatitis B virus (HBV) integration fragment of human hepatocellular carcinoma genome,containing the promoter of preS/S and the C terminal truncated preS/S open reading frame.PreS/S protein may have important roles in processing hepatoma in some HBV infected patients. The aim of the study was to study the activity of HBV preS/S protein on proliferating cell nuclear antigen (PCNA) promoter and to localize compartment of the preS/S protein in the liver cell line L02.Methods The authors studied the effect of the 3′ truncated preS/S on human PCNA promoter by co transfecting the expression plasmids of luciferase reporter gene,used the immunohistochemical method to localize the preS/S protein.Results The expression product of the plasmid,pKSH7C HpaⅠ,which contained the 3′ truncated preS/S and the flanking cellular sequences,stimulated the expression of PCNA promoter dose dependently,and its effect was 0.5 folds higher than control.Immunohistochemistry showed that the preS/S protein located in the cytosolic region of the liver cell line L02.Conclusion The HBV preS/S protein could stimulate the PCNA promoter of the liver cell,its effect was not direct,which suggests that the effect of preS/S protein on PCNA promoter was probably through the cell signal transduction pathway.