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

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蛋白细胞中的定位。结果：在人肝细胞L02中，含有上述HBV整合片段的质粒pKSH7C-Hpa I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，可能是通过细胞信号传导途径来影响PCNA活性。

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

BACKGROUND: 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. CONCLUSIONS: 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.