乙型肝炎病毒基因组中p53应答成分结合序列的确定及意义

目的：探讨ＨＢＶ与肿瘤抑制基因ｐ５３相互作用的机制及其在原发性肝癌发生中的意义．方法：应用计算机程序对ＨＢＶ全基因组进行比较分析，合成含ＤＮＡ－蛋白质结合位点的基因片段作为探针，与肝癌细胞核蛋白作用．通过凝胶电泳移动试验，凝胶电泳超移动试验，原位紫外线交联试验，确定ＨＢＶ与ｐ５３蛋白的特异性结合．应用带报道基因ＣＡＴ与ｐ５３，ＨＢＶＸ基因共转染，观察ＨＢＶ与ｐ５３蛋白相互作用的生物学功能．结果：ＨＢＶ基因组增强子Ｉ上游区域（１０４７～１０５９）存在ｐ５３基因应答成份结合位点序列，能特异性地与ｐ５３蛋白结合，使ｐ５３蛋白在细胞内积聚．结论：ＨＢＶ与ｐ５３存在ＤＮＡ－蛋白质结合关系，在ＨＢＶ感染相关的肝癌发生中具有非常重要的理论意义．

Significance and identification of p53 response element binding sequence in the genome of hepatitis B virus

Objective: In order to explore the mechanism of interaction of hepatitis B virus (HBV) with p53 protein and its role in the hepatocarcinogenesis. Methods: HBV genome was analysed by computer program. The probes containing specific DNA protein binding site in HBV genome were synthesized and reacted with nuclei protein extracted from hepatoma cell lines. Specific binding was determined by electrophoretic mobility shift assay, electrophoretic mobility supershift assay and in situ ultraviolet cross linking assay. Co transfection was performed using reporter gene CAT, p53 and dexamethasone inducible HBx to observe the biological function of HBV binding to p53 protein. Results: A p53 response element binding sequence is present in HBV genome at upstream of enhancer I from 1047 to 1059 bp. This sequence is capable of binding to p53 protein and increasing accumulation of p53 protein in cells. Conclusions: The results strongly suggest that DNA protein binding of HBV with p53 protein plays a significant role and it may be predominant mechanism in the pathogenesis of HBV associated hepatocellular carcinoma.