原发型肝癌的肝内HBVDNA整合状况

INTEGRATION OF HEPATITIS B VIRUS DNA IN HEPATOCELLULAR CARCINOMA

应用^(32)P标记的克隆HBVDNA片段探针对30例原发型肝癌病人的肝内组织进行了DNA电泳转移Southern杂交。结果检出HBVDNA整合者21例(70％),其中癌组织整合者18例(60％),癌外组织整合者16例(53％),双份组织均整合者13例(43％)。杂交带分析发现,不同例和同例肝内不同组织的HBVDNA整合模式都不相同,提示整合具随机性并可能发生整合和/或侧翼序列的基因重排。由于探针含HBV基因组中1.4～2.8kb的DNA顺序,故结果实际反映S基因及其下游增强子的整合状况。基因重排和增强子插入整合并活化细胞原癌基因的致癌机理在本文也进行了初步探讨。

To investigate the hepatitis B virus (HBV) DNA status in the liver When hepatoce-llular carcinoma (HCC) has developed, 30 paired tumorous and nontumorous liver tissue from 24 hepatitis B surface antigen (HBsAg)-seropositive and 6 HBsAg-negative patients with HCC were studied by Southern blot analysis which involved the using of 32P labelled HBVDNA-S subgenomic fragment as the probe and fast electrophoretic transfer of DNA onto Zetaprobe menbrane in place of capillary blot onto nitrocellulose menbrane. Twenty one (21/30 = 70%) integrants had been discovered, including 20 (20/24 = 83.3%) HBsAg positive and 1 (1/6-16.7%) HBsAg negative, among them 18 (60%) had integrated HBVDNA in tumorous, 16 (53%) in nontumorous and 13 (43%) in both tissue. The hybridization patterns of integrated HBVDNA were all different not only in different integrants but also in different parts of liver tissue of any integrant suggesting the randomness of viral integration and the rearrangement of integrated and/or flanking sequences. Since the subgenomic probe had the fragment of l.4-2.8 kb in HBV genome, the result specifically represented the status of S-gene and its downstream enhancer. Possibly, the carcinogenesis of HCC lies on the integration of HBV enhancers and ensuing activation of cellular oncogenes as well as the rearrangement of abnormal sequences and actively persistent hepatocellular necrosis.