肝细胞肝癌中乙肝病毒基因整合位点及临床病理分析

Identification of hepatitis B virus integration sites in hepatocellular carcinoma tissues from pations with chronic hepatitis B and its clinicopathological features

目的探讨乙型肝炎病毒(HBV)在肝细胞肝癌(HCC)染色体上的整合规律及其与临床病理的关系。方法收集40例HBsAg阳性HCC患者围手术期的一般临床资料和病理学资料,并进行随访。以40例HCC组织的DNA为模板,HBVX基因上游序列和人类基因组Alu重复序列为引物,应用巢式PCR原理,扩增出HBV X基因及其侧翼的人基因组DNA片段。PCR产物割胶回收后以ABI公司3700XL测序仪进行全自动测序。所获结果经美国国家生物技术信息中心(NCBI)BLAST及Mapviwer检索确认HBV整合在染色体上的精确位置。结合临床病理及随访资料分析HBV DNA整合对HCC患者的影响。结果 40份HCC组织中,18例存在HBV整合现象,整合的标本中15例正向插入宿主基因,7例反向插入宿主基因,其中4例既有正向插入,又有反向插入,有2例标本有两个HBV整合位点。从病毒基因分析,整合可发生于X基因的任意长度,且均以截短方式插入宿主细胞DNA。另有22份标本未检测到有整合。HBV整合与HCC患者在性别、年龄、AFP、癌栓及复发等方面无关(P>0.05);而与HBV DNA、肿瘤大小、分化程度呈正相关(P<0.05)。结论 HBV在HCC细胞染色体上的整合呈不均衡分布。HBV整合与HCC患者HBV DNA、肿瘤大小、分化程度呈正相关。

Objective To indentification the integration of hepatitis B virus （HBV） in HBV-related hepatocellular carcinoma （ HCC）, and to investigate their relations with the clinicopathological features. Methods Collection of 40 cases with HBV-related HCC during perioperative period in patients with clinical and pathological information and follow-up. Extracted DNA from 40 HCC liver tissue samples. According to the HBV X sequence and human Alu repeat, primers were designed respectively, and then amplify the nested polymerase chain reaction（PCR） with specially designed U-base primers. Integrated clones combined target HBV X gene and the adjacent cell gene sequences were established by PCR. The PCR product was purified and subject to direct sequencing by ABI 3700XL Auto sequencer. BCBI（ national center for biotechnology information） BLAST and MapViewer research were used for identification of HBV location on human genomes. Analysis of the association between the integration of HBV with clinicopathological features. Results In 40 HBsAg positive HCC samples, 18 cases showed the integration, and the other 22samples didn＇ t show any evidence of integra- tion. Among 18 samples with integration, forward insertions of HBV DNA into the host chromosomal DNA were found in 15 samples, and reverse insertions were found in 7 samples while both forward and reverse in sertions were found in 4 samples. Analysis from viral- cellular junctions suggested that the integrations were all happened with truncated viral DNA and could be in any locus of X gene. The HBV DNA intergration is closely related with HBV DNA and tumor size and differentiation degree（ P 〈 0. 05 ）, and nothing to do with the sex and age and AFP and tumor thrombus and recurrence （ P 〉 0.05 ）. Conclusons HBV DNA intergration is not distributed evenly throughout the host genome. The HBV DNA intergration is closely related with HBV DNA and tumor size and differentiation degree