Zhang An-Ye, Lai Ching-Lung, Poon Ronnie Tung-Ping, Huang Fung-Yu, Seto Wai-Kay, Fung James, Wong Danny Ka-Ho, Yuen Man-Fung
Department of Medicine, The University of Hong Kong, Hong Kong SAR, China.
State Key Laboratory for Liver Research, The University of Hong Kong, Hong Kong SAR, China.
J Gastroenterol Hepatol. 2016 Sep;31(9):1638-45. doi: 10.1111/jgh.13316.
Hepatitis B virus (HBV) full-length genomic mutations and quasispecies characteristics in hepatocellular carcinoma (HCC) were investigated.
Hepatitis B virus DNA was extracted from the tumor and non-tumor tissues of 16 HCC patients. Overlapping DNA fragments covering the entire HBV genome were amplified and sequenced. To study HBV sequence at the quasispecies level, the preS region was amplified and clonally sequenced. HBV mutation profiles, quasispecies complexity and diversity, and phylogenetic characteristics were assessed.
Fourteen patients had full-length HBV amplification. Hot-spot mutations at HBx aa130-131 and pre-S deletions were detected in 13 (93%) and 6 (43%) patients, respectively. Deletions in the X/preC/C regions were more frequently detected in the tumor than in the non-tumor tissues (P = 0.031). Compared with the non-tumor tissues, the tumor tissues had a lower quasispecies complexity (P = 0.014 and 0.043, at the nucleotide and amino acid levels, respectively) and diversity (P = 0.048 and 0.022, at the nucleotide and amino acid levels, respectively). Phylogenetic analysis showed that HBV sequences derived from tumor and non-tumor tissues were separately clustered, suggesting the occurrence of compartmentalization, which was confirmed by the correlation coefficient testing on both the number and length of branches of viral populations (all P < 0.02).
Hepatitis B virus mutation patterns in HCC tumor tissues and non-tumor tissues were different. HBV quasispecies within the preS region were compartmentalized, and tumor tissues had a lower genome complexity and diversity. Our study suggests HBV evolution is conditioned by the differential host cellular environment in HCC tumors.
研究肝细胞癌（HCC）中乙型肝炎病毒（HBV）全长基因组突变及准种特征。
从16例HCC患者的肿瘤组织和非肿瘤组织中提取乙肝病毒DNA。扩增并测序覆盖整个HBV基因组的重叠DNA片段。为了在准种水平研究HBV序列，扩增前S区并进行克隆测序。评估HBV突变谱、准种复杂性和多样性以及系统发育特征。
14例患者实现了HBV全长扩增。分别在13例（93%）和6例（43%）患者中检测到HBx aa130 - 131热点突变和前S区缺失。X/preC/C区的缺失在肿瘤组织中比在非肿瘤组织中更频繁地被检测到（P = 0.031）。与非肿瘤组织相比，肿瘤组织的准种复杂性较低（分别在核苷酸和氨基酸水平，P = 0.014和0.043）以及多样性较低（分别在核苷酸和氨基酸水平，P = 0.048和0.022）。系统发育分析表明，源自肿瘤组织和非肿瘤组织的HBV序列分别聚类，提示存在区室化，这通过对病毒群体分支数量和长度的相关系数测试得到证实（所有P < 0.02）。
HCC肿瘤组织和非肿瘤组织中的乙肝病毒突变模式不同。前S区内的HBV准种存在区室化，且肿瘤组织的基因组复杂性和多样性较低。我们的研究表明，HBV的进化受HCC肿瘤中不同宿主细胞环境的影响。
