Tu T, Mason W S, Clouston A D, Shackel N A, McCaughan G W, Yeh M M, Schiff E R, Ruszkiewicz A R, Chen J W, Harley H A J, Stroeher U H, Jilbert A R
Department of Molecular and Cellular Biology, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia.
Centenary Institute, Sydney, NSW, Australia.
J Viral Hepat. 2015 Sep;22(9):737-53. doi: 10.1111/jvh.12380. Epub 2015 Jan 26.
Hepatocyte clone size was measured in liver samples of 21 patients in various stages of chronic hepatitis B virus (HBV) infection and from 21 to 76 years of age. Hepatocyte clones containing unique virus-cell DNA junctions formed by the integration of HBV DNA were detected using inverse nested PCR. The maximum hepatocyte clone size tended to increase with age, although there was considerable patient-to-patient variation in each age group. There was an upward trend in maximum clone size with increasing fibrosis, inflammatory activity and with seroconversion from HBV e-antigen (HBeAg)-positive to HBeAg-negative, but these differences did not reach statistical significance. Maximum hepatocyte clone size did not differ between patients with and without a coexisting hepatocellular carcinoma. Thus, large hepatocyte clones containing integrated HBV DNA were detected during all stages of chronic HBV infection. Using laser microdissection, no significant difference in clone size was observed between foci of HBV surface antigen (HBsAg)-positive and HBsAg-negative hepatocytes, suggesting that expression of HBsAg is not a significant factor in clonal expansion. Laser microdissection also revealed that hepatocytes with normal-appearing histology make up a major fraction of the cells undergoing clonal expansion. Thus, preneoplasia does not appear to be a factor in the clonal expansion detected in our assays. Computer simulations suggest that the large hepatocyte clones are not produced by random hepatocyte turnover but have an as-yet-unknown selective advantage that drives increased clonal expansion in the HBV-infected liver.
在21例处于慢性乙型肝炎病毒（HBV）感染不同阶段、年龄在21至76岁的患者的肝脏样本中测量了肝细胞克隆大小。使用反向巢式PCR检测含有由HBV DNA整合形成的独特病毒-细胞DNA连接的肝细胞克隆。尽管每个年龄组患者之间存在相当大的差异，但最大肝细胞克隆大小倾向于随年龄增加。随着纤维化、炎症活动增加以及从HBV e抗原（HBeAg）阳性血清学转换为HBeAg阴性，最大克隆大小呈上升趋势，但这些差异未达到统计学显著性。有或无并存肝细胞癌的患者之间最大肝细胞克隆大小没有差异。因此，在慢性HBV感染的所有阶段均检测到含有整合HBV DNA的大肝细胞克隆。使用激光显微切割技术，在HBV表面抗原（HBsAg）阳性和HBsAg阴性肝细胞灶之间未观察到克隆大小的显著差异，这表明HBsAg的表达不是克隆扩增的重要因素。激光显微切割还显示，组织学外观正常的肝细胞构成了经历克隆扩增的细胞的主要部分。因此，肿瘤形成前状态似乎不是我们检测中所发现的克隆扩增的一个因素。计算机模拟表明，大肝细胞克隆不是由随机的肝细胞更新产生的，而是具有一种尚未明确的选择性优势，这种优势驱动了HBV感染肝脏中克隆扩增的增加。
