Dai W L, Chen Y, Li L, Jiang H Q, Gu J R
State Key Laboratory for Oncogene and Its Related Gene, Shanghai Cancer Institute, PRC.
Sci China B. 1993 Mar;36(3):329-38.
This is the first report to describe the presence of an HBV-like DNA sequence in two hepatoma and their tumor surrounding liver tissues, one precancerous and one non-malignant liver tissue of ducks collected from Qidong County of China. The HBV-like sequences were either in an episomal form of 3.2 kb or in an integrated form of various sizes, while the DHBV DNA sequences (3.0 kb) were either present or absent in these tissues and in different size pattern. Furthermore, there was no evidence of cross-hybridization between HBV-like DNA sequences in duck and DHBV DNA. A 3.2 kb HBV-like DNA sequence has been cloned from one duck hepatoma (40 K), designated as pDKHBV. The 3218 bp full-length nucleotide sequence of this clone has been determined, which had no apparent homology with Duck Hepatitis B Virus (DHBV) genome, but was highly homologous to human HBV adw2 subtype (99.0%). The sequence was composed of four open reading frames for HBV gene Pre-S/S, X, C and P respectively. In addition to multiple sites of point mutation, one nt and two nt deletion were detected downstream the initiation codon of Pre-S1 gene and at the 3' end of C gene respectively, thereby suggesting a frameshift mutation in Pre-S gene and C gene. Based on these results, it was implicated that an unusual HBV variant might exist in Qidong County, which might have transmitted into duck through some yet unknown mechanisms. The possibility from exogenous contamination could be thus excluded.
这是首篇描述在中国启东县采集的两只鸭肝癌及其癌周肝组织、一个癌前肝组织和一个非恶性肝组织中存在类乙肝病毒（HBV）DNA序列的报告。类HBV序列呈3.2kb的游离形式或各种大小的整合形式，而鸭乙肝病毒（DHBV）DNA序列（3.0kb）在这些组织中存在或不存在，且大小模式不同。此外，鸭中的类HBV DNA序列与DHBV DNA之间没有交叉杂交的证据。已从一只鸭肝癌（40K）中克隆出一个3.2kb的类HBV DNA序列，命名为pDKHBV。已确定该克隆的3218bp全长核苷酸序列，它与鸭乙肝病毒（DHBV）基因组没有明显同源性，但与人类HBV adw2亚型高度同源（99.0%）。该序列分别由HBV基因Pre - S/S、X、C和P的四个开放阅读框组成。除了多个点突变位点外，在Pre - S1基因起始密码子下游和C基因3'端分别检测到一个核苷酸和两个核苷酸的缺失，从而表明Pre - S基因和C基因发生了移码突变。基于这些结果，推测启东县可能存在一种不寻常的HBV变异体，它可能通过一些未知机制传播到鸭体内。因此可以排除外源污染的可能性。
