title: Specific hepatitis B virus integration in hepatocellular carcinoma DNA through a viral 11-base-pair direct repeat.
abstract: Integrated hepatitis B virus (HBV) DNA sequences have been cloned from cellular DNA of two human liver tumors. The structure of the clones was determined by restriction mapping, and the host-viral DNA junctions were sequenced. In each clone one junction mapped to within an 11-base-pair sequence, 5' T-T-C-A-C-C-T-C-T-G-C, which is directly repeated near the extremities of the cohesive-end region of the free viral genome. The two copies of this sequence are termed DR1 and DR2. While one clone carried a host-viral junction within DR1, the second one carried a host-viral junction within DR2. The first 1 or 2 base pairs of the repeat were deleted upon recombination with the host genome, leaving at the junctions a common 9-base-pair segment of HBV DNA, 5' C-A-C-C-T-C-T-G-C. The other two host-viral junctions mapped to the pre-S region and to the core region of the viral genome, showing no peculiar feature. These results show that HBV DNA can integrate via a specific viral DNA sequence.
mesh_terms: D001482:Base Composition; D001483:Base Sequence; D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000382:microbiology*; D003001:Cloning, Molecular; D004262:DNA Restriction Enzymes; D004273:DNA, Neoplasm / Q000235:genetics*; D004279:DNA, Viral / Q000235:genetics*; D006515:Hepatitis B virus / Q000235:genetics*; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics / Q000382:microbiology*; D009693:Nucleic Acid Hybridization
chemical_list: D004273:DNA, Neoplasm; D004279:DNA, Viral; D004262:DNA Restriction Enzymes