title: [Hepatitis B virus integration and oncogene activation].
abstract: In hepatitis B virus (HBV) related hepatoma samples there is a high frequency of HBV-DNA integration into the chromosome, but the frequency of integration in the early-stage of carcinogenesis is expected to be even higher. Structural an analysis of integrated HBV-DNA and chromosomal flanking DNAs disclosed that the marked rearrangement of chromosomal DNA is not directly linked to carcinogenesis. HBV-DNA integration and chromosomal DNA depletion occur even in chronic hepatitis tissues. Integration is, therefore, thought to trigger a series of reactions which lead to carcinogenesis. However, the oncogene is not detected within the HBV genome, and the HBV integration site in the chromosome is variable. As one approach to clarifying the cause and effect relationship between HBV-DNA integration and liver carcinogenesis DNA transfection experiments were conducted using mouse NIH3T3 cells to detect hepatoma-related oncogenes. As a result, the well-known N-ras gene and an unknown oncogene were independently isolated from different hepatoma tissues.
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000235:genetics; D004279:DNA, Viral / Q000235:genetics*; D005796:Genes; D005814:Genes, Viral; D006509:Hepatitis B / Q000235:genetics; D006511:Hepatitis B Antigens / Q000235:genetics; D006515:Hepatitis B virus / Q000235:genetics*; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics; D009857:Oncogenes
chemical_list: D004279:DNA, Viral; D006511:Hepatitis B Antigens