title: The effects of hepatitis B virus core promoter mutations on hepatitis B core antigen distribution in hepatocytes as detected by laser-assisted microdissection.
abstract: OBJECTIVE
  The severity of liver damage in patients with chronic hepatitis B is dependent on several factors such as subcellular localization of hepatitis B core antigen (HBcAg) and mutation of hepatitis B virus (HBV) DNA. Here we studied the interrelationship between these two factors both in situ and in vitro.
  
  
  METHODS
  Hepatocytes from liver biopsies showing expression of HBcAg only in the cytoplasm (n=6), only in the nucleus (n=4) and in both cytoplasms or nucleus of different hepatocytes (n=5) were picked up by laser-assisted microdissection and were checked for nucleotide sequences of core promoter region of HBV DNA. HepG2 and Huh7 cell lines transfected with wild and mutant HBV DNA were checked for localization of HBcAg.
  
  
  RESULTS
  The frequencies of core promoter mutations at nucleotide (nt) 1762 and nt 1764 was significantly higher in hepatocytes with cytoplasmic expression of HBcAg compared to that of nuclear expression of HBcAg (P<0.05). Cytoplasmic expression of HBcAg was observed more frequently in HepG2 and Huh7 cells transfected with HBV mutant type (nt 1762 and 1764) than HBV wild type (P<0.05).
  
  
  CONCLUSIONS
  Cytoplasmic localization of HBcAg was associated with HBV DNA mutations at nt 1762 and 1764.
authors.affiliation: Third Department of Internal Medicine, Ehime University School of Medicine, Shigenobu-Cho, Ehime 791-0295, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Kawai
authors.forename: Norio
authors.initials: N
authors.lastname: Horiike
authors.forename: Kojiro
authors.initials: K
authors.lastname: Michitaka
authors.forename: Morikazu
authors.initials: M
authors.lastname: Onji
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002478:Cells, Cultured; D003593:Cytoplasm / Q000821:virology; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D006512:Hepatitis B Core Antigens / Q000235:genetics*; D006515:Hepatitis B virus / Q000235:genetics* / Q000302:isolation & purification; D019694:Hepatitis B, Chronic / Q000473:pathology* / Q000821:virology*; D022781:Hepatocytes / Q000473:pathology / Q000821:virology*; D006801:Humans; D007834:Lasers; D008297:Male; D042282:Microdissection; D008875:Middle Aged; D009154:Mutation; D011401:Promoter Regions, Genetic / Q000235:genetics; D014162:Transfection
chemical_list: D004279:DNA, Viral; D006512:Hepatitis B Core Antigens