title: Bax and Bcl-2 protein expression in gastric precancerous lesions: immunohistochemical study.
abstract: OBJECTIVE
  Bcl-2 protein prolongs cell survival in the face of classical apoptotic stimuli, and is considered to be a suppressor of apoptosis. Bax plays a key role in apoptosis by accelerating cell death after an apoptotic stimulus. The aim of our study was to determine the roles of the Bax proapoptotic gene and the Bcl-2 antiapoptotic gene in the carcinogenesis of gastric cancer.
  
  
  METHODS
  One hundred and forty-five gastric biopsy specimens of chronic gastritis, atrophic gastritis, intestinal metaplasia and gastric dysplasia were studied. Using immunohistochemical methods, Bax and Bcl-2 protein expression was observed.
  
  
  RESULTS
  Bax was expressed in epithelial cells in all cases of chronic gastritis. Bax was not detected in 26% of specimens of atrophic gastritis. As intestinal metaplasia develops, Bax is further suppressed. In biopsy samples with dysplasia, Bax expression was demonstrated only in 12% of biopsy samples. Although Bcl-2 protein was not detected in chronic gastritis, aberrant expression was found in gastric epithelial intestinal metaplasia and dysplasia.
  
  
  CONCLUSIONS
  The suppression of Bax and overexpression of Bcl-2 protein is an early event in gastric tumorigenesis, before gastric dysplastic changes occur.
authors.affiliation: Gastroenterology Clinic, 251 Hellenic Air Force and Veterans General Hospital, Athens, Greece. gkanagnostopoulos@yahoo.gr
authors.forename: George K
authors.initials: GK
authors.lastname: Anagnostopoulos
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Stefanou
authors.forename: Evdokia
authors.initials: E
authors.lastname: Arkoumani
authors.forename: George
authors.initials: G
authors.lastname: Sakorafas
authors.forename: George
authors.initials: G
authors.lastname: Pavlakis
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Arvanitidis
authors.forename: Epameinondas
authors.initials: E
authors.lastname: Tsianos
authors.forename: Niki J
authors.initials: NJ
authors.lastname: Agnantis
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D005260:Female; D005756:Gastritis / Q000378:metabolism; D005757:Gastritis, Atrophic / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000473:pathology; D008297:Male; D008679:Metaplasia; D008875:Middle Aged; D011230:Precancerous Conditions / Q000378:metabolism* / Q000473:pathology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000473:pathology; D051028:bcl-2-Associated X Protein / Q000378:metabolism*
chemical_list: D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein