title: Effect of Helicobacter pylori infection on Bax protein expression in patients with gastric precancerous lesions.
abstract: OBJECTIVE
  To investigate the effect of Helicobacter pylori (H pylori) infection on Bax protein expression, and explore the role of H pylori in gastric carcinogenesis.
  
  
  METHODS
  H pylori was assessed by rapid urease test and Warthin-Starry method, and expression of Bax protein was examined immunohistochemically in 72 patients with pre-malignant lesions.
  
  
  RESULTS
  Bax protein was differently expressed in intestinal metaplasia and gastric dysplasia, and showed 63.99% positivity. The positivity of Bax protein expression in H pylori-positive gastric precancerous lesions (72.3%) was significantly higher than that in H pylori-negative gastric precancerous lesions (48.0%, chi2 = 4.191, P<0.05). H pylori infection was well correlated with the expression of Bax protein in gastric precancerous lesions (r = 0.978, P<0.01). After eradication of H pylori, the positivity of Bax protein expression significantly decreased in H pylori-positive gastric precancerous lesions (chi2 = 5.506, P<0.05). In the persisting H pylori-infected patients, the positivity of Bax protein expression was not changed.
  
  
  CONCLUSIONS
  H pylori infection may be involved in the upregulation of Bax gene, which might be one of the mechanisms of H pylori infection-induced gastric epithelial cell apoptosis. H pylori might act as a tumor promoter in the genesis of gastric carcinoma and eradication of H pylori could inhibit gastric carcinogenesis.
authors.affiliation: Department of Gastroe-nterology, General Hospital of Chinese People's Armed Police Forces, Beijing 100039, China. haifengliu333@hotmail.com
authors.forename: Hai-Feng
authors.initials: HF
authors.lastname: Liu
authors.forename: Wei-Wen
authors.initials: WW
authors.lastname: Liu
authors.forename: Guo-An
authors.initials: GA
authors.lastname: Wang
authors.forename: Xiao-Chun
authors.initials: XC
authors.lastname: Teng
mesh_terms: D001706:Biopsy; D005753:Gastric Mucosa / Q000382:microbiology / Q000473:pathology; D016481:Helicobacter Infections / Q000175:diagnosis / Q000378:metabolism*; D016480:Helicobacter pylori; D006801:Humans; D008679:Metaplasia / Q000378:metabolism / Q000473:pathology; D011230:Precancerous Conditions / Q000382:microbiology* / Q000473:pathology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism; D013274:Stomach Neoplasms / Q000382:microbiology* / Q000473:pathology; D051028:bcl-2-Associated X Protein / Q000235:genetics / Q000378:metabolism*
chemical_list: D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein