title: Roles of Helicobacter pylori infection and cyclooxygenase-2 expression in gastric carcinogenesis.
abstract: OBJECTIVE
  Cyclooxygenase (COX)-2 is over expressed in gastrointestinal neoplasm. Helicobacter pylori (H pylori) infection is causally linked to gastric cancer. However, the expression of COX-2 in various stages of H pylori-associated gastric carcinogenesis pathway has not been elucidated. Therefore, the aim of this study was to clarify the role of H pylori induced COX-2 expression during carcinogenesis in the stomach.
  
  
  METHODS
  Gastric biopsies from 138 subjects (30 cases of chronic superficial gastritis (CSG), 28 cases of gastric glandular atrophy (GA), 45 cases of gastric mucosal intestinal metaplasia (IM), 12 cases of moderate gastric epithelial dysplasia and 23 cases of gastric cancer) were enrolled. H pylori infection was assessed by a rapid urease test and histological examination (modified Giemsa staining). The expression of COX-1 and COX-2 in human gastric mucosa was detected by immunohistochemical staining.
  
  
  RESULTS
  H pylori infection rate was 64.3% in GA and 69.5% in gastric cancer, which was significantly higher than that (36.7%) in CSG (P<0.05). The positive expression rates of COX-2 were 10.0%, 35.7%, 37.8%, 41.7% and 69.5% in CSG, GA, IM, dysplasia and gastric cancer, respectively. From CSG to GA, IM, dysplasia and finally to gastric cancer, expression of COX-2 showed an ascending tendency, whereas COX-1 expression did not change significantly in the gastric mucosa. The level of COX-2 expression in IM and dysplasia was significantly higher in H pylori-positive than in H pylori-negative subjects (P<0.01).
  
  
  CONCLUSIONS
  COX-2 expression induced by H pylori infection is a relatively early event during carcinogenesis in the stomach.
authors.affiliation: Department of Geriatrics, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029, China. weihaosun@hotmail.com
authors.forename: Wei-Hao
authors.initials: WH
authors.lastname: Sun
authors.forename: Qian
authors.initials: Q
authors.lastname: Yu
authors.forename: Hong
authors.initials: H
authors.lastname: Shen
authors.forename: Xi-Long
authors.initials: XL
authors.lastname: Ou
authors.forename: Da-Zhong
authors.initials: DZ
authors.lastname: Cao
authors.forename: Ting
authors.initials: T
authors.lastname: Yu
authors.forename: Cheng
authors.initials: C
authors.lastname: Qian
authors.forename: Feng
authors.initials: F
authors.lastname: Zhu
authors.forename: Yun-Liang
authors.initials: YL
authors.lastname: Sun
authors.forename: Xi-Ling
authors.initials: XL
authors.lastname: Fu
authors.forename: Han
authors.initials: H
authors.lastname: Su
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D005260:Female; D005753:Gastric Mucosa / Q000382:microbiology / Q000473:pathology; D016481:Helicobacter Infections / Q000453:epidemiology*; D016480:Helicobacter pylori; D006801:Humans; D007527:Isoenzymes / Q000235:genetics*; D008297:Male; D008565:Membrane Proteins; D008875:Middle Aged; D009367:Neoplasm Staging; D018579:Patient Selection; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics*; D013274:Stomach Neoplasms / Q000201:enzymology / Q000382:microbiology* / Q000473:pathology
chemical_list: D007527:Isoenzymes; D008565:Membrane Proteins; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496511:PTGS1 protein, human; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases