Cyclooxygenase-2 expression in Helicobacter pylori-associated premalignant and malignant gastric lesions

Am J Pathol. 2000 Sep;157(3):729-35. doi: 10.1016/S0002-9440(10)64586-5.


Expression of cyclooxygenase-2 (COX-2) in various stages of the Helicobacter pylori-associated gastric carcinogenesis pathway has not been elucidated. We investigated the distribution and intensity of COX-2 expression in premalignant and malignant gastric lesions, and monitored the changes after H. pylori eradication. Gastric biopsies from H. pylori-infected patients with chronic active gastritis, gastric atrophy, intestinal metaplasia (IM), gastric adenocarcinoma, and noninfected controls were studied. Expression of COX-2 was evaluated by immunohistochemistry and in situ hybridization. Endoscopic biopsies were repeated 1 year after successful eradication of H. pylori in a group of IM patients for comparing COX-2 expression and progression of IM. In all H. pylori-infected patients, COX-2 expression was predominantly found in the foveolar and glandular epithelium and, to a lesser extent, in the lamina propria. In the noninfected group, only 35% of cases demonstrated weak COX-2 expression. Intensity of COX-2 was not significantly different between the chronic active gastritis, gastric atrophy, IM, and gastric adenocarcinoma groups. In 17 patients with IM, COX-2 expressions in the epithelial cells and stromal cells were reduced 1 year after H. pylori eradication. However, the changes in COX-2 expression did not correlate with progression/regression of IM. Both premalignant and malignant gastric lesions demonstrate strong COX-2 expression. Successful eradication of H. pylori leads to down-regulation of COX-2 expression but failed to reverse IM at 1 year.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / enzymology*
  • Adenocarcinoma / microbiology
  • Adenocarcinoma / pathology
  • Cyclooxygenase 2
  • Down-Regulation
  • Gastric Mucosa / enzymology*
  • Gastric Mucosa / microbiology
  • Gastric Mucosa / pathology
  • Helicobacter Infections / enzymology*
  • Helicobacter Infections / microbiology
  • Humans
  • Immunoenzyme Techniques
  • In Situ Hybridization
  • Isoenzymes / genetics
  • Isoenzymes / metabolism*
  • Membrane Proteins
  • Precancerous Conditions / enzymology*
  • Precancerous Conditions / microbiology
  • Precancerous Conditions / pathology
  • Prostaglandin-Endoperoxide Synthases / genetics
  • Prostaglandin-Endoperoxide Synthases / metabolism*
  • RNA, Messenger / metabolism
  • Stomach Neoplasms / enzymology*
  • Stomach Neoplasms / microbiology
  • Stomach Neoplasms / pathology


  • Isoenzymes
  • Membrane Proteins
  • RNA, Messenger
  • Cyclooxygenase 2
  • PTGS2 protein, human
  • Prostaglandin-Endoperoxide Synthases