Expression of cyclooxygenase-2 protein in gastric adenocarcinoma

J Surg Oncol. 1998 Nov;69(3):168-72. doi: 10.1002/(sici)1096-9098(199811)69:3<168::aid-jso9>;2-0.


Background and objectives: Epidemiological studies have suggested that the regular use of nonsteroidal antiinflammatory drugs, which inhibit cyclooxygenase (COX), reduces the risk of colon cancer. The inducible COX-2 isoform has been reported to be upregulated in colorectal carcinomas and may play a role in colorectal carcinogenesis. The purpose of this study was to investigate the expression of COX-2 protein in human gastric adenocarcinomas.

Methods: COX-2 protein expression was examined in 23 patients with gastric adenocarcinoma by immunoblotting and immunohistochemistry.

Results: There was an increase in COX-2 protein levels in 19 of the 23 carcinomas (83%) compared with the paired normal gastric mucosa by an immunoblot analysis. There was no correlation between tumor histology and COX-2 protein expression. An immunohistochemical study in the 19 cases showed diffuse COX-2 staining in the cytoplasm of cancer cells. Mononuclear cells or fibroblasts of the cancer stroma were not stained with COX-2. Sporadic staining for COX-2 was observed in the normal fundic or metaplastic glandular cells in all cases.

Conclusions: COX-2 protein expression was elevated in most human gastric adenocarcinomas in comparison to the normal mucosa. COX-2 may therefore play an important role in gastric carcinogenesis.

MeSH terms

  • Adenocarcinoma / enzymology*
  • Adenocarcinoma / pathology
  • Adult
  • Aged
  • Cyclooxygenase 2
  • Female
  • Gastric Mucosa / enzymology
  • Humans
  • Immunoblotting
  • Immunohistochemistry
  • Isoenzymes / metabolism*
  • Isoenzymes / physiology
  • Male
  • Membrane Proteins
  • Middle Aged
  • Peroxidases / metabolism
  • Prostaglandin-Endoperoxide Synthases / metabolism*
  • Prostaglandin-Endoperoxide Synthases / physiology
  • Stomach Neoplasms / enzymology*
  • Stomach Neoplasms / pathology


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