High expression of cyclooxygenase-2 in macrophages of human colonic adenoma

Int J Cancer. 1999 Nov 12;83(4):470-5. doi: 10.1002/(sici)1097-0215(19991112)83:4<470::aid-ijc6>3.0.co;2-f.

Abstract

Cyclooxygenase (COX)-2 is a possible molecular target for suppression of colon carcinogenesis by non-steroidal anti-inflammatory drugs (NSAIDs). However, the expression of COX-2 in human colonic tumors during the adenoma-carcinoma sequence has not been elucidated. In the present study, we examined immuno-histochemically the expression and localization of the COX-2 protein in human colonic adenomas and cancers. Twelve human colonic adenomas and 9 advanced cancers were studied. Immunoreactive COX-2 was predominantly and strongly expressed in sub-epithelial interstitial cells broadly present in the surface area of adenomas. The staining pattern of macrophages was similar to that observed for COX-2 in adenomas. Adjacent normal colonic mucosa was negative for COX-2 expression. In contrast, COX-2 was relatively weakly expressed in both tumor cells and interstitial cells in advanced colon cancers. In conclusion, the target of NSAIDs in preventing colon carcinogenesis may be the COX-2 expressed in interstitial cells, possibly macrophages, of colonic adenomas.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoma / enzymology*
  • Adenoma / metabolism
  • Adult
  • Aged
  • Aged, 80 and over
  • Antibody Specificity
  • Antigens, CD / biosynthesis
  • Antigens, Differentiation, Myelomonocytic / biosynthesis
  • Blotting, Western
  • Carcinoma / enzymology*
  • Carcinoma / metabolism
  • Colonic Neoplasms / enzymology*
  • Colonic Neoplasms / metabolism
  • Cyclooxygenase 2
  • Humans
  • Immunohistochemistry
  • Isoenzymes / biosynthesis*
  • Isoenzymes / immunology
  • Macrophages / enzymology*
  • Macrophages / metabolism
  • Membrane Proteins
  • Middle Aged
  • Prostaglandin-Endoperoxide Synthases / biosynthesis*
  • Prostaglandin-Endoperoxide Synthases / immunology

Substances

  • Antigens, CD
  • Antigens, Differentiation, Myelomonocytic
  • CD68 antigen, human
  • Isoenzymes
  • Membrane Proteins
  • Cyclooxygenase 2
  • PTGS2 protein, human
  • Prostaglandin-Endoperoxide Synthases