Bamba H, Ota S, Kato A, Adachi A, Itoyama S, Matsuzaki F
First Department of Internal Medicine, Saitama Medical Center, Saitama Medical School, Saitama, Japan.
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.
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.
