Expression of cyclooxygenase-1 and -2 and clinicopathologic features of colorectal cancer in northern Thailand.

Two isoforms of cyclooxygenase, COX-1 and COX-2, have been identified and shown to be involved in tumorigenesis. Although, overexpression of COX-2 in human cancers has been repeatedly reported, no data have hitherto been available for Thai patients. To cast light on the role(s) of COX enzymes in the development and progression of colorectal cancers and to determine the incidence of COX-2 overexpression, the expression levels of COX-1 and COX-2 proteins using Western blot analysis in tumor tissues and adjacent normal tissues obtained from 44 Thai patients with colorectal cancer.