The expression of COX-2 and its relationship to the apoptosis and proliferation in colorectal carcinoma

Objective To investigate the expression level of cyclooxygenase-2 (COX-2) and its effects on cell proliferation activity and apoptosis in colorectal carcinoma. Methods The expression of COX-2, proliferating cell nuclear antigen (PCNA) and apoptosis in 60 cases of colorectal carcinoma, 20 cases of colorectal adenoma and 20 cases of normal mucous were studied by the immunohistochemical and TUNEL methods, the apoptosis index(AI)and proliferation index(PI) were defined respectively. Results The positive expression rate of COX-2 in colorectal carcinoma was significantly higher than that in the other groups. Overexpression of COX-2 in colorectal carcinoma was related to its lymph node metastasis and the size of tumor and clinical stages. In the group with COX-2 positive expression, PI was higher than that in the group with COX-2 negative expression; whereas AI was higher in the latter group than in the former group. Conclusions The expression level of COX-2 may have a close correlation with cell proliferation and apoptosis, they may participate in oncogenesis and progression of colorectal carcinoma.