Over-Expression of Cyclooxygenase-2 in Colorectal Cancer Patients

Abstract

Background: Colorectal carcinoma (CRC) is the most common neoplasm of the gastrointestinal tract. COX-2<br />plays an important role in CRC development and is a key target for the regression of colorectal tumorigenesis by nonsteroidal<br />anti-inflammatory drugs. The present study was conducted to examine the relationship of the levels of COX-2<br />in CRC patients with the clinico-pathological parameters and also to assess its usefulness as a potential biomarker for<br />diagnosis of CRC. Methods: Prior to surgery, 30 CRC patients were enrolled and the samples from colon tumors and<br />surrounding tissues were taken after they underwent surgical intervention at PGIMER, Chandigarh. mRNA expression<br />levels of COX-2 were examined in 30 CRC and adjacent normal colonic mucosa by quantitative polymerase chain<br />reaction (qPCR). The expression of COX-2 was assessed by immunohistochemical method using rabbit polyclonal<br />antibodies against human COX-2 protein. Results: The quantitative relative expression of COX-2 mRNA was observed<br />to be significantly higher (p<0.05) in colorectal cancer tissues as compared to adjacent normal colon tissues. Also,<br />female CRC patients showed significantly higher (p<0.009) expression of COX-2 mRNA vis-a-vis male colorectal<br />cancer patients. This is the first study which has reported a direct relationship between COX-2 mRNA expressions in<br />male colorectal cancer patients versus females. Further, immunohistochemistry of COX-2 confirmed the quantitative<br />real time-PCR findings. Conclusion: Our study shows that COX-2 over expression in colorectal carcinoma patients<br />is closely associated with clinico-pathological parameters and is more pronounced in males versus females. Further,<br />COX-2 mRNA expression can serve as a potential biomarker for the diagnosis of CRC.