Over-Expression of Cyclooxygenase-2 in Colorectal Cancer Patients

Document Type: Research Articles

Authors

1 Department of Biophysics, Panjab University, Chandigarh, India.

2 Department of Gastroenterology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India.

3 Department of General Surgery, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India.

4 Centre for Nuclear Medicine, Panjab University, Chandigarh, India.

Abstract

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

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