Correlation of expression of COX-2 to clinical pathological characters and its catalytic products in gastric carcinoma

Objective To test the expression of cyclooxygenase-2 (COX-2) in gastric carcinoma and to investigate the relationship between the expression of COX-2 and clinical pathological characters, and its relation with its catalytic products, prostaglandin E2 (PGE2 ) and thromboxane A2 (TXA2). Methods The expression of COX-2 was examined by immunohistochemical staining and the levels of PGE2 and TXB, were examined using a ra-dioimmunoassay. Results COX-2 expression was detected in 62.2% of gastric carcinoma by immunohistochemical staining with COX-2 specific polyclonal antibodies. There was a close correlations between COX-2 expression and clinicopathological factors including tumor size ( P 0.05), lymph node metastasis (P 0.01) and TNM stage (P 0.05) . The cases with COX-2 expression showed significantly higher levels of PGE2 in the cancer tissues than in the normal gastric mucosa, and the levels of PGE2 in the cancer tissues with COX-2 expression were higher than in those without. The levels of TXB2 was not different between the normal and cancer tissue specimens in the patients with COX-2 expression or those without. Conclusion COX-2 overexpression was associated with tumor size, lymph node metastasis and TNM stage. Increased levels of PGE2 in the gastric carcinoma tissues were prominent in patients with COX-2 expression, so the role that COX-2 plays in the progression of gastric carcinoma may be associated with PGE2 biosynthesis.