Expression of COX-2 in normal and pyelonephritic kidney, renal intraepithelial neoplasia, and renal cell carcinoma.

Abstract

The role of inflammation in carcinogenesis is unknown. To determine the relationship between cyclooxygenase 2 (COX-2) expression, inflammation, and carcinogenesis in human renal cell carcinoma (RCC), we looked for COX-2 expression in normal and pyelonephritic kidney, renal intratubular neoplasia (RIN), and RCC tissues. COX-2 expression was assessed immunohistochemically in tissues obtained from 20 pyelonephritic kidneys, 16 normal kidneys, 19 RIN, and 75 RCC cases. COX-2 expression was found to be positive in 64% of RCCs. It was positive in 13 chronic pyelonephritic (65%), 9 normal (56%), and 15 RIN (79%) cases. COX-2 expression was significantly higher in RCC and RIN than the normal and pyelonephritic cases (p<0.001 and p<0.001, respectively). No statistically significant difference was noted between RCC and RIN cases. Although the function of COX-2 in tumor development has not been exactly elucidated, the increased expression of COX-2 in RIN and RCC might be a factor that may play a role in the development of RIN or progression to RCC, which warrants further research.