Expression of cyclooxygenase-2 (COX-2) in human invasive transitional cellcarcinoma (TCC) of the urinary bladder

Cyclooxygenase (COX)-inhibiting drugs have antitumor activity in canine and rodent models of urinary bladder cancer. Two isoenzymes of COX have been i dentified, COX-1 and COX-2. The purpose of this study was to characterize C OX-1 and COX-2 expression in human invasive transitional cell carcinoma of the urinary bladder by immunohistochemistry and Western blot analysis. COX- 2 was not expressed in normal urinary bladder samples but was detected in 2 5 of 29 (86%) invasive transitional cell carcinomas of the urinary bladder and in 6 of 8 (75%) cases of carcinoma in situ, These results indicate that COX-2 may play a role in bladder cancer in humans and support further stud y of COX-2 inhibitors as potential antitumor agents in human bladder cancer .