Expression of Cyclooxygenase-2 in Human Transitional Cell Carcinoma of the Urinary Bladder

• Published in: The American journal of pathology Vol. 158; no. 3; pp. 849 - 853
• Main Authors: Ristimäki, Ari, Nieminen, Outi, Saukkonen, Kirsi, Hotakainen, Kristina, Nordling, Stig, Haglund, Caj
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Elsevier Inc 01.03.2001; ASIP; American Society for Investigative Pathology
• Subjects: Adult; Aged; Biological and medical sciences; Biomarkers, Tumor - metabolism; Carcinoma, Transitional Cell - enzymology; Carcinoma, Transitional Cell - pathology; Cyclooxygenase 2; Female; Gene Expression; Humans; Immunohistochemistry; Isoenzymes - immunology; Isoenzymes - metabolism; Male; Medical sciences; Membrane Proteins; Middle Aged; Neoplasm Invasiveness; Nephrology. Urinary tract diseases; Prostaglandin-Endoperoxide Synthases - immunology; Prostaglandin-Endoperoxide Synthases - metabolism; Short Communications; Tumors of the urinary system; Urinary Bladder - enzymology; Urinary Bladder Neoplasms - enzymology; Urinary Bladder Neoplasms - pathology; Urinary tract. Prostate gland; Human; Immunohistochemistry; Prostaglandin-endoperoxide synthase; Urinary system disease; Carcinoma in situ; Enzyme; Malignant tumor; Urinary tract disease; Transitional cell carcinoma; Carcinogenesis; Invasion; Pathology; Urinary bladder; Bladder disease; Oxidoreductases
• ISSN: 0002-9440; 1525-2191
• DOI: 10.1016/S0002-9440(10)64033-3

Recent studies suggest that expression of cyclooxygenase-2 (Cox-2) is elevated in transitional cell carcinoma (TCC) of the urinary bladder and that inhibition of Cox-2 activity suppresses bladder cancer in experimental animal models. We have investigated the expression of Cox-2 protein in human TCCs ( n = 85), in in situ carcinomas (Tis) of the urinary bladder ( n = 17), and in nonneoplastic urinary bladder samples ( n = 16) using immunohistochemistry. Cox-2 immunoreactivity was detected in 66% (67 of 102) of the carcinomas, whereas only 25% (4 of 16) of the nonneoplastic samples were positive ( P < 0.005). Cox-2 immunoreactivity localized to neoplastic cells in the carcinoma samples. The rate of positivity was the same in invasive (T1–3; 70%, n = 40) and in noninvasive (Tis and Ta; 65%, n = 62) carcinomas, but noninvasive tumors had a higher frequency (32%) of homogenous pattern of staining (>90% of the tumor cells positive) than the invasive carcinomas (10%) ( P < 0.05). However, several invasive TCCs exhibited the strongest intensity of Cox-2 staining in the invading cells, whereas other parts of the tumor were virtually negative. Finally, strong Cox-2 positivity was also found in nonneoplastic ulcerations (2 of 2) and in inflammatory pseudotumors (2 of 2), in which the immunoreactivity localized to the nonepithelial cells. Taken together, our data suggest that Cox-2 is highly expressed in noninvasive bladder carcinomas, whereas the highest expression of invasive tumors associated with the invading cells, and that Cox-2 may also have a pathophysiological role in nonneoplastic conditions of the urinary bladder, such as ulcerations and inflammatory pseudotumors.