EXPRESSION OF CYCLOOXYGENASE-2 IN PATIENTS WITH BLADDER CARCINOMA

Abstract

Cyclooxygenase-2 is considered to have an important role in the development of metastasis in cancer due to angiogenesis function. The expression of cyclooxygenase-2 was found to be up-regulated in colorectal carcinoma and other cancers. We investigated cyclooxygenase-1 and 2 expressions in patients with bladder cancer, chronic cystitis and normal bladder. A total of 118 specimens were obtained from patients treated at Osaka City University Hospital for bladder cancer, including 10 with chronic cystitis and 8 with normal bladder tissue. Immunohistochemistry, with affinity purified antibodies against human cyclooxygenase-1 and 2 that did not have cross-reactivity with each other, and reverse transcriptase polymerase chain reaction to study the messenger RNA expression were performed. Although no marked expression of cyclooxygenase-2 was observed in the normal bladder, it was slightly seen in infiltrative inflammatory cells of chronic cystitis, and a higher expression was found in cancer cells. The extent and intensity of immunoreactive cyclooxygenase-2 polypeptides in cancer cells was statistically much greater than those in cells from normal bladder tissue. Moreover, correlation between cyclooxygenase-2 expression and tissue type or progression of bladder cancer was observed. Cyclooxygenase-2 expression was higher in grade 3 bladder cancer than in grade 1, and was higher in advanced than in early stage cancer. These results demonstrate that generated cyclooxygenase-2 in the cells of patients with bladder cancer might be significant in the proliferation of bladder malignant cells and development of invasions.