Overexpression of cyclooxygenase-2 in human prostate carcinoma and prostatic intraepithelial neoplasia-association with increased expression of Polo-like kinase-1.

Background: Cyclooxygenases (COX) as well as Polo-like kinases (PLK) are involved in proliferation and cell cycle regulation and have been suggested for preventive and therapeutic approaches in prostate carcinoma.

Methods: In this study, we studied expression and prognostic impact of COX-2 in invasive prostate carcinoma, prostatic intraepithelial neoplasia (PIN), atrophic glands, and normal prostatic glands, and investigated the association between COX-2 and PLK-1.

Results: We observed a positivity for COX-2 in 72.1% of PIN and in 44.7% of prostate carcinomas with an overexpression of COX-2 in prostate cancer and PIN compared to benign prostatic tissue (P < 0.0005). Furthermore, we observed a strong correlation between expression of PLK-1 and COX-2 (P < 0.0005).

Conclusions: To our knowledge, this is the first report of a correlation between COX-2 and PLK-1 in a malignant tumor. COX-2 and PLK-1 may be interesting targets for new molecular therapies in prostate cancer.