Increased expression of cyclooxygenase-2 and nitric: oxide synthase-2 in human prostate cancer

Cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2) and inducible nitric oxi de synthase-2 (NOS-2) each have an important role in angiogenesis. The expr ession of these genes was investigated in human prostate cancer by immunohi stochemistry, the expression of COX-1 and COX-2 being confirmed by mRNA ana lysis. Prostate cancer specimens from 12 patients were compared to control prostates from 13 patients operated on for bladder carcinoma. The intensity of COX-2 and NOS-2 immunostaining was significantly stronger in prostate c ancer cells than in the non-malignant glandular epithelium of the control p rostates. COX-2 and NOS-2 were clearly also expressed in the lesions of pro static intraepithelial neoplasia (PIN) in control prostates. COX-2 was dete cted in the muscle fibres of the hyperplastic stroma of some control prosta tes. No significant difference was detected in COX-1 expression between con trol and cancer prostates. These results indicate that the expression of CO X-2 and NOS-2 is elevated in prostatic adenocarcinoma and in PIN.