Expression of p27^(Kip1), cyclin D3 and Ki67 in BPH, prostate cancer and hormone-treated prostate cancer cells

p27^(Kip1), cyclin D3 and Ki67 are the markers of DNA damage and cell proliferation. The goal of the current study was to analyze expression of the markers in benign and malignant prostate cancer tissues. Activity of p27^(Kip1), cyclin D3 and Ki67 was immunohistochemically evaluated in different cells of BPH, prostate cancer (PCa) and hormonally treated prostate cancer (HTPCa) tissues. The tissue samples were derived by means of TURP or radical prostatectomy. Intensity of the expression was compared between the groups, and association was sought with clinical parameters. Total expression of p27^(Kip1) was significantly higher in BPH as compared with PCa. Epithelial marker expression was higher in HTPCa than in PCa. Intensity of the expression in epithelial, vascular and ductal cells was negatively associated with the tumor stage and Gleason grades. Total Ki67 activity was positively correlated with patient age and serum PSA level. There was significantly higher expression in PCa and hormone-escaped PCa (HEPCa) as compared with BPH. Epithelial and vascular marker expression was positively associated with tumor stage and Gleason grades. There was a positive correlation between cyclin D3 and serum PSA level. With the increase of Gleason grades, cyclin D3 expression increased significantly. Expression of p27^(Kip1) negatively correlated with Ki67 and cyclin D3, while the latter two markers correlated positively. p27^(Kip1) is down-regulated, whereas Ki67 and cyclin D3 are up-regulated in PCa. Intensity of the markers’ expression is associated with tumor stage and grades. Hormonotherapy of PCa causes activation of p27^(Kip1). HEPCa is characterized by increased Ki67 expression.