Immunoexpression of cell cycle regulators in canine prostate with proliferative lesions

Abstract

Immunostaining of p21, p27, p53, cyclin D1, c-myc was evaluated in normal canine prostate and prostate with proliferative disorders to verify the interaction between these regulators of cell cycle progression. From 106 samples of canine prostate obtained from a TMA block, 15 were considered normal, 16 diagnosed as benign prostatic hyperplasia (BPH), 30 as proliferative inflammatory atrophy (PIA), 20 as prostatic intraepithelial neoplasia (PIN), and 25 as prostatic carcinoma (PC). There was positive correlation between p21 and p27 for number of stained cells and staining intensity in all conditions and between c-myc and p53 in prostates with PIN. Considering the number of labeled cells, there was positive correlation between p21 and p53 in the normal prostate. Relative to the intensity of staining, there was positive correlation between p21 and p53 in prostate tissue with PIN and between p27 and c-myc in prostates with PIA. A negative correlation between c-myc and cyclin D1 was also identified in the glands with PIN, considering the number of labeled cells, and between p27 and c-myc in the prostates with PC for staining intensity. In conclusion, the expression of p21, p27, p53, cyclin D1 and c-myc varies according to type of proliferative lesion in canine prostate. Taken together, the results indicate low growth potential of the canine PC in the presence of p21 and p27 overexpression, cyclin D1 low expression and regular expression of c-myc, even with the expression of p53 mutant type. Further, it was possible reaffirm the premalignant potential of PIA and PIN in canine prostate.