Immunohistochemical expression of protein p16 in Wilms' tumor

Proliferative disorders including tumors are recognized as diseases of the cell cycle in which the crucial role belongs to the cyclin-dependent kinase family. The aim of this study was to investigate the expression of protein p16 in the normal kidney, and in Wilms tumor by immunohistochemistry to correlate the obtained results with tumor stage, histological type and prognostic group. We have investigated 28 cases of Wilms tumor, two Wilms tumor metastases in the lungs and one case of normal renal tissue. Protein p16 was over expressed in 20 cases of Wilms tumor. Expression of p16 was less frequent in stages III/IV/V than in stages I/III, showing no statistically significant correlation (p > 0.05). Intermediate risk groups of Wilms tumor showed more frequent p16 expression in comparison with high risk cases, showing no statistical significance (p > 0.05). Protein p16 expression was detected in all histologic types of Wilms tumor with the highest expression in the predominantly blastemal type (50%). There was a statistically significant difference between p16 expression in this and its expression in other histological types (p lt 0.05). The correlation between p16 expression and the predominantly blastemal histological type was statistically significant and showed that in such cases tumor cells can proliferate even in the presence of p16