Quantitative analysis of cyclin E and protein p34 cdc2 expression in superficial bladder cancer

In the present study, the expression of cyclin E and kinase p34 cdc2 was investigated in preinvasive bladder tumors. The study material consisted of bladder sections (grades: GI--16 cases, GII--10, and GIII--12) collected from 38 patients in the course of the tumor electroresection. Immunohistochemical examinations were carried out with immunoperoxidase method. Antigens were labeled with NCL-CYCLIN E or NCL-p34 cdc2 monoclonal antibodies (Novocastra, UK). Positive reaction was demonstrated using ABC-universal Kit (Novocastra, UK). Differences in the protein expression in relation to the tumor grade were determined with a non-parametric Mann-Whitney's test. Increasing grade of tumors was associated with down regulation of cyclin E visible as lower percentage of cyclin E-positive cells. These changes were statistically significant for GI group as compared to groups GII and GIII (p<0.001). There were no differences between the study groups in the p34 protein expression. Cyclin E expression was inversely correlated with tumor grade therefore may be helpful in establishing therapeutic procedure.