Protein kinase C (PKC) plays an important role in cellular differentiation and in the malignant process. In an earlier study, it was shown that the expression pattern of PKC
isoenzymes is altered in some
tumors compared to their corresponding normal tissue. In this study, we evaluated the pattern of PKC
isoenzyme immunostaining in bladder
transitional cell carcinoma (TCC) of different grades and stages and normal tissue. Twenty-seven TCC samples and six areas of normal bladder mucosa were stained with
antibodies specific for the PKC
isoenzymes: alpha, beta 1, beta 2, delta, and zeta. The sections were scored for intensity of staining, and the correlation with grade and stage of the
tumors was computed. The PKC alpha and beta 2 immunostains were intense in normal urothelium and in all evaluated
tumors.
PKC beta 1 and delta stains were intense in normal and low-grade and -stage
tumors and weak in high-grade and -stage
tumors. The opposite trend was found for PKC zeta. PKC
isoenzyme expression differs in invasive TCC compared to low-grade, low-stage TCC and normal urothelium. The value of these findings as a marker of
tumor aggressiveness should be further assessed.