Protein kinase C (PKC) isoenzymes immunohistochemistry in lymph node revealing solution-fixed, paraffin-embedded bladder tumors

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 ex pression pattern of PKC isoenzymes is altered in some tumors compared to th eir 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 specifi c for the PKC isoenzymes: alpha, beta 1, beta 2, delta, and zeta. The secti ons were scored for intensity of staining, and the correlation with grade a nd 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 a nd 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 isoenzpme expression differs in invasive TCC compared to low-grad e, low-stage TCC and normal urothelium. The value of these findings as a ma rker of tumor aggressiveness should be further assessed.