Patterns of protein kinase C isoenzyme expression in transitional cell carcinoma of bladder

We determined the pattern of protein kinase C (PKC) isoform expression in h uman cell lines by Western blotting and immunofluorescent staining techniqu es. In addition, we examined PKC isoform expression in tissue samples of tr ansitional cell carcinoma (TCC) of the bladder PKC delta, PKC beta II, and PKC eta were found primarily in the RT4 cell line (low-grade tumor), and PK C zeta was expressed most strongly in the SUP cell line (invasive tumor). I n tissue samples of urinary bladder cancer, PKC isoenzymes were expressed d ifferentially as a function of tumor stage and grade; expression of PKC bet a II and PKC delta was high in normal tissue and in low-grade tumors and de creased with increasing stage and grade of TCC. The opposite pattern was se en with PKC zeta. The differences in expression of specific isoenzymes as r elated to levels of malignancy of the cell lines and tissue samples suggest that the PKC family has an important role in normal and neoplastic urothel ium.