Type-specific expression of protein kinase C isozymes in CNS tumor cells.

We examined specific expression of protein kinase C (PK-C) isozymes in cultured human glial and neuronal cell lines, using type-specific monoclonal antibodies MC-1a, -2a, and -3a (Hidaka H. et al., J. Biol. Chem., 263 (1988) 4523-4526). Immunoblotting experiments revealed that a 80 kDa band of three kinds of glioblastoma cells (A-172, SK-MG-1, SK-MG-4) was stained with MC-3a, whereas that of neuroblastoma cells (SK-N-MC) reacted with MC-2a. Immunoenzymetric assay showed that glioblastoma cells (A-172, SK-MG-1, SK-MG-4) contained 127.6 +/- 14.4, 248.8 +/- and 148.5 +/- 35.8 ng/mg protein of type III. respectively, while neuroblastoma cells (SK-N-MC) contained 389.5 +/- 20.7 ng/mg protein of type II. These results suggest that PK-C isozymes may be specifically expressed, depending on types of central nervous system (CNS) tumor cells.