Tumorigenicity-associated expression of protein kinase C isoforms in rhabdomyosarcoma-derived cells

• Published in: FEBS letters 1992-05, Vol.303 (1), p.15-18
• Main Authors: Hanania, Nicole, Lezenes, Jacqueline Robert, Castagna, Monique
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Blotting, Northern; Blotting, Southern; Blotting, Western; DNA - genetics; EGTA; ethyleneglycol-bis (b-aminoethyl ether)N,N,N′,N′-tetraacetic acid; Fundamental and applied biological sciences. Psychology; GAPDH; Gene expression; gluceraldehyde-3-phosphate dehydrogenase; Isoenzymes - genetics; Isoenzymes - metabolism; Molecular and cellular biology; Molecular genetics; Muscle; Nucleic Acid Hybridization; phenylmethylsulfonyl fluoride; PKC; PMSF; protein kinase C; Protein Kinase C - genetics; Protein Kinase C - metabolism; Protein kinase C isoform; Rat rhabdomyosarcoma; Rats; Rhabdomyosarcoma - enzymology; Rhabdomyosarcoma - genetics; RNA, Neoplasm - genetics; Tumor Cells, Cultured
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(92)80467-U

Cell sublines were derived from Ni-induced rat rhabdomyosarcoma which differed in their degree of tumorigenicity. We compared the expression of protein kinase C isoforms α, β, γ and ε in three sublines developing tumors in syngeneic rats (Sy +) and in two sublines devoid of tumorigenicity in these animals (Sy −), with that of normal skeletal muscle. Northern and Western blotting experiments showed that PKC α was dramatically overexpressed in Sy − cells whereas it was underexpressed in Sy + cells. Southern blot analysis provided evidence for a 3-fold increase of PKC α-related DNA fragments in Sy − cells. Steady-state levels of the PKC ε-related transcript were also markedly decreased in Sy + cells. However, the expression of PKC β-related RNA was increased in these cells. Our data support the concept that the differential expression of the PKC isoforms may play a critical role in determining the neoplastic phenotype.