Tumorigenicity-associated expression of protein kinase C isoforms in rhabdomyosarcoma-derived cells.
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 alpha, beta, gamma and epsilon 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 alpha 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 alpha-related DNA fragments in Sy- cells. Steady-state levels of the PKC epsilon-related transcript were also markedly decreased in Sy+ cells. However, the expression of PKC beta-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.
Hanania
N
N
Groupe de laboratoires de l'IRSC, Villejuif, France.
Lezenes
J R
JR
Castagna
M
M
D000818:Animals; D015152:Blotting, Northern; D015139:Blotting, Southern; D015153:Blotting, Western; D004247:DNA / Q000235:genetics; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D009693:Nucleic Acid Hybridization; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism*; D012334:RNA, Neoplasm / Q000235:genetics; D051381:Rats; D012208:Rhabdomyosarcoma / Q000201:enzymology* / Q000235:genetics; D014407:Tumor Cells, Cultured
D007527:Isoenzymes; D012334:RNA, Neoplasm; D004247:DNA; D011493:Protein Kinase C