Effect of palmitoylcarnitine on the cellular differentiation, proliferation and protein kinase C activity in neuroblastoma nb-2a cells.
Palmitoylcarnitine is synthesized through the action of palmitoylcarnitine transferase I--an enzyme specifically inhibited by etomoxir. An increase of the intracellular content of palmitoylcarnitine in neuroblastoma NB-2a cells after administration of carnitine was correlated with an inhibition of cell proliferation and a concomitant promotion of differentiation processes. The activity of protein kinase C was measured in vivo, with cells permeabilized through the use of streptolysin O and a peptide substrate. Palmitoylcarnitine inhibited the phorbol ester stimulated reaction of the peptide phosphorylation in a concentration dependent way. The degree of protein kinase C inhibition was correlated with intracellular increase of the palmitoylcarnitine content, pointing to this compound as a natural modulator of protein kinase C activity.
Nałecz
K A
KA
Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology, Warsaw, Poland. knal@nencki.gov.pl.
Mroczkowska
J E
JE
Berent
U
U
Nałecz
M J
MJ
D000818:Animals; D002331:Carnitine / Q000032:analysis; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004852:Epoxy Compounds / Q000494:pharmacology; D051379:Mice; D009447:Neuroblastoma; D010172:Palmitoylcarnitine / Q000494:pharmacology*; D011493:Protein Kinase C / Q000378:metabolism*; D014407:Tumor Cells, Cultured / Q000737:chemistry / Q000166:cytology / Q000201:enzymology
D004791:Enzyme Inhibitors; D004852:Epoxy Compounds; D010172:Palmitoylcarnitine; D011493:Protein Kinase C; C054207:etomoxir; D002331:Carnitine