Supplementation of MCF-7 cells with essential fatty acids induces the activation of protein kinase C in response to IGF-1.
The effects of changing the composition of membrane lipids on protein kinase C (PKC) activation were studied in MCF-7 human breast cancer cells. The supply of linoleate or alpha-linolenate to MCF-7 cells altered cell membranes fatty acid composition but did not affect PKC activity. When the cells were additionally exposed to IGF-1, the same fatty acids caused a dramatic increase in membrane-bound PKC activity. We also found that the mitogenic response induced by IGF-1 was not enhanced in those conditions when PKC becomes activated by linoleate and alpha-linolenate. These data show that these fatty acids elicit a distinct route for the transmission of IGF-1 signal by inducing the PKC pathway. They suggest that linoleate and alpha-linolenate could control the biological response of MCF-7 cells to IGF-1.
Lanson
M
M
J.E. 313 Lipides et croissance, Faculté de Médecine, Tours, France.
Besson
P
P
Bougnoux
P
P
D001943:Breast Neoplasms; D004789:Enzyme Activation; D005227:Fatty Acids / Q000032:analysis; D005228:Fatty Acids, Essential / Q000494:pharmacology*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000494:pharmacology; D008563:Membrane Lipids / Q000737:chemistry / Q000378:metabolism; D010743:Phospholipids / Q000032:analysis / Q000737:chemistry; D011493:Protein Kinase C / Q000378:metabolism*; D017526:Receptor, IGF Type 1 / Q000378:metabolism; D015398:Signal Transduction; D014407:Tumor Cells, Cultured; D017962:alpha-Linolenic Acid / Q000494:pharmacology
D005227:Fatty Acids; D005228:Fatty Acids, Essential; D008041:Linoleic Acids; D008563:Membrane Lipids; D010743:Phospholipids; D017962:alpha-Linolenic Acid; D007334:Insulin-Like Growth Factor I; D019787:Linoleic Acid; D017526:Receptor, IGF Type 1; D011493:Protein Kinase C