Conjugated linoleic acid (CLA) inhibits growth of Caco-2 colon cancer cells: possible mediation by oleamide.
We have previously observed that dietary conjugated linoleic acid (CLA) inhibited colon tumorigenesis induced by 1,2-dimethylhydrazine in rats. The present study was performed to determine the mechanisms by which CLA inhibits colon cancer cell growth. CLA markedly inhibited Caco-2 cell growth, while linoleic acid (LA) slightly increased growth. Both CLA and LA increased the production of material reactive to antibodies against prostaglandin (PG)E2 and leukotriene (LT)B4, estimated by a competitive enzyme immunoassays (EIA), in a dose-dependent manner. However, the magnitude of the increase was markedly higher with CLA than that with LA, suggesting that this material was not PGE2 or LTB4. The active compound was isolated by thin-layer chromatography and the nuclear magnetic resonance and infrared spectra revealed that the structure was identical to that of oleamide. The purified oleamide inhibited cell growth and cross-reacted with the EIA. These results indicate that inhibition of Caco-2 cell growth by CLA may be due in part to increased oleamide production.
Kim
Eun Ji
EJ
Division of Life Sciences, Hallym University, Chunchon, Korea.
Jun
Jong-Gab
JG
Park
Hyun Suh
HS
Kim
Si-Min
SM
Ha
Yeong Lae
YL
Park
Jung Han Yoon
JH
D018938:Caco-2 Cells; D002455:Cell Division / Q000187:drug effects*; D015232:Dinoprostone / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism; D006801:Humans; D007975:Leukotriene B4 / Q000378:metabolism; D008041:Linoleic Acids / Q000494:pharmacology*
D005227:Fatty Acids; D008041:Linoleic Acids; D007975:Leukotriene B4; D015232:Dinoprostone