Effect of 8,9-epoxy eicosapentaenoic acid on human breast cancer cell line MDA-MB-231

Abstract

Studies have shown that fatty acids from fish and fish oils, like eicosapentaenoic acid (EPA) and docosapentaenoic acid (DHA) may have a beneficial role in cancer by inhibiting proliferation or inducing apoptosis of the cancer cells. Several mechanisms involving different metabolites (eicosanoids) of the fatty acids have been suggested for the anti-cancer actions, but the detailed effects are still not known. One of the eicosanoid groups of the fatty acids are epoxy-EPAs. Little have been investigated about epoxy-EPAs’ effect on cancer cells. This experiment is based on previous studies from this laboratory that have shown an anti-proliferative effect of epoxy-EPA on murine endothelial cells (unpublished data). In this study the effect of 8,9-epoxy-EPA was tested on human breast cancer cell line MDA-MB-231. The epoxide was tested alone and in combination with an epoxide hydrolase inhibitor, N’N-dicycyclohexylurea (DCU). Different cell viability assays were assessed to investigate the effect of 8,9-epoxy-EPA on cancer cell proliferation. Cell cycle and immunoblotting were carried out to test if cell cycle regulatory proteins were affected. 8,9-epoxy-EPA was found to increase cell viability of MDA-MB-231. No change in cell cycle regulatory proteins was found. 8,9-epoxy-EPA was also tested on the MDA-MB-231 cells together with a well known anti-cancer drug, paclitaxel. Cell viability assay and cell cycle analysis were assessed. An increase in cell viability of cell treated with both 8,9-epoxy-EPA and paclitaxel compared to cell treated with paclitaxel alone was found. No effect of 8,9-epoxy-EPA on cell cycle was observed. Results from these experiments are not what we expected based on previous studies. Further studies on cell mechanism and apoptosis are required to investigate possible differences in cell response to epoxide n-3 fatty acids.