Synthetic ω-3 Epoxyfatty Acids As Antiproliferative and Proapoptotic Agents in Human Breast Cancer Cells

omega-3-17,18-Epoxyeicosapentaenoic acid decreases cell proliferation and activates apoptosis, whereas its regioisomers stimulate growth. We evaluated synthetic omega-3 epoxides of saturated fatty acids as antiproliferative and pro-apoptotic agents in MDA-MB-231 breast cancer cells. The epoxides, but not their urea, amide, or carbamate isosteres, impaired ATP production, enhanced caspase-3 activity, and activated c-jun-N-terminal-kinase signaling, leading to cyclin D1 down-regulation and cell cycle arrest in G(1)-phase. Fatty acid omega-3 monoepoxides may represent a novel class of antitumor agents.