Effects of omega-3 fatty acids on components of the transforming growth factor beta-1 pathway: implication for dietary modification and prevention in ovarian cancer

Objective: We previously demonstrated that omega-3 fatty acids (OM-3FAs) have definitive inhibitory effects on ovarian cancer cell lines. We sought to determine whether the inhibitory effects of OM-3FAs were mediated by the transforming growth factor (TGF)-β1 signaling pathway. Study Design: Ovarian cancer cell lines were grown at 37°C in 5% CO₂ and treated with OM-3FAs, omega-6 fatty acids, and control at different concentrations for 24-72 hours. Enzyme-linked immunosorbent assay (ELISA) assay and Western blot analysis were used to measure TGF-β1, phosphorylated mothers against decapentaplegic (Smad)-3 and p21 protein levels. Results: An ELISA assay demonstrated that OM-3FA treatment increased TGF-β1 in all 3 Hey cell lines (P < .05). In both SKOV-3 and OVCAR-3 cells, TGF-β1 levels were not significantly increased. Western blots confirmed increases in TGF-β1, Smad-3 and p21 protein levels in Hey and HeyC2 but not SKOV-3 and OVCAR-3 cells. Conclusion: OM-3FAs increased the level of TGF-β1, Smad-3, and p21 protein in ovarian cancer cells known to be more sensitive to their inhibitory effect.