A study sought to determine if dietary omega-3 fatty acids (FAs), in relation to prostate cancer, inhibit angiogenesis and activate T-cells, and if these effects are dependent on host G-protein coupled receptor 120 (GPR120). The findings appeared in Prostate Cancer and Prostatic Diseases.
To conduct this study, Gausia luciferase labeled MycCaP prostate cancer cells (MycCaP-Gluc) were injected into the anterior prostate lobe of FVB mice. Tumors were confirmed via blood luminescence, and mice were put on a diet of either ω-3 or ω-6. Tumor weight, immune cell infiltration, and markers of angiogenesis were determined at five weeks after tumor injection.
The results demonstrated that feeding mice with an omega-3 diet markedly reduced orthotopic MycCaP-Gluc tumor growth relative to an ω-6 diet. The researchers observed that tumors from the ω-3 group had decreased M2-like macrophage infiltration and decreased expression of angiogenesis factors. DHA significantly inhibited M2 macrophage-induced endothelial tube formation and reversed M2 macrophage-induced T-cell suppression, and these DHA effects were mediated in part by M2 macrophage GPR120.
“Omega-3 FAs delayed orthotopic tumor growth, inhibited M2-like macrophage tumor infiltration, and inhibited M2-like macrophage-induced angiogenesis and T-cell suppression. Given the central role of M2-like macrophages in prostate cancer progression, GPR120-dependent ω-3 FA inhibition of M2-like macrophages may play an important role in prostate cancer therapeutics,” the researchers concluded.