Eicosapentaenoic acid reduces the invasive and metastatic activities of malignant tumor cells

Recent studies have shown that the cyclooxygenase and the 5-lipoxygenase pathways of arachidonic acid, are required for the invasive and metastatic activity of certain tumor cells. We show here that malignant murine melanoma and human fibrosarcoma cells cultured in media supplemented with eicosapentaenoic acid show a dose and time dependent decrease in invasiveness, in collagenase IV production and in the case of the murine cells, a reduced ability to metastasize to the lung after intravenous injection. It was also shown that a metabolite of eicosapentaenoic acid was less potent than the comparable arachidonic acid metabolite in restoring collagenase IV production and invasiveness after inhibition of the lipoxygenase pathway. These studies indicate that such supplements have the potential to reduce the metastasis of certain tumor cells, converting them to benign status.