Synergistic action of apoptosis induced by eicosapentaenoic acid and TNP‐470 on human breast cancer cells

Abstract
The effects of eicosapentaenoic acid (EPA) and an angiogenesis inhibitor (TNP‐470) on the suppression of breast cancer cell growth were examined in five human breast cancer cell lines (MDA‐MB‐231, T‐47D, MCF‐7, KPL‐1, and MKL‐F). In all five cell lines, EPA and TNP‐470 alone both showed tumor growth inhibition in a time‐ and dose‐dependent manner, and in combination, a synergistic effect was seen at high concentrations. EPA plus TNP‐470 treatment evoked apoptosis as confirmed by the appearance of sub G1 populations, by DNA fragmentation, and by cell morphology. With the combination, the expression of Bax and Bc1‐xS, the apoptosis‐enhancing proteins, was more up‐regulated and that of Bcl‐2 and Bcl‐xL, the apoptosis‐suppressing proteins, was more down‐regulated compared to the use of EPA or TNP‐470 alone, suggesting that their synergistic effect was due to an acceleration of apoptosis.