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

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 Bcl-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.