The Mechanism of the Synergistic Anticancer Effect of CDDP and EPA in the TE1 Cell Line.

Background/aim Eicosapentaenoic acid (EPA) is an unsaturated fatty acid with various bioactivities, including antitumor effects. We previously reported a synergistic antitumor effect of cisplatin (CDDP) and EPA. Here, we examined the underlying mechanism. Materials and methods The human oesophageal cancer cell line TE-1 was treated with the combination of EPA and CDDP. Nuclear translocation of NF-κB, a transcription factor involved in cytokine production, was detected by immunohistochemistry. IL-6 levels were measured by ELISA. Apoptosis and cell cycle distribution were evaluated by flow cytometry. Results Nuclear translocation of NF-κB in TE-1 cells was synergistically decreased by CDDP and EPA. IL-6 production was increased following treatment with CDDP, but treatment with EPA decreased IL-6 levels. Apoptosis was synergistically induced by CDDP and EPA. A G2/M cell cycle arrest was observed with the combination of CDDP and 150 μM EPA, and S phase arrest with the combination of CDDP and 100 μM EPA. Conclusion The combination of CDDP and EPA synergistically suppresses NF-κB nuclear translocation and increases apoptosis by inducing cell cycle arrest at the S or G2/M phase.