Abstract 4758: Benzaldehyde suppresses multiple signal pathways in cancer cells by regulating 14-3-3ζ-mediated protein-protein interactions

Abstract

Abstract Benzaldehyde is the simplest aromatic aldehyde constituent of almonds and many fruits. Anticancer effect of Benzaldehyde was first reported in 1980, and multi-institutional clinical trials were performed in those days in Japan. However trial was over without determination of effectiveness, only its safety was confirmed. The underlying mechanism why Benzaldehyde specifically suppresses growth of some particular cancer cells but not that of normal cells has not been elucidated. Therefore, we attempted to clarify the mechanism of anticancer effect of Benzaldehyde. In pancreatic cancer cell BxPC3 and in non-small cell lung cancer cell A549, we found that Benzaldehyde inhibits PI3K/AKT/mTOR, STAT3, NFκB and ERK pathways, those are major signaling pathways activated in cancer cells. Effects of Benzaldehyde on multiple signaling pathways are found to be derived from regulation of 14-3-3 family proteins which interact with phosphorylation sites of various proteins of multiple signals. In BxPC3 cells, Benzaldehyde treatment reduced the phosphorylation levels of 14-3-3-binding sites. Furthermore, we ectopically expressed seven isoforms of 14-3-3 in HEK293T cells and found that Benzaldehyde treatment significantly suppressed association of 14-3-3ζ with client proteins such as mTOR, Rictor, cRaf, STAT3 and FOXOs. The interaction of other isoforms of 14-3-3 with their client proteins was also partially reduced. But, the expression levels of those seven 14-3-3 isoforms were not significantly changed. Those data indicate that Benzaldehyde suppresses the interaction of 14-3-3ζ with its client proteins. Recent reports have shown that 14-3-3ζ is overexpressed in many cancers and acts as a signaling hub controlling the network of oncogenic pathways, suggesting that 14-3-3ζ associates with carcinogenesis, metastasis and resistance for chemotherapy and radiation. Hence, Benzaldehyde is considered to be a new class of anti-cancer agent inhibiting 14-3-3ζ-mediated tumor promoting and/or maintaining signals. Citation Format: Jun Saitoh, Hideyuki Saya. Benzaldehyde suppresses multiple signal pathways in cancer cells by regulating 14-3-3ζ-mediated protein-protein interactions. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4758.