Omega-3 Polyunsaturated Fatty Acids Induce Cell Cytotoxicity Through Apoptosis And Autophgy In Brain Cancer In Vitro And In Vivo

One of the most common and biologically aggressive of malignant astrocytic gliomas is glioblastoma (GBM). Studies have revealed a significant role of phosphatidylinositol-3-OH kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling activation during GBM development. Omega-3 polyunsaturated fatty acids (≥3-PUFAs) have been shown to inhibit several cancer cells growth such as breast cancer cells. Here, we examined the anticancer effect of α3-PUFAs in D54 malignant glioma (D54MG) cells. We show that docosahexaenoic acid (DHA), a α3-PUFA, induced apoptosis in D54MG cells, as confirmed by the formation of cleaved PARP, TUNEL assay and cytofluorometric analysis. DHA-treated D54MG cells also showed a significant increase in autophagic activity as revealed by LC3-II elevation, autophagic vesicles formation and autophagy flux assays, suggeting that both apoptosis and autophagy contribute to the DHA-induced tumor cell death. The DHA-induced cell death in D54MG cells was accompained by the activation of AMPK and decrease in the Akt phosphorylation. DHA also decreased the activity of mTOR and the level of its downstream molecule 4EBP as analyzed by the Western blot assay. DHA-induced apoptosis and autophagy were partially blocked by transient overexpression of Akt, supporting the inhibition of Akt being beneficial to the death of GBM cells. In in vivo studies, the growth of implanted murine GBM cells in Fat-1 transgenic mice, that can produce high levels of α3-PUFA, was significantly inhibited, and the apoptotic index was higher compared with wild type mice. Together, these results suggest that α3-FUFAs induce cell cytotoxicity through apoptosis and autophgy in brain cancer. [This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology(2011-0006232).] Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1985. doi:1538-7445.AM2012-1985