Abstract 3214: Resveratrol potentiates glycolytic inhibitor-induced neuroblastoma cell death independent of sirt activity

Abstract

Introduction: Low survival rates and severe side effects of current neuroblastoma treatments underline the need for more effective less toxic therapies. Compared to normal cells, cancer cells demonstrate high glucose consumption even under aerobic conditions, therefore; targeting the glycolytic pathway in cancer cells as a potential therapy is currently an area of intense investigation. The polyphenolic compound resveratrol which can be found in grapes, peanuts, red wine and purple grape juice, has demonstrated antitumor activities both in vitro and in vivo. Here we investigate the potential of inhibiting glycolysis in combination with resveratrol treatment. Methods: To inhibit glycolysis we used the glucose analog, 2-Deoxy-D-glucose (2-DG). N-MYC amplified neuroblastoma cells (NB1691) were exposed to low dose 2-DG (0.5 and 2mM) and resveratrol 10uM. Cell viability was determined at 72hr using MTS assay. Western blotting was used to determine cell signaling pathways and apoptotic protein levels. The role of the NAD+ dependent HDAC sirtuin 1 (sirt1) was determined using 50uM of the inhibitor sirtinol. Results: While 2-DG did reduce cell viability (2mM:82+4.4% of control), the combination of 2-DG and resveratrol significantly reduced cell viability (20+2.2%) compared to resveratrol alone (69+2.8%). Western blot analysis indicated a robust activation of AKT with 2-DG with treatment, however this activation was blocked with 10uM resveratrol. Furthermore, western blot analysis revealed that this was caspase dependent cell death. PI3K/Akt inhibitors wortmannin and LY-294002 (10uM each) also reduced cell viability in combination with 2-DG to approximately 40% compared to non-treated, confirming the protective role of AKT signaling in response to 2-DG treatment. To determine if resveratrol, a well-known activator of sirt1, inhibited AKT via sirt1, cells were pretreated with sirtinol. Inhibiting sirt1 did not prevent resveratrol's inhibition of AKT. Conclusions: The oncoprotein AKT mediates signaling processes involved in evading apoptosis and promoting cell proliferation and recently has been linked to glycolysis. Resveratrol significantly increased 2-DG-induced cell death by inhibiting the 2-DG induced increase in AKT activity independent of sirt1. Here we show that combining resveratrol with 2-DG, two relatively non-toxic agents can significantly reduce neuroblastoma cell viability. 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 3214. doi:1538-7445.AM2012-3214