Abstract 833: Benzyl isothiocyanate mediates glucose uptake through AKT activation in breast cancer cells

Abstract

Abstract We have shown previously that benzyl isothiocyanate (BITC) administration retards the development of mouse mammary tumors driven by Her-2 oncogene proving in vivo evidence for its chemopreventive efficacy. However, we also observed an increase in glucose uptake by tumor in BITC treatment group compared with control mice. Proteomics using tumors from control and BITC-treated mice revealed changes in proteins related to metabolism. Thus, we studied the mechanism by which BITC increases glucose uptake using four cell lines with different genetic backgrounds (e.g., ER+, ER-, HER-2+, triple negative). Consistent with in vivo findings, BITC treatment enhanced the protein levels of glucose transporters (GLUT1 and GLUT4) regardless of ER, HER-2 or p53 status. On the other hand, lactate dehydrogenase (LDH) was downregulated in response to BITC treatment. Pyruvate kinase (PKM2) as well as tricarboxylic cycle (TCA cycle) related enzymes (IDH1, PDH, MDH) were upregulated in BITC treated cells compared with control. In agreement with these results, BITC treatment increased glucose, pyruvate, and acetyl-CoA levels but decreases lactate level. These results suggested that elevated glucose after BITC treatment was largely utilized through TCA cycle. Because AKT is known to regulate tumor metabolism including glycolysis and oxidative phosphorylation, we explored its involvement in BITC-mediated metabolic alterations. To our surprise, BITC treatment resulted in a marked increase in activation of AKT. Pharmacological inhibition of AKT antagonized BITC-mediated increase in GLUT1 expression as well as increase in glucose and pyruvate levels. In addition, AKT inhibition augmented BITC-mediated inhibition of cell survival (colony formation), induction of apoptosis, and suppression of migration in human breast cancer cells. Based on these findings, we propose that mammary cancer chemopreventive efficacy of BITC may be augmented by a combination regimen involving an AKT inhibitor. This study was supported by the grantCA129347 awarded by the National Cancer Institute. Citation Format: Ruchi Roy, Shivendra V. Singh. Benzyl isothiocyanate mediates glucose uptake through AKT activation in breast cancer cells. [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 833.