Abstract 1283: Identification and activity of novel GLUT1 inhibitors in hepatocellular carcinoma

Abstract

Abstract Hepatocellular carcinoma (HCC) is an endemic disease globally, with a 5-year survival rate of 15%. Current treatment of late-stage HCC involves the use of chemotherapy and sorafenib, a multi-kinase inhibitor. Metabolic studies have indicated HCC has a high glycolysis rate, and is surrounded by a hypoglycemic microenvironment. Given the need for therapeutic options for HCC and its glycolytic nature, this study explored the activity of novel GLUT1 inhibitors in varied glucose concentrations. To assess target inhibition, [3H] deoxy-D-glucose (2DG) uptake assays were performed in HEK293 cells stably over-expressing GLUT1-4 individually. Six HCC cell lines were cultured in media with standard high glucose (HG:25mM) and low glucose/lactic acidosis (LGLA: 5mM glucose/20mM lactic acid) to mimic the hypoglycemic microenvironment. IC50s were assessed using the SRB assay, and other phenotypes using standard methods. Four novel GLUT1 inhibitors (IOM1-4) from the same chemical series were identified from diversity screening. The compounds exhibited differential potencies to GLUT proteins at the sub-μM level. The inhibitors reduced the uptake of 2DG, the extrusion of lactate, and increased apoptosis. In HCC cells, IC50s were lowest with IOM1 and 2 and highest with IOM4 (Table 1). HEP3B cells displayed exceptional sensitivity to the inhibitors. The ranking of potency according to the IC50s correlated with the 2DG uptake studies. There was no correlation between GLUT protein levels and IC50s. Significant differences in sensitivity to inhibitors were observed in cells cultured in HG and LGLA conditions. Cells cultured in LGLA had consistently lower glucose uptake compared those in HG conditions. In LGLA conditions, cells with low levels of reactive oxygen species (ROS) were more sensitive to GLUT1 inhibitors compared to cells with high ROS levels. In conclusion, GLUT1 inhibition can be influenced by microenvironment glucose levels and could be a strategy for HCC treatment. IC50 values (uM) for respective inhibitors in respective HCC cell linesCELL LINESInhibitorCultureC3AHEP3BHUH7PLCSKHEP1SNU449IOM1HG>5.00.8±0.040.3±0.06>5.01.4±0.451.7±0.38IOM1LGLA>5.00.2±0.134.0±1.20>5.00.1±0.021.6±0.28IOM2HG4.7±0.44<0.011.0±0.562.4±0.690.3±0.050.9±0.42IOM2LGLA>5.00.1±0.080.2±0.093.2±1.290.1±0.021.3±0.42IOM3HG>5.00.2±0.040.9±0.222.3±0.251.1±0.641.6±0.40IOM3LGLA>5.0<0.012.7±1.29>5.00.4±0.092.3±1.13IOM4HG>5.02.8±0.354.3±1.494.6±1.404.7±0.85>5.0IOM4LGLA>5.01.4±0.493.8±1.10>5.03.1±0.56>5.0 Citation Format: Bhaskar Bhattacharya, Sanamerjit S. Mann, Min Ji Han, Sarah HH Low, Gim Hwa Tan, Barry E. McGuinness, Sarah C. Trewick, Phillip M. Cowley, Alan Wise, Richie Soong. Identification and activity of novel GLUT1 inhibitors in hepatocellular carcinoma. [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 1283.