Fig. 1

CPI-613-induced GLS1 upregulation abrogates CPI-613 cytotoxicity in HNSCC cells. A The effect of CPI-613 on HNSCC cell viability determined by MTT after a three-day treatment. B The effect of CPI-613 on HNSCC cell viability in SeedEZ™ 3D scaffold after a fourteen-day treatment. Representative fluorescence images from HN30 and HN31 cells and quantitative data from three independent experiments are shown in the left and right panels, respectively. C-E The effect of CPI-613 on the protein levels of glycolytic and glutamine metabolism-related enzymes. Cell lysates collected from 2D culture dish (C) and SeedEZ™ 3D scaffold (D) were subjected to this analysis. Representative Western blotting images and quantitative data from three independent experiments are shown in (C, D) and (E), respectively. F The effect of CPI-613 on GLS1 levels in CPI-613 sensitive cell lines, HN12 and HN30. G The effect of CPI-613 on GSH level in HNSCC cells determined by a Glutathione Detection Assay Kit. (H) The effect of glutamine (Gln) on HNSCC cell viability determined by a colony formation assay. *p < 0.05, **p < 0.01