Fig. 6: Role of FLIP in cell death induced by glutamine deprivation.
A HCT116 (left panel) or MDA-MB468 (right panel) cells were cultured in the presence or absence of glutamine for the indicated times. Tubulin and GAPDH were used as protein-loading controls. Following these treatments, FLIPL and FLIPS levels were assessed by Western blotting. B Apoptosis was assessed in pBabe or FLIPL overexpressing HCT116 cells cultured in the presence or absence of glutamine for 48 h (left panel). Procaspase-8 levels, caspase-8 activation (cC8) and FLIPL overexpression were determined by Western-blotting after 30 h of glutamine starvation (right panel). C Apoptosis was assessed in pBabe or FLIPL-overexpressing MDA-MB468 cells cultured in the presence or absence of glutamine for 48 h. FLIPL overexpression was detected by Western blotting. In B and C data are presented as mean ± SD from at least three independent experiments. **P < 0.01; ***P < 0.001; two-way ANOVA test. Tukey’s multiple comparison test. D HCT116 cells were cultured in the presence or absence of glutamine for 16 h, with or without dimethyl α-ketoglutarate (5 mM). FLIP levels, ISR activation and TRAIL-R2 upregulation were assessed by Western blotting. In E apoptosis was assessed in HCT116 cells cultured in the presence or absence of glutamine for 48 hours, with or without dimethyl α-ketoglutarate. Data are presented as mean ± SD from at least three independent experiments. **P < 0.01; ***P < 0.001; two-way ANOVA test. Tukey’s multiple comparison test.
