Fig. 4: NRBF2-induced autophagy provides a metabolic advantage to GBM cells.

a Oxygen consumption rates (OCR) and extracellular acidification rates (ECAR) were measured by a Seahorse XFp Analyzer in U-87 MG and A172 cells with or without IR (3 Gy), IR-treated U-87 MG cells with or without NRBF2 knockout, and IR-treated A172 cells with or without NRBF2 knockdown. b OCR and ECAR were measured in IR-treated patient-derived GBM cells with or without NRBF2 knockdown. c–g Each bar graph shows the metabolite levels in WT and NRBF2 knockout U-87 MG cells. c ATP levels were determined in WT and NRBF2 knockout U-87 MG cells after irradiation (3 Gy). d TCA cycle metabolites such as citrate, succinate, fumarate, and malate were detected. e Metabolites of glycolysis-related pathways were determined by measuring the NADP⁺/NADPH ratio, glycerol-3-phosphate, and serine levels. f WT and NRBF2 knockout U-87 MG cells were incubated with [1-¹⁴C] oleic acid, and ¹⁴CO₂ production from the complete b-oxidation of [1-¹⁴C] oleic acid was analyzed. g After incubation with [9,10-³H] oleic acid (pulse) followed by incubation in DMEM (chase), media equivalent to 500 μg of cell protein were analyzed for radioactivity in the form of ³H₂O. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001 using an unpaired t test.