Fig. 3

Altered metabolite concentrations in IDH1-mutant and 2-HG-treated (72 h, 4 mM) U251 wt cells and the evaluation of the bioenergetic source of 2-HG production in U251 IDH1m cells (LC-MS measurements). a TCA cycle related metabolite levels (relative to wt) in IDH1m and 2-HG-treated U251 wt cells - (DMEM high glucose medium + 10% FBS + 2 mM L- glutamine). b Alterations in intracellular glutamate and 2-HG levels (relative to IDH1m) in 2-HG-treated U251 wt cells and in wt cells; u.d. = under detectable level - (DMEM high glucose medium 10% FBS + 2 mM L- glutamine). c Unlabelled and ¹³C-labelled intracellular 2-HG productions (% of total 2-HG pool) (24-h labelling period). To avoid starving condition, the medium was supplemented with 10% FBS and 10 mM D-glucose and/or 4 mM L-glutamine: 4 mM U-¹³C-glutamine labelling in D5030 + 10% FBS and 10 mM D-glucose; 10 mM U-¹³C-glucose labelling in D5030 + 10% FBS and 4 mM L-glutamine; or 10 mM 2-¹³C-acetate labelling in D5030 medium + 10% FBS + 10 mM D-glucose and 4 mM L-glutamine. Unlabelled 2-HG does not contain incorporated ¹³C atoms, M + 1/2/3/4/5 = mass number increased with 1/2/3/4 or 5 ¹³C atoms in 2-HG from different labellings; *:p < 0.05