Cisplatin

The NHC-Pt compounds were diluted in water with a maximum of 0.9% of DMSO in the final solution. Cisplatin (MYLAN, Saint-Priest, France) and dacarbazine (MEDAC, Lyon, France) solutions were prepared according to the manufacturer’s recommendations and diluted at the appropriate concentration using the dedicated cell culture medium.

Glioblastoma U251 and LN18 cell lines were cultured at 37 °C in a humidified atmosphere with 5% CO₂ in Dulbecco's modified Eagle's medium (DMEM) containing 5 g/l glucose and supplemented with 100 U/ml penicillin, 100 μg/ml streptomycin, 2 mM Gln and, respectively, 10% and 5% fetal calf serum (FCS). T98 cells were cultured in DMEM 1 g/l glucose, supplemented with penicillin, streptomycin, Gln and 10% FCS. Cells were seeded in 12-well plates and transfected with Lipofectamine 2000 transfection reagent as recommended by the manufacturer (Life Technologies, Carlsbad, CA, USA). The expression vectors for wild-type and mutated IDH1 and IDH2 were described previously.^{38 (link)} U251, LN18 and T98 stable cells lines overexpressing IDH were selected using geneticin (Life Technologies). Hydroxyglutarate was purchased from Peptech (Bedford, MA, USA) and αKG, dimethyl-αKG and oxamate from Sigma (St Louis, MO, USA). For cell death experiments, 0.5 × 10⁶ cells were plated and treated the next day with 50 μg/ml ETO (Mylan, St Priest, France), 50 ng/ml TRAIL (PreproTech, Neuilly sur-Seine, France), 60ng/ml FASL (PreproTech) and 15 μg/ml cisplatin (Mylan). γ-Irradiation was carried out in a Faxitron CP160 irradiator (Faxitron X-ray Corporation, Tucson, AZ, USA) at a dose rate of 5 Gy. The number of dead cells was evaluated by FACS after incubation of 5 min with propidium iodide (Sigma).