G7513 100ml

Human glioblastoma cell lines U87 and U87-TxR were grown in Minimum Essential Medium (M2279-500ML, Sigma, United Kingdom) supplemented with 10% fetal bovine serum (F0804, Sigma-Aldrich, Germany), 2 mM glutamine (G7513-100ML, Sigma, United Kingdom), 5,000 U/ml penicillin, and 5 mg/ml streptomycin (cat. no. 15140122, Gibco^TM, Thermo Fisher Scientific, United States). Rat glioma cell lines C6 and RC6 were grown in Dulbecco’s Modified Eagle Medium (cat. no. 01-056-1A, Biological Industries, United States), supplemented with 10% fetal bovine serum, 2 mM L-glutamine, 5,000 U/ml penicillin, and 5 mg/ml streptomycin. U87 and C6 cell lines were obtained from American Type Culture Collection (ATCC, Rockville, MD, United States) and the U87-TxR cell line was selected by continuous exposure to stepwise increasing concentrations of PTX from the U87 cell line, while the RC6 cell line was established from the C6 cell line after carmustine selective pressure (Podolski-Renic et al., 2011 (link); Stojkovic et al., 2015 (link)). All cell lines were grown at 37°C in a humidified 5% CO₂ atmosphere.

Human osteosarcoma cells (U2OS) (https://www.cellosaurus.org/CVCL_0042) were originally obtained from the American Tissue Culture Collection (ATCC® HTB-96™) and were maintained at the Heinrich Pette Institute for several years^{52 (link)}. The cells were used in previous studies. U2OS cells were cultured in full growth medium composed of DMEM low glucose (SIGMA, D5546), supplemented with 10% FCS (REF), 1% penicillin/streptomycin (SIGMA, P4333), 100 µM pyruvate (SIGMA, S8636), 4 mM L-glutamine solution (SIGMA, G7513-100ML), and 1 g/L D-( +)-glucose solution (SIGMA, G8769). The cells were cultured in T75 flasks (Greiner, 658,175) at 37 °C with 5% CO₂. During the cultivation process, the growth medium was refreshed every other day, and cells were reseeded once they reached approximately 80% confluence. For experiments involving reduced glucose or glutamine levels, glutamine-only or glucose-only medium conditions were prepared accordingly. Additionally, experiments were conducted using either default or dialyzed FCS (Thermo-Fischer, A3382001).

For the cytotoxic assays, MRC-5 cells (ATCC CCL-171, human lung fibroblasts) were used. Cells were cultured in Minimum Essential Medium (MEM, 31095-029, Life Technologies-Gibco^R) supplemented with 10% heat-inactivated fetal calf serum (CVFSV00-0U, Eurobio, Courtaboeuf, France) and 2 mM L-glutamine (G7513-100 mL, Sigma Aldrich, Saint Louis, MD, USA), at 37 °C in a 5% CO₂ humidified atmosphere.