Cell culture

U-87MG, U-251MG, U-118MG, LN-18, SH-SY5Y, GL-261MG and Neuro-2a cells were maintained at 37°C and 5% CO₂ in the recommended culture medium and supplements. The G7 glioma-derived stem cell (GSC) cell line was grown using specific glioblastoma stem cell medium, as described previously [32]. Primary astrocyte and glia cells were prepared as described previously [57]. Newborn 2-3 day old mice (C57Bl/6) were sacrificed using CO₂ and their brains were quickly removed and digested with 0.25% trypsin for 15 min at 37°C. The cell suspension was centrifuged through a 10% FCS solution and the obtained cells were grown in DMEM with 10% FCS, 5% CO₂ at 37°C. Cells were used within 7 days.