Sh sy5y

U-2 OS cells (Sigma-Aldrich) were cultured in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% fetal bovine serum (FBS) and penicillin/streptomycin. NB cell lines SK-N-FI (Sigma-Aldrich), SK-N-AS (ATCC), SH-SY5Y (CLS Cell Lines Service), CHLA-90 (CCOG), IMR-32 (CLS Cell Lines Service) and SK-N-BE(2) (DSMZ) cells were cultured in specific media. SK-N-FI, SK-N-AS and SH-SY5Y cells were cultured in DMEM supplemented with 10% FBS, 0.1 mM Non-Essential Amino Acids (NEAA), and penicillin/streptomycin. CHLA-90 cells were cultured in DMEM supplemented with 20% FBS, 1× ITS (Gibco) and penicillin/streptomycin. IMR-32 cells were cultured in Minimum Essential Medium (MEM) supplemented with 10% FBS, 1 mM sodium pyruvate, 1× GlutaMAX (Gibco) and penicillin/streptomycin. SK-N-BE(2) cells were cultured in DMEM/F-12 media supplemented with 10% FBS, 1× GlutaMAX and penicillin/streptomycin. All cell lines were routinely tested for mycoplasma contamination and confirmed to be mycoplasma negative.

We chose two human brain cell lines for our studies: The human neuroblastoma cell line SH-SY5Y (Cat.No. CRL-2266, ATCC LGC Standards GmbH, Wesel, Germany) and the human primary glioblastoma cell line U-87 MG (Cat.No. 300367, CLS Cell Lines Service GmbH, Eppelheim, Germany).
U-87 MG and SH-SY5Y cells were cultured in 1:1 MEM Eagle/Ham’s F12 medium containing Earle’s salts, L-glutamine, and sodium bicarbonate (Cat.No. M4655 and N6658, Sigma-Aldrich Chemie GmbH, Munich, Germany) supplemented with 10% fetal bovine serum (Cat.No. S0615, Biochrom GmbH, Berlin, Germany) and 1% penicillin/streptomycin (Cat.No. P0781, Sigma-Aldrich Chemie GmbH, Munich, Germany). Both cell lines were incubated in separate culture flasks at 37 °C in a 95% air and 5% CO₂ atmosphere. Cell culture medium was changed every 2–3 days. A mixture of phosphate-buffered saline (PBS, Cat.No. 18912014, Gibco Thermo Fisher Scientific, Waltham, MA, USA), 0.025% (w/v) trypsin, and 0.011% (w/v) ethylenediaminetetraacetic acid (EDTA, Cat.No. L2143, Biochrom GmbH, Berlin, Germany) was applied for 3–4 min to detach the cells prior to cell counting and seeding.