Imr 32

The glioblastoma cell line U-87 MG (ATCC HTB-14) and the neuroblastoma cell line IMR-32 (ATCC CCL-127) were purchased from the American Type Culture Collection (ATCC, USA). Their clinical status and culture conditions were referenced on the ATCC website (www.atcc.org). Cells (1.25 × 10⁵ cells/well) were cultured in 6-well plates with medium containing 10% FBS for 48 h for IMR-32 and for 24 h for U-87 MG. Both cell lines were then treated with a serum-free medium for different times (24 h for IMR-32 and 48 h for U-87MG) in the absence or presence of the recombinant human insulin-like growth factor 2 (IGF2; I2526, Sigma, St. Louis, MO, USA) at indicated concentrations for a final 24 h incubation.

Human neuroblastoma cell lines SH-SY5Y, BE(2)-C and IMR 32 were obtained from the European Collection of Authenticated Cell Cultures (Salisbury, UK), whereas the human neuroblastoma cell line Kelly was from CLS Cell Lines Service GmbH (Eppelheim, Germany). The cell lines were authenticated by the vendors. SH-SY5Y and BE(2)-C cells were grown in Ham’s F12/MEM medium (1:1) (Sigma-Aldrich) containing 2 mM L-glutamine (Sigma-Aldrich) and 1% non-essential amino acids (NEAA) (Sigma-Aldrich). IMR 32 cells were grown in MEM medium (Sigma-Aldrich) containing 2 mM L-glutamine and 1% NEAA. Kelly cells were cultured in RPMI 1640 containing 2 mM L-glutamine (Sigma-Aldrich). Culture media were supplemented with 10% fetal calf serum (FCS) and 100 U/mL penicillin-100 µg/mL streptomycin (Sigma-Aldrich). Cells were maintained at 37 °C in a humidified atmosphere of 5% CO₂ in air. Sub-confluent cultures were split every 72 h and seeded at the density of 1–3 × 10⁴/cm² using 0.25% trypsin/EDTA (Sigma-Aldrich). After resuscitation, cells were used for no more than 10–15 passages. Cells were periodically checked for mycoplasma contamination by using the MycoFluor Mycoplasma Detection kit (Invitrogen-Life Technologies).