Be 2 m17

The human neuroblastoma cell lines BE(2)-C, SK-N-BE(2), and BE(2)-M17 were from the American Type Culture Collection (Manassas, VA, USA); KELLY were from the cell line repository at the Greehey Children’s Cancer Research Institute at the University of Texas Health, San Antonio. The miR-506-3p mimic, analogs, and negative control oligos were purchased from Sigma-Aldrich (St. Louis, MO, USA).

Human melanoma cell lines (SK-MEL-3, A375, C32, and Malme-3M cells) and human neuroblastoma cell lines (SK-N-SH, SK-N-AS, SK-N-MC, SH-SY-5Y, BE2-M17, and IMR-32 cells) were purchased from the American Type Culture Collection (ATCC). Dulbecco’s Modified Eagle Medium (DMEM; Gibco, USA) supplemented with 1 % penicillin/streptomycin and 10 % fetal bovine serum (FBS; Invitrogen, Carlsbad, CA, USA) was used to culture cells at 37°C with 5% CO₂.

Histiocytic lymphoma U937, chronic myelogenous leukemia K562, T-cell leukemia Jurkat, Burkitt lymphoma Raji, prostate cancer PC-3 and DU145, lung adenocarcinoma A549 cell lines were purchased from DSMZ (Braunschweig, Germany). Neuroblastoma SH-SY5Y, SK-N-AS and BE(2)-M17 and breast cancer MCF-7 and MDA-MB-231 cell lines were obtained from the American Type Culture Collection (ATCC, Manassas, VA, USA). Cells were cultured in RPMI 1640 or DMEM medium (Lonza, Verviers, Belgium) supplemented with 10% (v/v) fetal calf serum (FCS; Lonza, Verviers, Belgium) and 1% (v/v) antibiotic-antimycotic (BioWhittaker, Verviers, Belgium) at 37 °C and 5% of CO2. Experiments were performed in culture medium containing 10% of FCS with cells in exponential growth phase. Cells were routinely controlled to exclude mycoplasma contamination. Non-adherent cells were seeded in fresh complete medium at concentrations of 300 000 cells/ml. After 1 h of recovery in the incubator, they were treated at the indicated concentrations. Adherent cells were seeded 36 h before treatment at concentrations of 5000 cells/ well in 96-well plates for viability and proteasome activity assays or 300 000 cells/well in 6-well plates for all the other assays.

Six human NB cell lines (SK-N-AS, SK-N-FI, SK-N-DZ, IMR-32, BE(2)-M17 and SH-SY5Y) were purchased from the American Type Culture Collection (Manassas, VA, USA). Cell culture reagents were purchased from Invitrogen (Carlsbad, CA, USA). SK-N-AS, SK-N-FI and SK-N-DZ were cultured with Dulbecco's modified Eagle's medium (DMEM) containing L-glutamine; IMR-32 was cultured with Eagle's Minimum Essential Medium (MEM) containing sodium pyruvate; BE(2)-M17 was cultured with a 1:1 mixture of MEM and F-12 medium containing sodium pyruvate; SH-SY-5Y was cultured with a 1:1 mixture of DMEM and F-12 medium. All of the above culture mediums contain 10% (v/v) heat-inactivated fetal bovine serum (FBS), 10 mM nonessential amino acids and antibiotic-antimycotic. Cells were cultured in 5% CO₂ humidified incubator at 37°C.