Fig. 3: NPI-0052 induced oxidative stress in medulloblastoma cells.

a MB cells (ICb-1299 and DAOY) were treated with 0, 0.002 and 0.01 ng/μL NPI-0052 for 24 h. MB cells were labelled with DiOC6(3) (3,3′-dihexyloxacarbocyanine iodide) a marker of mitochondrial membrane potential. Cells were analysed by flow cytometry and the geometric means were recorded (n = 3). Data are represented as geometric means ± SD. Values significantly higher than the control (*P < 0.01; **P < 0.001; ***P < 0.0001) are indicated. b MB cells (ICb-1299, CHLA-01-MED, CHLA-01R-MED and DAOY) were treated with 0, 0.002, 0.01 and 0.1 ng/μL of NPI-0052. Level of H₂O₂ generated after 18 h of treatment was measured using the Amplex red hydrogen peroxide assay (n = 3). Data are represented as mean ± SD. *P < 0.01; **P < 0.001; ***P < 0.0001. c, d DAOY and ICb-1299 cells were treated with different concentrations of NPI-0052 (0, 0.002 and 0.01 ng/µL) for 24 h. c Total glutathione and d reduced and oxidized glutathione ratio (GSH/GSSG) were measured by using the GSH/GSSG-Glo Assay Kit (n = 3). Data are represented as mean ± SD. **P < 0.001; ***P < 0.0001. e Human MB cells (ICb-1299 and DAOY) were treated for 18 h with 0.002 ng/μL NPI-0052, 60 nM N-acetyl-cysteine (NAC) or 5 μM vitamin C (Vit.C). Cell viability was determined with CellTiter-Glo (n = 3) ± SEM; *P < 0.01, **P < 0.001; ***P < 0.0001