FIG 3.

H₂O₂-induced cell death is caspase independent and iron dependent. (A) WT HAP1 cells were treated with 350 μM H₂O₂ or 5 μM camptothecin (CPT) in the presence of 200 μM Q-VD-OPh or DMSO. Cell survival was assessed after 3 days of treatment using trypan blue. Error bars represent SEM (n = 3 independent experiments). *, P < 0.05 (compared to WT cells treated with DMSO). (B) WT HAP1 cells were treated with 350 μM H₂O₂ or 5 μM rotenone (RTN) in the presence of various concentrations of deferoxamine (an iron chelator), and cell survival (relative to control samples treated with the corresponding concentrations of deferoxamine without H₂O₂ or RTN) was assessed using trypan blue after a 24-h treatment. Error bars represent SEM (n = 3 independent experiments). **, P < 0.004; ***, P < 0.002 (compared to cells without deferoxamine).