FIGURE 5.

Effect of chelator-iron complexes on the phosphorylation of JNK and p38. The expression of JNK (phospho-Thr-183/Tyr-185) (A) and p38 (phospho-Thr-180/Tyr-182) (B) in DMS-53 cells after incubation with either chelator alone (250 μm DFO or 25 μm Dp44mT) or chelator-iron(III) complexes at the same concentrations for 24 h/37 °C. The hexadentate DFO-iron complex was examined at a 1:1 molar ratio (chelator-iron(III) ratio; 250 μm). Tridentate Dp44mT was assessed at 1:1 molar ratio (chelator/iron(III) ratio; 25 μm) or 2:1 molar ratio (chelator/iron(III) ratio; 25:12.5 μm). The iron(III) complexes were pre-formed using ferric chloride (FeCl₃). FeCl₃ at 12.5, 25, or 250 μm was included as a relevant control as it is a component of the complexes. Western blotting was performed using rabbit anti-human phospho- and nonphospho-specific antibodies for JNK or p38. Densitometry of phospho- and nonphospho-JNK includes both bands. The panels and the densitometric analysis are a typical experiment from three performed or mean ± S.E. of at least three experiments, respectively. **, p < 0.01.