FIGURE 7.

Small interfering RNA-based down-regulation of p38 expression abrogates the hemin-stimulated erythroid differentiation of K562 cells. Cells were transfected with control siRNA or p38 siRNA, as described under “Experimental Procedures.” A, cell lysates were subjected to Western blot analysis using anti-p38 mAb or anti-β-actin. Data are representative of three individual experiments. B, cells untransfected (None) or transfected with control siRNA or p38 siRNA were stimulated for 2 days with hemin (50 μm) alone or hemin plus TNIIIA2 (75 μg/ml) and then examined for detection of hemoglobinized cells. Each point represents the mean ± S.E. of triplicate determinations. Data are representative of three individual experiments. *, p < 0.01 compared with control.