p38 and JNK control the cell response to sub-apototic doses of doxorubicin differently.

<p>(A):effects of exposure to 0,25 µM doxorubicin on MAPK activation by western blot using antibodies specific for phosphorilated (Ph) and total p38 and JNK (left panel). Bar graph showing values for ph-MAPK normalizzated to the amount of total enzyme and expressed as the relative increase above control value, which was set at 100 (right panel). (B) and (C): bar-graphs showing the effects of pre-treatment with the JNK inhibitor, SP600125, the p38 inhibitor, SB203580 and NAC on the percentage of SA-b-gal and ssDNA positive cells (panel B) and p16^INK4A protein levels (panel C). (D): merge of SA-b-gal staining (blue) and immunocytochemistry for p16^INK4A (brown) in cells exposed to doxorubicin and pre-treated with or without SP600125, SB203580, or NAC (magnification, ×400)<b>.</b> ct, control; Dox, 0.25 µM doxorubicin. SB, p38 inhibitor; SP, JNK inhibitor. *p<0.05 vs ct; § p<0.05 vs Dox.; ¤ p<0.05 vs. SP+Dox; # p<0.05 vs. SB+Dox.