The activation of PKC-δ and JNK1 is essential for doxorubicin-induced senescence. The activation of PKC-δ and JNK1 is essential for doxorubicin-induced senescence. MCF7 cells were treated with rottlerin or SP600125 at the indicated times following doxorubicin treatment, and SA-β-Gal activity was analyzed 6 d later. A. Intervals when rottlerin affected doxorubicin-induced senescence. B. Intervals when SP600125 affected doxorubicin-induced senescence. Sae Lo Oom Lee et al. Mol Cancer Res 2009;7:1845-1853 ©2009 by American Association for Cancer Research