Effect of down-regulation of eEF-2K by siRNA on doxorubicin efficacy against breast cancer cells.

<p>(<b>A</b>) Western blot analysis demonstrated that knockdown of eEF-2K in doxorubicin-treated MDA-MB-231 cells further reduced cyclin D1 levels while increasing p27^Kip1 levels. (<b>B</b>) Knockdown of eEF-2K using two different siRNA enhances efficacy of doxorubicin-induced (0.1 and 0.5 ìM) apoptosis of MDA-MB-231 breast cancer cells. Apoptosis was detected by Annexin V staining and the percentage of positive cells was quantified by FACS analysis after 48 h of doxorubicin treatment. (<b>C</b>) Down-regulation of eEF-2K enhances inhibition of Src and FAK activity and increases caspase-9 cleavage in doxorubicin-treated MCF-7/DoxR cells.