Enforced expression of Mcl-1 or Bcl-xL protects cells from PD/dasatinib-mediated lethality. (A) K562/pCEP and K562/Mcl-1/cl9 cells were exposed to PD (5 μM) and dasatinib (0.6 nM) for 48 hours, after which the percentage of apoptotic cells was determined by annexin-V/PI. ** denotes significantly less than values obtained for empty vector cells (P < .05). (B) Cells were exposed to PD/dasatinib for 24 hours, and then the whole cells were lysed and subjected to WB analysis using the indicated primary antibodies. (C) Similarly, K562/pSFFV, K562/Bcl-xL/cl-11, and K562/Bcl-xL/cl-12 cells were exposed to PD/dasatinib for 48 hours, after which the percentage of apoptosis was determined. *** denotes significantly less than values obtained for empty vector cells (P < .001). (D) Cells were exposed to PD/dasatinib for 24 hours, after which the cytosolic fraction was extracted and WB used to monitor cyt-c release. Alternatively, whole cells were lysed and subjected to WB analysis using the indicated primary antibodies. For all studies, each lane was loaded with 25 μg protein; blots were stripped and reprobed with antitubulin antibody to ensure equal loading and transfer of protein. For all studies, 2 additional experiments yielded equivalent results.
