Coadministration of MK-0457 and vorinostat results in inactivation and down-regulation of wt and T315I Bcr/Abl kinases. (A) K562 and LAMA84 cells were incubated with 5 to 100 nM MK with or without Vor (K562: 2 μM; LAMA84: 1.5 μM) for 48 hours (K562) or 24 hours (LAMA84). (B) Ba/F3 cells with wt or T315I Bcr/Abl were treated with 0.1 to 0.5 μM MK with or without 1.5 μM Vor for 48 hours. (A,B) After drug treatment, cells were lysed, and Western blot analysis was performed to assess expression of total and phosphorylated forms of Bcr/Abl and CrkL. Each lane was loaded with 30 μg protein; blots were stripped and reprobed with antibodies to β-actin to ensure equal loading and transfer. Results are representative of 3 separate experiments. Protein bands of phospho-CrkL were quantified using an imaging system as described in “Western blot.” Values reflect the ratio of integrated densitometric determinations between untreated and drug-treated cells. Veh indicates vehicle. Two additional studies yielded equivalent results.