Immunoblot analysis of anti- and proapoptotic proteins and cell death in CLL cells treated with SGI-1776. CLL primary cells were treated with 0.1% vehicle DMSO alone or 0.3, 1, 3, or 10 μmol/L SGI-1776 for 24 hours, then harvested and lysed. The protein levels of (A) PARP, XIAP, and Bcl-2 were immunoblotted from lysates (patient no. 2); (B) Bcl-X_L, Bcl-2, Bak, and Bax (patient no. 4); and (C) Mcl-1, caspase-3, and cleaved caspase-3, total c-Myc, and phospho c-Myc(Ser62) were analyzed by immunoblot and normalized by the use of GAPDH as a loading control. (D) Quantitation of Mcl-1 protein levels normalized to GAPDH levels in CLL cells (patients nos. 1-4) treated with SGI-1776 as detected by immunoblot. The results represent the mean ± SEM from 4 patient samples.