Effects of HDAC inhibitors and tozasertib on BCR-ABL-positive primary CML cells. (A) Primary CML cell samples and blastic phase samples were cultured at a concentration of 4 × 105 cells/mL in the presence of HDAC inhibitors (vorinostat or pracinostat) and/or tozasertib for 72 h. The number of viable cells was calculated for each group. *P < 0.05, tozasertib treatment versus tozasertib with HDAC inhibitors in the same line. (B) Primary cells were treated with HDAC inhibitors (vorinostat or pracinostat) and/or tozasertib for 24 h. Total extracts were analyzed by immunoblotting with phospho-specific anti-Crk-L, -cleaved PARP, and -acetyl histone H4 Abs. Actin was used as the loading control. Band intensities were quantified using ImageJ software. Results in A and B are representative of 3 different experiments.