PIM inhibition alters RNA splicing in AML cell lines. (A) Quadrant plot of PIM-inhibitor–induced splicing index changes for 2427 events occurring in EOL-1 and MOLM-16 cells. Quadrant 1, up in MOLM-16, down in EOL-1; quadrant 2, up in MOLM-16 and EOL-1; quadrant 3, down in MOLM-16, down in EOL-1; quadrant 4, down in MOLM-16, up in EOL-1. (B) Incidence of alternative splicing event changes by type in AZD1208-treated MOLM-16 and EOL-1 cells compared to control (vehicle treated) cells. (C) TaqMan quantitative RT-PCR validation of microarray data for MCL-1L and MCL-1S isoforms in AZD1208-treated MOLM-16 and EOL-1 cells. Normalized expression (n = 3 biological replicates) with standard error of the mean is plotted. Data analysis was performed in BioRad CFX Manager 3.1., and significance values (P value) of normalized relative expression of MCL-1S to MCL-1L are displayed for 1-way analysis of variance comparisons with P <.05. (D) RT-PCR to detect CHAC1 alternative splicing in PIM-inhibitor–treated MOLM-16 or EOL-1 cells.