DPY30 KD impaired proliferation of MLL1-fusion–mediated leukemia cells. MLL1-fusion–mediated human leukemia cell lines were depleted of DPY30 by shRNAs (#2 and #5 for MOLM-13, and #2 for other cell lines). (A) The DPY30 KD efficiency was determined by qRT-PCR and normalized against ACTB. Averages ± SD from 3 independent biological repeats (infections) are plotted, except for THP-1 cells (2 biological repeats). (B) Cell growth was monitored. Averages ± SD from 3 biological repeats are plotted, except for THP-1 cells (2 biological repeats). (C) Cell proliferation was monitored by BrdU incorporation after culture in the presence of BrdUTP for 1 hour. Percentage of cells in S/G2/M phases were quantified by 7-AAD staining of fixed cells. Apoptotic cells were quantified as Annexin V-positive and 7-AAD negative populations of unfixed cells. Averages ± SD from 3 biological repeats are plotted, except for THP-1 cells (2 biological repeats). *P < .05; ***P < .001 (Student t test). (D) Colony formation assay by serial plating. Averages ± SD from 2 biological repeats are plotted. *P < .05; **P < .01; ***P < .001 (Student t test). (E) Effects of DPY30 KD (short hairpin [sh]#2 and #5) on H3K4 methylation in MOLM-13 cells was examined by western blot analysis. (F) Expression of genes from Figure 1F was also examined for MOLM-13 cells by qRT-PCR against GAPDH. Averages ± SD from 3 biological repeats are plotted. P < .05 (Student t test) between control and either DPY30 shRNAs for all genes except between control and DPY30 sh#5 for MCM3.