Synergistic effect of CX-4945 and WDR5 inhibitor on arresting cell proliferation and cell cycle in T-ALL. (A-B) Effect of the combination of CX-4945 and WDR5 inhibitor vs single drug on cell proliferation in CEM (A) and MOLT4 cells (B). (C-F) Synergistic analysis of the 2 inhibitors on proliferation arrest in CEM (C-D) and MOLT4 cells (E-F) with combination index (C,E) and Bliss models (D,F). Cells were treated with the indicated doses of drugs for 72 hours. (G-J) Effect of the combination of CX-4945 and WDR5 inhibitor vs single drug controls on cell cycle arrest in CEM (G, representative images; H, bar graph) and MOLT4 (I, representative images; J, bar graph) cells. Cells were treated with indicated doses of the drugs for 72 hours. (K-N) Effect of the combination of CX-4945 and WDR5 inhibitor vs the single drug control on mRNA levels of CCNE2 (K,M) and CDK2 (L,N) in CEM and MOLT4 cells. The cells were treated with indicated doses of the drugs for 72 hours, and the mRNA levels were quantitated with qPCR. ∗P < .05; ∗∗P < .01; ∗∗∗P < .001. PI, propidium iodine; OI, OICR-9429.