Discovery of WDR5–MLL1 and HDAC Dual-Target Inhibitors for the Treatment of Acute Myeloid Leukemia

Targeting the WDR5–MLL1 protein–protein interaction (PPI) is considered to be an effective approach for the treatment of MLL-rearranged leukemia. However, interfering with WDR5–MLL1 PPI reduces methylated H3K4 levels and induces a decline in acetylated H3 levels, which may contribute to the suboptimal cellular efficacy of WDR5 inhibitors. We observed that cotreatment with WDR5–MLL1 PPI and HDAC inhibitors augmented the antiproliferative effect in MV-4-11 cells. Thus, a series of dual-target inhibitors was developed by merging the pharmacophores of the WDR5 and HDAC inhibitors. Among the developed inhibitors, compound 32d displayed an 89-fold increase in antiproliferative efficacy and induced potent cell apoptosis by impeding the DNA damage repair signaling pathway. Furthermore, the administration of 30 mg/kg of compound 32d was well tolerated, inhibiting MV-4-11 xenograft growth by 87.1%. Our investigation established the therapeutic effectiveness of the developed WDR5–MLL1/HDAC dual-target inhibitor against acute myeloid leukemia, providing a valuable tool for further exploration of crosstalk between the two targets.