Chromatin state changes induced by targeted degradation of MLL-AF9 are phenocopied by combined DOT1L and MENIN inhibition. [ChIP-Seq]

Using ChIP-seq we examined the occupancy changes of various histone marks and chromatin-bound proteins following accute MLL-AF9 degradation in MLL-AF9-HA-FKPB12 transformed human (HCB1) cells. We also examined occupancy changes of various chromatin-bound proteins in human MLL-AF9-HA-FKBP12 transformed cells (HCB1) and MOLM13 cells in response to DOT1L inhibition, Menin-MLL inhibition, and the combination of DOT1L and Menin-MLL inhibition. We assessed chromatin state changes in human cells (HCB1) following MLL-AF9 degradation. Specifically, human MLL-AF9-HA-FKBP12 cells (HCB1) were treated with 500nM dTAG-VHL or DMSO for 3 hours and 24 hours and chromatin occupancy of various histone marks, members of the MLL-AF9 multi-protein comlex, and the RNA Pol2 machienery was probed. We also assessed chromatin occupancy changes of MLL-AF9 (HA), DOT1L and Menin in the human MLL-AF9-HA-FKBP12 cells (HCB1) after four days of drug treatment with EPZ-5676, VTP-50469, or DMSO control. Lastly, we assessed MLL-AF9 (HA) and H3K27ac in the human MLL-AF9-HA-FKBP12 cells (HCB1) and MOLM13 cells following four days of drug treatment with EPZ-5676, VTP-50469 and the drug combination, compared to DMSO.