IKAROS and MENIN are Functionally Cooperative Therapeutic Targets in Acute Myeloid Leukemia

Genome-scale functional genetic screening was utilized to identify resistance mechanisms and synthetic lethal interactions during small molecule targeting of MENIN and DOT1L in MLL1-rearranged AML. Chromatin regulatory complexes are found to modulate the therapeutic response to these inhibitors, and IKZF1/IKAROS is identified as an essential transcriptional regulator that supports leukemia gene expression through extensive chromatin co-occupancy with MENIN and the transcription factor MEIS1. Furthermore, we show that combined IKAROS degradation with imide drugs and MENIN inhibition using VTP-50469 leads to synergistic anti-leukemic effects through rapid induction of apoptotic cell death both in vitro and in vivo. This study uncovers a previously underappreciated role for IKAROS in AML and cooperativity among IKAROS, MLL1/MENIN and MEIS1 in maintaining leukemogenic transcription.