m6a and NuRD complexes regulate monocytic differentiation and resistance to BCL2/BCL2L1 inhibitors in AML

A major remaining challenge is the development of venetoclax resistance, frequently driven by compensatory transcriptional programs that promote cell survival and differentiation. These changes reduce dependence on BCL2 in favor of alternative anti-apoptotic BCL2 family members such as MCL1 or BCL2L1 (BCL-XL).

Using CRISPR-based genome-wide perturbation screens, we investigated the genetic dependencies of venetoclax and the BCL2/BCL2L1 dual inhibitor AZD4320. We identified the N6-methyladenosine (m6A) writer RBM15, and the Nucleosome Remodeling and Deacetylase (NuRD) complex interactor ZMYND8 as novel mediators of resistance to both venetoclax and AZD4320. Loss of RBM15 or ZMYND8 induced drug resistance, concurrent with alterations in BCL2 family expression and monocytic differentiation.