Novel Strategy against AML by Rescuing Loss of Phase Separation of Pathogenic NPM1c

Abstract

Nucleophosmin (NPM1) is a nucleolar protein that participates in many biological processes through phase separation. In acute myeloid leukemia (AML), nearly one-third of cases harbor NPM1c mutations. Previous studies mainly focused on the contribution of the additional NES in NPM1c mislocalization and AML development; however, the mechanisms underlying the relationship between aberrant localization and phase separation of NPM1c remain poorly understood. In this study, we demonstrate that loss of phase separation (LoPS) with RNA is associated with NPM1c mislocalization, which uncovers a new strategy for therapeutic targeting of NPM1c. Leveraging high-throughput screening, we identify a potent small molecule capable of rescuing NPM1c LoPS in vitro and effectively restoring the nucleolar localization of NPM1c within cells. Remarkably, this compound demonstrates anti-leukemia activity in both AML cell lines and patient-derived blasts. Overall, these findings indicate a promising avenue for developing new AML therapies against NPM1c by reinstating its phase separation capabilities. One-Sentence SummaryRescuing the lost phase separation capacity of NPM1c unveils a promising AML therapy.