Targeting USP2 induces degradation of PML-RARα with or without drug-resistant mutations in acute promyelocytic leukemia.

Despite the high efficacy of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) in treating acute promyelocytic leukemia (APL), approximately 10-20% of patients develop drug resistance due to mutations in PML-RARα and other factors. Here, we find that inhibition of USP2 with ML364 or USP2 silencing reduces PML-RARα protein levels in both ATRA-sensitive and ATRA-resistant APL cells, and this effect is reversed by proteasome inhibition. Conversely, USP2 overexpression enhances PML-RARα stability. Mechanistically, USP2 interacts with and deubiquitinates PML-RARα, including its drug-resistant mutants. Consistent with PML-RARα degradation, ML364 treatment significantly induces apoptosis in APL cell lines and primary leukemia cells. In conclusion, this study identifies USP2 as a novel deubiquitinating enzyme for PML-RARα and highlights USP2 inhibition as a potential therapeutic strategy for APL with PML-RARα mutations.