The role of RAS mutations in leukemia progression, differentiation, and drug resistance.

Mutations in the RAS gene family (NRAS, KRAS) are critical drivers of late-stage acute myeloid leukemia (AML) progression. They are frequently detected in relapsed/refractory AML and AML transformed from myelodysplastic syndrome (MDS). Occurring as late-stage genetic events, RAS mutations synergize with early drivers to promote leukemogenesis. While mutually exclusive with FLT3-ITD mutations, they coexist with KIT, RUNX1, CEBPA mutations and MLL rearrangements. Granulocyte-monocyte progenitors (GMPs) serve as the cellular origin for RAS-mutant leukemia stem cells (LSCs). Ultimately, RAS mutations drive monocytic differentiation of LSCs and venetoclax (VEN) resistance through BCL-2 family rewiring. Beyond AML, they are hallmark genetic lesions in juvenile myelomonocytic leukemia (JMML) and present in 15%-20% of pediatric acute lymphoblastic leukemia (ALL) cases. Here, we propose a comprehensive pathogenic model and targeted therapeutic framework focusing on RAS, MCL-1, BCL2L1 to overcome drug resistance and improve patient outcomes.