Targeting p16INK4a-mediated cellular senescence as a therapeutic strategy for FLT3-ITD-driven acute myeloid leukemia.

Cellular senescence serves as a critical tumor-suppressive mechanism across various cancer types, yet its role in FLT3-ITD-positive acute myeloid leukemia (AML) remains poorly understood. Through the analysis of multiple sequencing datasets, we identified that FLT3-ITD-positive patients with low p16INK4a expression have significantly worse prognoses. Consistent with these clinical findings, knockout of p16INK4a in mice was shown to accelerate FLT3-ITD AML onset. Mechanistic investigations further revealed that the FLT3-ITD mutation suppresses p16INK4a expression via the STAT5A-E2F3-EZH2 signaling axis. This downregulation of p16INK4a allows cells to evade senescence, thereby promoting increased malignancy and establishing a positive feedback loop that exacerbates disease progression. This mechanism provides a molecular explanation for the poorer long-term survival observed in this patient subset. Furthermore, the FLT3-ITD-STAT5A/E2F3/EZH2-p16INK4a axis identified in this study represents a promising therapeutic target for addressing refractory FLT3-ITD AML with low p16INK4a expression.