Leptin is abundant within marrow adipose tissue, yet its impact on acute myeloid leukemia (AML) therapy response is undefined. Here, we report that elevated bone-marrow leptin and blast-cell leptin-receptor (LEPR) levels strongly associate with poor cytarabine (Ara-C) clearance and reduced survival in newly diagnosed AML patients. Mechanistic and functional validation in human AML lines, primary blasts, and two syngeneic mouse models (MLL-AF9, AML1-ETO9a) shows that exogenous leptin markedly blunts Ara-C cytotoxicity, whereas the high-affinity LEPR antagonist Allo-aca restores chemosensitivity without altering baseline leukemia growth. Leptin up-regulates LEPR and triggers JAK2/STAT3 signaling that boosts mitochondrial complex Ⅰ activity, oxidative phosphorylation, and mitochondrial reactive oxygen species (mtROS); the resulting mtROS surge activates a compensatory antioxidant program that shields blasts from drug-induced oxidative damage. These data identify an adipokine-driven metabolic circuit governing AML chemoresistance and reveal LEPR blockade as a tractable strategy to improve outcomes, underscoring adipose-tumor crosstalk as a general therapeutic vulnerability.
© 2026. The Author(s).