Marrow leptin-LEPR signaling rewires mitochondrial oxidative metabolism to confer chemoresistance in acute myeloid leukemia.

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.