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

## TL;DR

High levels of leptin in bone marrow help leukemia cells resist chemotherapy by changing their energy use, and blocking leptin receptors can restore treatment effectiveness.

## Contribution

Identifies a new metabolic mechanism of chemoresistance in AML driven by marrow leptin-LEPR signaling and shows that LEPR blockade can restore chemosensitivity.

## Key findings

- Elevated marrow leptin and LEPR levels correlate with poor Ara-C clearance and reduced AML patient survival.
- Leptin activates JAK2/STAT3 signaling, boosts mitochondrial activity, and protects blasts from drug-induced oxidative damage.
- Blocking LEPR with Allo-aca restores chemosensitivity without affecting baseline leukemia growth.

## Abstract

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.