Cancer cachexia in STK11/LKB1-mutated non-small cell lung cancer is dependent on tumor-secreted GDF15.

Cachexia is a wasting syndrome involving adipose, muscle, and body weight loss in cancer patients. Tumor loss-of-function mutations in STK11/LKB1, a regulator of AMP-activated protein kinase, induce cancer cachexia (CC) in preclinical models and are linked to weight loss in non-small cell lung cancer (NSCLC) patients. This study examines the role of the integrated stress response (ISR) cytokine growth differentiation factor 15 (GDF15) in regulating cachexia using patient-derived and engineered STK11/LKB1-mutant NSCLC lines. Tumor cell-derived serum GDF15 levels are elevated in mice bearing these tumors. Treatment with a GDF15-neutralizing antibody or silencing GDF15 from tumor cells prevents adipose/muscle loss, strength decline, and weight reduction, identifying tumors cells as the GDF15 source. Restoring wild-type STK11/LKB1 in NSCLC lines with endogenous STK11/LKB1 loss reverses the ISR and reduces GDF15 expression rescuing the cachexia phenotype. Collectively, these findings implicate tumor-derived GDF15 as a key mediator and therapeutic target in STK11/LKB1-mutant NSCLC-associated cachexia.