Radiation-induced autophagy regulates fibroblast mitochondrial metabolism and crosstalk with triple-negative breast cancer cells

Patients with triple-negative breast cancer (TNBC) experience high recurrence rates despite current interventions, which include radiation therapy (RT). Tumor cells thought to be involved in recurrence may survive in part due to their interactions with irradiated fibroblasts following treatment. How fibroblasts metabolically respond to RT and influence the behavior of TNBC cells is poorly understood. In this study, we demonstrate that irradiated fibroblasts undergo dynamic mitochondrial changes that are regulated by autophagy, resulting in a metabolic profile characterized by high levels of mitochondrial respiration and fatty acid oxidation. These metabolic adaptations lead to a secretory profile that induces an aggressive phenotype in TNBC cells that is mitigated when fibroblast autophagy is blocked. Our work reveals a burgeoning link between post-RT metabolic adaptations in fibroblasts and crosstalk with TNBC cells that promotes a microenvironment conducive to recurrence.