Evolutionary Trajectory of Radioresistance in Lung Cancer Brain Metastasis Organoids

Radiotherapy (RT) is a cornerstone treatment for lung cancer brain metastasis (LCBM), yet acquired radioresistance frequently leads to recurrence. The molecular and metabolic mechanisms underlying this adaptive evolution at single-cell resolution remain poorly defined. Patient-derived organoids (PDOs) from LCBM tissues were established to model clinical radiation responses. Paired pre- and post-RT samples underwent single-cell RNA sequencing (scRNA-seq) to delineate transcriptional, metabolic, and regulatory alterations associated with radioresistance. Single-cell analysis revealed substantial population remodeling following RT, characterized by depletion of proliferative cells and enrichment of a resilient Hypoxic-EMT subpopulation. Pseudotime analysis demonstrated lineage plasticity, showing a transition from proliferative to mesenchymal states. Mechanistically, a viral mimicry response involving NF-κB and STAT signaling supported stress adaptation. Resistant cells exhibited a hypermetabolic phenotype marked by metabolic plasticity, including hybrid bioenergetics coupling glycolysis with oxidative phosphorylation, enhanced lipid turnover via simultaneous fatty acid synthesis and degradation, and increased glutathione metabolism for reactive oxygen species buffering. Pharmacogenomic profiling indicated concurrent chemotherapy resistance but collateral sensitivity to PI3K/MEK inhibitors and epigenetic therapies. These findings provide a high-resolution atlas of radioresistance in LCBM and suggest that targeting the Hypoxic-EMT niche or oxidative-antioxidant balance may overcome therapeutic resistance.