Targeting LDHA Palmitoylation Sensitizes GBM to Chemoradiotherapy via Suppressing Palmitic Acid Induced Glycolytic Reprogramming.

Glioblastoma (GBM) is a lethal malignancy characterized by therapeutic resistance and recurrence, which are driven by dynamic cellular metabolic adaptation within the tumor microenvironment. However, the precise molecular metabolic mechanisms remain poorly understood. Here, we found that palmitic acid (PA) accumulates in hypoxic pseudopalisading regions of GBM and drives the formation of mesenchymal (MES) GBM and the hypoxia myeloid-derived macrophages (MDM) subpopulation, establishing an interactive tumor-promoting niche that fuels GBM recurrence. Maechanistically, PA induces ZDHHC12-mediated palmitoylation of lactate dehydrogenase A (LDHA) at cysteine 163. This enhances LDHA enzymatic activity, promoting glycolytic reprogramming that reinforces the MES phenotype and confers resistance to chemoradiotherapy. Concurrently, palmitoylation facilitates the exosomal sorting of LDHA, which is internalized by MDMs, inducing their polarization into an immunosuppressive, glycolytic hypoxia-MDM subset, which cooperatively shapes an immunosuppressive pseudopalisading niche with MES glioma stem cells to promote GBM recurrence. Critically, we identified the small molecule Rutin as a potent inhibitor of LDHA-Cys163 palmitoylation, thereby re-sensitizing GBM to chemoradiotherapy. This study defines a metabolic circuit in recurrent GBM driven by crosstalk between PA-activated MES-GBM cells and hypoxia-MDMs. The small molecule Rutin disrupts this circuit, re-sensitizing GBM to chemoradiotherapy and offering a promising strategy to overcome post-treatment recurrence.