TMET-14. <i>NOTCH3</i> mediates metabolic reprogramming and ferroptosis resistance in meningiomas

Abstract NOTCH3 is increasingly implicated for its oncogenic role in many malignancies, including meningiomas. While prior work has linked NOTCH3 expression to higher-grade meningiomas and radiation therapy resistance, the metabolic phenotype of NOTCH3 activation remains unexplored in meningioma. This study demonstrates that NOTCH3 in meningiomas mediates a metabolic shift toward fatty acid oxidation (FAO), depleting lipid availability and conferring resistance to ferroptosis. Single-cell RNA sequencing of NOTCH3⁺ human meningioma cells (14,080 cells from 22 meningiomas) reveals a correlation with CD36, a membrane-bound fatty acid transporter that facilitates fatty acid uptake and directs them toward FAO. Patient-derived primary meningioma cells stratified by NOTCH3 and CD36 expression demonstrated increased maximal mitochondrial respiration in the presence of palmitate, suggesting functional upregulation of lipid metabolism in NOTCH3-expressing meningioma cells. Using the CH157-MN meningioma model, this study shows a shift in lipid catabolism with NOTCH3 intracellular domain (ICD) overexpression (CH157-MNNOTCH3 ICD) compared with empty vector controls (CH157-MNEV). Untargeted metabolomic profiling of CH157-MNNOTCH3 ICD cells revealed decreased fatty acyl-carnitine species relative to CH157-MNEV controls. Bulk RNA sequencing demonstrated upregulation of canonical FAO genes and downregulation of fatty acid synthesis genes, confirming enhancement of lipid metabolism with NOTCH3 overexpression. Targeted fatty acid analysis revealed depletion of intracellular fatty acids in CH157-MNNOTCH3 ICD cells. Functional extracellular flux assays confirmed elevated oxidative respiration in the presence of palmitate, indicating increased mitochondrial oxidative capacity. Finally, CH157-MNNOTCH3 ICD cells exhibited increased resistance to RSL3-induced ferroptosis, a phenotype reversed with CPT1 inhibition. These data establish a link between NOTCH3 signaling, lipid metabolic reprogramming, and ferroptosis evasion in aggressive meningioma cells. This metabolic shift may contribute to the malignant behavior observed in NOTCH3-expressing meningiomas, offering new insight into the biochemical vulnerabilities of these tumors.