ANGI-09. NPC2-DRIVEN ANGIOGENESIS IN THE MESENCHYMAL SUBTYPE OF GLIOBLASTOMA

Abstract Glioblastoma (GBM) is the most common primary malignant brain tumor, characterized by aggressive proliferation, high invasiveness, and extensive angiogenesis, leading to a poor prognosis with a 5-year survival rate of less than 5%. Among GBM’s molecular subtypes, the mesenchymal (MES) subtype exhibits the poorest prognosis, notable for widespread necrosis, inflammation, and elevated expression of angiogenesis-related genes. This study aimed to elucidate GBM subtype-specific microenvironmental and angiogenic mechanisms to identify novel therapeutic strategies. Utilizing spatial GeoMx transcriptomic analysis on patient tissues, we compared blood vessels (BVs) and tumor core (TC) regions across GBM subtypes. NPC2 expression was remarkably higher in the BVs of the MES subtype, showing 16- and 4-fold increases compared to classical and proneural subtypes, respectively. Immunofluorescence (IF) staining corroborated these findings in patient tissues, demonstrating the highest NPC2 expression in MES subtype BVs, mirroring the endothelial cell marker CD31. Survival analysis revealed that higher NPC2 expression was significantly associated with poorer overall survival (OS) and disease-free survival (DFS) in GBM patients. To assess the functional role of NPC2, we suppressed its expression in human brain microvascular endothelial cells (HBMECs), leading to significant reductions in proliferation, wound healing, and invasion. These angiogenesis-related phenotypic changes were further validated using a 3D organ-on-a-chip model, recapitulating the blood-brain barrier. In conclusion, NPC2 is specifically highly expressed in the endothelial cells of mesenchymal GBM and is critically involved in regulating tumor angiogenesis. Our findings suggest that targeting NPC2 in endothelial cells represents a potential novel therapeutic strategy for mesenchymal GBM.