Exploring the Dual Role of Extracellular Vesicles in Coagulation and Immune Modulation in Glioblastoma
Background: Glioblastoma (GBM) is often complicated by venous thromboembolism (VTE), primarily driven by tissue factor (TF) and podoplanin (PDPN). These factors promote local hypercoagulation and microthrombosis, thereby contributing to tumor progression by enhancing migration, invasion, and inflammation. Both TF and PDPN can be released via extracellular vesicles (EVs), which carry procoagulant and immunomodulatory cargo.Methods: We developed a translational workflow combining biobanked tumor samples, clinical data, ex vivo GBM cultures, and coagulation assays to investigate mechanisms of hypercoagulation. Intraoperative blood coagulation was profiled using ClotPro. Gene expression of coagulation-related markers was analyzed in tumor tissues and cell lines, complemented by RNAseq-based profiling of coagulation-inflammation links. Functional coagulation assays included clotting time, platelet aggregation, and EV-based analysis of prothrombotic and immunomodulatory activity.Results: Peripheral coagulation in GBM patients was largely unaltered. However, tumor tissues consistently showed high TF and PDPN expression and markedly low tissue factor pathway inhibitor (TFPI) levels (p < 0.001), indicating a shift toward a procoagulant phenotype. Patient-derived GBM cell lines showed variable TF and PDPN expression, which correlated with clotting potential. Distinct procoagulant mechanisms were observed, with some cells engaging both TF-mediated thrombin generation and PDPN-driven platelet activation. EVs isolated from GBM patient plasma and culture media showed similar procoagulant characteristics, with activity proportional to TF expression and immune-modulating effects. Notably, GBM-derived EVs modulated microglial behavior, induced senescence, and triggered immune polarization in a cell line-dependent manner, likely contributing to tumor microenvironment remodeling.Conclusion: GBM-associated hypercoagulability is shaped by heterogeneous tumor-intrinsic pathways and EV-mediated mechanisms. The dual role of EVs in promoting coagulation and modulating immune responses highlights their potential as biomarkers and therapeutic targets for individualized thromboprophylaxis in GBM patients.