BIOM-15. CD142 EXPRESSION IN GLIOBLASTOMA CELLS AS A POTENTIAL BIOMARKER FOR THROMBOTIC RISK STRATIFICATION

Abstract Venous thromboembolism (VTE) is a frequent and serious complication in glioblastoma (GBM), with incidence rates significantly higher than in other solid tumors. Tissue Factor (TF/CD142), the primary initiator of the extrinsic coagulation cascade, is increasingly implicated in promoting a prothrombotic tumor microenvironment. Beyond coagulation, CD142 contributes to tumor progression and angiogenesis, making it a promising biomarker for both prognostic evaluation and therapeutic stratification. This study aimed to assess CD142 expression at the cellular level using flow cytometry across a panel of GBM cell lines. Surface CD142 levels were quantified in HEK293T (negative control), BxPC3 (pancreatic cancer, positive control), and four GBM cell lines (SF126, U343MG, HROG05, U87MG). Samples were stained using a validated anti-CD142 antibody and analyzed under identical acquisition settings. Mean fluorescence intensity (MFI) served as a proxy for surface expression. HEK293T cells exhibited minimal CD142 expression (MFI= 2.02). BxPC3 cells displayed high expression (MFI= 52.38), validating assay sensitivity. Notably, GBM cells segregated into two populations: a high-expressing group (MFI= 23.50) and a lower-expressing group (MFI= 10.05). Both subsets showed expression levels markedly higher than the negative control. The higher GBM group reached approximately 45% of the BxPC3 signal, indicating biologically relevant TF upregulation. These findings highlight heterogeneous but elevated CD142 expression in GBM cells and support its involvement in the hypercoagulable phenotype associated with GBM. The identification of distinct subpopulations may reflect underlying tumor heterogeneity or activation states. Quantitative flow cytometry of CD142 may represent a valuable tool for identifying GBM patients at elevated thrombotic risk. Further studies in patient-derived samples and correlation with clinical VTE events are warranted.