PDCD10-Deficient Tumor Cells Reprogram Angiogenesis Through Paracrine Endothelial Activation and GSC-like Plasticity in GBM

Glioblastoma (GBM) is characterized by extensive neo-angiogenesis, which drives rapid tumor growth and therapeutic resistance. We previously identified PDCD10 as a tumor suppressor in GBM. Here, we investigated whether PDCD10 loss promotes neo-angiogenesis through paracrine signaling and GBM cell plasticity. PDCD10 knockdown (shPDCD10) enhanced endothelial angiogenic activity after treatment with conditioned medium (CM) from shPDCD10 cells and in a direct co-culture model. Moreover, application of CM to the chicken chorioallantoic membrane increased vascular branching in an in vivo angiogenesis model. Antibody array analysis detected elevated levels of multiple pro-angiogenic factors following PDCD10 depletion. In a GBM mouse model, shPDCD10 tumors exhibited pronounced hypervascularity and stromal expansion. Indeed, immunofluorescence revealed colocalization of CD31 with the tumor cell reporter RFP in a subset of implanted shPDCD10 GBM cells, suggesting that these tumor cells acquired an endothelial molecular signature. PDCD10 loss also promoted a glioma stem cell (GSC)-like phenotype, characterized by enhanced clonogenicity, sphere formation, and upregulation of Nestin, KLF4, and SOX2. Under endothelial induction conditions, shPDCD10 sphere-derived cells exhibited endothelial-like characters, showing greater tube-forming capacity and increased Ac-LDL uptake. Taken together, these findings demonstrate that PDCD10 loss promotes GBM neo-angiogenesis involving complementary paracrine and GSC-like plasticity mechanisms, highlighting PDCD10 as a potential therapeutic target to suppress neo-angiogenesis in GBM.