GBM cell microvesicles carrying gDNA oncogenic sequences cross the BBB and reach the peripheral blood.

11073 Background: Glioblastoma (GBM) is the most common primary malignant brain tumor in adults accounting for 60-75% of astrocytic tumors. It corresponds to WHO grade IV. Microvesicles (MVs) are vesicles that can be found in body fluids from patients with different types of cancer. These MV can be classified into apoptotic breakdown (up to several µm), plasma membrane blebbing (100 to 1,000 nm), and exosomes (less than 100 nm) released by fusion of endosomal-derived multivesicular bodies They play a crucial role in tumor progression since they can mediate intercellular communication, inflammation, angiogenesis and coagulation. We have identified, for the first time, the presence of genomic DNA sequences corresponding to oncogenes from all three types of MVs. These three types of MVs can cross the bbb and reach the peripheral blood where gDNA sequences might be used as biomarkers to stratify patients and evaluate response to treatment. Methods: GBM-initiating cells were isolated from surgical samples and ...