Measurement of VEGF Content in Exosomes and Subsequent Tumor Tubulogenesis and In Vivo Angiogenesis Functional Assays

Vascular endothelial growth factor (VEGF) plays a vital role in angiogenesis, and is also involved in tumor cell growth and immunosuppression, showing very complex roles. VEGF-exosomes are released by tumor endothelial cells (ECs) following anti-angiogenesis therapies (AATs). Transwell assays enable the detection of migration and invasion capacities of tumor cells. Matrigel assays are used to evaluate the angiogenesis capacities of ECs. Here we describe the detection of VEGF content in exosomes by nano-flow cytometry, enzyme-linked immunosorbent assay (ELISA), and western blotting, and demonstrate the procedure for detection of the colon formation of tumor cells induced by exosomes, the angiogenesis of tumor cells co-cultured with ECs, the angiogenesis of tumor cells induced by exosomes in Matrigel assay in vitro and tumor xenografts.