The effects of ovarian cancer cell-derived exosomes on vascular endothelial growth factor expression in endothelial cells

Ovarian carcinoma is considered as a major clinical challenge worldwide. Exosomes, nano-sized intraluminal vesicles of multivesicular bodies, are secreted by most types of cells and play an important role in intercellular communication. Cancer cell-derived exosomes can develop cancer progression and metastasis by manipulating the local and distant biological environments. Angiogenesis is an important contributor to tumor progression. Vascular endothelial growth factor (VEGF) is the most potent pro-angiogenic protein and induces proliferation, sprouting, and vessel formation by endothelial cells. In this study, exosomes derived from ovarian epithelial cancer cells OVACAR-3 (exo-OVCAR-3) were successfully isolated and characterized by scanning electron microscopy in terms of size and morphology. Cellular internalization of exosomes labeled with PKH fluorescent dye was monitored by a fluorescence microscope. Our results elucidated that exosomes treatment (100 µg/ml) had a promoting effect on VEGF expression and secretion in endothelial cells. Furthermore, we demonstrated that exo-OVCAR-3 caused an increase in the proliferation and migration rate of endothelial cells. It seems that inducing VEGF by exo-OVCAR-3 can influence the vascular behavior of endothelial cells in vitro.