Exosomes: Definition, Role in Tumor Development and Clinical Implications.

Exosomes are microvesicles released by cells in both physiological and pathological situations. They are surrounded by a lipid bilayer with proteins derived from the origin cell, and contain a variety of molecules, such as nucleic acids. They represent an emerging mechanism of intercellular communication, and they play an important role in the pathogenesis of cancer, stimulating proliferation and aggressiveness of cancer cells, inducing a microenvironment favorable to tumor development and controlling immune responses. Because of the growing understanding of the potential implications of extracellular vesicles in the development of malignancies, research on exosomes, and its role as a diagnostic and therapeutic tool, constitutes nowadays a very exciting and promising field.