Composition, Physicochemical and Biological Properties of Exosomes Secreted from Cancer Cells

Exosomes are small lipid vesicles secreted by a variety of cells. They were originally assumed to provide cells with the mean to dispose of unneeded proteins, nucleic acids, and lipids. However, exosomes are now known to play a role in intercellular communication. Cancer cells have been shown to secrete exosomes to not only modulate their immediate microenvironment, but also to exert effects in distant tissues and organs. To fully understand cancer exosomes and their function, it is important to elucidate their molecular composition. Here we provide an overview of exosome biogenesis, composition, and physicochemical properties. We also describe how their secretion from cancer cells can be affected by exposure to specific drugs.