Cell-derived Extracellular Vesicles Open New Perspectives for Cancer Research

This review summarizes the current knowledge about human cell-derived extracellular vesicles (EVs) and their emergence as mediators of a new important mechanism of cell-to-cell communication. A special focus is given on the increasing involvement of tumor cell-derived EVs in cancer. The increased amounts of tumor EVs, when compared with their physiological counterparts have been evidenced in various kinds of cancers. Moreover, these tumor EVs are conveying specific molecular components, proteins, mRNAs and miRNAs, DNA fragments. Some of these compounds actively participate to cancerization processes in the near or remote tumor environments. The cooperation in these tumor “communicasomes” of part of the 98% noncoding genomic DNA with the nano/micro extracellular bullets, long considered as cell “dust”, but in fact precisely reflecting the physiological state of the cells, is really fascinating. The search for cancer biomarkers in various tumor EVs is under intense investigation both “in vitro” and in the clinic. Potential use of some of these biomarkers, as biological theranostic tools for diagnosis/prognosis and therapy of many cancers, is a new hopeful thread in cancer research. However, there is still a long way before reaching the promising goal. The first priorities should be to ensure a standardization of EVs purification and nomenclature, to efficiently sort out the different EVs species among their greatly yet uncontrolled heterogeneity and to define a strategy for using the most relevant cancer biomarkers as theranostic tools in the battle to fight cancer.