Extracellular Vesicles and Integrins: Partners in Cancer Progression (original) (raw)

Tumor development and metastasis depend on the crosstalk between tumor cells and their surroundings. Microenvironment modification is made not only by cellcell contacts or by soluble ligands but also by secreted extracellular vesicles (EVs) that are uptaken by non-transformed cells. EVs carry regulatory proteins, DNA, RNA, and miRNAs and also are enriched with integrins, adhesion receptors that mediate crucial events during tumor development. After internalization and sorting into cells, integrins are incorporated into EV membranes within the multivesicular bodies (MVB) and are secreted, bound to EV surface, upon fusion of MVB-plasma membrane. The role of EV-carried integrins in tumor progression has been described in several levels, although the complete mechanism by which they actuate is still not completely understood. Regarding main cellular events occurring from primary tumor formation to establishment of secondary tumors, EVs are known as active players in epithelial-mesenchymaltransition (EMT), angiogenesis, invasion and migration, and pre-metastatic niche (PMN) formation. Considering the role of cellular integrins in the aforementioned events, here we reexamine the role of EVs in tumor progression with focus on EV-carried integrins.