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Inhibition of αvβ3 integrin impairs adhesion and uptake of tumor-derived small extracellular vesicles


Altei WF , Pachane BC , Dos Santos PK , Ribeiro LNM , Sung BH , Weaver AM , Selistre-de-Araújo HS , . Cell communication and signaling : CCS. 2020 9 25; 18(1). 158


BACKGROUND: Extracellular vesicles (EVs) are lipid-bound particles that are naturally released from cells and mediate cell-cell communication. Integrin adhesion receptors are enriched in small EVs (SEVs) and SEV-carried integrins have been shown to promote cancer cell migration and to mediate organ-specific metastasis; however, how integrins mediate these effects is not entirely clear and could represent a combination of EV binding to extracellular matrix and cells.

METHODS: To probe integrin role in EVs binding and uptake, we employed a disintegrin inhibitor (DisBa-01) of integrin binding with specificity for αvβ3 integrin. EVs were purified from MDA-MB-231 cells conditioned media by serial centrifugation method. Isolated EVs were characterized by different techniques and further employed in adhesion, uptake and co-culture experiments.

RESULTS: We find that SEVs secreted from MDA-MB-231 breast cancer cells carry αvβ3 integrin and bind directly to fibronectin-coated plates, which is inhibited by DisBa-01. SEV coating on tissue culture plates also induces adhesion of MDA-MB-231 cells, which is inhibited by DisBa-01 treatment. Analysis of EV uptake and interchange between cells reveals that the amount of CD63-positive EVs delivered from malignant MDA-MB-231 breast cells to non-malignant MCF10A breast epithelial cells is reduced by DisBa-01 treatment. Inhibition of αvβ3 integrin decreases CD63 expression in cancer cells suggesting an effect on SEV content.

CONCLUSION: In summary, our findings demonstrate for the first time a key role of αvβ3 integrin in cell-cell communication through SEVs. Video Abstract.