TY - JOUR TI - uPAR-expressing melanoma exosomes promote angiogenesis by VE-Cadherin, EGFR and uPAR overexpression and rise of ERK1,2 signaling in endothelial cells AU - Biagioni, Alessio AU - Laurenzana, Anna AU - Menicacci, Beatrice AU - Peppicelli, Silvia AU - Andreucci, Elena AU - Bianchini, Francesca AU - Guasti, Daniele AU - Paoli, Paolo AU - Serratì, Simona AU - Mocali, Alessandra AU - Calorini, Lido AU - Del Rosso, Mario AU - Fibbi, Gabriella AU - Chillà, Anastasia AU - Margheri, Francesca T2 - Cellular and molecular life sciences: CMLS AB - Exosomes (Exos) have been reported to promote pre-metastatic niche formation, proliferation, angiogenesis and metastasis. We have investigated the role of uPAR in melanoma cell lines-derived Exos and their pro-angiogenic effects on human microvascular endothelial cells (HMVECs) and endothelial colony-forming cells (ECFCs). Melanoma Exos were isolated from conditioned media of A375 and M6 cells by differential centrifugation and filtration. Tunable Resistive Pulse Sensing (TRPS) and Nanoparticle tracking analysis were performed to analyze dimension and concentration of Exos. The CRISPR-Cas 9 technology was exploited to obtain a robust uPAR knockout. uPAR is expressed in melanoma Exos that are internalized by HMVECs and ECFCs, enhancing VE-Cadherin, EGFR and uPAR expression in endothelial cells that undergo a complete angiogenic program, including proliferation, migration and tube formation. uPAR loss reduced the pro-angiogenic effects of melanoma Exos in vitro and in vivo by inhibition of VE-Cadherin, EGFR and uPAR expression and of ERK1,2 signaling in endothelial cells. A similar effect was obtained with a peptide that inhibits uPAR-EGFR interaction and with the EGFR inhibitor Gefitinib, which also inhibited melanoma Exos-dependent EGFR phosphorylation. This study suggests that uPAR is required for the pro-angiogenic activity of melanoma Exos. We propose the identification of uPAR-expressing Exos as a potentially useful biomarker for assessing pro-angiogenic propensity and eventually monitoring the response to treatment in metastatic melanoma patients. DA - 2020/11/25/ PY - 2020 DO - 10.1007/s00018-020-03707-4 DP - PubMed J2 - Cell Mol Life Sci LA - eng SN - 1420-9071 KW - Angiogenesis KW - Endothelial cells KW - Exosomes KW - Melanoma cells KW - uPA/uPAR system ER -