Tumor-Derived Exosomes Promote the Angiogenic Function of Vascular Endothelial Cells by Activating the miR-423-5p/EFNA3 Signaling Pathway

Angiogenesis plays a key role in promoting the growth and metastasis of breast tumors. Tumor exosomes (EXs) contribute to angiogenesis in various tumor tissues by transferring their carried RNAs. MiR-423-5p was enriched in multiple tumors and implicated in tumor growth. In this study, we investigated the roles and underlying mechanisms of tumor-derived EXs and their carried miR-423-5p in regulating human umbilical vein endothelial cell (HUVEC) functions. EXs derived from MCF-7 cells (MCF-7 EXs) or with miR-423-5p knockdown (MCF-7 EXs SimiR-423-5p ) were collected and incubated with ECs, and then the proliferation, migration, and tube formation abilities of ECs were detected. We found that miR-423-5p was enriched in breast cancer, MCF-7 cell lines and their derived EXs. After coculture with HUVECs, MCF-7 EXs merged into HUVECs and subsequently increased the miR-423-5p expression, proliferation, migration, and tube formation abilities of HUVECs, paralleling the increased EFNA3 and Notch1 expression, which was partially abolished by miR-423-5p knockdown. Altogether, our data suggest that MCF-7 EXs enriched with miR-423-5p promote the angiogenic function of vascular endothelial cells by activating the miR-423-5p/EFNA3/Akt signaling pathway.