Exosomes Secreted from Mesenchymal Stem Cells Carry miR-486-5p to Inhibit Cell Proliferation and the Epithelial-Mesenchymal Transition Process to Treat Human Lung Cancer by Down-Regulating MIER3

Exosomes are nano-vesicles that can shuttle active cargoes. Mesenchymal stem cells play a complex function in tumour progression.We investigated the effect of miR-486-5p, an exosome of human bone marrow-derived MSCs on lung cancer. We found that miR-486-5p, carried in mesenchymal stem cells and mesenchymal stem cell-derived exosomes, regulates MIER3 expression by binding to its 3’UTR, thereby inhibiting the epithelial-mesenchymal transition process of A549 cells. In vivo, we demonstrated that exosome treatment reduced the area of tumour necrosis, increased the expression of miR-486-5p and inhibited the epithelial–mesenchymal transition process in mice. In conclusion, mesenchymal stem cell-derived exosomal miR-486-5p directly and negatively targets MIER3 to inhibit lung cancer.