Extracellular vesicles extracted from bone marrow mesenchymal stem cells carrying MicroRNA-342-3p inhibit the INHBA/IL13Rα2 axis to suppress the growth and metastasis of breast cancer

Increasing focus has come to the role of extracellular vesicles (EVs) in various cancers. Hence, we designed this study to explore the mechanism whereby microRNA-342-3p (miR-342-3p)-containing EVs derived from BMSCs might affect breast cancer. MCF-7 breast cancer cell line was co-incubated with the EVs isolated from rat BMSCs, followed by alteration of miR-342-3p and INHBA expression. Microarray-based analyses predicted a possible regulatory mechanism involving miR-342-3p, INHBA, and IL13Rα2 in breast cancer, which was verified by luciferase reporter, RNA pull-down, and RIP assays. Besides, in order to evaluate the effects of miR-342-3p on the biological features of breast cancer cells in vitro and in vivo, we employed the scratch assay, Transwell assay, CCK-8 assay, and nude mouse tumorigenicity assay. miR-342-3p carried by BMSC-EVs was transferred into breast cancer cells through co-culture, which inhibited the proliferation and metastasis of breast cancer cells in vitro. miR-342-3p downregulated the expression of INHBA, which further repressed the expression of IL13Rα2. Finally, the in vivo experimental results revealed the inhibitory role of miR-342-3p in tumor growth and metastasis in nude mice. To sum up, BMSC-EVs carrying miR-342-3p could prevent breast cancer growth and metastasis by downregulating the INHBA/IL13Rα2 axis, highlighting a potential target for anti-cancer treatment for breast cancer.