Exosomes from human adipose-derived mesenchymal stem cells promote migration through Wnt signaling pathway in a breast cancer cell model.

Human mesenchymal stem cell (MSC)-conditioned medium (CM) was previously reported to affect the biology of tumor cells; however, the precise mechanisms remain unclear. Here, we show that MSCs secreted 40-100 nm particles, which have the typical characteristics of exosomes, and these MSC-derived exosomes promoted migration of the breast cancer cell line MCF7. Global gene expression profiling revealed that several cancer-related signaling pathways were upregulated after exosome treatment in MCF7, and the Wnt signaling pathway was further confirmed to be activated. Our findings demonstrated a new mechanism through which MSC-CM may contribute to tumor cell migration.