Extracellular vesicles derived from mesenchymal stem cells suppress breast cancer progression by inhibiting angiogenesis.

ABSTRACT

Previous studies have highlighted the antitumor effects of mesenchymal stem cell­derived extracellular vesicles (MSC­EVs), positioning them as a promising therapeutic avenue for cancer treatment. However, some researchers have proposed a bidirectional influence of MSC­EVs on tumors, determined by the specific tissue origin of the MSCs and the types of tumors involved. The present study aimed to elucidate the effects of human placenta MSC­derived extracellular vesicles (hPMSC­EVs) on the malignant behavior of a mouse breast cancer model of 4T1 cells in vitro and in vivo. The findings revealed that hPMSC­EVs significantly inhibited the proliferation, migration and colony formation of cultured 4T1 mouse breast cancer cells without inducing apoptosis. Exposure to conditioned medium from 4T1 cells pretreated with hPMSC­EVs resulted in decreased angiogenic activity, accompanied by the downregulation of angiogenesis­promoting genes in human umbilical vein endothelial cells. In murine xenograft models derived from the 4T1 cell line, local administration of hPMSC­EVs substantially hindered tumor growth. Further results revealed that hPMSC­EVs inhibited angiogenesis in vivo, as reflected by the use of a vascular growth factor receptor 2­Fluc transgenic mouse model. In summary, the results confirmed that hPMSC­EVs negatively modulated breast cancer growth by suppressing tumor cell proliferation and migration via an indirect antiangiogenic mechanism. These results underscored the therapeutic potential of EVs, suggesting a promising avenue for alternative anticancer treatments in the future.