Fig. 2.

MSCs have some adverse effect on tumor cells, such as differentiation of vascular endothelial cells in melanoma, enhancing the expansion of gastric cancer cell lines, inducing of cancer stem cells (CSCs) that are involved in metastasis, tumorigenesis, and recurrence of tumors. When co-cultured with peripheral blood mononuclear cells (PBMC), MSCs from breast cancer promote the development of CD4⁺CD25^highFOXP3⁺ regulatory T cells. MSCs derived from breast cancer tissues contain high levels of immunosuppressive mediators, such as IL-4, TGFβ and IL-10. Upregulation of bone morphogenetic proteins (BMPs), including BMP2, BMP4 and BMP6 in ovarian cancer derived MSCs can promote the development of CSCs