SUMMARY. The impact of multipotent mesenchymal stem cell (MMSC) derivatives on breast cancer cells in vitro and in vivo was estimated. The significant cytostatic effect of products of human bone marrow MMSC on tumor population was detected. These cells inhibited the migration of tumor cells to the suspention fraction and promoted an increase in the expression of tumor associated markers – cytokeratins and EpCAM in 2D and 3D cell cultures, but only in 3D culture the expression of vimentin was increased. A single-dose injection of mouse bone marrow MMSC cytosol led to the decrease in tumor growth in thigh muscles. Moreover, the injection of cytosol of these cells affected the preservation of muscle tissue integrity and promoted normalization of biochemical blood indicators of animals, which were grafted with tumor cells.
Keywords: MCF-7, bone marrow multipotent mesenchymal stromal cells, Balb/2c, multicellular tumor spheroids, Ehrlich ascite carcinoma