Influence of human bone marrow mesenchymal stem cells on proliferation of chronic myeloid leukemia cells

Background and Objective: Bone marrow mesenchymal stem cells (MSCs) are of particular interest due their potential clinical use in tissue engineering. MSCs could secret soluble factor(s) upon stimulation. This study was to evaluate the influence of human bone marrow MSCs on proliferation of chronic myeloid leukemia cells, and assess the secretion of cytokines in the supernatant induced by MSCs. Methods: Bone marrow MSCs extracted from healthy donors were cultured in DMEM-LG. The surface markers on the third passage MSCs were detected by flow cytometry. MSCs were co-cultured with chronic myeloid leukemia mononuclear cells (CML-MNCs) at various ratios. Cell proliferation was measured by flow cytometry. The interferon (IFN)-α level in the supernatant was analyzed by ELISA assay. Results: The primary and passaged MSCs mostly appeared fibroblast-like and showed strong capacity of growth and reproduction. The membrane marker CD44 was positive and CD45 was negative on the surface of MSCs. Co-culture of MSCs with CML-MNC significantly inhibited the proliferation of CML-MNC. The IFN-α level in the supernatant of cell culture was significantly higher in the co-culture groups than in the CML-MNC control group (p < 0.001). Secretion of IFN-α was elevated with the increase of the MSC concentration and co-culture duration. Conclusion: Co-culture of MSCs with CML could secrete a substantial amount of IFN-α, thus to inhibit the proliferation of CML cells.