Effects of adult human bone marrow mesenchymal stem cells on the growth of K562 cells

Objective:To study the effects of adult human bone marrow mesenchymal stem cells(MSCs)on the growth of K562 cells in vitro. Method: Mononuclear cells were obtained from 5 ml adult human bone marrow by density gradient centrifugation with Percoll solution. Adult human MSCs were cultured in Dulbeccos Modified Eagle's Medium with low glucose (LG-DMEM) containing 10% fetal calf serum at a density of 2×105 cell/cm2. The purity of MSCs were identified with the spindle-fibroblastic morphology by microphotograph and the phenotypes were analyzed by fluorescence-activated cell sorter (FACS). The ultrastructure of MSCs was observed under transmission electron microscope. MSCs were plated in 24 well plates. After treated with mitomycin, MSCs were cocultured with K562 cells. Effects of MSCs on the growth of K562 cells in vitro were investigated. The growth of K562 cells was measured by cell-count method. Result: Compared with the cell growth curve of the K562 cells a-lone, the K562 cells cocultured with MSCs grew slowly and the exponential phase of growth wasn't significant. Conclusion: Adult human bone marrow mesenchymal stem cells suppressed the growth of K562 cells in vitro. The results indicated that MSCs might have the potential to inhibit tumor cell growth. The mechanism was still to be investigated.