Influence Of Human Mesenchymal Stem Cells On Proliferation Of Chronic Myeloid Leukemia Cells

Objective Mesenchymal stem cells (MSCs) are multipotential non-hematopoieticprogenitor cells of the adult marrow. They are capable of differentiating into various lineages of the mesenchyme. MSCs can stabilize and repair the hematopoietic mkroenvironment, and promote the proliferation and differentiation of hematopoietic stem cells. MSCs display immunosuppressive properties in allogenic bone marrow transplantation (ALLo-BMT), so they can prevent graft-versus-host disease (GVHD) and prolong the survival of organ transplants derived from stem cell donors. Many data show MSCs have some ability of graft-versus-leukemia (GVL),but the related mechanism is still not clear. This study was aimed to evaluate the influence of human mesenchymal stem cells on proliferation of chronic myeloid leukemia cells, and detect the production of IFN-alpha (IFN-α) in the supernatant of the cultivation.Methods To isolate, purify the MNCs from healthy human bone marrow bydensity gradient centrifugation and then passage them in vitro by adherent culture; observe the cells growth by inverted phase contrast microscope and observe the cells morphologic features and structure by Wright's staining; detect the third passage cell membrane's marker by flow cytometer. Chronic myeloid leukemia mononuclear cells (CML-MNC) cultivated in suspension and adhesively cultivated with MSCs were collected respectively and cell proliferation curves were drawn; We put them into five groups: MSCs cultured with CML-MNC (10:1,1:1,1:10); MSCs or CML-MNC cultured alone as control. The secretion of IFN-αwas analyzed by ELIS A on the third and sixth day.Results The primary cells and cultured passage cells mostly were fibroblast cellswhich had powerful capacity of growth and reproduction. The membrane marker showed that CD44 are positive while CD45 were negative; The cell proliferation curves showed that the proliferation of CML-MNC had been inhibited significantly adhesively cultivated with MSCs. The secretion of IFN-αof CML-MNC was lower than other groups (p<0.001). If we enlarged the concentration of MSCs in coculture group, the secretion of IFN-αwill be larger. If we prolonged the time of cultivation, the secretion of IFN-αwill be more.Conclusion MSCs can secrete more IFN-αwhen cultured in leukemicmicroenvironment, so we can give stem cells transplantation to treat leukemia a new thinking.