Objective To explore the feasibility of establishing mouse model of leukemia by transplantion of human acute lymphoblastic leukemia (ALL) CD34⁺CD38- cells into immunodeficient (NOD/SCID) mice, and to study the capability of self-renewal and proliferation in the mice. MethodsThe CD34⁺CD38- cells were isolated from ALL patients and then identified, and the CD34-CD38⁺ cells were used as control. These cells were transplanted into sublethally irradiated NOD/SCID mice by tail-vein injection of 10⁴ cells per recipient. The changes of peripheral blood were monitored continuously, and histopathological examination of the bone marrow, spleen and liver was performed in each death or dying mouse. ResultsThe number of leukocytes in mouse peripheral blood was increased after inoculation of CD34⁺CD38- or CD34-CD38⁺ cells at 4 weeks, peaked at 8 weeks up to 15×10⁹～20×10⁹/L, and also increased the number of original and blast lymphocytes. There were mainly increased the number of the original and blast lymphocytes (40%) in the bone marrow, as well as the leukemic cells infiltrating in the spleen and liver of CD34⁺CD38- mice, which was more obvious than that of the control CD34-CD38⁺ mice. ConclusionsCD34⁺CD38- cells from ALL patients can be successfully transplanted into NOD/SCID mice to induce leukemia, indicating that the CD34⁺CD38- cells have the capability of self-renewal and proliferation. This model can be used as an important and useful tool for studies on leukemia-initiating cells. 