[Biological characteristics of bone marrow-derived mesenchymal stem cells in children with acute leukemia]

This study was aimed to investigate the conditions of culturing in vitro mesenchymal stem cells (MSCs) derived from bone marrow of children with acute leukemia and the biological characteristics of MSCs from leukemia children. The bone marrow MSCs of acute leukemia children were isolated by density gradient centrifugation combined with adherent segregating method and cultured in DMEM/F12. The morphology of Wright stained MSCs was observed under inverted microscope. Cell surface markers were analyzed with flow cytometry. The growth characteristic features of cultured MSCs was measured with MTT method. Induced adipogenic and osteogenic differentiation of MSCs in appropriate induction media was observed. The results indicated that BM-MSCs of acute leukemia children could be successfully cultured in vitro in appropriate conditions. At 24 hours of culture the MSCs began to adhere to wall, grew in colony and appeared in different shapes. As the culture lasted, the MSCs proliferated continuously and shaped in fusiform. After 2 - 3 weeks of culture, MSCs covered the bottom of culture flask. The analysis of growth feature showed that MSCs were in latency for 3 days, and then entered into growth period. After 8 days of culture the growth of MSCs showed to be in plateau stage. The shape of MSCs in 1st and 2nd generation showed to be heterogeneous but the 3rd generation to be homogeneous with long-fusiform. Cells were arranged in shape of whirlpool or radiation. The surface marker analysis showed that the MSCs were positive for CD105, CD29, CD13, but negative for CD34, CD45, CD14 and HLA-DR. The MSCs from leukemia children could be induced into adipocytes and osteocytes in appropriate conditions. It is concluded that (1) MSCs derived from children with acute leukemia can be successfully cultured and passaged in vitro; (2) MSCs from leukemia children not received chemotherapy are more successfully cultured in vitro than those received chemotherapy; (3) the common biological characteristics of MSCs from children with acute leukemia are same as the MSCs from healthy person.