OBJECTIVETo establish a MDS mouse model with iron overload and to study the effect of iron overload on MDS.

METHODSThe exogenous mutant gene RUNX1-S291fs was inserted into the mice bone marrow mononuclear cell's genome in mice by retrovirus and transplanted into C57BL/6 mice irradiated by Co γ-ray. After 8 weeks,intraperitoneal injection of iron was performed to establish an MDS mouse model with iron overload. After 24 weeks of transplantation, the peripheral blood, bone marrow, femur, liver and spleen of mice were taken, then the morphological characteristics of peripheral blood and bone marrow cells were observed by Wright's staining; the liver, spleen and bone marrow were stained with Prussian blue to observe the iron deposition. The surface antigens of bone marrow cells were detected by flow cytometry. Bone marrow mononuclear cells and spleen tissue proteins were detected by Western blot to confirm the transfection of RUNX1-S291fs gene and expression of protein. The blood routine and transplanted cell chimeric rate of mice were monitored periodically.

RESULTSCompared with the empty plasmid control mice, levels of leukocyte and hemoglobin as well as platelet were decreased in RUNX1-S291fs mutant mice; the peripheral blood cells and bone marrow cells showed pathological hematopoiesis; the liver and spleen enlarged significantly; the tissue structure of femur, liver and spleen was abnormal; the expression of bone marrow cell surface antigens was abnormal. Bone marrow cells and spleen tissue expressed the RUNX1-S291fs protein. Compared with the controlled mice injected with normal saline, iron deposition occurred in the bone marrow, liver and spleen stained with Prussian blue in the mice injected with iron agent.

CONCLUSIONMice engineered to carry exogenous mutant gene RUNX1-S291fs and injected with iron showed pathologic features of MDS and iron overload, resulting in establishing MDS iron overloaded mouse model successfully, which lays a foundation for studying the effect of iron overload on MDS.