Establishment of AML Mouse Model by Transplantation of Hematopoietic Cells from MLL-AF9 Transgenic Mice / 中国实验血液学杂志

OBJECTIVE@#To establish a leukemia mouse model induced by transplantation of hematopoietic cells from mixed lineage leukemia (MLL)-AF9 transgenic mice so as to provide the basis for the mechanism research and drug screening of acute myeloid leukemia (AML).@*METHODS@#MLL-AF9 knock-in mice were bred and identified. When the mice developed leukemia, white blood cell (WBC) count in peripheral blood, flow cytometry and morphology method were analyzed to identify the disease. When the WBC count in peripheral blood was more than 100×10@*RESULTS@#The natural onset times of leukemia on MLL-AF9 knock-in mice were 22-28 weeks. The spleens of the transgenic mice enlarged and the bone marrow showed the immature forms of myeloid leukemia cells. Both the bone marrow and spleen cells highly expressed myeloid markers, CD11b and Gr-1. At least 0.5×10@*CONCLUSION@#The leukemia model of hematopoietic cell transplantation based on MLL-AF9 transgenic mice is successfully established, which can be used for the study of the pathogenesis and evaluation of therapeutic effect of AML.

Vibsanin A combined with tyrosine kinase inhibitors induces HL-60 cell differentiation by down-regulating c-Myc expression / 国际药学研究杂志

Objective: To explore the molecular mechanisms underlying the acute myeloid leukemia(AML)HL-60 cell differentiation induced by natural compound vibsanin A combined with tyrosine kinase inhibitors(TKI). Methods: Cell surface marker CD11b expression was detected by flow cytometry in HL-60 cells after treatment of the cells with vibsanin A in combination with imatinib or saracatinib for 72 h,and the cell morphology was examined by Wrigh-Giemsa staining. qRT-PCR and Western blot were used to examine the expression of differentiation-related C/EBPα,C/EBPβ, and c-Myc at both mRNA and protein levels in HL-60 cells after the cells were treated with the two drug combinations for various time(0-24 h). The recombinant lentiviral vector expressing c-Myc was constructed and used to transfect HL-60 cells in which the c-Myc cDNA was ectopically over expressed. The effect of c-Myc expression on the HL-60 cell differen-tiation induced by vibsanin A combined with TKI was investigated using the transfected HL-60 cells. Results: Vibsanin A combined with imatinib or saracatinib significantly enhanced HL-60 cell differentiation. Both drug combinations downregulated the expression of c-Myc at both mRNA and protein levels(P<0.01)in the HL-60 cells. In the transfected HL60 cells,the ectopic c-Myc overexpression could significantly counteract the down-regulated c-Myc expression and inhibit the cell differentiation induced by the vibsanin A/TKI combination. Conclusion: The combination of vibsanin A with imatinib or saracatinib could induce the HL-60 cell differentiation,probably via the downregulation of c-Myc expression