Granulocytes and moncytes are derived from a small population of bone marrow progenitor cells which can be assayed in vitro by their ability to form colonies of myeloid cells in semisolid medium (colonyforming unit, CFUGM). This colony formation requires the presence of specific glyocoproteins termed colony stimulating factors (CSF), produced by activated T cells and monocytes. CFUGM are present in low frequency in bone marrow, and it has been very difficult to isolate these cells. As a result, very little is known about the events which regulate proliferation and differentiation of these critical cells. The longterm objectives of this project are to understand the mechanisms which regulate CFUGM. An important step in this process is the development of techniques to purify these rare cells. Using a series of monoclonal antibodies developed in our laboratory, we have developed a technique to enrich CFUGM approximately 100 fold from normal bone marrow. These purified CFUGM have been used to: 1) develop a sensitive and specific assay for CSF activity, 2) immunize mice to produce new progenitor cell antibodies, 3) directly investigate the role of HLADR surface antigens in the regulation of myelopoiesis, and 4) investigate the effects of cloned lines of human natural killer cells on CFUGM. In the continuation of this project, it is proposed to use purified progenitor cells to assist in the screening for monoclonal antibodies to the major growth factor of CFU-GM, G,-CSF; to generate monoclonal antibodies to the GMCSF receptor using an antiidiotype approach, and to initiate investigation of the early transmembrane events (calcium flux, membrane potential changes) induced in immature myeloid cells by GM-CSF and a variety of other humoral regulators of myelopoiesis. It is anticipated that an improved knowledge of the mechanisms of regulation of normal stem cells may also be ultimately useful in understanding the abnormal regulation of myelopoiesis in disorders such as AML.

National Institute of Health (NIH)
National Cancer Institute (NCI)
Research Project (R01)
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Hematology Subcommittee 2 (HEM)
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Dana-Farber Cancer Institute
United States
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Jiang, Jingrui; Griffin, James D (2010) Wnt/?-catenin Pathway Modulates the Sensitivity of the Mutant FLT3 Receptor Kinase Inhibitors in a GSK-3? Dependent Manner. Genes Cancer 1:164-76
Chen, J; Imanaka, N; Chen, J et al. (2010) Hypoxia potentiates Notch signaling in breast cancer leading to decreased E-cadherin expression and increased cell migration and invasion. Br J Cancer 102:351-60
Weisberg, E; Ray, A; Barrett, R et al. (2010) Smac mimetics: implications for enhancement of targeted therapies in leukemia. Leukemia 24:2100-9
Weisberg, Ellen; Roesel, Johannes; Furet, Pascal et al. (2010) Antileukemic Effects of Novel First- and Second-Generation FLT3 Inhibitors: Structure-Affinity Comparison. Genes Cancer 1:1021-32
Weisberg, Ellen; Choi, Hwan Geun; Ray, Arghya et al. (2010) Discovery of a small-molecule type II inhibitor of wild-type and gatekeeper mutants of BCR-ABL, PDGFRalpha, Kit, and Src kinases: novel type II inhibitor of gatekeeper mutants. Blood 115:4206-16
Weisberg, E; Deng, X; Choi, H G et al. (2010) Beneficial effects of combining a type II ATP competitive inhibitor with an allosteric competitive inhibitor of BCR-ABL for the treatment of imatinib-sensitive and imatinib-resistant CML. Leukemia 24:1375-8
Weisberg, Ellen; Choi, Hwan Geun; Barrett, Rosemary et al. (2010) Discovery and characterization of novel mutant FLT3 kinase inhibitors. Mol Cancer Ther 9:2468-77
Jin, Baofeng; Shen, Huangxuan; Lin, Shuibin et al. (2010) The mastermind-like 1 (MAML1) co-activator regulates constitutive NF-kappaB signaling and cell survival. J Biol Chem 285:14356-65
Weisberg, E; Sattler, M; Ray, A et al. (2010) Drug resistance in mutant FLT3-positive AML. Oncogene 29:5120-34
Fernandes, Margret S; Reddy, Mamatha M; Gonneville, Jeffrey R et al. (2009) BCR-ABL promotes the frequency of mutagenic single-strand annealing DNA repair. Blood 114:1813-9

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