Related Experiment Video
Updated: Sep 28, 2026
Culture of Macrophage Colony-stimulating Factor Differentiated Human Monocyte-derived Macrophages
Published on: June 30, 2016
Chronic myelomonocytic leukemia requires granulocyte-macrophage colony-stimulating factor for growth in vitro and in
Hayley S Ramshaw1, Peter G Bardy, Melissa A Lee
1Cytokine Receptor Laboratory, Division of Human Immunology, IMVS, Adelaide, South Australia, Australia.
Insights
Chronic myelomonocytic leukemia (CMML) cells depend on granulocyte-macrophage colony-stimulating factor (GM-CSF) for growth. Blocking GM-CSF with E21R inhibited CMML cell growth in vitro and in vivo, suggesting a potential therapeutic target.
Area of Science:
- Hematology
- Oncology
- Molecular Biology
Background:
- Chronic myelomonocytic leukemia (CMML) is a challenging hematologic malignancy with limited treatment options.
- Understanding the underlying mechanisms driving CMML proliferation is crucial for developing effective therapies.
Purpose of the Study:
- To investigate the role of granulocyte-macrophage colony-stimulating factor (GM-CSF) in the pathogenesis of CMML.
- To evaluate the therapeutic potential of targeting GM-CSF in CMML.
Main Methods:
- In vitro colony assays using methylcellulose to assess CMML cell growth in the presence or absence of the GM-CSF antagonist E21R.
- Development of an in vivo model using immunodeficient mice transgenic for human GM-CSF to evaluate CMML cell engraftment.
Main Results:
- CMML cells from all tested patients formed spontaneous colonies sensitive to E21R, with up to 92% reduction in growth.
- E21R inhibited GM-CSF-stimulated CMML colony formation but not interleukin-3-stimulated growth.
- CMML cells engrafted in human GM-CSF transgenic mice but not in nontransgenic mice, confirming GM-CSF dependence in vivo.
Conclusions:
- GM-CSF is a significant growth determinant for CMML cells, acting through autocrine or paracrine mechanisms.
- Targeting GM-CSF with therapies like E21R shows promise for controlling CMML growth in a subset of patients.
Objective:
Chronic myelomonocytic leukemia (CMML) is a heterogeneous disease with no effective treatments or cure. Several factors have been implicated in its pathogenesis. In the current study, we studied the dependence of CMML on granulocyte-macrophage colony-stimulating factor (GM-CSF).
Materials And Methods:
We used in vitro colony assays in methylcellulose where CMML cells were tested in the presence or absence of the specific GM-CSF antagonist E21R. We also developed an in vivo model in which CMML cells were tested for their ability to engraft into immunodeficient mice transgenic for human GM-CSF.
Results:
Bone marrow cells from seven of seven patients with CMML formed spontaneous colonies that were sensitive to E21R treatment, with reduction in colony growth by up to 92%. E21R also inhibited colony formation by CMML patient cells stimulated by exogenously added GM-CSF but not interleukin-3. In in vivo experiments we observed engraftment of CMML cells (but not normal cells) in immunodeficient mice transgenic for human GM-CSF. None engrafted in nontransgenic mice. Cell dose escalation showed that the optimal number was 0.5 to 1 x 10(8) peripheral blood mononuclear cells per mouse, which is equivalent to an infusion of 0.2 to 3.6 x 10(6) CD34(+) cells. Time course experiments showed that maximal engraftment occurred 6 weeks after injection.
Conclusions:
These results demonstrate that in some CMML patients, GM-CSF produced by either autocrine or paracrine mechanisms is a major growth determinant. The results suggest that therapies directed at blocking this cytokine could control the growth of some CMML patients in vivo.
Related Concept Videos
01:15Differentiation of Common Myeloid Progenitor Cells
01:01Regulation of Hematopoietic Stem Cells