Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04141 (granulocyte-macrophage colony-stimulating factor)
 6,790 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To study the role of different cytokine combinations on the proliferation and differentiation of highly purified primitive progenitor cells, a serum-free liquid culture system was used in combination with phenotypic and functional analysis of the cells produced in culture. CD34+ CD45RAlo CD71lo cells, purified from umbilical cord blood by flow cytometry and cell sorting, were selected for this study because of their high content of clonogenic cells (34%), particularly multipotent progenitors (CFU-MIX, 12% of all cells). Four cytokine combinations were tested: (1) mast cell growth factor (MGF; a c-kit ligand) and interleukin-6 (IL-6); (2) MGF, IL-6, IL-3, and erythropoietin (Epo); (3) MGF, IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF)/IL-3 fusion protein (FP), macrophage colony-stimulating factor (M-CSF), and granulocyte-CSF (G-CSF); and (4) MGF, IL-6, FP, M-CSF, G-CSF, and Epo. Maximum numbers of erythroid progenitors (BFU-E, up to 55-fold increase) and mature erythroid cells were observed in the presence of MGF, IL-6, IL-3, and Epo, whereas maximum levels of myeloid progenitors (CFU-C, up to 70-fold increase) and mature myeloid cells were found in cultures supplemented with MGF, IL-6, FP, M-CSF, and G-CSF. When MGF, IL-6, FP, M-CSF, G-CSF, and Epo were present, maximum levels of both erythroid and myeloid progenitors and their progeny were observed. These results indicate that specific cytokine combinations can act directly on primitive hematopoietic cells resulting in significant expansion of progenitor cell numbers and influencing their overall patterns of proliferation and differentiation. Furthermore, the observations presented in this study suggest that the cytokine combinations used were unable to bias lineage commitment of multipotent progenitors, but rather had a permissive effect on the development of lineage-restricted clonogenic cells.
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PMID:Cytokine-induced selective expansion and maturation of erythroid versus myeloid progenitors from purified cord blood precursor cells. 768

The effect of mast cell growth factor (MGF) was studied on erythropoietin (Epo)-dependent and Epo-independent ("spontaneous") erythroid colony formation in patients with polycythemia vera (PV). MGF stimulated both Epo-dependent and Epo-independent erythroid colony formation from PV peripheral blood progenitor cells in vitro at a dose similar to normal erythroid progenitor. In addition, evidence was obtained that the stimulating effect of MGF was a direct effect on the erythroid progenitor and independent of serum. Antibodies against interleukin-1 (IL-1), IL-3, granulocyte-macrophage colony-stimulating factor (GM-CSF), and Epo could not abolish the enhancing effect of MGF. This was also supported by the finding that sorted CD34+ cells could be stimulated by MGF in the presence and absence of Epo. Finally, it was demonstrated that the spontaneous erythroid colony formation could not be ascribed to spontaneous release of MGF in the culture medium since anti-MGF did not affect the colony numbers. In conclusion, MGF has a direct stimulatory effect, independent of serum, on both Epo-dependent and Epo-independent erythroid colony formation in PV.
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PMID:Recombinant human mast cell growth factor supports erythroid colony formation in polycythemia vera in the presence and absence of erythropoietin and serum. 768 83

Previous studies have suggested that erythroid progenitors derived from patients with chronic myelogenous leukemia (CML) in chronic phase may have reduced proliferative capacity. Considering recent evidence that mast cell growth factor (MGF) enhances the proliferative capacity of normal erythroid burst-forming units (BFU-E), we examined whether MGF could increase the proliferative potential of CML erythroid progenitors to normal capacity. To evaluate the total proliferative capacity achieved, the BFU-E were divided into four subpopulations (XL = extra large, L = large, M = medium, S = small) and colonies were aspirated to determine the cellularity of BFU-E from each subpopulation. MGF alone or in combination with MoT cell line conditioned medium (MoCM) or granulocyte-macrophage colony-stimulating factor (GM-CSF) + interleukin-3 (IL-3) significantly increased the proliferative capacity of erythropoietin (EPO) dependent CML and normal BFU-E. Although the total number of BFU-E generated were similar, the number of BFU-E with high proliferative potential were considerably less in CML BFU-E populations. BFU-E designated XL (129,000-431,000 cells) were only found in MGF cultures and only normal BFU-E had this proliferative capacity. BFU-E designated L were increased in both normal and CML BFU-E populations but less CML BFU-E had this proliferative capacity (mean number 25% of normal) and CML L BFU-E from 2/3 CML patients comprised fewer cells than normal L BFU-E. Normal BFU-E populations comprised 16-24% high proliferative BFU-E (XL + L) in contrast to 4-5% high proliferative BFU-E (L only) comprising CML BFU-E populations.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Differences in the composition and in the efficiency of red cell production of normal and CML erythroid progenitor populations are highlighted by response to human c-kit ligand. 769 Apr 36

The pathophysiological abnormalities leading to marrow failure and leukemogenesis in children with Fanconi anemia (FA) are not understood. We tested the hypothesis that the Fanconi anemia mutation results in insufficient production of hematopoietic growth factors by stromal cells by quantifying constitutive and induced production of interleukin-6 (IL-6), granulocyte-macrophage colony-stimulating factor (GM-CSF), granulocyte colony-stimulating factor (G-CSF), macrophage colony-stimulating factor (M-CSF), and steel factor (SF) by untransformed fibroblasts from eight patients with FA from five different families. While no abnormalities were noted in SF or M-CSF production, we noted substantial variability in IL-6, GM-CSF, and G-CSF responses of cells obtained from different FA patients. Responses ranged from blunting to augmentation when compared to normal controls. Because there was variation between fibroblast strains from affected members of two multiplex sibships, however, it is clear that neither augmentation nor blunting is a direct effect of the FA mutations. In addition, because there was discordance between the G-CSF responses and the GM-CSF and IL-6 responses, the abnormalities noted in IL-1 responsiveness must lie distal to IL-1 receptor function and to stimulus-response coupling pathways shared between the three cytokines.
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PMID:Constitutive and induced expression of hematopoietic growth factor genes by fibroblasts from children with Fanconi anemia. 769 32

A number of cytokines have been implicated in the suppression of myeloid stem and progenitor cell proliferation. It has been suggested that some of these act directly on the stem/progenitors themselves, based on the effects of these cells, plated in culture at low seeding densities, on highly enriched populations. These studies, however, do not definitively rule out effects on accessory cells. To more rigorously evaluate direct-acting suppressive effects of cytokines, such cytokines were assessed for their effects on colony formation initiated by single bone marrow (BM) or umbilical cord blood (CB) CD34 cells sorted into single wells in the presence of a combination of growth-stimulating cytokines (erythropoietin [Epo], steel factor [SLF], granulocyte-macrophage colony-stimulating factor [GM-CSF], and interleukin-3 [IL-3]) and in the presence or absence of serum. Under these conditions, it was demonstrated that H-ferritin, transforming growth factor-beta 1 (TGF-beta 1), and members of the chemokine family (macrophage inflammatory protein-1 alpha [MIP-1 alpha], MIP-2 beta, platelet factor 4 [PF4], IL-8, and macrophage chemotactic and activating factor [MCAF]) had direct significant suppressive activities on single stem/progenitor cells from adult human BM in the presence or absence of serum. Single sorted CB cells were much less sensitive to inhibition by these cytokines. The reasons for this differential sensitivity are not known. Of possible relevance to this for cytokines, such as H-ferritin and the chemokines that have actions during S-phase of the cell cycle, CB progenitors were in slower cycle at initiation of culture than were BM progenitors.
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PMID:Comparative effects of suppressive cytokines on isolated single CD34(3+) stem/progenitor cells from human bone marrow and umbilical cord blood plated with and without serum. 769 34

The availability of recombinant human hematopoietic growth factors (rhHGFs) for clinical use has the potential to significantly decrease the morbidity and cost of autologous bone marrow transplantation (ABMT) and to make this therapeutic modality available to a broader patient population. Three rhHGFs currently have Food and Drug Administration-approved indications, although only one has a specific indication for ABMT. Recombinant human granulocyte-macrophage colony-stimulating factor and granulocyte colony-stimulating factor have been used in several trials of ABMT. Recombinant human erythropoietin is less well studied to date in the setting of ABMT. Several investigational rhHGFs, including interleukin-3, -6, and -11, PIXY 321 (a granulocyte-macrophage colony-stimulating factor/interleukin-3 hybrid), and kit ligand (also known as "stem cell factor"), have the potential for affecting multiple lineages.
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PMID:Hematopoietic growth factors in autologous bone marrow transplantation. 769 7

We have examined the effect of mast cell growth factor (MGF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and interleukin-3 (IL-3), singly or in combination, on the growth of normal and aplastic anemia (AA) bone marrow in clonogenic assay and long-term bone marrow culture (LTBMC). MGF stimulated colony-forming unit-granulocyte/macrophage (CFU-GM), burst-forming unit-erythroid (BFU-E), and mixed colony-forming unit (consisting of granulocyte-macrophage and erythroid elements) (CFU-GEM) colony formation from both normal and AA marrow. The three-factor combination stimulated the greatest number of colonies. Marrow from less severely affected AA patients was stimulated to produce the highest number of colonies, and a normal response was possible if progenitors were present. When added to LTBMC, MGF alone had little effect. GM-CSF and IL-3 stimulated increased numbers of progenitor cells harvested each week from normal and AA LTBMC. This resulted in normal colony numbers in some patients, the majority of whom were less severely affected than the patients who did not respond in LTBMC. The three-factor combination was additive for normal CFU-GM production. However, no further increases in AA LTBMC resulted from the addition of MGF to GM-CSF and IL-3. The partial correction in clonogenic assay with MGF in some AA patients raises the possibility of therapeutic benefit. We failed to demonstrate increased progenitor cell numbers in AA LTBMC, however. Further studies may overcome possible limitations to progenitor cell proliferation.
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PMID:In vitro response of normal and aplastic anemia bone marrow to mast cell growth factor and in combination with granulocyte-macrophage colony-stimulating factor and interleukin-3. 811 28

The introduction of a retrovirus vector expressing p210bcr-abl (P210) into the human factor-dependent cell line M07E resulted in the rapid outgrowth of factor-independent cells. Early after infection, four factor-independent clones were isolated and analyzed in greater detail along with mass populations obtained from separate infections. High levels of P210 tyrosine kinase activity were measured in the factor-independent cells. The mass populations and three of the four clones remained responsive to exogenous growth factors. Concentrated conditioned media isolated from the factor-independent populations and from all clones contained biologically active granulocyte-macrophage colony-stimulating factor (GM-CSF); interleukin-3 (IL-3) was detected at low levels in the mass population and in two of the clones. Neutralizing antibodies to IL-3, GM-CSF, and mast cell growth factor inhibited proliferation of the factor responsive clones by 60% to 90%. These results indicate that the growth autonomy of the P210-expressing M07E cells was acquired via an autocrine mechanism. In addition to factor-independent growth, P210-expressing M07E cells readily acquired a more mature megakaryocytic phenotype compared with control M07E cells. These data provide experimental evidence that expression of P210 tyrosine kinase in human hematopoietic cells induced growth factor secretion resulting in a pleiotropic effect on growth factor dependence and differentiation.
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PMID:Expression of bcr-abl abrogates factor-dependent growth of human hematopoietic M07E cells by an autocrine mechanism. 812 48

The FLT3/FLK2 receptor tyrosine kinase is closely related to two receptors, c-Kit and c-Fms, which function with their respective ligands, Kit ligand and macrophage colony-stimulating factor to control differentiation of haematopoietic and non-haematopoietic cells. FLT3/FLK2 is thought to be present on haematopoietic stem cells and found in brain, placenta and testis. We have purified to homogeneity and partially sequenced a soluble form of the FLT3/FLK2 ligand produced by mouse thymic stromal cells. We isolated several mouse and human complementary DNAs that encode polypeptides with identical N termini and different C termini. Some variants contain hydrophobic transmembrane segments, suggesting that processing may be required to release soluble ligand. The purified ligand enhances the response of mouse stem cells and a primitive human progenitor cell population to other growth factors such as interleukins IL-3 and IL-6 and to granulocyte-macrophage colony-stimulating factor, and also stimulates fetal thymocytes.
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PMID:Ligand for FLT3/FLK2 receptor tyrosine kinase regulates growth of haematopoietic stem cells and is encoded by variant RNAs. 814 51

Because limited studies examined effects of transforming growth factor (TGF) beta 1 on growth of human acute myelogenous leukemia (AML) cells, we used factor-dependent and primary AML cells to assess TGF-beta 1 effects on human AML cell growth. OCI-AML1 cells were growth inhibited by TGF-beta 1 regardless of which growth factor was used as a stimulus. In contrast, AML-193 cells were resistant to TGF-beta 1 when grown with or without growth factors. UCSD/AML1 cells were sensitive to TGF-beta 1 inhibition when grown with most cytokines but were relatively resistant to TGF-beta 1 in the presence of macrophage colony-stimulating factor (M-CSF). Although cells grown from 5 of 6 AML patients were inhibited by TGF-beta 1, cells from 1 AML patient were growth stimulated by TGF-beta 1 in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF), M-CSF, or mast cell growth factor (kit ligand). Thus, 3 growth patterns with TGF-beta 1 were observed: (a) sensitivity to growth inhibition; (b) resistance; and (c) factor-dependent resistance. Further studies showed that AML-193 and UCSD/AML1 cells expressed type II TGF-beta 1 receptors and that ability of TGF-beta 1 to decrease GM-CSF receptors did not correlate with growth inhibition. AML-193 cells and UCSD/AML1 cells grown with M-CSF could be propagated in 1 ng/ml TGF-beta 1, but UCSD/AML1 cells grown with GM-CSF and TGF-beta 1 died. Morphology and agarose gel analysis of DNA showed UCSD/AML1 cells underwent apoptosis when grown with GM-CSF and TGF-beta 1 but not with M-CSF and TGF-beta 1. Similar studies of OCI-AML1 cells showed that TGF-beta 1 induced apoptosis of cells grown in 5637 bladder cell-conditioned medium or GM-CSF. These studies indicate that human AML cells exhibit heterogeneous growth responses to TGF-beta 1 and that some effects of TGF-beta 1 on myeloid cells occur through programmed cell death.
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PMID:Effects of transforming growth factor beta 1 on growth and apoptosis of human acute myelogenous leukemia cells. 832 49


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