Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023467 (acute myeloid leukemia)
 35,200 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Deficiency of the granulocyte-macrophage colony-stimulating factor (GM-CSF)/interleukin-3 (IL-3)/IL-5 receptors common beta chain (betac) is a cause of fatal respiratory failure. betac deficiency manifests as pulmonary alveolar proteinosis (PAP). PAP has heterogenous etiologies that may be genetic or aquired. Some cases of PAP have been reported to be associated with hematologic malignancies such as acute myeloid leukemia (AML). In mice, the PAP phenotype was generated by targeted deletion of the gene for betac and can be treated by transplantation of wild-type bone marrow into betac -/- mice. Thus, our findings in betac -/- mice provide evidence for a causal relationship between the lung disease and the hematopoietic system. We describe here expression defects of betac or betac plus GM-CSF receptor alpha chain (GM-CSFR alpha) in 3 pediatric patients with AML and PAP symptoms. All of the patients' leukemic cells failed to express normal levels of betac. The leukemic cells of patients no. 2 and 3 additionally lacked the expression of GM-CSFR alpha, as shown by flow cytometry. Strikingly reduced or absent function of betac was demonstrated in clonogenic progenitor assays with absent colony-forming unit (CFU) growth after GM-CSF or IL-3 stimulation. The response to growth factors acting via a growth factor receptor distinct from the GM-CSF/IL-3/IL-5 system (recombinant human granulocyte colony-stimulating factor [rhG-CSF]) was normal. After antileukemic treatment, the pulmonary symptoms resolved and betac or betac plus GM-CSFR alpha expression was normal. Our findings provide evidence that a defect in the expression of betac or betac plus GM-CSFR alpha on AML blasts can be associated with respiratory failure in patients with AML.
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PMID:Defective expression of granulocyte-macrophage colony-stimulating factor/interleukin-3/interleukin-5 receptor common beta chain in children with acute myeloid leukemia associated with respiratory failure. 969 96

We have analyzed the effects of IL-15, a growth factor with IL-2-like properties produced by dendritic and stromal cells, on 3 GM-CSF/IL-3-dependent AML cell lines: M-07e, UT-7 and TF-1. M-07e cells proliferated in response to IL-15, while UT-7 and TF-1 cells failed to respond. In addition, IL-15 supported long-term proliferation of M-07e cells, thus allowing selection of a subline (M-07SB), which displayed an enhanced sensitivity to IL-15. M-07e and M-07SB cells undergo apoptosis following 48-hr growth factor (GM-CSF or IL-15) starvation, as detected by cytofluorimetric analysis and DNA laddering. IL-15 (20 ng/ml) prevented apoptosis in both cell lines. M-07e and M-07SB expressed IL-2R beta, IL-2R gamma, Jak-1 and Jak-3 mRNA, while IL-15R alpha mRNA was undetectable. In contrast, IL-15R alpha was expressed in UT-7 and TF-1 cells, which lacked expression of IL-2R beta mRNA and, in the case of UT-7, also of Jak-3 mRNA. Accordingly, surface IL-2R beta protein was identified only in M-07e and M-07SB cells, by indirect immunofluorescence, while no expression of IL-2R alpha and IL-15R alpha was detected. Anti-IL-2R beta antibodies (10 microg/ml) efficiently blocked (90% inhibition) the proliferation and the anti-apoptotic effect induced by IL-15, while anti-GM-CSFR alpha antibodies had no effect. Anti-IL-2R gamma antibodies were less efficient at proliferation inhibition but synergized with suboptimal concentrations of anti-IL-2R beta antibodies. Our data suggest a role of IL-15 as an anti-apoptotic and mitogenic growth factor for a subset of myeloid leukemias expressing a functional IL-2R beta/gamma complex.
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PMID:Interleukin (IL)-15 induces survival and proliferation of the growth factor-dependent acute myeloid leukemia M-07e through the IL-2 receptor beta/gamma. 975 51

The severe combined immunodeficient (SCID) mouse model may be used to evaluate new approaches for the treatment of acute myeloid leukemia (AML). We have previously demonstrated the killing of SCID mouse leukemia initiating cells by in vitro incubation with human GM-CSF fused to Diphtheria toxin (DT-huGM-CSF). In this report, we show that in vivo treatment with DT-huGM-CSF eliminates AML growth in SCID mice. Seven cases of AML were studied. SCID mice were treated intraperitoneally with the maximally tolerated dose of 75 microg/kg/day for 7 days. Antileukemic efficacy was determined at days 40 and 80 after transplantation, by enumerating the percentages of human cells in SCID bone marrow using flow cytometry and short tandem repeat polymerase chain reaction (STR-PCR) analysis. Four out of seven AML cases were sensitive to in vivo treatment with DT-huGM-CSF at both evaluation time points. In three of these cases, elimination of human cells was demonstrated by flow cytometry and STR-PCR. One AML case showed moderate sensitivity for DT-huGM-CSF, and growth of the two remaining AML cases was not influenced by DT-huGM-CSF. Sensitivity was correlated with GM-CSFR expression. Our data show that DT-huGM-CSF can be used in vivo to reduce growth of AML and warrant further development of DT-huGM-CSF for the treatment of human AML.
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PMID:GM-CSF receptor targeted treatment of primary AML in SCID mice using Diphtheria toxin fused to huGM-CSF. 984 26

Acquired mutations in the granulocyte colony-stimulating factor receptor (G-CSFR) occur in a subset of patients with severe congenital neutropenia (SCN) who develop acute myelogenous leukemia (AML). These mutations affect one allele and result in hyperproliferative responses to G-CSF, presumably through a dominant-negative mechanism. Here we show that a critical domain in the G-CSFR that mediates ligand internalization is deleted in mutant G-CSFR forms from patients with SCN/AML. Deletion of this domain results in impaired ligand internalization, defective receptor downmodulation, and enhanced growth signaling. These results explain the molecular basis for G-CSFR mutations in the pathogenesis of the dominant-negative phenotype and hypersensitivity to G-CSF in SCN/AML.
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PMID:Deletion of a critical internalization domain in the G-CSFR in acute myelogenous leukemia preceded by severe congenital neutropenia. 988 5

We analyzed tandem duplication in the juxtamembrane (JM) domain of the FLT3 (FMS-like tyrosine kinase 3/FLK2, CD135) gene in 94 children with acute myeloid leukemia (AML) and evaluated its correlation with clinical features. Longer polymerase chain reaction (PCR) products were observed in five patients; 1/3 of M0, 119 of M1, 1/39 of M2, 1/9 of M3 and 1/12 of M5. The sequence analyses of abnormal PCR products showed that all the abnormal products were derived from tandem duplications involving the JM domain and that all the lengthened sequences were in-frame as we previously reported. Statistical analyses revealed a significantly lower incidence of the tandem duplication in childhood AML patients than in adult patients (P < 0.05), and significantly shorter disease-free survival in patients with mutant FLT3 than in patients with wild-type FLT3 (P < 0.05). Our results suggest that the tandem duplication in the JM domain of the FLT3 gene is not a frequent phenomenon but might be a factor of poor prognosis in childhood patients with AML.
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PMID:Internal tandem duplication of the FLT3 gene and clinical evaluation in childhood acute myeloid leukemia. The Children's Cancer and Leukemia Study Group, Japan. 1004 58

Chronic idiopathic neutropenia is regarded as a benign disorder without risk of malignant transformation. We present two patients with chronic idiopathic neutropenia who showed disease progression to acute myeloid leukaemia. Sequence analysis of the granulocyte-colony stimulating factor receptor (G-CSFR) gene from leukaemic DNA did not reveal any mutations and microsatellite analysis provided no evidence of microsatellite instability or loss of constitutional heterozygosity. These case studies suggest that chronic idiopathic neutropenia may constitute a preleukaemic condition in some patients. Alterations of the G-CSFR or defective DNA mismatch repair do not appear to be involved in malignant transformation.
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PMID:Two case studies of chronic idiopathic neutropenia preceding acute myeloid leukaemia. 1023 15

Patients with severe congenital neutropenia (SCN) are at increased risk for the development of acute myelogenous leukemia (AML). In the subset of patients with SCN that progresses to AML, acquired mutations in the receptor for granulocyte colony-stimulating factor (G-CSF) have been detected that result in the expression of truncated forms of the G-CSF receptor (G-CSFR) protein. G-CSFR truncation mutants from these patients transduce hyperproliferative growth responses. In this paper, we show that the most frequently isolated mutant G-CSFR form from patients with SCN/AML (delta716) confers resistance to apoptosis and prolongs cell survival through a mechanism involving Akt, a downstream target of PI3-kinase. G-CSF stimulation of cells expressing the G-CSFR truncation mutant induces sustained activation of Akt and prolonged phosphorylation of the pro-apoptotic protein Bad, resulting in enhanced cell survival. Extension of cell survival allowing for sufficient time for the acquisition of additional oncogenic events may represent an important mechanism by which G-CSFR mutations contribute to leukemogenesis. These data provide further insight into the pathophysiologic contribution of G-CSFR mutations to AML. (Blood. 2000;95:2132-2137)
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PMID:Granulocyte colony-stimulating factor receptor mutations in severe congenital neutropenia transforming to acute myelogenous leukemia confer resistance to apoptosis and enhance cell survival. 1070 85

In acute myeloid leukemia (AML), granulocyte colony-stimulating factor receptor (G-CSFR) proliferative and maturational signaling pathways are uncoupled. Seven human G-CSFR mRNA isoforms exist, named class I through class VII. The 183-amino acid cytosolic domain of the class I isoform provides all signaling activities. The class IV isoform is "differentiation defective" because the carboxy-terminal 87 amino acids are replaced with 34 amino acids of novel sequence. In more than 50% of AML samples, the class IV/class I G-CSFR mRNA ratio is aberrantly elevated compared to normal CD34(+) bone marrow cells. We hypothesized that the increased relative expression of class IV G-CSFR in AML uncouples proliferative and maturational G-CSFR signaling pathways. To test this, we transfected the G-CSF-responsive murine cell line 32Dcl3 with class IV G-CSFR cDNA. After 10 days of G-CSF stimulation, clones expressing class IV G-CSFR had greater percentages of myeloblasts and promyelocytes than controls (53% +/- 13% versus 3% +/- 2%). Differential counts over time demonstrated delayed G-CSF-driven maturation in 5 class IV-expressing clones, with 2 clones demonstrating a subpopulation that completely failed to differentiate. Heterologous class IV expression did not affect G-CSF-dependent proliferation. Class IV/murine G-CSFR mRNA ratios after 24 hours of G-CSF stimulation for 3 of the 5 clones (range, 0. 090 to 0.245; mean, 0.152 +/- 0.055) are within the range of class IV/class I mRNA ratios seen in patients with AML. This indicates that aberrantly increased relative class IV G-CSFR expression seen in AML can uncouple G-CSFR proliferative and maturational signaling pathways.
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PMID:Inhibition of granulocyte colony-stimulating factor-mediated myeloid maturation by low level expression of the differentiation-defective class IV granulocyte colony-stimulating factor receptor isoform. 1082 13

The t(8;21) translocation is one of the most frequent chromosomal abnormalities associated with acute myeloid leukemia (AML). In this translocation, the AML1 (CBFA2/PEBP2aB) gene is disrupted and fused to the MTG8 (ETO) gene. The ectopic expression of the resulting AML1-MTG8 fusion gene product in L-G and 32Dcl3 murine myeloid precursor cells stimulates cell proliferation without inducing morphologic terminal differentiation into mature granulocytes in response to granulocyte-colony stimulating factor (G-CSF). This study found that the ectopic expression of AML1-MTG8 elevates the expression of the G-CSF receptor (G-CSFR). Analysis of the promoter region of the G-CSFR gene revealed that up-regulation of G-CSFR expression by AML1-MTG8 does not depend on the AML1-binding sequence, but on the C/EBP (CCAAT/enhancer binding protein) binding site. The results suggest that the overproduction of G-CSFR is at least partly mediated by C/EBPepsilon, whose expression is activated by AML1-MTG8. The ectopic expression of G-CSFR in L-G cells induced cell proliferation in response to G-CSF, but did not inhibit cell differentiation into mature neutrophils. Overexpression of C/EBPepsilon in L-G cells also stimulated G-CSF-dependent cell proliferation. High expression levels of G-CSFR were also found in the leukemic cells of AML patients with t(8;21). Therefore, G-CSF-dependent cell proliferation of myeloid precursor cells may be implicated in leukemogenesis.
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PMID:AML1-MTG8 leukemic protein induces the expression of granulocyte colony-stimulating factor (G-CSF) receptor through the up-regulation of CCAAT/enhancer binding protein epsilon. 1089 64

Point mutations in the granulocyte colony-stimulating factor receptor (G-CSFR) gene have been linked to the development of secondary leukemia in patients with congenital neutropenia (CN). This report presents data on a now 18-year-old patient with CN who has received G-CSF treatment since 1989 and who developed acute myeloid leukemia (AML) in 1998. To evaluate whether there is an association between the occurrence of point mutations of the G-CSFR gene and development of secondary AML, DNA/messenger RNA of neutrophils and mononuclear cells from this patient were analyzed at different time points by polymerase chain reaction and subsequent cloning by DNA sequencing of representative numbers of individual clones. Findings suggest an increasing instability of the G-CSFR gene in time as judged by increasing numbers of mutations proposed to be one important step in the development of AML in this patient.
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PMID:Time course of increasing numbers of mutations in the granulocyte colony-stimulating factor receptor gene in a patient with congenital neutropenia who developed leukemia. 1123 34


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