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)

ELF-153 is a cell line that has been established from a patient with a poorly differentiated acute myeloid leukemia associated with an acute myelofibrosis. A majority of cells had a blast morphology with the phenotype of a myeloid hematopoietic progenitor, ie, CD34+, CD33+, CD13+, HLA-DR+, but CD38-, and the remaining cells (5% to 10%) expressed platelet restricted proteins such as CD41, CD42, CD36, CD61, and von Willebrand factor; some of them were polyploid (up to 32N) and exhibited demarcation membranes and alpha granules. No erythroid or other lineage-specific markers were detected. Proliferation of ELF-153 cells was highly stimulated by interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor and to a lesser extent by stem cell factor and IL-6. In contrast, the cell line did not respond to erythropoietin, leukemia inhibitory factor, IL-7, IL-11, granulocyte colony-stimulating factor, and basic fibroblast growth factor. ELF-153 cells could be separated by flow cytometry into three discrete cell populations (CD34+/CD61-, CD34+/CD61+, and CD34-/CD61+) with different proliferative and endomitotic properties corresponding to distinct stages of the mega karyocyte (MK) differentiation. This MK differentiation, which involved a minority of ELF-153, could be increased in the presence of 5-azacytidine and phorbol ester, but could not be significantly modified by growth factors. By contrast, cytochalasin B dramatically induced polyploidization without differentiation. It is noteworthy that association of 5-azacytidine to cytochalasin B dramatically induced the production of polyploid MK cells. To understand the molecular mechanisms underlying this MK differentiation, the expression of GATA-1 and GATA-2 was investigated in subpopulations of ELF-153. A high level of GATA-1 and GATA-2 mRNA was only present in the CD61+ cells. Therefore, these two transactivating factors may play an important role in the MK differentiation of ELF-153. We conclude that ELF-153 might be an important tool to investigate the mechanisms by which transcription factors control differentiation of MK progenitors.
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PMID:Growth and differentiation of the human megakaryoblastic cell line (ELF-153): a model for early stages of megakaryocytopoiesis. 751 73

Stimulation of clonogenic acute myeloid leukemia (AML) cells by hematopoietic growth factors (HGF) is capable of enhancing cytosine-arabinoside (Ara-C) cytotoxicity in vitro. Until now it has not been known to what extent in vitro Ara-C cytotoxicity can be restored by HGF stimulation in samples from previously treated AML patients. Therefore, we studied the individual effects of the hematopoietic growth factors (HGF) granulocyte colony-stimulating factor (G-CSF), interleukin-3 (IL-3), and granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulation on the Ara-C sensitivity of clonogenic leukemic cells from six patients with newly diagnosed AML. These results were directly compared with the outcome using AML samples from the same patients at relapse or primary refractory AML. In one patient, a sample of the second relapse was also studied. The results were expressed as IC50 values, and were used to calculate sensitivity ratios, defined as the ratio of the IC50 value with drug exposure alone and with HGF plus Ara-C. In AML samples treated with Ara-C alone and no HGF, IC50 values of Ara-C in relapsed/refractory AML were greater than IC50 values of AML cells at diagnosis. Addition of either HGF enhanced the Ara-C cytotoxicity for the relapsed samples significantly (for G-CSF p = 0.036, IL-3 p = 0.036, and for GM-CSF p = 0.036). The values of Ara-C sensitization of AML samples due to HGF at relapse did not significantly differ from those at diagnosis. However, enhancement of Ara-C cytotoxicity to AML progenitors by IL-3 or GM-CSF stimulation was significantly less in the cell specimens from AML recurrence patients as compared with the original diagnosis samples. In three AML samples at diagnosis and at their relapse, Ara-C incorporation into the DNA was determined. IL-3 stimulation enhanced Ara-C incorporation in all samples tested. Nevertheless, Ara-C incorporation in the relapsed samples was significantly less than that in the diagnosis samples of the same patients. A good correlation between Ara-C incorporation and bromodeoxyuridine (BrdU) incorporation was found. The results indicate that HGF stimulation in relapsed/refractory AML enhances Ara-C cytotoxicity, but not to the level that was observed with AML samples at diagnosis.
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PMID:Hematopoietic growth factor stimulation and cytarabine cytotoxicity in vitro: effects in untreated and relapsed or primary refractory acute myeloid leukemia cells. 752 89

The application of hematopoietic growth factors in the treatment on acute myeloid leukemia (AML) may principally aim at shortening the period of treatment associated neutropenia and reducing the rate of infectious complications by their post-therapeutic administration but may also be used to increase the sensitivity of leukemic blasts to antileukemic therapy by pretherapeutic growth stimulation. Both aspects were addressed in subsequent clinical phase II studies and preclinical investigations. In a first clinical trial, 36 patients with high-risk AML received granulocyte-macrophage colony-stimulating factor (GM-CSF) after successful cytoreductive chemotherapy and experienced a shortening of the period of post-therapeutic neutropenia by 6 to 9 days, leading to a significant reduction of treatment-associated deaths from 39% to 14%. In preclinical studies an enhancement of the cytotoxicity of cytosine arabinoside (AraC) on leukemic blasts could be shown by pretreatment with GM-CSF or IL-3. Investigations on the impact of hematopoietic growth factors on the intracellular metabolism of AraC indicated that this effect was primarily mediated by an increase in the activity of DNA-polymerase-alpha. The evaluation of different doses of AraC showed the most marked increase after the combination of GM-CSF with conventional rather than high doses of AraC. Based on these preclinical experiments, a prospective randomized trial was subsequently initiated investigating the effect of GM-CSF before and during induction, consolidation, and the first two cycles of maintenance chemotherapy in newly diagnosed AML. This ongoing trial has enrolled 67 patients at the current time. An early interim analysis showed no differences in remission rates but a tendency toward a longer remission duration in patients receiving GM-CSF. These data indicate that hematopoietic growth factors like GM-CSF in particular may provide a new perspective in the treatment of acute myeloid leukemia with the possibility of reducing treatment associated mortality and perhaps of increasing the efficacy of antileukemic treatment.
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PMID:New perspectives in the treatment of acute myeloid leukemia by hematopoietic growth factors. 752 49

In a randomized study of 18 adult patients with high-risk or advanced acute myeloid leukemia (AML) we investigated the effect of supplementing conventional induction chemotherapy with recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF). For comparison, a historical control group of 90 patients treated for de novo AML with conventional chemotherapy during the previous period, 1984-1990, was also analyzed. Before induction chemotherapy, 10 patients were randomized to receiving rhGM-CSF, starting on day 1 to 3 before chemotherapy and continued for a maximum of 21 days after the start of induction treatment. Fatal complications and treatment outcome did not differ between the study groups and historical controls. Nor were there any differences between the groups in terms of hematological toxicity, e.g. time to three-lineage regeneration and need for supportive therapy. However, sequential weekly bone marrow examinations revealed a prolonged reduction of the relative number of myeloid (CD33-positive) marrow cells in the rhGM-CSF treated group. Although the small number of patients studied may not permit a definite conclusion, this randomized study did not demonstrate major beneficial effects of combining rhGM-CSF with standard induction chemotherapy in high-risk patients with AML.
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PMID:Priming and treatment with molgramostim (rhGM-CSF) in adult high-risk acute myeloid leukemia during induction chemotherapy: a prospective, randomized pilot study. 754 Jan 47

Thrombopoietin (TPO) is a newly identified hematopoietic growth factor that stimulates both megakaryopoiesis and thrombopoiesis through its interaction with a specific cell surface receptor encoded by the c-mpl proto-oncogene. In an effort to investigate the effect of TPO on human myeloid leukemia cells, the expression of c-mpl and the proliferative response to recombinant human (rh) TPO were investigated in a series of patients with acute myeloblastic leukemia (AML). Of 50 cases of AML, the c-mpl mRNA was detectable by means of Northern blot analysis in 26 cases, and the in vitro treatment with rhTPO led to proliferation of AML cells in 22 cases. The c-mpl expression and proliferative response to rhTPO was observed in all subtypes of AML and did not correlate with French-American-British classification, whereas all cases of M7-type AML cells expressed c-mpl and proliferated in response to rhTPO. Furthermore, rhTPO-induced proliferation of AML cells was augmented with the addition of interleukin-3 (IL-3), IL-6, stem cell factor, or granulocyte-macrophage colony-stimulating factor. These results suggested that c-mpl may be functional in terms of supporting proliferation of various types of AML cells and that TPO may contribute, at least in part, to abnormal growth of the cells, especially in combination with other hematopoietic growth factors.
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PMID:Growth response of acute myeloblastic leukemia cells to recombinant human thrombopoietin. 754 72

Apoptotic cell death induced by cross-linking Fas receptor (FasR/CD95) has been investigated in human acute myelogenous leukemia (AML) cells. FasR-mediated growth inhibition and DNA fragmentation could be induced in certain cases of AML. Interestingly, when DNA synthesis and G1 -> S transition in the cell cycle were enhanced by interleukin-3 or granulocyte-macrophage colony-stimulating factor, Fas-insensitive blast cells acquired cellular susceptibility toward FasR-mediated growth inhibition. To further evaluate an association between the Fas-R-mediated action and a specific phase of the cell cycle, a FasR+ leukemic cell line, MML-1, was established from a patient with AML. The morphologic feature of dying cells and DNA fragmentation indicated that FasR cross-linking induced apoptotic cell death in MML-1 cells. Cell cycle arrest in G1A phase with the treatment of phorbol 12-myristate 13-acetate or thymidine rendered MML-1 cells resistant to FasR-mediated apoptosis without downregulation of surface FasR expression. However, S-phase arrest with 5-fluorouracil could neither enhance nor inhibit FasR-mediated apoptosis. Simultaneous DNA/RNA quantification analysis revealed the selective loss of cells in G1B compartment, accompanied by the increase of apoptotic nuclei in sub-G1 fraction. These findings suggested that FasR-mediated apoptotic signals could be transduced into cells in G1B compartment and G1A -> G1B transition might augment the induction of FasR-mediated apoptosis.
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PMID:Fas receptor (CD95)-mediated apoptosis is induced in leukemic cells entering G1B compartment of the cell cycle. 757 53

We have investigated the effects of interleukin-4 (IL-4) on the proliferation of chronic myelomonocytic leukemia (CMMoL) cells in the chronic and leukemic transformation phases in vitro. CMMoL cells formed colonies spontaneously in both phases. IL-4 suppressed the spontaneous growth in the chronic phase, but on the other hand, stimulated colony formation in the leukemic transformation phase. Anti-IL-6 antibody inhibited spontaneous colony formation in both phases. CMMoL cells in both phases produced high levels of IL-6, compared with those produced by acute myelogenous leukemia (AML) cells showing myelomonocytic differentiation and normal monocytes. IL-4 suppressed the IL-6 production by CMMoL cells in both phases. None of anti-IL-6, anti-macrophage colony-stimulating factor (M-CSF), anti-granulocyte-macrophage colony-stimulating factor (GM-CSF), anti-tumor necrosis factor-alpha (TNF-alpha) and anti-IL-1-beta antibodies inhibited IL-4-stimulated colony formation. These results suggest that IL-4 directly stimulates the growth of CMMoL cells once leukemic transformation has occurred and that the therapeutic use of IL-4 for CMMoL should be viewed with caution, especially in the leukemic transformation phase.
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PMID:IL-4 stimulates the growth of chronic myelomonocytic leukemia cells (CMMoL) once leukemic transformation has occurred. 759 69

Leukemic relapse is the major complication following autologous bone marrow transplantation (BMT) in acute myeloblastic leukemia (AML). Previously, we have shown that recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) infusion after autologous BMT has the ability to augment endogenous activated killer (AK) cell function which may play a role in the eradication of minimal residual disease. However, the clinical application of rhGM-CSF in patients with AML has been limited by its potential stimulatory effect on the malignant clone. Here we report the effect of rhGM-CSF 5 micrograms/kg/day infusion on AK cell function in 20 patients with AML undergoing autologous BMT. AK cell function was investigated before autologous BMT, during rhGM-CSF therapy and after withdrawal. In addition, its influence on the actuarial risk of relapse is analyzed and compared with a historical control group of 20 patients transplanted immediately before initiation of this study. rhGM-CSF significantly enhanced AK cell function. During rhGM-CSF treatment, median AK cell function rose from 1.8% before autologous BMT (range 0-8%) to 35% (range 3-80%) and remained increased after cessation of rhGM-CSF (median 20%; range 0-36%; P < 0.001). After a median follow-up of 24 months, the actuarial risk of relapse is 37.4% in rhGM-CSF-treated patients compared with 49.5% in controls (P = 0.05). Interestingly, none of the 7 patients with an AK cell activity > or = 20% in the first 2-5 weeks after autologous BMT have relapsed compared with 6 of 9 patients with an AK cell activity < 20% (P < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Recombinant human granulocyte-macrophage colony stimulating factor (rhGM-CSF) administration after autologous bone marrow transplantation for acute myeloblastic leukemia enhances activated killer cell function and may diminish leukemic relapse. 767 Apr 1

Myelodysplastic syndromes (MDS) are clonal disorders of the multipotent hematopoietic stem cell characterized by ineffective hematopoiesis and associated with marrow hypercellularity, increased intramedullary cell death and peripheral cytopenias of varying severity. Patients with myelodysplasia have a propensity (20% to 30% of cases) to undergo transformation into acute myeloid leukemia (AML), and a large body of evidence indicates that MDS represent steps in the multiphasic evolution of AML. Progression of the disease is characterized by expansion of the abnormal clone and inhibition of normal hematopoiesis leading to deterioration of the blood cell count and/or development of AML. MDS are relatively unusual in childhood, representing only 3% of pediatric hematological malignancies, although it has been reported that up to 17% of pediatric AML cases may have a previous myelodysplastic phase. The first systematic attempt at morphological classification of MDS was provided by the French-American-British (FAB) group. However, the FAB classification of MDS is only partially applicable in children. Some variants are extremely rare or absent (refractory anemia with ring sideroblasts and chronic myelomonocytic leukemia), and other peculiar pediatric disorders, represented by juvenile chronic myelogenous leukemia (JCML) and the monosomy 7 syndrome, are not included. Moreover, since there is a partial overlap between pediatric MDS and myeloproliferative disorders and the variants occurring in young children have rather specific features, some confusion still surrounds the nosographical definition of childhood MDS, so that none of the proposed classifications are widely accepted and used. Characteristically, some genetic conditions such as Fanconi's anemia, Shwachman's and Down's syndromes predispose to the development of MDS in childhood. The most common variants of childhood MDS are represented by JCML and the monosomy 7 syndrome, both disorders typically occurring in young children. JCML is characterized by a spontaneous growth of granulocyte-macrophage progenitors that show a striking hypersensitivity to granulocyte-macrophage colony-stimulating factor. Clinical presentation resembles that of some myeloproliferative disorders, with massive organomegaly usually not observed in the classically reported variants of MDS. Clinical features of the monosomy 7 syndrome resemble those observed in JCML and a differential diagnosis between these two entities relies upon the higher percentage of fetal hemoglobin, the more pronounced decrease in platelet count and, in some cases, the lack of the peculiar cytogenetic abnormality in the latter. With the number of children being cured of cancer constantly rising, a significant increase in secondary or chemotherapy-related myelodysplasia is being observed, and these disorders represent a formidable challenge for pediatric hematologists due to their poor response to chemotherapy.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Myelodysplastic syndromes: the pediatric point of view. 767 22

We have investigated the stimulative effects of mast cell growth factor (MGF) in primary acute myeloid leukemia (AML) in vitro. MGF stimulated DNA synthesis of purified leukemic blasts in eight out of 10 cases and colony formation in four cases in serum-free (SF) culture. MGF synergized with interleukin-3 (IL-3; four out of 10 cases), granulocyte-macrophage colony-stimulating factor (GM-CSF; three out of 10 cases), granulocyte colony-stimulating factor (G-CSF; six out of 10 cases), macrophage colony-stimulating factor (M-CSF; one out of 10 cases) and erythropoietin (EPO; one out of 10 cases) when added to culture in combination. Synergistic effects of MGF in combination with other CSFs were also seen in the colony assay. Antibodies against GM-CSF, M-CSF, G-CSF, and IL-6 did not inhibit the MGF response, suggesting that the stimulative effect of MGF was not mediated through autocrine release of those cytokines. Cell recovery data in liquid cultures that contained MGF, IL-3, or MGF + IL-3, indicated that both MGF and IL-3 augmented the maintenance of clonogenic cells as compared to nonsupplemented cultures, but the effect of the combination of IL-3 + MGF did not show synergy. In contrast, activation of DNA synthesis by MGF was abrogated in the presence of tumor necrosis factor (TNF; four out of 10 cases) and interleukin-4 (IL-4; two out of 10 cases). Fluorescence-activated cell sorting (FACS) analysis with anti c-kit antibodies revealed MGF receptor expression in eight out of nine cases, often in a subpopulation of the cells. Scatchard analysis of MGF receptors in two cases indicated the presence of 1460 and 41,500 (mean) binding sites, respectively, of high affinity (Kd 40-160 pmol/l). The MGF dose-response curve in the presence of IL-3 or GM-CSF resulted in a higher plateau of DNA synthesis, however no shift in the dose response was apparent. The respective reciprocal dose response relations to GM-CSF, IL-3, or G-CSF were similarly elevated when MGF was added. MGF did not alter IL-3 and GM-CSF receptor expression, nor did IL-3, GM-CSF, G-CSF, TNF, or IL-4 influence MGF binding to AML cells.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Effects of mast cell growth factor on acute myeloid leukemia cells in vitro: effects of combinations with other cytokines. 768 Apr 1


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