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)

To investigate possible mechanisms of growth factor expression in acute myeloid leukemia, genes for granulocyte macrophage colony-stimulating factor (GM-CSF) were analyzed by Southern blots in 20 patients, for M-CSF in 13, for interleukin-6 (IL-6) in 14, for IL-6 receptor in 14 and for G-CSF in five patients. Only in one patient a complex rearrangement of the G-CSF gene with possible amplification was noted indicating rarity of direct alterations of growth factor genes in acute myelogenous leukemia (AML). Spontaneous m-RNA expression for GM-CSF was found in only one of 20 patients, and for IL-6 in eight of 11 patients. In vitro incubation of AML cells of eight patients with recombinant tumor necrosis factor for 24 hr revealed induction of GM-CSF m-RNA expression in three cases and GM-CSF protein expression in two of them. These data suggest that spontaneous GM-CSF production occurs rarely in AML and that monokines, such as tumor necrosis factor, may induce GM-CSF in AML cells. Therefore, interactions of AML cells with normal or malignant accessory cells may be important for autocrine stimulation in AML. Our data suggest that ectopic growth factor secretion is not the primary cause of generating AML but may contribute to progression of the disease. Alternatively, AML may represent a heterogenous group of leukemias with different etiology but similar phenotype.
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PMID:Mechanisms of growth factor expression in acute myeloid leukemia (AML). 219 15

Equilibrium binding of 125I-labeled recombinant granulocyte macrophage colony-stimulating factor (GM-CSF) to the blast cells of acute myeloblastic leukemia (AML) revealed the presence of two classes of binding components of high and low affinity, with dissociation constants (Kd) in the range of 5-10 pM and 1-10 nM, respectively. Specificity studies revealed that interleukin-3 (IL-3) could partially inhibit the binding of GM-CSF to AML blasts and to the cells of the leukemic lines M07-E, KG-1, and HL-60. The inhibition of GM-CSF binding by IL-3 was directly dependent on the presence of IL-3 receptors. Analysis of competition curves indicated that the Kd and the number of binding sites per cell of unlabeled and iodinated GM-CSF were identical. In contrast, the inhibition of GM-CSF binding by IL-3 was mediated by IL-3 occupancy of a high affinity receptor only, with the same number of sites as the high affinity GM-CSF receptor but a slightly higher Kd. Despite this competitive binding, IL-3 augmented AML blast proliferation in the presence of GM-CSF, indicating that the two growth factors have converging pathways in supporting blast proliferation. In striking contrast to AML blasts, GM-CSF binding to neutrophils was compatible with the presence of only one class of binding site of intermediate affinity (Kd approximately 100-160 pM). Furthermore, IL-3 does not compete for the binding of GM-CSF to neutrophils.
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PMID:IL-3 inhibits the binding of GM-CSF to AML blasts, but the two cytokines act synergistically in supporting blast proliferation. 220 26

Human acute myelocytic leukemia (AML) marrow cells respond to stimulation with increased proliferation and enhanced intracellular metabolism of the cytotoxic antimetabolite 1-B-D arabinofuranosylcytosine (ara-C). Our previous studies have focused on the drug-induced humoral stimulatory activity (HSA) present in serum following initial cytoreduction which augments in vitro growth and biochemical pharmacology. The activity of HSA likely relates to the presence of multiple stimulators. The effect of 18-hr culture in purified recombinant human granulocyte-macrophage colony stimulating factor (rhGM-CSF) (1 ng/ml) on in vitro AML marrow cell [3H]dThd incorporation into DNA, intracellular ara-C activation to the triphosphate form (ara-CTP), and subsequent ara-CTP retention were determined in leukemic cells of 11 patients and compared with cells similarly cultured in HSA-containing sera. The stimulatory effects of rhGM-CSF and HSA on both growth and pharmacologic parameters were comparable for each AML population, with maximal response to both regulators detected for FAB M2. These data demonstrate that GM-CSF acts similarly to HSA as an active stimulator of leukemic cell proliferation and net intracellular ara-C metabolism in vitro, and support clinical trials designed to examine the role of rhGM-CSF in enhancing ara-C cytotoxicity by increasing the growth fraction of drug-responsive target cells in vivo.
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PMID:Effects of rhGM-CSF on intracellular ara-C pharmacology in vitro in acute myelocytic leukemia: comparability with drug-induced humoral stimulatory activity. 220 33

Interleukin-1 (IL-1) has hemopoietin-1 (H-1) activity, i.e., it synergizes with macrophage-colony stimulating factor (M-CSF), granulocyte-macrophage-CSF (GM-CSF) and interleukin-3 (IL-3) in stimulating in vitro colony formation of hematopoietic progenitor cells. In this study the synergistic activity of IL-1 was investigated on IL-3 and GM-CSF induced growth of acute myeloid leukemia colony forming cells (AML-CFU) in vitro. Among 12 cases of human AML, IL-1 significantly elevated IL-3 stimulated colony numbers in eight instances and enhanced GM-CSF induced colony growth in five cases. As IL-1 is an inducer of cytokine production and since tumor necrosis factor (TNF) elevates IL-3 or GM-CSF induced proliferation of AML-CFU, we examined whether IL-1 enhanced AML-CFU growth via the induction of TNF production. Neutralizing anti-TNF-alpha antibodies significantly decreased IL-1/IL-3 or IL-1/GM-CSF stimulated colony numbers in six of seven cases studied, whereas anti-TNF-beta had no effect, indicating that endogenously produced TNF-alpha costimulated the growth of AML-CFU. Furthermore, AML blast cells stimulated by IL-1 released increased amounts of TNF-alpha (between 25 and 533 pg/ml; median 255 pg/ml) into the culture medium (TNF-alpha specific radioimmunoassay) as compared with noninduced AML cells (less than 1 to 149 pg TNF-alpha/ml; median 31 pg/ml). Thus, the effect of IL-1 on AML-CFU proliferation is not the result of direct activation of AML progenitors, but IL-1 stimulates the release of TNF-alpha by AML cells and endogenous TNF subsequently synergizes with IL-3 or GM-CSF.
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PMID:Hemopoietin-1 activity of interleukin-1 (IL-1) on acute myeloid leukemia colony-forming cells (AML-CFU) in vitro: IL-1 induces production of tumor necrosis factor-alpha which synergizes with IL-3 or granulocyte-macrophage colony-stimulating factor. 220 34

Chemotherapy (CT) induced critical neutropenia remains a major dose limiting problem in acute leukemias. In order to reduce the phase of risk we gave recombinant human GM-CSF to 30 patients at high risk of early death with acute myeloid leukemia (AML). 19 patients with untreated AML and 1 patient with AML late relapse were 65+ years of age and were treated for CT by the TAD9 regimen. 10 patients at all ages had AML early or second relapse and received S-HAM CT. Starting on day 4 after CT GM-CSF 250 micrograms/m2/d was given by continuous i.v. infusion until neutrophils recovered. GM-CSF reduced the median recovery time of neutrophils by 4 days in the TAD9 and 9 days in the S-HAM CT group when compared to controls. After the CT induced aplasia 3 patients with AML showed a regrowth of their blasts which after the stop of GM-CSF was reversible in 1 patient and unaffectedly continued in 2 patients. 57% of patients attained a complete remission, and the median age of the responders was 65 (34-84) years. Remission duration was not found to be reduced. Thus, GM-CSF reduces CT toxicity with a low risk of promoting the disease and may allow more effective antileukemic treatment.
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PMID:Recombinant human GM-CSF following chemotherapy in high-risk AML. 220 65

A study of bone marrow stromal elements in murine acute myeloid leukemia (AML) was carried out. Our previous studies had indicated marrow stromal deficiency in murine AML. In the current investigation, separate stromal cells were cultured and the results obtained have shown that, while marrow stromal macrophages are normal in leukemia and express adequate amounts of IL-1, the fibroblasts are markedly reduced. However, if sufficient fibroblasts are pooled in vitro, they produce adequate amounts of CSF. Test of TNF alpha in leukemic cells CM, as possible cause of marrow stromal inhibition in leukemia, had not disclosed this cytokine. Further, it was observed that total body lethal irradiation of leukemic mice aggravates the stromal deficiency, confirming results of our previous investigations. It is concluded that bone marrow stromal deficiency in murine AML is due to decreased fibroblasts and, implicitly, reduced CSF production.
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PMID:Bone marrow stromal elements in murine leukemia: decreased CSF-producing fibroblasts and normal IL-1 expression by macrophages. 222 38

We studied the effect of preincubation with recombinant GM-CSF on the activity of cytarabine and doxorubicin against clonogenic acute myeloid leukemia cells (CFU-AML). Leukemia cells from seven persons with AML, three myeloid cell lines (HL60, KG1, K562) and two control cell lines (U937, MOLT3) were tested. Preincubation with GM-CSF (0.01-0.1 microgram/ml) increased DNA synthesis as measured by tritiated thymidine incorporation and intranuclear Ki67 expression in cells from six persons with AML and in HL60 cells. Leukemia cells preincubated with GM-CSF for 6-48 h were exposed to cytarabine (2-200 micrograms/ml) or doxorubicin (0.01-0.1 microgram/ml) for 3 h and CFU-AML assayed. This approach further reduced CFU-AML in samples from six persons with AML and in HL60 and KG1 cells compared to cells not preincubated with GM-CSF prior to drug treatment. In most instances, reduced CFU-AML correlated with GM-CSF induced DNA synthesis. These data suggest a possible strategy of GM-CSF pretreatment to increase anti-leukemia efficacy of chemotherapy in AML.
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PMID:GM-CSF incubation prior to treatment with cytarabine or doxorubicin enhances drug activity against AML cells in vitro: a model for leukemia chemotherapy. 223 47

In patients with acute myeloblastic leukemia incomplete response to induction chemotherapy and short disease-free survival may be related to cell kinetic quiescence of leukemic cells. In this in vitro study, we tested the hypothesis that treatment with cytokines and subsequent chemotherapy (ARA-C, daunorubicin) can increase proliferation and enhance leukemic cell kill. We evaluated the effects of recombinant human interleukin-3 (rh-IL-3), granulocyte-macrophage colony stimulating factor (rhGM-CSF) and granulocyte colony stimulating factor (rhG-CSF) alone and in combination on AML (N = 11) and blastic phase CML (N = 3) samples. Cellular DNA and RNA, incorporation of bromodeoxyuridine (BrdU), cell growth fraction, cell viability, and differentiation markers were evaluated in vitro. A decrease of the quiescent cell population (p = 0.003) and an increase in S-phase cells (p = 0.001) was observed in 8/11 AML samples treated with cytokine combinations. Pronounced heterogeneity or proliferative response was seen between individual cases and different cytokines, but in the majority of the samples IL-3 was most effective. Significantly increased Ki67 expression (p = 0.009) and BrdU incorporation (p = 0.01) were also found after exposure to cytokines indicating an increase in growth fraction. DNA synthesis time was unaffected. Eight samples of AML were treated for 24 hr with ara-C following 2 days of in vitro cytokine incubation. Evaluation of leukemic cell kill showed increased cytotoxicity in three of those five samples which had significant depletions of G0 cells and increases in S-phase. None of the leukemic samples without recruitment from G0 had an increase in ARA-C cytotoxicity. This study provides detailed cell kinetic analysis of cytokine effects on AML blasts and provides a rationale for a novel approach to the treatment of AML.
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PMID:Kinetic rationale for cytokine-induced recruitment of myeloblastic leukemia followed by cycle-specific chemotherapy in vitro. 224 6

Based on the results of preclinical and in vitro studies demonstrating enhanced granulocytic proliferation and differentiation induced by granulocyte-monocyte and granulocyte-colony stimulating factors (GM-CSF and G-CSF), these recombinant human haemopoietic growth factors have been used to treat cytopenic patients with myelodysplastic syndromes (MDS). Laboratory investigations have shown responsiveness of enriched haemopoietic precursors in vitro to the proliferative and granulocytic differentiative stimuli of G-CSF, generally without increased clonal regeneration. To date, five short-term phase I/II clinical trials using GM-CSF have demonstrated that 38 of 45 treated patients had improvements in neutrophil counts, 14 had increased reticulocyte counts, with three of these patients having decreased red blood cell transfusion requirements, and eight had a transient increase in platelets. In 12 patients an increase in marrow and/or peripheral blood blasts was noted. Seven patients progressed to acute myeloid leukaemia (AML), particularly patients with greater than 15% marrow blasts. In a longer term study, five patients received GM-CSF for two to nine weeks, although only one maintained increased neutrophil counts, one developed antibodies to GM-CSF and one's condition evolved into AML. Eighteen patients have been treated for two months in phase I/II clinical trials with G-CSF, 16 of whom had normalization of neutrophil counts with improved marrow maturation, five had increased reticulocyte counts with three having decreased transfusion requirements, four had transient increases in blasts and no substantial changes in platelet counts were noted. Eleven patients have received maintenance therapy with G-CSF for 6-16 months and 10 had persistent increases in neutrophil counts with enhanced marrow myeloid maturation. Decreased infectious episodes were noted in these patients at times at neutrophil improvements. Four of the 18 patients have subsequently developed AML after 6-16 months. Both CSFs were well tolerated, although the incidence of fever, myalgias and bone pain was more prominent in patients receiving GM-CSF at higher doses. In vitro correlates with these in vivo results were demonstrated as laboratory studies showed that G-CSF had greater myeloid differentiative and less proliferative effects for MDS marrow than did GM-CSF. Marrow cytogenetic studies after treatment generally indicated persistence of the initial normal and/or abnormal clones. These studies have demonstrated that both G-CSF and GM-CSF improve neutrophil counts in a high proportion of patients with MDS and that chronic administration of G-CSF elicits persistent neutrophil responses and may decrease infections. Phase III controlled trials are required to determine whether the natural history of this disorder will be altered by use of colony stimulating factors.
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PMID:The use of haemopoietic growth factors in the treatment of myelodysplastic syndromes. 227 14

Chemosensitivity of purified AML blasts to daunomycin was examined under conditions of CSF stimulation and compared with clinical outcome of DNR combination chemotherapy. AML blasts from 16 patients were purified, incubated serum-free in the presence of optimal concentrations of a complete cocktail of IL-3, GM-CSF and G-CSF to provoke cell proliferation maximally, and DNR drug sensitivity in vitro was assessed by inhibition of DNA synthesis in response to titrated DNR concentrations. The sensitivity of proliferating AML cells to DNR did not correlate with the clinical response of the patients as identical dose-response curves were obtained for complete responders (n = 6), partial responders (n = 5) and resistant cases (n = 5). As a major part of the AML population was induced to enter DNA synthesis in vitro, these data suggest that the manoeuvre of cell cycle stimulation has abrogated cellular resistance to daunomycin and rendered in vivo, apparently refractory cells susceptible to the anthracycline.
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PMID:Susceptibility of acute myeloid leukemia (AML) cells from clinically resistant and sensitive patients to daunomycin (DNR): assessment in vitro after stimulation with colony stimulating factors (CSFs). 233 90


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