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)

In the present study the effects of the 48-hour administration of granulocyte-macrophage colony-stimulating factor (GM-CSF) (100 U/mL) or interleukin-3 (IL-3) (100 U/mL) on the proliferative activity of leukemic cells and on the intracellular metabolism and cytotoxic efficacy of a subsequent 12-hour application of cytosine arabinoside (ara-C) at doses of 0.1, 1.0, 10.0, and 100.0 mumol/L were evaluated on bone marrow cells from 17 patients with acute myeloid leukemia. After GM-CSF or IL-3, a 1.2- to 2.4-fold increase in S-phase cells was observed in nine of 14 GM-CSF and seven of 11 IL-3 cases. 3H-Cytosine arabinoside incorporation into the DNA was enhanced 1.33- to 18.3-fold over respective controls in 14 of 17 patients. While in control specimens are ara-C dose-dependent increase in 3H-ara-C uptake was accompanied by a corresponding rise in intracellular ara-C-5' triphosphate (ara-CTP) levels, ara-CTP concentrations were not increased after GM-CSF or IL-3 exposure, resulting in a higher ara-C to ara-CTP ratio over controls. This finding may be explained by a stimulatory effect of GM-CSF and IL-3 on ara-C phosphorylating enzymes and a more rapid incorporation of ara-CTP into the DNA of leukemic blasts. These effects translated into a 2.2- to 229.0-fold increase in the cytotoxic activity of ara-C against clonogenic leukemic cells after GM-CSF or IL-3 pretreatment. Hence, GM-CSF and IL-3 enhance the intracellular metabolism of ara-C and its incorporation into the DNA of leukemic cells leading to a higher antileukemic activity of ara-C on clonogenic leukemic cells (CFU-L).
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PMID:Granulocyte-macrophage colony-stimulating factor and interleukin-3 enhance the incorporation of cytosine arabinoside into the DNA of leukemic blasts and the cytotoxic effect on clonogenic cells from patients with acute myeloid leukemia. 155 73

Hematopoietic growth factors (HGFs) interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) individually have been shown to increase the percentage of acute myeloid leukemia (AML) blasts in S phase and enhance the cytotoxic effects of Ara-C against these blasts in culture. We compared in vitro the effects of a combined treatment with GM-CSF (10 ng/mL) plus IL-3 (10 ng/mL) on the metabolism and cytotoxicity of Ara-C in normal bone marrow mononuclear cells (NBMMC) and AML blasts. NBMMC from six healthy volunteers and AML blasts from 10 patients were incubated for 20 hours with or without IL-3 plus GM-CSF, followed by a concurrent treatment with Ara-C for 4 additional hours. Exposure to the HGFs and Ara-C produced significantly higher intracellular Ara-CTP levels as well as higher Ara-CTP/dCTP pool ratios in AML blasts as compared with NBMMC. Treatment with HGFs resulted in [3H] Ara-C DNA incorporation that was significantly higher in AML blasts versus NBMMC. This selective improvement of Ara-C metabolism in AML blasts was associated with an enhanced Ara-C-mediated leukemia colony-forming unit (CFU) growth inhibition. In contrast, exposure to HGFs resulted in an improved colony growth of normal CFU granulocyte-monocyte and CFU-granulocyte, erythroid, monocyte, megakaryocyte. These in vitro studies indicate that a combined treatment with IL-3 plus GM-CSF may improve the selectivity of Ara-C against AML blasts.
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PMID:Treatment with interleukin-3 plus granulocyte-macrophage colony-stimulating factors improves the selectivity of Ara-C in vitro against acute myeloid leukemia blasts. 182 60

In preparation for a clinical trial using GM-CSF on days 4-10 of sequential high-dose cytarabine (ara-C) and asparaginase (ASNase) on days 1-3 and 8-10, potential interactions between the protein synthesis inhibitor ASNase and GM-CSF were evaluated. Granulocyte-macrophage colony-stimulating factor (GM-CSF) can stimulate acute myeloid leukemia (AML) cells to proliferate in vitro and in vivo. Log phase HL-60 cells were exposed to ara-C (10 microM x 3 h) and/or ASNase (10 U/ml during the last 2 h of ara-C). Ara-C and/or ASNase was removed and cells were incubated with or without GM-CSF (10 ng/ml). After 24, 48 and 72 h of GM-CSF there was no significant difference in the S phase fraction of cells exposed to ASNase prior to GM-CSF. Soft agar cloning efficiency was determined after retreatment with ara-C +/- ASNase 24 h into the GM-CSF incubation. GM-CSF enhanced cytotoxicity for all combinations, although this effect was of borderline significance (P = 0.0621); addition of ASNase to the treatment regimen significantly (P = 0.0229) enhanced cytotoxicity without any evidence of a negative interaction with GM-CSF. In addition, ara-C metabolism was assessed during simultaneous exposure to ara-C (10 microM x 3 h) +/- ASNase (10 U/ml the last 2 h) +/- GM-CSF (10 ng/ml beginning 24 h prior to ara-C). Ara-C incorporated into DNA (P = 0.0302) and ara-CTP formation (P = 0.0084 and P = 0.0003 at 2 and 3 h timepoints, respectively) were both increased significantly by GM-CSF, with modest non-significant increases with ASNase exposures. Neither ASNase nor GM-CSF inhibited the effects of the other in this in vitro model. Therefore, when appropriately scheduled, both GM-CSF and ASNase may potentiate ara-C cytotoxicity.
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PMID:GM-CSF and asparaginase potentiate ara-C cytotoxicity in HL-60 cells. 788 38

Because in vitro studies have indicated that granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulates arabinosylcytosine (ara-C) metabolism in leukemia blasts, we analyzed the pharmacokinetics of ara-C triphosphate (ara-CTP) in the blasts of patients with chronic myelogenous leukemia who were undergoing therapy with GM-CSF and ara-C. Patients received a 2-h infusion of 1.0 g/m2 ara-C followed by daily infusions of GM-CSF (125 micrograms/m2/day i.v. over 6 h) for 2-4 days. After the last GM-CSF infusion, a second, identical dose of ara-C was administered. The cellular pharmacokinetics of ara-CTP in circulating blasts were determined during and after each ara-C dose, and the area under the accumulation and elimination curve (AUC) measured over 12 h was compared before and after GM-CSF. Ara-CTP accumulation peaked within 1 h after the end of each ara-C infusion. Comparison of the AUC of ara-CTP before and after GM-CSF administration suggested that in the blasts of three of four patients, GM-CSF treatment decreased the ara-CTP AUC; the AUC values were altered only slightly in a fourth patient. Studies of these patients' blasts incubated in vitro with ara-C before and after clinical infusion of GM-CSF revealed similar ara-CTP accumulation patterns. Together, these studies suggest that 2-4 days of GM-CSF administration does not increase the accumulation of ara-CTP in the circulating blasts from patients in the blastic phase of chronic myelogenous leukemia.
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PMID:Effect of granulocyte-macrophage colony-stimulating factor on the metabolism of arabinosylcytosine triphosphate in blasts during therapy of patients with chronic myelogenous leukemia. 809 26

Hematopoietic growth factors may be useful in improving the clinical effectiveness of arabinofuranosylcytosine (ara-C). In vitro studies have indicated that interleukin 3(IL-3) and, to a lesser extent, granulocyte-macrophage colony-stimulating factor (GM-CSF), but not G-CSF or M-CSF, may be capable of specifically augmenting the ability of ara-C to kill leukemic myeloid cells by pharmacological and cytokinetic mechanisms including increase of intracellular ara-CTP/dCTP pool ratios and enhanced ara-C DNA incorporation in leukemic blast cells, decrease of IC 90 of ara-C for leukemic colony-forming cells (CFC) as compared with normal CFC growth, and recruitment of quiescent leukemic cells into the cell cycle. In contrast, the combination of ara-C with M-CSF or with the leukemia inhibitory factor (LIF) appears to be useful in overcoming the block in differentiation of leukemic blast, while the effects of GM-CSF and IL-3 on ara-C-induced differentiation appear limited. The combined treatment of human myeloid leukemia cells by ara-C and LIF is associated with down-regulation of c-myc gene expression, transcriptional activation of jun/fos gene expression, and features of functional differentiation (e.g., the capability to reduce nitroblue tetrazolium, to express lysozyme, or to display differentiation-related surface receptors including C3bi and the c-fms protein). On the basis of these in vitro studies first clinical trials are underway that are examining the efficacy of ara-C combinations with these molecules for the treatment of myeloid disorders.
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PMID:Modulation of cytotoxicity and differentiation-inducing potential of arabinofuranosylcytosine in myeloid leukemia cells by hematopoietic cytokines. 846 21

The effect of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) on the intracellular metabolism of cytosine arabinoside (Ara-C) was comparatively analyzed in normal bone marrow mononuclear cells (NBMMC) from eight healthy volunteers and in leukemic blasts from 50 patients with acute myeloid leukemia (AML). Pretreatment with GM-CSF (100 U/ml) for 48 h resulted in a significant enhancement of DNA synthesis in both cell types: 21 of 35 AML specimens were found to be responsive to GM-CSF as defined by an increase of 3H-TdR incorporation into the DNA > 1.5-fold while NBMMC from normal donors were responsive in all cases. In GM-CSF responsive AML blasts, overall DNA polymerase and DNA polymerase alpha activity increased from a median of 84.4 to 96.1 and from 3.45 to 5.2 pmol/min x mg as compared to a median of 96.7 to 189.9 and 1.2 to 2.2 pmol/min x mg in NBMMC (P < 0.05). Median Ara-C-mediated inhibition of DNA synthesis was significantly more effective in AML blasts as compared to NBMMC (76.5 vs 55.0% at 0.05 microM and 99.0 vs 96.0% at 5.0 microM Ara-C, P < 0.01) but was not influenced by GM-CSF pretreatment. Similarly, intracellular Ara-CTP levels were higher in AML blasts as compared to NBMMC (median of 46.9 vs 18.7 at 1 microM, 167.8 vs 48.0 at 10 microM and 337.5 vs 59.5 ng/10(7) cells at 100 microM extracellular Ara-C, P < 0.01) but showed no enhancement in the presence of GM-CSF. Median deoxycytidine (DCK) and thymidine kinase (TK) activity were only slightly increased in AML blasts after GM-CSF priming. In contrast, NBMMC revealed a significant increase in TK activity after GM-CSF pretreatment (from a median of 1.9 to 3.6 pmol/min x mg, P = 0.039). At low; intermediate and high extracellular Ara-C concentrations GM-CSF pretreatment resulted in a significant enhancement of the 3H-Ara-C incorporation into the DNA in both GM-CSF responsive AML blasts and NBMMC (median of 1.3 to 2.1- and 1.4 to 1.6-fold, P < 0.05). GM-CSF non-responsive AML blasts showed no change in 3H-Ara-C incorporation into the DNA in response to GM-CSF at low Ara-C concentrations but significant increases at intermediate and high extracellular Ara-C concentrations (median increases of 1.63-fold at 1.06 microM with P = 0.01 and 1.37-fold at 10 microM extracellular Ara-C with P = 0.0+005). NBMMC revealed significantly lower GM-CSF-induced increases of the 3H-Ara-C incorporation into the DNA as compared to the effect of GM-CSF priming on DNA synthesis (median increases of 1.4 to 1.7-fold vs 2.6-fold, P < 0.05). These data reveal a different effect of GM-CSF priming on the metabolism of Ara-C in normal vs leukemic cells which may cause a preferential increase in the antileukemic cytotoxicity of Ara-C in the presence of GM-CSF.
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PMID:Differential effect of GM-CSF pretreatment on intracellular Ara-C metabolism in normal bone marrow mononuclear cells vs acute myeloid leukemia (AML) blasts. 909 97