Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023473 (chronic myeloid leukemia)
 18,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have established a novel human megakaryoblastic cell line, designated as MEG-A2, from a patient with megakaryoblastic crisis of Philadelphia (Ph) chromosome positive chronic myelogenous leukemia. MEG-A2 cells showed positive phenotypes for periodic acid Schiff and alpha-naphthylbutyrate esterase reactions, but were negative for myeloperoxidase and naphthol ASD chloroacetate esterase reactions. Flow cytometric analyses of cell surface markers revealed that MEG-A2 cells had a low level of GP IIb/IIIa expression as well as apparent expressions of CD4, CD7, CD13, CD33 and CD34 antigens, but no expression of GP Ib nor glycophorin A. Stimulation with phorbol 12-myristate 13-acetate (PMA) dramatically increased the expression of megakaryocyte-related markers such as HPL-3, J15, Pit-1, Y2/51 and AN51 in MEG-A2 cells. The PMA-stimulation also induced expression of platelet peroxidase (PPO) in MEG-A2 cells on electromicroscopic observation. Proliferative responses to granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3) or erythropoietin were observed, and the expression of GP IIb/IIIa was increased by stimulation with GM-CSF, IL-3, erythropoietin and interleukin-6 (IL-6). Protein S mRNA expression was seen in cultured cells on Northern blot analysis. Expression of platelet factor 4 mRNA was induced in PMA-stimulated cells, and a marked accumulation of protein was observed in the culture medium. In conclusion, a new cell line, MEG-A2, belongs to the relatively immature megakaryocytic lineage and has markedly increased megakaryocytic characteristics with PMA stimulation.
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PMID:Establishment and characterization of an immature human megakaryoblastic cell line, MEG-A2. 786 73

Cytokines represent a growing number of biologically highly active polypeptides, which exert important functions in haematopoiesis and immune response. Cytokines are predominantly released by activated lymphocytes and macrophages. Increasing insight into the role of these factors was accompanied by large scale availability made possible by genetic engineering. Several cytokines represent accepted therapeutical vehicles, others are still under investigation. To date the following indications are established part of therapy: Correction of renal anaemia by erythropoietin as well as interferon for hairy cell leukaemia and chronic myeloid leukaemia. Especially the example of hairy cell leukaemia emphatically demonstrates the potency of cytokines, because a hitherto incurable disease can now be converted into durable remission. Recently neutropenic states have become subject to causal therapy by haematopoietic growth factors. Further cytokines offer promising capacities and will experience clinical testing in the near future.
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PMID:[Therapeutic use of cytokines]. 837 44

Interleukin-4 (IL-4) is a cytokine with pleiotropic activities. In normal bone marrow cultures grown in the presence of either granulocyte-macrophage colony-stimulating factor (GM-CSF) or interleukin-3 (IL-3), IL-4 suppresses granulocyte-macrophage colony-forming unit (CFU-GM) proliferation but it enhances the colony-stimulatory effect of granulocyte colony-stimulating factor (G-CSF). We studied the effect of IL-4 on chronic myelogenous leukemia (CML) bone marrow or peripheral blood cells from 30 patients using the CFU-granulocyte-erythrocyte-monocyte-megakaryocyte colony culture assay. In several repetitive experiments, IL-4 inhibited CFU-GM colony replication by 24 to 65% in a dose-dependent fashion at concentrations ranging from 0.01 to 10 micrograms/ml when patients' cells were cultured in the presence of erythropoietin alone or with phytohemagglutinin-conditioned medium, GM-CSF, or IL-3. The addition of 100 U/ml of IL-1 beta to the CML cultures partially reversed the inhibitory effect of IL-4. Incubation of CML low-density peripheral blood cells with IL-4 resulted in down-regulation of IL-1 beta and IL-6 production in three of four samples, suggesting that the suppressive effect of IL-4 is mediated by inhibition of IL-1 and by other mechanisms including inhibition of IL-6 production. In contrast to the stimulatory effect exerted by IL-4 on G-CSF-dependent CFU-GM progenitor proliferation in normal marrow, the addition of IL-4 to CML cultures grown in the presence of G-CSF resulted in a divergent effect: suppression of CML CFU-GM in two, stimulation in three, and no significant effect in two CML patients' samples. It is therefore possible that IL-4 may have an in vivo antiproliferative effect in a subpopulation of CML patients.
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PMID:Suppression of chronic myelogenous leukemia colony growth by interleukin-4. 842 75

The Norwegian Society of Haematology has worked out guidelines for the use of granulocyte-colony stimulating factor and granulocyte-monocyte colony stimulating factor and interferon alpha in clinical haematological practice. We recommend not using growth factors as a routine to prevent or to treat fever in patients with granulocytopenia induced by cytostatics, or patients with myelodysplastic syndromes. At present such treatment should be restricted to clinical trials. The same conclusion was reached in regard to use of erythropoietin in the case of myelodysplastic syndromes. Harvesting of stem cells from peripheral blood is a well documented indication for administration of growth factors. Interferon alpha as maintenance treatment for cases of multiple myeloma and low grade malignant lymphoma delays progression of the disease but does not improve chance of survival. There is no documentation of improved quality of life. Use of interferon alpha is not justified as a routine treatment for multiple myeloma. In chronic myelogenous leukemia, interferon alpha seems to be equal to or better than hydroxyurea, and may be considered for patients who cannot undergo allogeneic bone marrow transplantation.
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PMID:[Treatment with growth factors and cytokines in hematologic diseases]. 880 16

Pure red cell aplasia (PRCA) was found in a male patient with chronic myelocytic leukemia after major ABO incompatible bone marrow transplantation (BMT). He had blood group O, and received BMT from an HLA identical sibling (blood group A). Erythrocyte-depleted marrow was transplanted. Methotrexate for short time and cyclosporine (CyA) were used for graft versus host disease (GVHD) prophylaxis. Engraftment of neutrophils and platelets were observed on day 14 and 22, respectively. The Ph1 chromosome disappeared on day 133. However engraftment of erythrocytes was not observed on day + 280. Bone marrow puncture revealed depletion of erythrocyte precursors. Anti-A isoagglutinin was persisted. There was no evidence of acute or chronic GVHD. Administration of prednisolone, discontinuance of CyA and subcutaneous infusion of recombinant human erythropoietin failed to improve PRCA. Bolus methylprednisolone (m-PSL) therapy started on day 284 resulted in rapid increase in reticulocyte counts within 6 days, which was followed by normal hemoglobin concentrations. We conclude that bolus m-PSL may be one treatment for PRCA after BMT.
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PMID:[Treatment with bolus methylprednisolone for pure red cell aplasia after ABO incompatible bone marrow transplantation in a patient with chronic myelocytic leukemia]. 869 68

The growth factor of hematopoiesis, G-CSF and GM-CSF, are now extremely useful in stem cell transplantation (SCT). Their main indications are given in this short paper. They accelerate hematopoietic recovery and they reduce morbidity and mortality after autologous SCT. GM-CSF can protect from hematopoietic toxicity of Gancyclovir and can reduce the mortality related to autologous and allogeneic graft failure. The combination of GM-CSF, G-CSF and erythropoietin can replace autologous SCT after a high dose therapy. G and GM-CSF are used to mobilise peripheral stem cells and allow peripheral blood stem cell transplantation. G-CSF given after a chemotherapy is able to mobilise Philadelphia negative stem cells in chronic myelocytic leukemia patients. Finally allogeneic peripheral blood stem cell mobilised by G-CSF in healthy donor is now a new field of clinical trials.
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PMID:[Contribution of hematopoietic growth factors and especially in the context of grafts of hematopoietic stem cells]. 888 Nov 2

Myeloproliferative disorders (MPD) constitute a group of hematopoietic neoplasms at the myeloid stem cell level. Myeloid stem cells and/or progenitor cells from MPD have been considered sensitive to hematopoietic growth factors, including erythropoietin, thrombopoietin and stem cell factor (SCF). SCF is a ligand for c-kit receptor with tyrosine kinase. We analysed the gene alteration of the c-kit extracellular domain in MPD patients by PCR-SSCP and subsequent nucleotide sequencing. The point mutation in the N-terminal part of the domain, codon 52 (Asp-->Asn), was found in two patients with primary myelofibrosis and one with chronic myelogenous leukemia. We review the literature regarding the role of SCF/c-kit system in the oncogenesis of leukemia and MPD, and then discuss the significance of our finding in the context of growth advantage of the mutated clones over the normal clones.
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PMID:c-kit Point mutation in patients with myeloproliferative disorders. 916 38

Polycythaemia vera (PV) is a myeloproliferative disorder characterized by haematopoietic progenitor cells being hypersensitive to cytokines such as erythropoietin, interleukin-3, stem cell factor and insulin-like growth factor 1, which results in an increased production of mature blood cells. The pathogenetic cellular mechanism(s) behind this hypersensitivity to cytokines is unknown, but the number of cytokine receptors and the interaction between ligand and receptor are normal in PV. Interest has therefore focused on post-receptor mechanism(s). Haematopoietic cell phosphatase (HCP) is an intracellular tyrosine phosphatase that has been demonstrated to regulate proliferative signals negatively induced by the cytokines mentioned above. Moreover, motheaten mice that genetically lack HCP have an increased amount of erythroid progenitors that are hypersensitive to Epo, and patients with familial polycythaemia have been shown to exhibit a mutation of the Epo receptor gene that includes the docking site for HCP. We therefore studied mRNA expression of HCP in pure populations of CD34+ cells, granulocytes, platelets and lymphocytes from patients with PV, chronic myeloid leukaemia (CML) or essential thrombocythemia (ET), as well as healthy controls. Using a polymerase chain reaction analysis employing specific primers for HCP, we failed to detect any abnormalities of HCP expression in PV in any of the cell populations that were examined. Moreover, HCP mRNA expression was similar in ET and CML compared to controls. Finally, Western blot analysis revealed a normal HCP protein content in PV granulocytes and platelets. We therefore conclude that neither an impaired expression of the HCP gene nor a defect in HCP protein synthesis is present in PV, and does not seem to play a role in the aetiology of this disorder.
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PMID:No evidence for an altered mRNA expression or protein level of haematopoietic cell phosphatase in CD34+ bone marrow progenitor cells or mature peripheral blood cells in polycythaemia vera. 941 43

CRKL is a 39 kDa adapter protein, originally cloned in proximity to the BCR gene on chromosome 22, which has a key regulatory role in hematopoietic cells. CRKL has one SH2 and two SH3 domains, with 60% homology to CRK II. CRKL is a prominent substrate of the BCR/ABL oncoprotein in chronic myelogenous leukemia and binds to both BCR/ABL and c-ABL. CRKL has been shown to be tryosine phosphorylated in response to normal hematopoietic growth factor receptor signaling with ligands such as thrombopoietin, erythropoietin or steel factor. Additionally, CRKL is involved in signaling initiated by crosslinking of beta integrins, and B cell or T cell receptors. Structurally, the amino-terminal SH3 domain of CRKL has been shown to bind proteins such as C3G, SOS, PI3-K, c-ABL or BCR/ABL. The SH2 domain of CRKL can bind to tyrosine phosphorylated proteins such as CBL, HEF1, CAS or paxillin. This review summarizes the current knowledge on the function of this unique adapter protein in normal hematopoietic and leukemic cell signaling.
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PMID:Role of the adapter protein CRKL in signal transduction of normal hematopoietic and BCR/ABL-transformed cells. 959 59

Adoptive immunotherapy with donor lymphocyte infusions (DLI) is an effective treatment for relapsed chronic myeloid leukemia (CML) after allogeneic stem cell transplantation. To identify the effector and target cell populations responsible for the elimination of the leukemic cells in vivo we developed an assay to measure the frequency of T lymphocyte precursor cells capable of suppressing leukemic progenitor cells. Target cells in this assay were CML cells that were cultured in the presence of stem cell factor, interleukin 3, granulocyte-macrophage colony-stimulating factor, granulocyte colony-stimulating factor, and erythropoietin. [3H]thymidine incorporation at day 7 represented the proliferation of the progeny of the CD34(+) CML progenitor cells, and not of the more mature CD34(-) CML cells. Effector cells were mononuclear cells, which were used in a limiting dilution analysis to measure the frequencies of CML progenitor cell-inhibitory lymphocyte precursors (PCILp) in peripheral blood of seven patients before and after DLI for relapsed CML. In the six patients who entered complete remission, a 5- to 100-fold increase of PCILp was found during the clinical response. In the patient with resistant relapse the frequency of PCILp was <10 per ml before and after DLI. Leukemia-reactive helper T lymphocyte precursor frequencies remained unchanged after DLI. A significant increase in cytotoxic T lymphocyte precursor frequency against more mature leukemic cells was found in only two responding patients. These results indicate that T cells specifically directed against CD34(+) CML progenitor cells mediate the antileukemic effect of DLI.
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PMID:T cells recognizing leukemic CD34(+) progenitor cells mediate the antileukemic effect of donor lymphocyte infusions for relapsed chronic myeloid leukemia after allogeneic stem cell transplantation. 970 16


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