Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026986 (myelodysplastic syndrome)
 14,926 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Radiation leukemia virus (RadLV)-induced preleukemic (PL) latency is characterized by the appearance of virus-infected PL cells in the thymus. The survival of these PL cells is dependent upon autostimulation with interleukin 4 (IL-4). We have intervened prophylactically in RadLV-induced preleukemia by using cyclosporin-A (CSA), which inhibits IL-4 production, and an immunotoxin (ITx) that kills PL cells. CSA efficiently inhibited IL-4 secretion from RadLV-induced PL and leukemic cells, and its administration to PL mice caused a significant delay in their death. An ITx consisting of anti-RadLV glycoprotein-70 (gp70) antibody coupled to ricin A chain efficiently inhibited protein synthesis in virus-infected cells in vitro and, when injected into PL mice, also delayed their death. Combined treatment with CSA and ITx prevented 75% of the treated PL mice from developing lymphoma. These results show that the development of malignancy from a premalignant state can be averted by a combination of therapeutic modalities that decrease the size and growth rate of the premalignant cell population.
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PMID:Treatment of premalignancy: prevention of lymphoma in radiation leukemia virus-inoculated mice by cyclosporin A and immunotoxin. 173 46

In order to maintain adequate circulating numbers of blood cells, the bone marrow must produce billions of cells each day and must be able to rapidly increase production by 10-20-fold in response to infection and hemorrhage. The existence of circulating factors that regulate this process has been suspected for over 100 years. Recently, the genes encoding these growth factors were cloned and their functions are now identified. Interleukin-3 (IL-3) acts on the most primitive hematopoietic stem cell, driving this self-renewing cell to produce progeny of all hematopoietic lineages. Granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulates the granulocyte-macrophage progenitor cell, as well as cells committed to the erythroid lineage, to differentiate. G-CSF and M-CSF stimulate the most differentiated myeloid progenitors to produce granulocytes and monocytes/macrophages, respectively. Erythropoietin stimulates the differentiation of late erythroid progenitors. In the lymphoid progenitor lineage, IL-2 stimulates T cell differentiation; IL-4 and IL-6 stimulate differentiation of B cells. The colony-stimulating factors also enhance function and cause activation of the mature cells whose production they induce. In clinical trials, these hormones have successfully ameliorated anemia in renal failure, chronic disease, and in prematurity. They have improved pancytopenias in aplastic anemia, myelodysplastic syndromes, and congenital cytopenias, and they have hastened recovery from chemotherapy and bone marrow transplantation.
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PMID:Hematopoietic hormones: from cloning to clinic. 267 59

A number of cytokines are used as haemopoietic growth factors and this review focuses on toxicities associated with granulocyte-macrophage colony-stimulating factor (GM-CSF), granulocyte colony-stimulating factor (G-CSF), interleukin (IL)-1, IL-3, IL-4, IL-6 and macrophage colony-stimulating factor (M-CSF). Both GM-CSF and G-CSF, currently approved for clinical use, are generally well tolerated by the majority of patients during short term administration. Constitutional symptoms and bone pain are the most frequently reported adverse effects, but they are rarely treatment-limiting. Reactivation of rheumatoid symptoms, and exacerbation of autoimmune thyroiditis or autoimmune haematological disorders have sometimes been described. Severe cardiovascular complications include the possibility for arterial thromboses and the vascular leak syndrome, which is more specifically observed with GM-CSF. Reports of several cases and small series of patients have suggested that growth factors might increase the pulmonary toxicity of chemotherapy, a possibility that remains debated and requires further attention. Generalised or local cutaneous reactions are frequently noted with GM-CSF. Leukocytoclastic vasculitis was observed with both growth factors, while neutrophilic dermatoses have been mostly described with G-CSF. Exacerbation of psoriasis and isolated anaphylactic reactions have appeared with GM-CSF and G-CSF. The hepatotoxic potential of the growth factors is not clearly established, but the occurrence of coagulation abnormalities has recently been reported. Renal and biological disturbances are usually transient. Long term treatment with GM-CSF and G-CSF also seems to be well tolerated, but the possible occurrence of several adverse events, i.e. bone disorders, leukaemia, unmasking or acceleration of underlying disease, require further investigation in patients receiving prolonged treatment, as in myelodysplasia. Finally, antibodies against growth factors have been reported only with GM-CSF. Other cytokines are still under investigation. Flu-like and constitutional symptoms, sometimes dose-limiting, have been reported with IL-1, IL-3, IL-4 and IL-6, while M-CSF was occasionally associated with such adverse effects. More specific adverse events, also frequently considered as dose-limiting toxicities, include hypotension with IL-1, severe headache or skin rash with IL-3, and nasal congestion and gastroduodenal lesions with IL-4. Severe capillary leak syndrome has been reported only with IL-4. M-CSF toxicity is minimal and limited to reversible but sometimes dose-limiting thrombocytopenia and ophthalmological symptoms with the recombinant product. Again, the safety of long term administration of these cytokines has not yet been determined, and IL-3-induced disease progression in myelodysplastic patients has been suggested.
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PMID:Clinical toxicity of cytokines used as haemopoietic growth factors. 865 81

Interstitial deletion of chromosome 5q is a common cytogenetic abnormality observed in MDS. We have used fluorescence in situ hybridization (FISH) to determine accurately the percentage of cytogenetically abnormal peripheral blood cells. YAC and cosmid probes localized to chromosome 5q were hybridized to interphase nuclei from purified polymorphonuclear cells (PMNs) from six MDS patients with chromosome 5 deletions. Per patient, 25-67% of the cells exhibited one signal for the 5q31-q33 specific probes IL-4, D5S207 and c-fms. This percentage was constant for the various probes utilized for each patient. Hybridization of the same probes to PMNs from healthy individuals and hybridization of probes (D5S39 and D5S498) localized outside the deleted segments to PMNs of the patients, resulted in 90-95% nuclei with two signals. In addition, FACS-purified peripheral blood cells were investigated by FISH using the IL-4 cosmid. This demonstrated that the hybridization pattern in monocytes was similar to that observed in PMNs, whereas T-lymphocytes showed no loss of signals. These results indicate that a subfraction of the myeloid progenitor cells have acquired the 5q deletion.
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PMID:Mosaicism of the 5q deletion as assessed by interphase FISH is a common phenomenon in MDS and restricted to myeloid cells. 909 92

We have compared the phenotypic and functional characteristics of dendritic cells (DC) generated in vitro from the peripheral blood mononuclear fraction of myelodysplastic syndrome (MDS) patients (four refractory anaemia, four refractory anaemia with excess of blasts) with DCs generated in a similar way from eight healthy donors. After 10 d of culture in the presence of GM-CSF and IL-4, reduced numbers and percentages of DCs were obtained in MDS subjects. MDS DCs exhibited significantly lower expression of CD1a, CD54, CD80 and MHC class II molecules. Their ability to stimulate T lymphocytes in an allogeneic mixed leucocyte reaction was reduced in comparison to normal subjects. Furthermore, MDS DCs also showed a reduced receptor-mediated endocytosis as demonstrated by FITC-dextran uptake. Simultaneous fluorescence in situ hybridization (FISH) and immunophenotypic analysis demonstrated that MDS DCs have the same cytogenetic abnormality of the malignant clone. Taken together these findings indicate that, in MDS, DCs are part of the malignant clone and exhibit a deficient antigen uptake and presentation.
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PMID:Phenotypic and functional characteristics of monocyte-derived dendritic cells from patients with myelodysplastic syndromes. 1060 93

Dendritic cell (DC) differentiation was investigated in samples from two acute promyelocytic leukaemia (APL) patients with classic translocation t(15;17)(q22;q21). After 18 d of culture in the presence of granulocyte-macrophage colony-stimulating factor, interleukin 4 and tumour necrosis factor alpha, 10-15% of pathological promyelocytes had differentiated into DC-like cells, as demonstrated by immunological and functional characteristics and by analysis of CD1a+ cells. In one patient, analysed at relapse and after developing a picture of secondary myelodysplastic syndrome (MDS), three different populations of DCs were demonstrated, two of which derived from pathological myeloid precursors (the APL and the MDS clones). This patient's DCs also presented abnormal dextran uptake. Our results demonstrated that pathological myeloid precursors in APL can differentiate into DC-like elements and that different populations of pathological DCs may coexist in the same patient.
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PMID:Dendritic cells in acute promyelocytic leukaemia. 1156 70

Functional dendritic cells (DC) are professional antigen-presenting cells (APC) and can be generated in vitro from healthy as well as from leukaemic cells from AML patients giving rise to APC of leukaemic origin presenting leukaemic antigens. In a comparative methodological analysis of 50 AML samples, we could already show that leukaemia-derived DC can regularly be generated under serum-free culture conditions. In this study, we describe the generation and characterization of DC from different mononuclear cell (MNC) fractions from 24 myelodysplastic syndrome (MDS) patients under those different serum-free culture conditions, determine the optimal culture conditions and compare the results with that from 23 healthy donors. In parallel cultures, we compared DC harvests after 7- or 14-day culture, with total or adherent MNC or T-cell-depleted MNC or PB or BM-MNC, thawn or fresh MNC, in Xvivo or CellGro serum-free media, +/-10% autologous plasma or +/-FL. In detail, we could show that MDS-DC harvests compared to healthy DC were higher after 10- to 14-day culture; total or adherent PB or BM-MNC fractions yield comparable DC counts; however, from MACS-depleted MNC fractions or thawn MNC lower DC counts can be generated. Whereas the addition of FL increases the DC harvest, the addition of autologous plasma in many cases has inhibitory influence on DC maturation, CellGro and Xvivo media yield comparable DC counts. Optimal harvest of vital and mature DC from MDS samples was obtained with a GM-CSF, IL-4, FL and TNF-alpha containing serum-free Xvivo medium after 10-14 days of culture (18/26% DC; 54/64% vital DC; 59/51% mature DC were generated from MDS/healthy MNC samples). Surface marker profiles (e.g. costimulatory antigen expression) of DC obtained from MDS samples were comparable with that of healthy DC. The leukaemic derivation of MDS-DC was demonstrated by the persistence of the clonal cytogenetic aberration in the DC or by coexpression of leukaemic antigens on DC. Autologous T-cell activation of leukaemia-derived DC was demonstrated in cases with MDS. Autologous T cells proliferate and upregulate DC-contact-relevant antigens. We are the first who demonstrate that the generation of leukaemia-derived DC is feasible not only in AML but also in MDS under serum-free culture conditions giving rise to DC with comparable characteristics as healthy DC and offering an antileukaemia-directed immunotherapeutical vaccination strategy in AML and MDS.
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PMID:Leukaemia-derived dendritic cells can be generated from blood or bone marrow cells from patients with myelodysplasia: a methodological approach under serum-free culture conditions. 1609 Nov 27

Thrombocytosis is not a frequent event in myelodysplasia (MDS) and is observed mainly in 5q- syndrome and MDS/myeloproliferative (MPD) overlap syndromes. The pathogenetic mechanism of thrombocytosis in 5q- has not been fully elucidated to-date. Bortezomib is a proteasome inhibitor which seems to be effective in MDS. We present here the first case in the literature with MDS/MPD syndrome, sole 5q- anomaly and thrombocytosis in which bortezomib administration normalized platelet count, produced a major erythroid response, and reduced levels of interleukin-6 (IL-6) and TNF-alpha while increased levels of IL-4 in the bone marrow plasma. The study of such cases will reveal the exact role of bortezomib in the management of MDS/MPD.
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PMID:Bortezomib is an effective agent for MDS/MPD syndrome with 5q- anomaly and thrombocytosis. 1682 Feb 6

The aim of the review is to summarize current knowledge concerning active immunotherapy in leukemia. The molecular mechanisms and selected clinical implications of different cancer vaccines used in pediatric and adult leukemias are discussed. Escape of neoplasmatic cells from elimination by host cells can be caused by immunological disturbances, such as the production of immunosuppressive cytokines and downregulation of costimulatory and adhesion molecules. Cells of acute lymphoblastic leukemia and chronic lymphocytic leukemia can be induced into antigen-presenting cells with the CD40 ligation system. After CD40 stimulation, leukemic cells achieve the phenotypic and functional characteristics of dendritic cells. In many studies it was confimed that these cells stimulate auto- and/or allogeneic T-cell response. Immunological response can be of cellular and humoral origin and is extensively examined. Similar effects using different cytokines such as GM-CSF, TNF-alpha, and IL-4 can be observed in acute myeloid leukemia and myelodysplastic syndromes. Clinical experience with such vaccines is limited, but the results of some preliminary reports are quite promising. Cancer vaccines are safe, result in host response, and probably prolong patients survival.
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PMID:[Experimental and selected clinical aspects of active immunotherapy in leukemia]. 1688 8

Dendritic cells (DC) are pivotal for T cell-mediated immunity. We investigated the early and terminal maturation of monocyte-derived DC (MoDC) in myelodysplastic syndromes (FAB subtypes refractory anemia (MDS-RA) or refractory anemia with ringed sideroblasts (MDS-RARS)). Immature MoDC were obtained by culture of monocytes with GM-CSF and IL-4 for 8 days. To obtain mature MoDC, TNF-alpha was added during the final three culture days. T cell proliferation and T cell cytokine secretion in mixed lymphocyte reactions (MLR) unveiled a strong reduction of allostimulatory capacity of mature but also of immature MoDC from MDS patients. Immature MoDC from MDS patients exhibited an almost normal immunophenotype, but secreted substantially less IL-12 and more IL-10 in response to LPS/IFN-gamma than normal controls. Terminal addition of TNF-alpha to GM-CSF/IL-4 treated monocytes failed to extinguish cytokine production by MDS MoDC and failed to induce the expected membrane upregulation of costimulatory and other ligands as in normal controls. While our data provide further support for previous studies that have indicated an impaired differentiation of immature towards mature MoDC, they also clearly demonstrate a qualitatively and quantitatively altered cytokine secretion at the level of immature MoDC, which may in part explain the reduced allostimulatory capacity of these cells. These alterations may contribute to immune modulation of the clinical phenotype of marrow failure in MDS, and may have to be considered when designing DC-based immunotherapeutic strategies for MDS.
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PMID:Immature and mature monocyte-derived dendritic cells in myelodysplastic syndromes of subtypes refractory anemia or refractory anemia with ringed sideroblasts display an altered cytokine profile. 1718 53


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