Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P15088 (mast cell)
 14,925 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mastocytosis is a rare disease characterized by increase in mast cell numbers. The most frequent organ identified as the site of increased numbers of mast cells is the skin. However, uncontrolled growth of mast cells may occur in many other organs and tissues; this disease is called systemic mastocytosis. Nowadays there are four categories of mast cell disease: 1) indolent mastocytosis, 2) mastocytosis with a hematologic disorder, 3) aggressive mastocytosis, and 4) mast cell leukemia. Although the diagnosis of systemic mastocytosis rests finally on identification of mast cells by histopathological examination of the involved tissues, radiological studies may suggest more decisive tests. In this paper the authors discuss usefulness of different methods of radiological imaging in the diagnostics of mastocytosis.
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PMID:[Systemic mastocytosis: significance of contemporary methods of imaging in diagnosis of this disease]. 793 60

Cytokine-activation pathways in mast cells are supposed to play a significant role in host defense mechanisms and allergic reactions. Interleukin-4 (IL-4) is a well-characterized regulator of growth and function of mast cells. The human mast cell line HMC-1 was established from a patient suffering from mast cell leukemia and was shown to expose IL-4 binding sites. In the present study, the effects of recombinant human (rh) IL-4 and other rh cytokines (IL-2, IL-3, IL-6, IL-8) on expression of cytokine mRNA in HMC-1 cells were examined by Northern blot analysis using oligonucleotide probes. Tumor necrosis factor alpha (TNF-alpha) and IL-1 beta transcripts were found to be expressed constitutively in HMC-1 cells, whereas transcripts for IL-3, IL-4, IL-5, IL-6, and granulocyte-macrophage colony-stimulating factor (GM-CSF) could not be detected. Of all cytokines tested, rhIL-4 was found to down-regulate IL-1 beta mRNA expression and formation of immunoreactive IL-1 beta protein in HMC-1 cells. The effect of IL-4 on IL-1 beta gene product expression was time- and dose-dependent (maximum effects obtained with 100 U/mL of rhIL-4). No effect of IL-4 on expression of TNF-alpha mRNA in HMC-1 cells was observed. These results raise the possibility that human mast cells are a source of both TNF-alpha and IL-1 beta. Furthermore, our study provides evidence that IL-4 regulates IL-1 beta gene product expression in HMC-1 cells. The HMC-1 cell line should be a useful tool for studying cytokine activation pathways in human mast cells.
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PMID:Tumor necrosis factor alpha and interleukin-1 beta mRNA expression in HMC-1 cells: differential regulation of gene product expression by recombinant interleukin-4. 833 Jun 51

A 12-year-old, female 5q- syndrome case of refractory anemia with excess of blasts in transformation (RAEB-T) evolving to mast cell leukemia is described. This case was admitted because of general fatigue, when her peripheral blood count revealed anemia and leukocytosis with basophil-like cells. RAEB-T was diagnosed based on the laboratory findings of her peripheral blood and bone marrow aspiration, which revealed over 10% peripheral blast cells and dysmyelopoietic changes in all three lineages. Chromosomal analysis of the bone marrow cells showed 46, XX, 5q-. Six months later, the RAEB-T phase evolved to acute leukemia, despite prednisolone, vitamin D3, oxymetholone and low-dose cytosine arabinoside treatment. She had remarkable pancytopenia, hemorrhage, and hepatosplenomegaly, which were not responsive to daunomycin, enocitabine, etoposide, and 6-mercaptopurine, and eventually died. This case was unique in that her karyotype changed to normal; 46, XX, and her blast cells were mast cell lineage during the overt leukemic phase. Interestingly, some blasts were intermediate cells possessing the ultrastructural features typical of both basophils and mast cells.
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PMID:[Mast cell leukemia evolved from RAEB-T (5q-syndrome) in a 12 year-old girl]. 869 90

Mastocytosis is a term collectively used for a heterogeneous group of disorders characterized by abnormal growth and accumulation of mast cells. Clinical symptoms occur from the release of chemical mediators and the pathologic infiltration of cells. Three major groups of patients with mastocytosis can be distinguished: i) cutaneous mastocytosis, ii) mastocytosis involving the skin and one or more extracutaneous organ(s), and iii) visceral mastocytosis without involvement of the skin. Groups ii) and iii) account for approximately 15-20% of all cases and have been referred to as systemic mastocytosis. Cutaneous mastocytosis typically presents as urticaria pigmentosa or diffuse cutaneous mastocytosis. These patients usually have a benign course. In contrast, systemic mastocytosis is a diffuse hematologic process with an increased risk to develop aggressive disease. In these patients, additional hematologic abnormalities or a second hematologic process, such as a myeloproliferative or myelodysplastic syndrome, or acute leukemia, may develop. Malignant mastocytosis and mast cell leukemia are rare forms of mastocytosis and characterized by uncontrolled and progressive proliferation and infiltration of mast cells in diverse organs. These patients often present without cutaneous lesions and have a very unfavorable prognosis. Because of the immature morphology of the cells it is often difficult to establish the diagnosis in such patients. However, the use of antibodies to mast cell antigens has recently improved the diagnostic efficiency in patients with suspected mast cell disease. No effective therapy for patients with malignant mastocytosis is known, although some patients may benefit from corticosteroid and interferon alpha treatment. The present article gives an overview of current knowledge about the biology, heterogeneity and treatment of human mastocytosis.
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PMID:Biology, classification and treatment of human mastocytosis. 876 23

Activating mutations in the Kit receptor tyrosine kinase have been identified in both rodent and human mast cell leukemia. One activating Kit mutation substitutes a valine for aspartic acid at codon 816 (D816V) and is frequently observed in human mastocytosis. Mutation at the equivalent position in the murine c-kit gene, involving a substitution of tyrosine for aspartic acid (D814Y), has been described in the mouse mastocytoma cell line P815. We have investigated the mechanism of oncogenic activation by this mutation. Expression of this mutant Kit receptor tyrosine kinase in a mast cell line led to the selective tyrosine phosphorylation of a 130-kDa protein and the degradation, through the ubiquitin-dependent proteolytic pathway, of a 65-kDa phosphoprotein. The 65-kDa protein was identified as the src homology domain 2 (SH2)-containing protein tyrosine phosphatase SHP-1, a negative regulator of signaling by Kit and other hematopoietic receptors, and the protein product of the murine motheaten locus. This mutation also altered the sites of receptor autophosphorylation and peptide substrate selectivity. Thus, this mutation activates the oncogenic potential of Kit by a novel mechanism involving an alteration in Kit substrate recognition and the degradation of SHP-1, an attenuator of the Kit signaling pathway.
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PMID:Oncogenic mutation in the Kit receptor tyrosine kinase alters substrate specificity and induces degradation of the protein tyrosine phosphatase SHP-1. 896 11

We investigated the mechanism of constitutive activation of c-kit receptor tyrosine kinase (KIT) found in the FMA3 murine mastocytoma cell line, and compared it with the mechanisms observed in other tumor mast cell lines (the HMC-1 human mast cell leukemia cell line, the RBL-2H3 rat mast cell leukemia cell line, and the P-815 murine mastocytoma cell line). The c-kit gene obtained from FMA3 cells was found to have 21-base deletion at the juxtamembrane domain of KIT, thereby leading to the constitutive activation of KIT. The deletion at the juxtamembrane domain resulted in constitutive dimerization of c-kit proteins, whereas the point mutation that were detected at the kinase domain of KIT in HMC-1, RBL-2H3, and P-815 cells caused constitutive activation of KIT without dimerization. These constitutively activating mutations of c-kit may play a role in development of mast cell tumors.
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PMID:Mechanisms of constitutive activation of c-kit receptor tyrosine kinase. 920 3

The contributions of mast cells to the pathology of allergic diseases, as well as to the expression of immunoglobulin E (IgE)-dependent host responses to parasites, reflect both the amounts and types of cytokines and other mediators that are released by these cells in such settings. Whereas mast cells cannot intrinsically express immunologically specific functions, the binding of IgE to high-affinity IgE receptors (Fc epsilonRI) on the surface of mast cells primes these cells to secrete cytokines and other biologically active products upon subsequent exposure to specific antigens. We now report that both HMC-1, a growth factor-independent human mast cell leukemia cell line, and growth factor-dependent human umbilical cord blood-derived mast cells can secrete the multifunctional C-C chemokine, macrophage inflammatory protein-1alpha (MIP-1alpha). In addition, we found that in vitro exposure of human umbilical cord blood-derived mast cells to concentrations of IgE within the range observed in the serum of subjects with allergic diseases or parasite infections, which markedly up-regulates the ability of these cells to bind IgE to their surface, also significantly enhances the ability of the cells to secrete MIP-1alpha upon subsequent passive sensitization with IgE and challenge with anti-IgE. Thus, IgE-dependent enhancement of human mast cell IgE-binding ability permits these cells to respond to Fc epsilonRI-dependent challenge with significantly increased secretion of MIP-1alpha, a chemokine that can have diverse functions in inflammation, allergic reactions, and host responses to infection.
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PMID:Production of macrophage inflammatory protein-1alpha by human mast cells: increased anti-IgE-dependent secretion after IgE-dependent enhancement of mast cell IgE-binding ability. 927 61

Nerve growth factor (NGF) can influence mast cell development and function in murine rodents by interacting with its receptors on mast cells. We now report the identification of mRNA transcripts of full-length tyrosine kinase-containing trkA, trkB, and trkC neurotrophin receptor genes in HMC-1 human mast cell leukemia cells. Although HMC-1 cells lacked p75 mRNA, they expressed transcripts for the exon-lacking splice variant of trkA (trkAI), truncated trkB (trkB.T1), and truncated trkC. By flow cytometry, HMC-1 cells exhibited expression of TrkA, TrkB, and TrkC receptor proteins containing full-length tyrosine kinase domains. NGF stimulation of HMC-1 cells induced tyrosine phosphorylation of TrkA protein, increased expression of the early response genes c-fos and NGF1-A, and activation of ERK-mitogen-activated protein (MAP) kinase, results which indicate that TrkA receptors in HMC-1 cells are fully functional. Highly purified populations of human lung mast cells expressed mRNAs for trkA, trkB and trkC, whereas preparations of human umbilical cord blood-derived mast cells expressed mRNAs for trkA and trkC, but not trkB. Moreover, preparations of human umbilical cord blood-derived immature mast cells not only expressed mRNA transcript and protein for TrkA, but exhibited significantly higher numbers of chymase-positive cells after the addition of NGF to their culture medium for 3 weeks. In addition, HMC-1 cells expressed mRNAs for NGF, brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3), the cognate ligands for TrkA, TrkB, and TrkC, whereas NGF and BDNF transcripts were detectable in human umbilical cord blood mast cell preparations. Taken together, our findings show that human mast cells express a functional TrkA receptor tyrosine kinase and indicate that NGF may be able to promote certain aspects of mast cell development and/or maturation in humans. Our studies also raise the possibility that human mast cells may represent a potential source for neurotrophins.
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PMID:Expression of functional TrkA receptor tyrosine kinase in the HMC-1 human mast cell line and in human mast cells. 929 13

The primary role of protooncogene c-kit in mast cell differentiation is supported by the development of mast cells from CD34+/CD117+(c-kit) myeloid precursors. Growth factor independence, neoplastic transformation and differentiation of mast cells were found in association with c-kit activating mutations in both murine and human mastocytoma and mast cell diseases. We have identified a novel c-kit mutation (D816Y) in peripheral blood mononuclear cells from a patient with AML (M2), massive presence of mast cells in bone marrow and rapid progression of the disease. The mutation, a G-->T transversion at nt 2467 of the c-kit gene resulting in Asp816-->Tyr substitution, corresponds to the D814Y and D817Y mutations identified and characterized in the murine P815 mastocytoma and the rat RBL-2H3 mast cell leukemia cell lines. The absence of SCF transcripts that we found by RTPCR in the patient's blasts indicates that, also in humans, this activating mutation leads to SCF independent growth. The expression of the mutant allele on Kit signaling may be further enhanced by trisomy of chromosome 4 (carrying the c-kit gene) in the patient's blasts. From these findings it is concluded that mast cells could be generated from a leukemic CD34/CD117-positive clone, that combines the antigenic expression of mast cell precursor to the growth and differentiation factor-independence which was derived by the c-kit D816Y mutation.
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PMID:In vivo differentiation of mast cells from acute myeloid leukemia blasts carrying a novel activating ligand-independent C-kit mutation. 971 3

Mastocytosis represents a mast cell proliferative disease that generally runs a benign clinical course, with spontaneous remissions mostly by puberty in childhood-onset disease, although rare forms, particularly in adult-onset disease, can be associated with (pre)malignant hematologic disorders and very rarely present as mast cell leukemia or malignant mastocytosis. Reasons for this divergent clinical behavior of childhood- versus adult-onset disease are unknown. Recently, two activating mutations in the intracellular domain of the proto-oncogene c-kit, which encodes a tyrosine kinase receptor for the mast cell growth factor stem cell factor, have been detected in the human leukemic mast cell line HMC-1. We have therefore studied lesional skin biopsies from patients with adult- and childhood-onset indolent mastocytosis for the presence of these codon 560 and 816 mutations. C-kit coding DNA sequences were amplified and analyzed by mutation-specific restriction analyses, and mutated polymerase chain reaction products were additionally cloned and sequenced. The codon 816 mutation was found in all six samples from adult patients, but not in any of the 11 specimens from children. In addition, the codon 560 mutation could be demonstrated for the first time in indolent mastocytosis, namely in two of four specimens from adult patients, but not in those from two children. These data thus provide a possible explanation for the divergent clinical behavior of adult- versus childhood-onset indolent mastocytosis, with the first being associated with an activating mutation, possibly as part of a neoplastic process, and the latter representing most likely a reactive process of an as yet unknown pathogenesis.
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PMID:Identification of activating c-kit mutations in adult-, but not in childhood-onset indolent mastocytosis: a possible explanation for divergent clinical behavior. 985 47


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