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)

Systemic mast cell disease is characterized by an abnormal infiltration of mast cells involving several parenchymal organs and the bone marrow. Its spectrum of clinical and histologic presentation is highly variable and is not necessarily correlated with prognosis. Mast cell disorders presenting as atypical infiltrates in the bone marrow may simulate or be associated with other hematolymphoid malignancies, from which they must be distinguished. The paucity of reliable histochemical and immunohistochemical markers for the detection of mast cells in paraffin sections further confounds this diagnosis. The authors have employed immunohistochemistry for the C-KIT encoded tyrosine kinase receptor protein, CD117, for detection of mast cells on paraffin sections of 89 bone marrow specimens including systemic mast cell disease and other disorders. CD117 staining was found in all cases of mast cell disorders (seven of seven), and in one case of chronic myelogenous leukemia in blast crisis. None of the other myeloid disorders tested (0 of 16), or any of the cases of Hodgkin's disease (0 of 12), B-cell lymphomas (0 of 32), T-cell lymphomas (0 of 3), or histiocytic proliferations (0 of 3) showed staining for CD117. CD117 expression is effective in the separation of mast cell disease from disorders that may simulate it histologically.
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PMID:Utility of paraffin section immunohistochemistry for C-KIT (CD117) in the differential diagnosis of systemic mast cell disease involving the bone marrow. 1063 91

Mast cells are likely to play a role in angiogenesis under pathological conditions. Solid tumor growth is dependent on angiogenesis, but the influence of mast cells on angiogenesis in non-Hodgkin's lymphoma, (NHL) is not clear. We investigated mast cell number and vessel count in 61 cases of NHL. We also evaluated expression of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF), both important cytokines for angiogenesis. The number of mast cells was greater in T-cell lymphomas than in B-cell lymphomas. Of the T-cell lymphomas, the greatest number of mast cells was observed in the angioimmunoblastic T-cell lymphoma (AIL). In all NHLs, significant correlation was found between vessel count and the number of mast cells (p < 0.0001) and between vessel count and the number of VEGF-expressing cells (p < 0.05) but not between vessel count and bFGF-expressing cells. Strong correlation was detected between the number of mast cells and the number of VEGF-expressing cells (p < 0.0001) in all NHLs. Double fluorescence staining of VEGF mRNA and mast cell tryptase revealed that mast cells expressed VEGF mRNA. Our data suggest that mast cells play a very important role in angiogenesis by expressing VEGF in NHL, especially in AIL.
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PMID:Angiogenesis and mast cells in non-Hodgkin's lymphoma: a strong correlation in angioimmunoblastic T-cell lymphoma. 1169 1

The principles of the new WHO classification of haematopoietic and lymphoid tumours are based on those defined in the Revised European American classification of Lymphoid neoplasms (REAL), published by the International Lymphoma Study Group (ILSG) in 1994. Thus, the new WHO classification may be considered an updated version of the REAL classification rather than of the old WHO classification published in 1976. Disease entities are defined on the basis of morphological, phenotypic, genotypic, and clinical data. The relative impact of these characteristics varies among different diseases and there is "no gold standard". Thus, the strict hierarchy among diagnostic criteria, headed by morphology and followed by immunohistochemistry and genetics, has been discontinued. The WHO classification not only encompasses lymphoid tumours but extends to myeloid, mast cell and histiocytic/dendritic cell malignancies. Neoplasms are primarily stratified according to their tumour cell lineage. For each neoplasm a cell of origin is postulated. The classification of lymphoid malignancies recognises three major categories, B-cell neoplasms, T-/NK-cell neoplasms, and Hodgkin lymphomas. B-cell and T-cell lymphomas are further divided into precursor neoplasms and mature neoplasms, the latter being subdivided according to their clinical manifestation into disseminated/leukaemic, extranodal and nodal malignancies. In contrast to previous classifications, the neoplasms are grouped neither according to their histological grade (Kiel classification) nor according to their clinical aggressiveness (International Working Formulation). However, the histological grade is considered a prognostic factor which enters into the description of each disease entity. Hodgkin's disease, now more appropriately termed Hodgkin lymphoma, comprises nodular lymphocyte-predominant Hodgkin lymphoma and classical Hodgkin lymphomas of nodular sclerosis, mixed cellularity, lymphocyte-depleted and lymphocyte-rich subtype. For practical purposes this minireview disregards the description of myeloid, macrophage/histiocytic, dendritic cell and mast cell disorders. Furthermore, the present paper is restricted to those lymphoid tumours that are not already identically described in the REAL classification, in order to focus on what is really new in the WHO classification.
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PMID:Who is WHO and what was REAL? 1258 44

Signaling by stem cell factor and Kit, its receptor, play important roles in gametogenesis, hematopoiesis, mast cell development and function, and melanogenesis. Moreover, human and mouse embryonic stem cells express Kit transcripts. Stem cell factor exists as both a soluble and a membrane-bound glycoprotein while Kit is a glycoprotein receptor protein-tyrosine kinase. The complete absence of stem cell factor or Kit is lethal. Gain-of-function mutations of Kit are associated with several human neoplasms including acute myelogenous leukemia, gastrointestinal stromal tumors, mastocytomas, and nasal T-cell lymphomas. Binding of stem cell factor to Kit results in receptor dimerization and activation of protein kinase activity. The activated receptor becomes autophosphorylated at tyrosine residues that serve as docking sites for signal transduction molecules containing SH2 domains. Kit activates Akt, Src family kinases, phosphatidylinositol 3-kinase, phospholipase Cgamma, and Ras/mitogen-activated protein kinases. Kit exists in active and inactive conformations as determined by X-ray crystallography. Kit consists of an extracellular domain, a transmembrane segment, a juxtamembrane domain, and a protein kinase domain that contains an insert of about 80 amino acid residues. The juxtamembrane domain inhibits enzyme activity in cis by maintaining the control alphaC-helix and the activation loop in their inactive conformations. The juxtamembrane domain also inhibits receptor dimerization. STI-571, a clinically effective targeted protein-tyrosine kinase inhibitor, binds to an inactive conformation of Kit. The majority of human gastrointestinal stromal tumors have Kit gain-of-function mutations in the juxtamembrane domain, and most people with these tumors respond to STI-571. STI-571 binds to Kit and Bcr-Abl (the oncoprotein of chronic myelogenous leukemia) at their ATP-binding sites.
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PMID:Structure and regulation of Kit protein-tyrosine kinase--the stem cell factor receptor. 1622 10

Among the intestinal tumors of hematopoietic cell origin, lymphoma is the most common in the dog. Herein, we characterized the clinical and pathologic features of 11 dogs (average age, 10.6 +/- 2.5 years) with T-cell lymphoma of the intestinal tract with eosinophil infiltrates. No sex predominance was apparent. All had localized tumor masses in the small intestine. Grossly, the intestinal wall was thickened, and the lumen of the affected intestine was usually narrowed. Microscopically, we observed transmural diffuse invasion of round to pleomorphic tumor cells. Tumor cells showed varying morphology, from scanty to abundant cytoplasm, and round to ovoid nuclei with scattered to dense chromatin. In seven of the dogs, tumor cells had infiltrated into the epithelium. All showed infiltration of eosinophils and all 11 tumors had a T-cell phenotype (CD3+, CD79-). Only one tumor stained positive for the mast cell marker c-kit and none was positive for mast cell tryptase. We did not observe ultrastructurally apparent granules in any of the tumor cells. These results suggest that, in dogs, T-cell lymphomas of intestinal origin resemble mast cell tumors of intestinal origin with respect to cell structure and eosinophil infiltration. Therefore, in the absence of epitheliotropism, it is difficult to confirm the differential diagnosis without immunostaining for mast cell and lymphocyte markers, including mast cell tryptase, c-kit, CD3, and CD79.
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PMID:T-cell lymphoma with eosinophilic infiltration involving the intestinal tract in 11 dogs. 1667 80

Multiple myeloma oncogene 1/interferon regulatory factor 4 (MUM1/IRF4) is involved in lymphoid cell differentiation, particularly in the production of plasma cells. We examined the immunoreactivity of mouse monoclonal antibody Mum-1p to MUM1/IRF4 and compared it with expression of CD79a and CD20 in 109 plasmacytomas in 107 dogs. Tissues had been fixed in formalin and embedded in paraffin. One hundred one of 109 (93.5%) tumors were positive for MUM1/IRF4. The staining was nuclear with weak cytoplasmic reaction. Fifty-nine of 105 (56.2%) plasmacytomas were positive for CD79a; only 21 of 108 (19.4%) cases were positive for CD20. MUM1/IRF4 staining was performed on 139 other tumors including B- and T-cell lymphomas, histiocytic proliferations, mast cell tumors, and melanocytic tumors. The only MUM1/IRF4-positive nonplasmacytic tumors were 10 B-cell lymphomas and 1 anaplastic lymphoma. We conclude the following: 1) Antibody Mum-1p is very specific for canine plasmacytomas, 2) antibody Mum-1p is superior in sensitivity and specificity to CD79a and CD20 for the identification of canine plasmacytomas in formalin-fixed, paraffin-embedded tissues, 3) canine lymphomas that express MUM1/IRF4 are few and usually of B-cell origin, 4) other canine leukocytic and melanocytic tumors do not express MUM1/IRF4, and 5) prospective studies are needed to determine whether the expression of MUM1/IRF4, particularly in lymphomas, has prognostic significance.
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PMID:Immunohistochemical detection of multiple myeloma 1/interferon regulatory factor 4 (MUM1/IRF-4) in canine plasmacytoma: comparison with CD79a and CD20. 1803

Statins, initially developed as antimicrobials, are primarily considered cholesterol-lowering agents. Recently, researchers discovered anti-inflammatory properties of statins. Studies on the effects of statins and the alterations noted include: bench work that supported a Th1/Th2 skew to Th1, altered lymphocyte migration, inhibition of MHC-II induction and cytokine release on antigen-presenting cells, inhibition of mast cell degranulation and inhibition of Th17 cells and IL-17 production. In addition to the anti-inflammatory properties, statins have been found to induce apoptosis in melanoma models. The potential therapeutic value of statins is illustrated in the management of alopecia areata, atopic dermatitis, psoriasis, systemic lupus erythematosus, cutaneous T-cell lymphomas, cutaneous melanoma, mastocytosis and more. This manuscript presents a comprehensive review of statins and their potential dermatologic application.
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PMID:Statins in skin: research and rediscovery, from psoriasis to sclerosis. 2068 42