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

The cDNAs encoding wild type (WT) human receptor tyrosine kinase c-Kit and a constitutively activated mutant, V816Kit, were introduced into granulocyte-macrophage colony-stimulating factor (GM-CSF )-dependent early murine hemopoietic cells, which had been transformed with activated Myb. WTKit cells were able to grow in the presence of the human ligand for Kit, stem cell factor (SCF ), but displayed reduced growth and clonogenic potential in either SCF or GM-CSF compared with the parental cells in GM-CSF. In contrast, V816Kit cells grew without factor at a higher rate than the parental cells in GM-CSF and displayed increased clonogenicity. Dissection of the growth characteristics in liquid culture showed that in the presence of appropriate factors, the different populations had similar proliferation rates, but that V816Kit profoundly increased cell survival compared with WTKit or parental cells. This suggests that the signals transduced by WTKit activated with SCF, and by V816Kit, were not identical. Also, WTKit and V816Kit-expressing cells both varied from the early myeloid progenitor phenotype of the parental cells and gave rise to a small number of large to giant adherent cells that expressed macrophage (alpha-naphthyl acetate) esterase and neutrophil (naphtol-AS-D-chloroacetate) esterase, were highly phagocytic and phenotypically resembled histiocytes. Thus, WTKit activated by SCF and V816Kit were able to induce differentiation in a proportion of Myb-transformed myeloid cells. The factor independent V816Kit cells, unlike the parental and WTKit expressing cells, were shown to produce tumors of highly mitotic, invasive cells at various stages of differentiation in syngeneic mice. These results imply that constitutively activated Kit can promote the development of differentiated myeloid tumors and that its oncogenic effects are not restricted to lineages (mast cell and B-cell acute lymphoblastic leukemia), which have been reported previously. Furthermore, the mixed populations of cells in culture and in the tumors phenotypically resembled the leukemic cells from patients with monocytic leukemia with histiocytic differentiation (acute myeloid leukemia-M5c), a newly proposed subtype of myeloid leukemia.
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PMID:Expression of constitutively activated human c-Kit in Myb transformed early myeloid cells leads to factor independence, histiocytic differentiation, and tumorigenicity. 937 65

Diagnosis of systemic mastocytosis (SM) is mainly based on the morphological demonstration of compact mast cell infiltrates in various tissue sites. In almost all patients such infiltrates are detected in the bone marrow. Reliable immunohistochemical markers for the diagnosis and grading of SM have been established, but various differential diagnoses including myeloproliferative neoplasms, basophilic and eosinophilic leukemias may be very difficult to delineate. Even more challenging is the recognition of hematological neoplasms with signs of mast cell differentiation but not fulfilling diagnostic criteria for SM, especially the rare myelomastocytic leukemia. It is also important to separate the reactive state of mast cell hyperplasia from indolent variants of SM, especially those with a very low degree of bone marrow infiltration and absence of compact mast cell infiltrates. When the lymphocytic component of the SM infiltrate is very prominent, SM may be confused with an indolent lymphoma, especially lymphoplasmacytic lymphoma which almost always shows a marked reactive increase in mast cells. In aggressive and leukemic variants of SM, mast cells may be very atypical and devoid of metachromatic granules. This hypogranulation can be regarded as cellular atypia and may lead to the misdiagnosis aspect of monocytic leukemia or histiocytic neoplasm. Regarding immunohistochemical anomalies, mast cells in aggressive and leukemic SM have been found to express CD30 (Ki1-antigen). Thus, anaplastic large cell lymphoma or Hodgkin's disease may first be considered rather than SM. There is increasing evidence that most patients with long-standing adult-type urticaria pigmentosa-like skin lesions have in fact indolent SM. Therefore, such skin lesions are an important clue to the correct diagnosis in these patients. However, in aggressive or leukemic SM skin lesions are usually absent and then the correct diagnosis relies on an appropriate investigation of bone marrow biopsy specimens using both SM-related immunohistochemical markers (tryptase, KIT, CD25, CD30) but also markers excluding potential differential diagnoses. Investigation for presence of the activating KIT point mutation D816V is very helpful to establish a correct diagnosis of SM in all the difficult cases exhibiting a low degree of bone marrow infiltration or puzzling morphological findings.
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PMID:Differential diagnoses of systemic mastocytosis in routinely processed bone marrow biopsy specimens: a review. 2061 12