Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P10721 (c-kit)
 6,575 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Interstitial cells of Cajal (ICC) are well described in the bowel wall. They are c-kit positive and play a role as pacemaker cells. Similar c-kit-positive cells have recently been described in the human bladder. The aim of this study was to characterize interstitial cells of the bladder detrusor using a panel of antibodies directed against CD117/c-kit, CD34, CD31, S100, tryptase, neurofilament, NSE, Factor-VIII and GFAP. A striking finding was an interstitial type of cell which is CD34 immunoreactive (CD34-ir) but CD117/c-kit negative. The cells have a tentacular morphology, enveloping and intermingling with individual muscle fasicles. Morphologically and immunohistochemically, they show no neurogenic, endothelial or mast cell differentiation. Transmission electron microscopy (TEM) showed the presence of interstitial cells with a round-to-oval nucleus, sparse perinuclear cytoplasm and long flattened processes, ramifying primarily in a bipolar fashion. Using immunoelectron microscopy (I-TEM) it was possible to view CD34 gold labelling of cells corresponding to interstitial cells. Although similar CD34-positive cells have been demonstrated in the bowel wall, they have never been described in the detrusor. The ontogeny and function of CD34-ir, a kit-negative cell, is unknown, but it may be involved in smooth muscle contraction.
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PMID:CD34-positive interstitial cells of the human detrusor. 1809 58

Interstitial Cajal-like Cells (ICLC) were recently recognized in a plethora of non-digestive organs. Here, we describe a cell type of rat mesentery sharing ultrastructural and immunohistochemical features with ICLC. Mesenteric ICLC were demonstrated by transmission electron microscopy (TEM) and further tested by light microscope immunohistochemistry. The cell described here fulfils the TEM diagnostic criteria accepted for ICLC: location in the connective interstitium; close vicinity to nerves, capillaries and other interstitial cells; characteristic long, moniliform cell processes; specialized cell-to-cell junctions; caveolae; mitochondria at 5-10% of cytoplasmic volume; rough endoplasmic reticulum at about 1-2%; intermediate and thin filaments, microtubules; undetectable thick filaments. The processes of this mesenteric ICLC were particularly long, with a mean length of 24.91 microm (10.27-50.83 micorm), and a convolution index of 2.32 (1.37-3.63) was calculated in order to measure their potential length. Mean distances versus main target cells of ICLC-nerve bundles, vessels, adipocytes and macrophages-were 110.69, 115.80, 205.07 and 34.65 nm, respectively. We also tested the expression of CD117/c-kit, CD34, vimentin, alpha-smooth muscle actin, nestin, NK-1, tryptase and chymase and the antigenic profile of the mesenteric ICLC was comparable if not identical with that recently observed in ICLC from other extra-digestive tissues. Due to the peculiar aspect of the mesenteric ICLC processes it can be hypothesized that these cells form a three-dimensional network within the mesentery that is at the same time resistant and deformable following stretches consequent to intestine movements, mainly avoiding blood vessels closure or controlling blood vessels rheology. It remains, however, to be established if and how such cells are connected with the archetypal enteric ICC.
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PMID:Interstitial Cajal-like cells in rat mesentery: an ultrastructural and immunohistochemical approach. 1819 43

The expression of c-kit, a protooncogene tyrosine kinase receptor (CD117), in phyllodes tumors of the breast has been the subject of recent investigations. We examined stromal c-kit expression by immunohistochemistry in 68 cases comprising fibroadenomas, fibroadenomas with cellular stroma, and benign, borderline, and malignant phyllodes tumors. Membrane staining was identified in the epithelium of 82% of cases, representing all diagnostic categories in the study. Membrane and cytoplasmic staining was detected in scant cells in the stroma in 74% of the cases in the study, again, across all diagnostic entities. However, when toluidine blue and tryptase staining was performed, the staining pattern matched that of c-kit in the number of cells and their distribution, thereby confirming the presence of mast cells and excluding any appreciable level of true stromal c-kit staining. One borderline and one malignant phyllodes tumor showed a diffuse weak stromal signal, which could not be accounted for by toluidine blue and tryptase. These cases were further tested for the presence of known activating mutations of c-kit and PDGFR-alpha, and yielded negative results. Our findings indicate that c-kit is an unlikely player in the pathogenesis of fibroepithelial lesions of the breast. The positive stromal staining suggested previously by other authors may be attributed to mast cells. C-kit, therefore, has neither a diagnostic nor a prognostic role in phyllodes tumors, and there is no rationale for the treatment of recurrent of malignant phyllodes tumor patients with tyrosine kinase inhibitors.
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PMID:Expression of c-kit in fibroepithelial lesions of the breast is a mast cell phenomenon. 1850 Feb 66

During the last two decades different scientific groups have investigated the phenotype and function of in vitro generated human mast cells (MC). The cells have been shown to display variable surface markers and functional characteristics. The phenotypic differences may reflect different culture conditions, protocols or the use of different progenitors. To investigate the significance of different progenitors, we have compared MC generated from CD133(+) progenitor cells from cord blood (CBMC) or peripheral blood (PBMC). The progenitors were cultured for 7 weeks in the presence of IL-6 and SCF, with addition of IL-3 the first 3 weeks, and FCS during week 7. The phenotype of the established MC was characterized by surface marker expression levels, metachromasia, histamine and tryptase contents and their function was evaluated by receptor-mediated release of histamine and PGD(2). The generated metachromatic (<99%) MC were 75% tryptase(+), regardless of the source of progenitor cell. Expression of c-kit/CD117, CD203c, and FcepsilonRI was comparable. The density of c-kit/CD117 receptors on CBMC was higher that of PBMC (p<0.001). The density of CD203c and FcepsilonRI was higher on PBMC (p<0.001). PBMC contained more histamine (p<0.001), expressed more FcepsilonRI (p<0.001) and released more histamine (p<0.001) and PGD(2) (p<0.001) upon ligation of FcepsilonRI, than CBMC. Culture with IL-4 increased expression of tryptase, FcepsilonRI, CD117 and CD203c, secretion of histamine and PGD(2) of PBMC, and histamine secretion of CBMC. Cord and peripheral blood may give rise to different types of MC. The question addressed should determine the progenitor cell and protocol to be used.
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PMID:Comparison of short term in vitro cultured human mast cells from different progenitors - Peripheral blood-derived progenitors generate highly mature and functional mast cells. 1853 84

Gain-of-function mutations in the proto-oncogene c-kit have been considered the molecular mechanism of neoplastic proliferation of mast cells. However, the importance of c-kit gene mutations is not well evaluated in canine mast cell tumors (MCTs). In the present study, we established and characterized a mast cell line, HRMC, derived from a dog with MCT. We also examined c-kit mutations in HRMC cells and assessed an inhibitory effect of a tyrosine kinase inhibitor, STI571, on HRMC cells. HRMC cells had cytoplasmic metachromatic granules, chymase and tryptase, and expressed both KIT and FcepsilonRI on the cell surface. HRMC cells contained histamine and released beta-hexosaminidase through FcepsilonRI cross-linking and calcium ionophore stimulation. Nucleotide sequence analysis demonstrated no mutations in an open reading frame of c-kit cDNA and genomic DNA of the juxtamembrane domain of c-kit in HRMC cells. STI571 did not show any inhibitory effects on the proliferation of HRMC cells. These findings clearly demonstrated the existence of c-kit mutations-independent neoplastic canine mast cell proliferation. The growth factor-independent mast cell line established in this study might be valuable to explore novel mechanisms of c-kit mutations-independent neoplastic proliferation of mast cells in dogs.
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PMID:Identification of c-kit mutations-independent neoplastic cell proliferation of canine mast cells. 1868 74

Mastocytosis are characterized by an accumulation of abnormal mast cells in various tissues. Their incidence is estimated at 1/150,000 patients. Pure cutaneous mastocytosis which are mainly observed during childhood may resolve spontaneously during adolescence, whereas systemic mastocytosis involving one or more organs or tissues are more observed in adults. The initial event leading to mastocytosis is believed to be related to activating mutations in c-kit receptor, thus resulting in increased proliferation of mast cells precursors, migration in various tissues and degranulation leading to clinical signs. This nosologic entity does not belong to allergic diseases. Their perioperative management involves a multidisciplinary approach. The degranulation of mast cells with subsequent clinical symptoms can be triggered by psychological, chemical, traumatic, physical (rubbing, extreme temperatures...) agents. Avoiding these triggers should be realized whenever possible according to each patient. The premedication has not proven its efficiency. Tryptase measurement is part of the preoperative biological assessment. The clinical signs severity is related to the cardiovascular homeostasis disturbances (arterial hypotension, cardiovascular collapse, cardiac arrest). The cardiovascular symptoms do not correlate to the cutaneous versus systemic description of the disease. The drug of choice for the treatment of the severe cardiovascular signs is epinephrine associated to vascular loading. The aim of this literature review is to suggest the different modalities of perioperative care of patients with mastocytosis.
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PMID:[Mastocytosis and anaesthesia]. 1909 49

A 4-year-old female Richardson's ground squirrel (Spermophilus richardsonii) presented with multicentric nodules arising from the skin of the middle of the tail and lumbosacral regions. Histologically, the nodules were composed of a proliferation of spindloid to pleomorphic cells that sometimes formed sheets and fascicular to storiform patterns. Diffuse infiltration of eosinophils was also noted. The results of immunohistochemistry indicated positive labeling for vimentin, mast cell tryptase, c-kit, and Ki-67. Toluidine blue stain revealed fine, metachromatic, cytoplasmic granules. The histologic diagnosis was mast cell tumor. The neoplasm recurred and metastasized to the right lumbar lymph node 1 month later.
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PMID:Spontaneous cutaneous mast cell tumor with lymph node metastasis in a Richardson's ground squirrel (Spermophilus richardsonii). 1913 21

Increased numbers of mast cells (MCs) in the testis have been associated with testicular dysfunction, where accumulation of MCs occurs. Furthermore, it has been reported that MCs might affect sperm function as it has been demonstrated that MC-derived tryptase in the seminal fluid might reduce sperm motility. Although MCs have been detected in rat epididymis, only little is known about the presence of MCs in human seminal plasma. Thus, we analysed MC numbers in the ejaculate of men during routine semen analysis of male patients suspected for infertility (n = 100). MCs were detected by c-kit (CD117) expression using flow cytometry. Thereby, we detected significant numbers of MCs in the ejaculate of most patients (559 +/- 525 MCs ml(-1), mean +/- SD). However, we could neither detect a correlation with respect to MCs and sperm count, motility or morphology nor to the seminal inflammatory markers like polymorphonuclear elastase. Nevertheless, a significant correlation of MCs to spermatozoa-bound IgA (r = 0.5; P = 0.03; n = 21) was observed. It is concluded that significant numbers of MCs can be detected in the human ejaculate without necessarily influencing sperm function. A potential role of MCs in seminal plasma as well as the association between MCs and IgA on spermatozoa remains to be elucidated.
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PMID:Mast cells in the seminal plasma of infertile men as detected by flow cytometry. 1914 22

Mast cells (MCs) display a diversity of roles that may contribute to the stromal microenvironment alterations during tumor progression. The aim of this study was to investigate MC populations expressing tryptase and c-kit in lip squamous cell carcinoma (lip SCC) (n=37), actinic cheilitis (AC) (n=15) and normal lip mucosa (control) (n=6), as well as their relationship with microscopic parameters (collagen degeneration, elastin changes, angiogenesis and proliferative index). Tryptase, c-kit, CD31 and Ki-67 expressions were analyzed by means of immunohistochemistry and collagen and elastic fibers were visualized with Picrosirus and Verhoeff's stain, respectively. The numbers of tryptase+ MC were significantly higher in lip SCC when compared with control (P=0.01), while a similar density of these cells was observed in AC and lip SCC (P=0.09). The density of c-kit+ MC was similar in all groups examined (P=0.65). MC migration (c-kit+/Tryptase+ relationship) was 69% in lip SCC, 60% in AC and 100% in control. The number of CD31+ blood vessels was significantly higher in the lip SCC when compared with control and AC (P<0.01). The increase of MCs and angiogenesis in lip SCC may reflect an important modification in the tumor microenvironment during squamous photo-carcinogenesis.
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PMID:Density and migration of mast cells in lip squamous cell carcinoma and actinic cheilitis. 1922 48

An 11-year old Caucasian female with a remote history of urticaria pigmentosa presented with a neck mass. A biopsy demonstrated a large intradermal nodule composed of unusually large epithelioid mast cells, including a prominent subset with bi-lobed and multi-lobed nuclei. By immunohistochemistry, the cells expressed CD117 (C-Kit), mast cell tryptase, CD68, and CD25, and were negative for CD163, CD1a, and S-100, confirming the diagnosis of mastocytoma. Equally prominent was an admixed infiltrate of CD68 and CD163-positive xanthomatous histiocytes that included Touton-type giant cells. Eosinophils were abundant. At 7 months follow-up, there was no recurrence of the lesion following complete excision. However, given the unusual cytologic features, close clinical observation is warranted, as the long-term biologic potential of mastocytoma with this degree of cytologic atypia is uncertain. Awareness of this unusual morphologic variant is also important as the histologic features may mimic such childhood neoplasms as juvenile xanthogranuloma and Langerhans cell histiocytosis.
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PMID:Histiocyte-rich pleomorphic mastocytoma: an uncommon variant mimicking juvenile xanthogranuloma and Langerhans cell histiocytosis. 1960 70


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