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Query: UNIPROT:P10721 (c-kit)
 6,575 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Totipotent murine ES cells have an enormous potential for the study of cell specification. Here we demonstrate that ES cells can differentiate to hemopoietic cells through the proximal lateral mesoderm, merely upon culturing in type IV collagen-coated dishes. Separation of the Flk1+ mesoderm from other cell lineages was critical for hemopoietic cell differentiation, whereas formation of the embryoid body was not. Since the two-dimensionally spreading cells can be monitored easily in real time, this culture system will greatly facilitate the study of the mechanisms involved in the cell specification to mesoderm, endothelial, and hemopoietic cells. In the culture of ES cells, however, lineages and stages of differentiating cells can only be defined by their own characteristics. We showed that a combination of monoclonal antibodies against E-cadherin, Flk1/KDR, PDGF receptor(alpha), VE-cadherin, CD45 and Ter119 was sufficient to define most intermediate stages during differentiation of ES cells to blood cells. Using this culture system and surface markers, we determined the following order for blood cell differentiation: ES cell (E-cadherin+Flk1-PDGFRalpha-), proximal lateral mesoderm (E-cadherin-Flk1+VE-cadherin-), progenitor with hemoangiogenic potential (Flk1+VE-cadherin+CD45-), hemopoietic progenitor (CD45+c-Kit+) and mature blood cells (c-Kit-CD45+ or Ter119+), though direct differentiation of blood cells from the Flk1+VE-cadherin- stage cannot be ruled out. Not only the VE-cadherin+CD45- population generated from ES cells but also those directly sorted from the yolk sac of 9.5 dpc embryos have a potential to give rise to hemopoietic cells. Progenitors with hemoangiogenic potential were identified in both the Flk1+VE-cadherin- and Flk1+VE-cadherin+ populations by the single cell deposition experiment. This line of evidence implicates Flk1+VE-cadherin+ cells as a diverging point of hemopoietic and endothelial cell lineages.
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PMID:Progressive lineage analysis by cell sorting and culture identifies FLK1+VE-cadherin+ cells at a diverging point of endothelial and hemopoietic lineages. 952 12

We describe here that lineage phenotype- negative (Lin)(-)c-kit(+) hematopoietic progenitor cells (HPCs) from day 13 postcoitus (dpc) murine fetal liver (FL) can generate dendritic cell (DC) precursors when cultured in vitro in the presence of PA6 stromal cells plus granulocyte/macrophage colony-stimulating factor (GM-CSF) + stem cell factor (SCF) + Flt3 ligand (Flt3L) for 12 to 14 days, and develop into mature DCs when stimulated with GM-CSF plus mouse tumor necrosis factor alpha (mTNFalpha) for an additional 3 to 5 days. A transwell culture system showed that the generation of DC precursors depended on the support of PA6 cell-secreted soluble factor(s). The mature DCs derived from 13 dpc FL Lin(-)c-kit(+) HPCs showed characteristic morphology and function of DCs and expressed high levels of Ia, CD86, and CD40 molecules, low levels of DEC205, E-cadherin, and F4/80 molecules, but barely detectable CD11c antigen. Once FL-derived HPCs were cultured without GM-CSF, NK1.1(+) cells developed in the presence of PA6 cells + SCF + Flt3L. These NK1.1(+) cells could develop into DC precursors at an earlier stage of differentiation by reculturing with PA6 cells + SCF + Flt3L + GM-CSF, but they would be irreversibly committed to NK cell precursors without GM-CSF after 3 days, suggesting that GM-CSF plays a critical role in controlling the transition of DC and NK cell precursors from 13 dpc FL-derived Lin(-)c-kit(+) HPCs. This study represents the first success in generating mature DCs in vitro from murine FL HPCs. (Blood. 2000;95:138-146)
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PMID:Development of dendritic cells in vitro from murine fetal liver-derived lineage phenotype-negative c-kit(+) hematopoietic progenitor cells. 1060 96

Primordial germ cells (PGCs) are the founders of the gametes. They arise at the earliest stages of embryonic development and migrate to the gonadal ridges, where they differentiate into oogonia/oocytes in the ovary, and prospermatogonia in the testis. The present article is a review of the main studies undertaken by the author with the aim of clarifying the mechanisms underlying the development of primordial germ cells. Methods for the isolation and purification of migratory and post-migratory mouse PGCs devised in the author's laboratory are first briefly reviewed. Such methods, together with the primary culture of PGCs onto suitable cell feeder layers, have allowed the analysis of important aspects of the control of their development, concerning in particular survival, proliferation and migration of mouse PGCs. Compounds and growth factors affecting PGC numbers in culture have been identified. These include survival anti-apoptotic factors (SCF, LIF) and positive regulators of proliferation (cAMP, PACAPs, RA). Evidence has been provided that the motility of migrating PGCs relies on integrated signals from extracellular matrix molecules and the surrounding somatic cells. Moreover, homotypic PGC-PGC interaction has been evidenced that might play a role in PGC migration and in regulating their development. Several molecules (i.e. integrins, specific types of oligosaccharides, E-cadherin, the tyrosine kinase receptor c-kit) have been found to be expressed on the surface of PGCs and to mediate adhesive interactions of PGCs with the extracellular matrix, somatic cells and neighbouring PGCs.
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PMID:Regulation of primordial germ cell development in the mouse. 1106 20

The AP-2 transcription factor plays a pivotal role in regulating the expression of several genes involved in tumor growth and progression of melanoma. We determined, by Western blot, variation in the level of expression of AP-2 and three of its downstream targets, c-kit, E-cadherin, and p21 in several human melanoma cell lines and, by immunohistochemistry, in a group of 99 histological samples including benign and malignant melanocytic lesions. A significant negative correlation between AP-2 expression level and tumor thickness was found. Moreover, AP-2 expression was positively associated with E-cadherin and c-kit expression. In contrast, there was a significant negative association between AP-2 and p21 expression levels. These findings suggest that p21 is independent of AP-2 transactivator function during the latest phases of melanoma progression. Finally, AP-2, c-kit, E-cadherin, and p21 expression levels did not show to be able to distinguish between dysplastic nevi and nevi without dysplasia. We conclude that changes in the expression of these proteins are involved in the later phases of melanoma progression, and may be responsible for the transition from local invasive melanoma to metastasis.
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PMID:Expression of AP-2 transcription factor and of its downstream target genes c-kit, E-cadherin and p21 in human cutaneous melanoma. 1159 5

The growing understanding of the epigenetic changes associated with cancer, including aberrant promoter methylation of tumor suppressor genes that afford selective growth advantages to human neoplasms, suggests that the characterization of gene methylation patterns among gastrointestinal stromal tumors (GISTs) may be useful for predicting tumor behavior. Thirty-eight c-kit-positive gastric stromal tumors were subjected to methylation-specific polymerase chain reaction (MSP) to detect promoter methylation associated with 11 candidate tumor suppressor genes (p16/INK4a, APC, MGMT, hMLH1, p73, E-cadherin, RAR-beta, RASSF1A, RB, ER, and DAPK), established to have a role in tumorigenesis of several solid human organs. Aberrant methylation of any of the 11 candidate tumor suppressor genes was detected in 84% of all GISTs. In decreasing order of frequency, the six most commonly methylated genes were: MGMT (47%), p16 (45%), RASSF1A (40%), E-cadherin (37%), hMLH1 (34%), and APC (31%). For all of the GISTs, promoter methylation was less reliable than tumor mitotic rate in predicting 5-year tumor-free survival for the GISTs; however, E-cadherin methylation was a multivariate prognostic factor for early recurrence of GISTs (50% at 2 years; P=0.030). Among the mitotically active (>5 per 50 high-power field), histologically indistinguishable GISTs, E-cadherin methylation was an independent predictor of tumor-related mortality: 5-year disease-free survival was worse for the E-cadherin methylated GISTs (19%) compared to the E-cadherin unmethylated tumors (71%; P=0.010). Detection of methylation within selected genes may afford a reliable and accurate molecular marker system for predicting neoplastic behavior among GISTs. This study supports the methylation status of E-cadherin as a prognostic marker for early GIST recurrence and survival.
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PMID:Tumor suppressor gene hypermethylation as a predictor of gastric stromal tumor behavior. 1467 10

The existence of a complex population of mRNA in human sperm is well documented but their role is not yet elucidated. Using discontinuous density gradients, we have isolated high and low motile sperm from the same semen sample. The levels of different transcripts coding for molecules either involved in nuclear condensation (protamines 1 and 2) or in capacitation [endothelial nitric oxide synthase (eNOS), neuronal nitric oxide synthase (nNOS) and c-myc] were then assessed in the two populations using semi-quantitative RT-PCR. Sperm viability was estimated by eosin-nigrosin staining and by hypo-osmotic swelling test; apoptosis percentage was measured by the TdT (terminal deoxynucleotidyl transferase)-mediated dUDP nick-end labelling technique. The contamination by somatic and germ cells was assessed by looking for specific molecular markers of these cells, respectively CD-45 and E-cadherin for somatic cells and c-kit for germ cells. The viability of sperm was unchanged in high and low motile fractions, as well as DNA fragmentation percentage. The amount of Prm-1 mRNA was significantly higher in low density motile than in the high motile fraction. In most of high motile sperm samples eNOS and nNOS transcripts were undetectable whereas they were present in the low motile sperm. In contrast, no significant variation was found in the c-myc/Prm-2 mRNA ratio between the two populations. Moreover, a partial or complete disappearance of c-myc transcripts was observed after capacitation. Thus analysing mRNA profiles could be helpful as a diagnostic tool and prognosis value for fertilization.
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PMID:Analysis and significance of mRNA in human ejaculated sperm from normozoospermic donors: relationship to sperm motility and capacitation. 1510 Mar 85

The zinc-finger transcription factors Snail and Slug are involved in different processes controlling cell differentiation and apoptosis. They also appear to be involved in tumor progression. Their putative involvement in mammary gland development has not been specifically examined so far. Slug is expressed at a significant level in normal breast, and indirect evidence suggests it could be implicated in tubulogenesis. As an antiapoptotic agent, it could also protect epithelial cells from death during ductal lumen formation and during breast involution. In breast carcinomas, Snail transcription factors have been linked to tumor progression and invasiveness. Possible mechanisms include repression of the E-cadherin gene by Snail or Slug. However, it is not clear how this transcriptional activity is implicated in vivo. Other possible mechanisms involve maintenance of a plastic phenotype by Slug that could participate in local invasion of ductal carcinomas, and interference with apoptotic pathways that could contribute to global tumor growth and radioresistance. These processes probably also involve interactions with estrogen, EGF, or c-kit pathways.
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PMID:Roles of the transcription factors snail and slug during mammary morphogenesis and breast carcinoma progression. 1530 12

Epithelial cells in embryonic day (ED) 12.5 murine fetal liver were separated from hematopoietic cell populations using fluorescence-activated cell sorting (FACS) and were characterized by immunocytochemistry using a broad set of antibodies specific for epithelial cells (alpha-fetoprotein [AFP], albumin [ALB], pancytokeratin [PanCK], Liv2, E-cadherin, Dlk), hematopoietic/endothelial cells (Ter119, CD45, CD31), and stem/progenitor cells (c-Kit, CD34, Sca-1). AFP(+)/ALB(+) cells represented approximately 2.5% of total cells and were positive for the epithelial-specific surface markers Liv2, E-cadherin, and Dlk, but were clearly separated and distinct from hematopoietic cells (Ter119(+)/CD45(+)). Fetal liver epithelial cells (AFP(+)/E-cadherin(+)) were Sca-1(+) but showed no expression of hematopoietic stem cell markers c-Kit and CD34. These cells were enriched by FACS sorting for E-cadherin to a purity of 95% as defined by co-expression of AFP and PanCK. Purified fetal liver epithelial cells formed clusters in cell culture and differentiated along the hepatocytic lineage in the presence of dexamethasone, expressing glucose-6-phosphatase (G6P) and tyrosine amino transferase. Wild-type ED12.5 murine fetal liver cells were transplanted into adult dipeptidyl peptidase IV knockout mice and differentiated into mature hepatocytes expressing ALB, G6P, and glycogen, indicating normal biochemical function. Transplanted cells became fully incorporated into the hepatic parenchymal cords and showed up to 80% liver repopulation at 2 to 6 months after cell transplantation. In conclusion, we isolated and highly purified a population of epithelial cells from the ED12.5 mouse fetal liver that are clearly separate from hematopoietic cells and differentiate into mature, functional hepatocytes in vivo with the capacity for efficient liver repopulation. Supplementary material for this article can be found on the HEPATOLOGY website (http://www.interscience.wiley.com/jpages/0270-9139/suppmat/index.html).
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PMID:Purification and characterization of mouse fetal liver epithelial cells with high in vivo repopulation capacity. 1589 27

To identify additional alterations to c-kit or platelet-derived growth factor receptor alpha (PDGFRA) genes in gastrointestinal stromal tumors (GIST), we investigated the methylation status of nine known methylation-sensitive CpG islands (p15, p16, p73, 0-6-methylguanine-DNA methyltransferase, E-cadherin, mutL homolog 1, colon cancer nonpolyposis type 2 (escherichia), methylated in tumors [MINT]1, MINT2, and MINT31), and compared the results with the malignant potential and gain-of-function mutation types of GIST. Thirty-five GIST (c-kit mutations in 25 cases, PDGFRA mutations in seven cases, and lacking either mutation in three cases) were subjected to methylation-specific polymerase chain reaction to detect the methylation status of the nine methylation-sensitive CpG islands. Aberrant DNA methylation of these loci was found in 94% of all GIST. The rates of DNA methylation at each locus were as follows: hMLH1, 60%; MINT2, 51%; MGMT, 49%; p73, 49%; p16, 20%; E-cadherin, 14%; MINT1, 9%; p15, 6%; and MINT31, 0%. CpG islands methylator phenotype, which was defined as methylation involving more than three gene promoters, was found in 57% of GIST with c-kit or PDGFRA gene mutations. According to the risk categories, CpG islands methylator phenotype was present in 55% of low-risk GIST, and in 58% of high-risk GIST. Our results suggested that in addition to c-kit or PDGFRA mutations, the aberrant methylation of CpG islands, especially of mismatch-repair genes, may have a role in the tumorigenesis of GIST.
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PMID:Aberrant methylation status of known methylation-sensitive CpG islands in gastrointestinal stromal tumors without any correlation to the state of c-kit and PDGFRA gene mutations and their malignancy. 1827 23

Chromophobe renal cell carcinoma (RCC) is subdivided into typical and eosinophilic variants. We report such two cases with focus on imprint cytology and fluorescence in situ hybridization (FISH). The first case is a 53-year-old Japanese man and the second is a 76-year-old Japanese man. Histologically, the diagnosis of typical and eosinophilic variants of chromophobe RCC was suspected. In imprint cytology, irregularity of nuclear membrane, binucleation, perinuclear halo, and thick cell border were observed. Immunohistochemically, neoplastic cells of both tumors were positive for cytokeratin 7, E-cadherin, c-kit, and CD10. In FISH study, both tumors revealed the monosomy of chromosomes 10 and 21. Additionally, FISH study in eosinophilic variant of chromophobe RCC showed the disomy of chromosomes 7 and 17. In conclusion, we suggest that the combination study of imprint cytology and FISH of chromosomes 10 and 21 as well as routine histology may contribute to the accurate diagnosis of chromophobe RCC.
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PMID:Chromophobe renal cell carcinoma: useful diagnostic application of imprint cytology and fluorescence in situ hybridization of chromosomes 10 and 21 in two cases of typical and eosinophilic variants. 1910 13


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