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

We tried to efficiently generate human dendritic cells (DCs) from CD34+ peripheral blood hematopoietic progenitor cells mobilized by high-dose chemotherapy and subsequent administration of granulocyte colony-stimulating factor, using a liquid suspension culture system. Among various combinations, the combination of c-kit ligand, flt-3 ligand, c-mpl ligand (TPO), and interleukin (IL)-4 most potently generated the number of CD1a+CD14- DCs in cultures containing granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor alpha (TNF-alpha). The delayed addition of IL-4 on day 6 of culture gave rise to an additional increase in the yield of CD1a+CD14-DCs that were characterized by the expression of HLA-ABC, HLA-DR, CD80, CD86, and CD83. The majority of the sorted CD1a-CD14+ cells derived from 6-day culture of CD34+ cells gave rise to CD1a+CD14- DCs and CD1a-CD14+ macrophages on day 12 of culture in the presence and absence of IL-4, respectively. These findings suggest that IL-4 promotes the differentiation of CD1a- CD14+ cells derived from mobilized CD34+ peripheral blood hematopoietic progenitors to CD1a+ CD14- DCs. The majority of these DCs expressed CD68 but not the Langerhans-associated granule antigen, a finding that suggests they emerge through the monocyte differentiation pathway. The addition of TPO and IL-4 to cultures did not affect the potential of DCs to stimulate the primary allogeneic T-cell response. These findings demonstrated that the combination of c-kit ligand plus flt-3 ligand plus TPO with GM-CSF plus TNF-alpha, followed by IL-4, is useful for ex vivo generation of human DCs from mobilized CD34+ peripheral blood progenitors.
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PMID:Efficient ex vivo generation of human dendritic cells from mobilized CD34+ peripheral blood progenitors. 1172 65

To date, constitutively activating point mutations reported in hematopoietic growth factor receptors in patients with acute myeloid leukemia (AML) have been restricted to receptors with intrinsic tyrosine kinase activity such as c-kit and FLT3. We describe here a Thr617Asn mutation in the transmembrane domain of the non-tyrosine kinase receptor for granulocyte colony-stimulating factor (G-CSF) in the blast cells of two out of 555 AML patients examined. The mutant receptor conferred growth factor independence on factor-dependent Ba/F3 cells. In the absence of ligand, immunoblotting showed weak phosphorylation of JAK2, STAT3, ERKs 1 and 2 and the receptor itself, and there was approximately 70% of maximal growth in a proliferation assay. All signals were significantly enhanced in the presence of G-CSF. Retroviral transduction of mutant receptor into primary hematopoietic CD34+ cells induced G-CSF independent myeloid differentiation as assessed by the development of neutrophils and surface expression of CD11b and CD14. These results confirm the importance of the transmembrane domain for receptor function and suggest that introduction of an asparagine residue can cause sufficient stabilization of helix-helix interactions in the absence of ligand to activate downstream signaling pathways involved in directing proliferation and differentiation.
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PMID:An activating mutation in the transmembrane domain of the granulocyte colony-stimulating factor receptor in patients with acute myeloid leukemia. 1220 10

Umbilical cord blood (UCB) provides immediate access to haemopoietic stem/progenitor cells (HSPC) but low cell number restricts use in full adult bone marrow reconstitution. This study investigated early ex vivo expansion kinetics of UCB AC133+ cells (2-4 x 10(4)/ml), mononuclear cells (MNC, 1-2 x 10(6)/ml) and AC133negative cells (AC133(neg), 2-4 x 10(4)/ml) in stroma-free 8 d liquid culture (fetal bovine serum-supplemented Iscove's-modified Dulbecco's medium (IMDM) with either 'K36EG'[c-Kit ligand, interleukin 3 (IL-3), IL-6, erythropoietin, granulocyte colony-stimulating factor] or 'TPOFL' (thrombopoietin, Flt-3 ligand). Cell enumeration, apoptosis assay and AC133/CD34/CD38 antigen immunophenotyping were performed at d 0, 3, 5 and 8. All three cell populations went through a proliferation lag phase between d 3 and d 5. AC133+ cells recovered better from lag phase with significantly higher fold increase (FI) when compared with MNC and AC133(neg) populations (K36EG FI: 15.04 +/- 5.46; TPOFL FI: 8.59 +/- 2.92, P < 0.05). After 8 d, populations lacking AC133+ cells were significantly more inclined to undergo apoptosis under proliferative conditions (P < 0.01). Also, when compared with K36EG, 8 d TPOFL-expanded AC133+ cells encompassed a significantly higher percentage of AC133+ and CD34+ early HSPC (K36EG: 20.50 +/- 2.36; TPOFL: 47.00 +/- 7.69; P < 0.05). In conclusion, TPOFL synergism demonstrated the potential for AC133+ HSPC ex vivo expansion inducing self-renewal, early HSPC maintenance and promoting cell survival status.
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PMID:AC133+ umbilical cord blood progenitors demonstrate rapid self-renewal and low apoptosis. 1240 95

This study assessed the ability of recombinant human stem cell factor (rHuSCF) to mobilize stem cells in 44 patients who had failed a prior mobilization (CD34(+) yield 0.5-1.9 x 10(6)/kg BW) with filgrastim-alone or chemotherapy-plus-filgrastim. The same mobilization regimen was used with the addition of rHuSCF. In the filgrastim-alone group (n=13), rHuSCF 20 microg/kg was started 3 days before filgrastim and continued for the duration of filgrastim. In the chemotherapy-plus-filgrastim group (n=31), rHuSCF 20 microg/kg/day plus filgrastim 5-10 microg/kg/day were administered concurrently. Leukaphereses were continued to a maximum of four procedures or a target of >or=3 x 10(6) CD34(+) cells/kg. In both groups, CD34(+) yield (x 10(6)/kg BW) of the study mobilization was higher than that of the prior mobilization (median: 2.42 vs 0.84 P=0.002 and 1.64 vs 0.99 P=<0.001, respectively). In all 54 and 45% of patients in the filgrastim-alone group and chemotherapy-plus-filgrastim group, respectively, reached the threshold yield of 2 x 10(6)/kg. The probability of a successful mobilization was the same in those with a CD34+ yield of 0.5-0.75 x 10(6)/kg BW in the prior mobilization as in those with 0.76-1.99 x 10(6)/kg BW. Downmodulation of c-kit expression and a lower percentage of Thy-1 positivity in the mobilized CD34(+) cells were noted in the successful mobilizers compared with those in the poor mobilizers. This study shows that rhuSCF is effective in approximately half the patients who had failed a prior mobilization and allows them to proceed to transplant. It also points to the likely role of the SCF/c-kit ligand pair in mobilization.
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PMID:Successful mobilization of peripheral blood stem cells after addition of ancestim (stem cell factor) in patients who had failed a prior mobilization with filgrastim (granulocyte colony-stimulating factor) alone or with chemotherapy plus filgrastim. 1263 28

To investigate the relationship between c-kit expression and cell cycle regulation by endogenous transforming growth factor-beta (TGF-beta) in human bone marrow hematopoietic progenitor cells, CD34+ CD38- c-kit(low/-) and CD34+ CD38- c-kit(high) populations were cultured in stem cell factor, thrombopoietin, interleukin-3 (IL-3), IL-6, granulocyte colony-stimulating factor, granulocyte/macrophage colony-stimulating factor and anti-TGF-beta, and analyzed for cell cycle status. Arrest in G0/G1 was most prominent in the precultured CD34+ CD38- c-kit(low/-) subset (95.62 +/- 4.15%). While postcultured CD34+ CD38- c-kit(high) cells initiated from CD34+ CD38- c-kit(high) cells entered cell cycle within 36 hr, postcultured CD34+ CD38- c-kit(low/-) cells initiated from CD34+ CD38- c-kit(low/-) cells remained dormant until 36 hr and entered cell cycle within 90 hr. Anti-TGF-beta increased the percentage of S/G2M phase postcultured CD34+ CD38- c-kit(high) cells (from 19.08 +/- 11.95 to 47.04 +/- 2.93%), but no significant change was observed in postcultured CD34+ CD38- c-kit(low/-) cells. These results suggest that endogenous TGF-beta plays an important role in the cell cycle arrest of c-kit(high) but not c-kit(low/-) cells in CD34+ CD38- cells, which proliferate without undergoing differentiation. The different regulatory mechanism of cell cycle entry of the CD34+ CD38- c-kit(high) and CD34+ CD38- c-kit(low/-) subsets might be the result of differences in their sensitivity to endogenous TGF-beta.
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PMID:Correlation of c-kit expression and cell cycle regulation by transforming growth factor-beta in CD34+ CD38- human bone marrow cells. 1466 98

Intrahepatic cholangiocarcinoma (ICC) and combined hepatocellular and cholangiocarcinoma (HC-CC) are known to arise occasionally in hepatitis-related cirrhosis, although their clinicopathological features remain unclarified. In this study, we characterized the ICC (9 cases) and ICC elements of HC-CC (11 cases) arising in nonbiliary cirrhosis. Thirty-three hepatocellular carcinomas (HCC) associated with nonbiliary cirrhosis and 24 ICC without cirrhosis were used as controls. Prominent neutrophilic infiltration was frequent in ICC with cirrhosis (78%) and ICC elements of combined HC-CC (72%). Neutrophilic infiltration-related cytokines (interleukin 8, granulocyte colony-stimulating factor [G-CSF], and granulocyte macrophage colony-stimulating factor [GM-CSF]) were expressed frequently and intensely in carcinoma cells of ICC with cirrhosis (40%, 80%, and 60%, respectively) and in ICC elements of the combined one (13%, 38%, and 63%, respectively). Interleukin 8 was expressed in 18% of ICC without cirrhosis, irrespective of neutrophilic infiltration. Neutrophilic infiltration and expression of G-CSF and GM-CSF were in parallel (P < 0.05). G-CSF and GM-CSF mRNA were detected by RT-PCR in tissue specimens expressing G-CSF and GM-CSF at the protein level. Such neutrophilic infiltration and expression of G-CSF and GM-CSF were not evident in controls. The expressions of c-kit and c-Met, as a hematopoietic and hepatic stem cell marker, were seen frequently in ICC with cirrhosis (80% and 80%, respectively) and ICC elements of the combined one (63% and 50%, respectively). The present study revealed that the frequent expression of G-CSF and GM-CSF is a characteristic of ICC with cirrhosis and ICC in combined carcinoma, probably representing a phenotype of fetal hepatic parenchymal cell. The expression of these cytokines may be causally related to prominent neutrophilic infiltration.
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PMID:Intrahepatic cholangiocarcinoma in cirrhosis presents granulocyte and granulocyte-macrophage colony-stimulating factor. 1469 21

Haemopoietic stem/progenitor cell (HSPC) development is regulated by extrinsic and intrinsic stimuli. Extrinsic modulators include growth factors and cell adhesion molecules, whereas intrinsic regulation is achieved with many transcription factor families, of which the HOX gene products are known to be important in haemopoiesis. Umbilical cord blood CD133+ HSPC proliferation potential was tested in liquid culture with 'TPOFLK' (thrombopoietin, flt-3 ligand and c-kit ligand, promoting HSPC survival and self-renewal), in comparison to 'K36EG' (c-kit-ligand, interleukins-3 and -6, erythropoietin and granulocyte colony-stimulating factor, inducing haemopoietic differentiation). TPOFLK induced a higher CD133+ HSPC proliferation (up to 60-fold more, at week 8) and maintained a higher frequency of the primitive colony-forming cells than K36EG. Quantitative polymerase chain reaction analysis revealed opposite expression patterns for specific HOX genes in expanding cord blood CD133+ HSPC. After 8 weeks in liquid culture, TPOFLK increased the expression of HOX B3, B4 and A9 (associated with uncommitted HSPC) and reduced the expression of HOX B8 and A10 (expressed in committed myeloid cells) when compared to K36EG. These results suggest that TPOFLK induces CD133+ HSPC proliferation, self-renewal and maintenance, up-regulation of HOX B3, B4 and A9 and down-regulation of HOX B8 and A10 gene expression.
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PMID:Thrombopoietin, flt3-ligand and c-kit-ligand modulate HOX gene expression in expanding cord blood CD133 cells. 1524 65

Bone marrow (BM) cells are reported to contribute to the process of regeneration following myocardial infarction. However, the responsible BM cells have not been fully identified. Here, we used 2 independent clonal studies to determine the origin of bone marrow (BM)-derived cardiomyocytes. First, we transplanted single CD34(-) c-kit(+)Sca-1(+) lineage(-) side population (CD34(-)KSL-SP) cells or whole BM cells from mice ubiquitously expressing enhanced green fluorescent protein (EGFP) into lethally irradiated mice, induced myocardial infarction (MI), and treated the animals with granulocyte colony-stimulating factor (G-CSF) to mobilize stem cells to the damaged myocardium. At 8 weeks after MI, from 100 specimens we counted only 3 EGFP(+) actinin(+) cells in myocardium of CD34(-) KSL-SP cells in mice that received transplants, but more than 5000 EGFP(+) actinin(+) cells in whole BM cell in mice that received transplants, suggesting that most of EGFP(+) actinin(+) cells were derived from nonhematopoietic BM cells. Next, clonally purified nonhematopoietic mesenchymal stem cells (MSCs), cardiomyogenic (CMG) cells, that expressed EGFP in the cardiomyocyte-specific manner were transplanted directly into BM of lethally irradiated mice, MI was induced, and they were treated with G-CSF. EGFP(+) actinin(+) cells were observed in the ischemic myocardium, indicating that CMG cells had been mobilized and differentiated into cardiomyocytes. Together, these results suggest that the origin of the vast majority of BM-derived cardiomyocytes is MSCs.
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PMID:Nonhematopoietic mesenchymal stem cells can be mobilized and differentiate into cardiomyocytes after myocardial infarction. 1529 8

Adult bone marrow-derived cells can participate in muscle regeneration after bone marrow transplantation. In recent studies a single hematopoietic stem cell (HSC) was shown to give rise to cells that not only reconstituted all of the lineages of the blood, but also contributed to mature muscle fibers. However, the relevant HSC derivative with this potential has not yet been definitively identified. Here we use fluorescence-activated cell sorter-based protocols to test distinct hematopoietic fractions and show that only fractions containing c-kit(+) immature myelomonocytic precursors are capable of contributing to muscle fibers after i.m. injection. Although these cells belong to the myeloid lineage, they do not include mature CD11b(+) myelomonocytic cells, such as macrophages. Of the four sources of mature macrophages tested that were derived either from monocytic culture, bone marrow, peripheral blood after granulocyte colony-stimulating factor mobilization, or injured muscle, none contributed to muscle. In addition, after transplantation of bone marrow isolated from CD11b-Cre-transgenic mice into the Cre-reporter strain (Z/EG), no GFP myofibers were detected, demonstrating that macrophages expressing CD11b do not fuse with myofibers. Irrespective of the underlying mechanisms, these data suggest that the HSC derivatives that integrate into regenerating muscle fibers exist in the pool of hematopoietic cells known as myelomonocytic progenitors.
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PMID:Hematopoietic contribution to skeletal muscle regeneration by myelomonocytic precursors. 1535 85

OP-9 cells are stromal cells derived from macrophage colony-stimulating factor (M-CSF)-deficient osteopetrotic mice. To evaluate the OP-9 capability to sustain long-term hematopoiesis, we reported the expansion of granulocyte colony-stimulating factor (G-CSF)-mobilized human peripheral blood (PB) CD34(+) cells in co-culture with murine OP-9 and MS-5 stromal cells, either transfected with various combinations of adenovectors (Ad) expressing c-kit ligand (KL) (either soluble or transmembrane form), thrombopoietin (TPO), flt-3/flk2 ligand (FL), and granulocyte-macrophage (GM)-CSF or with weekly addition of these cytokines. Expression of TPO as well as association of TPO, FL, and KL increased progenitor cell and week-6 cobblestone area forming cell (CAFC) production in all stromal co-cultures. Similar progenitor expansion was obtained by weekly addition of soluble cytokine. Five weeks of co-culture with OP9 and TPO, FL + KL resulted in the greatest expansion of progenitor cells and week-6 CAFC as measured by secondary assay on MS-5. In contrast to MS-5 and TPO or TPO + FL + KL cultures where hematopoiesis declined by week 4, progenitor as well as week-6 CAFC expansion continued for over 3 months in TPO + FL + KL OP9 cocultures. This was associated with decrease of CD14(+) macrophage production. The addition of human macrophage (M)-CSF or CD14(+) cells to the co-culture decrease progenitor and stem cell expansion; however, murine M-CSF to OP-9 co-cultures did not decrease progenitor expansion. High levels of stromal-derived factor-1 (SDF-1) production by MS-5 and low or absent production by OP-9 may account for stem cell adhesion and CAFC formation in the former cultures and the predominance of stem and progenitor cells in the nonadherent fraction in the latter cultures.
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PMID:Osteopetrotic mouse stroma with thrombopoietin, c-kit ligand, and flk-2 ligand supports long-term mobilized CD34+ hematopoiesis in vitro. 1630 36


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