Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.1.1.148 (Thy1)
 1,210 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Suspension and attachment cultures of Y79 human retinoblastoma cells were treated with all-trans retinoic acid (RA) for up to 10 days to assess its effect on growth and cell-surface expression of immunoglobulin superfamily antigens MHC class I and class II, ICAM-1, NCAM and Thy1. RA up to 10 microM induced growth inhibition, and marked morphological differentiation with extension of prominent processes resembling neurites was seen in attachment cultures. However, above 10 microM RA produced extensive cell death. We also observed increased cell-surface expression of MHC class I, ICAM-1, NCAM and Thy1 on Y79 cells treated with 10 microM over 10 days; constitutive MHC class II expression was not apparent, nor did RA treatment appear to induce Y79 cells to express MHC class immunoreactivity. The up-modulation of cell-adhesion molecules (NCAM, ICAM-1 and Thy1) and immune recognition molecules (NCAM, ICAM-1 and MHC class I), associated with reduced growth and tumour cell differentiation, suggests that RA may have a potential role in regulating the growth and development of retinoblastoma tumours.
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PMID:Human retinoblastoma: in vitro differentiation and immunoglobulin superfamily antigen modulation by retinoic acid. 922 76

Myelodysplastic syndrome (MDS) is believed to be a stem-cell disorder involving cytopenia and dysplastic changes in three hematopoietic lineages. However, the involvement of pluripotent stem cells and progenitor cells has not been clarified conclusively. To address this issue, we used fluorescence in situ hybridization (FISH) of blood and bone marrow (BM) smears for mature cells and FISH of cells sorted by fluorescence-activated cell sorting for progenitor cells. Seven patients with MDS associated with trisomy 8 were studied. FISH showed +8 in granulocytes, monocytes, and erythroblasts, but not in lymphocytes. Sorted cells of T (CD3(+)), B (CD19(+)), and NK cells (CD3(-)CD56(+)) from peripheral blood did not contain +8, nor did CD34(+) subpopulations from BM including B (CD34(+)CD19(+)), T/NK (CD34(+)CD7(+)) progenitors, and pluripotent stem cells (CD34(+)Thy1(+)). The +8 chromosome abnormality was identified in stem cells only at the level of colony-forming unit of granulocyte-erythrocyte-macrophage-megakaryocyte (CFU-GEMM; CD34(+)CD33(+)). It may thus be concluded that cells affected by trisomy 8 in the context of MDS are at the CFU-GEMM level and that cells of lymphoid lineage are not involved. These results provide new insights into the biology of MDS and suggest that intensive chemotherapy and autologous BM transplantation may become important therapeutic strategies.
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PMID:Fluorescence in situ hybridization of progenitor cells obtained by fluorescence-activated cell sorting for the detection of cells affected by chromosome abnormality trisomy 8 in patients with myelodysplastic syndromes. 976 74

Transplantation of genetically marked donor cells in mice have unambiguously identified individual clones with full differentiative potential in all lymphoid and myeloid pathways. Such evidence has been lacking in humans because of limitations inherent to clonal stem cell assays. In this work, we used single cell cultures to show that human cord blood (CB) contains totipotent CD34(+) cells capable of T, B, natural killer, and granulocytic cell differentiation. Single CD34(+) CD19(-)Thy1(+) (or CD38(-)) cells from fresh CB were first induced to proliferate and their progeny separately studied in mouse fetal thymic organotypic cultures (FTOCs) and cocultures on murine stromal feeder layers. 10% of the clones individually analyzed produced CD19(+), CD56(+), and CD15(+) cells in stromal cocultures and CD4(+)CD8(+) T cells in FTOCs, identifying totipotent progenitor cells. Furthermore, we showed that totipotent clones with similar lymphomyeloid potential are detected in the bone marrow of nonobese diabetic severe combined immunodeficient (NOD-SCID) mice transplanted 4 mo earlier with human CB CD34(+) cells. These results provide the first direct demonstration that human CB contains totipotent lymphomyeloid progenitors and transplantable CD34(+) cells with the ability to reconstitute, in the marrow of recipient mice, the hierarchy of hematopoietic compartments, including a compartment of functional totipotent cells. These experimental approaches can now be exploited to analyze mechanisms controlling the decisions of such primitive human progenitors and to design conditions for their ampification that can be helpful for therapeutic purposes.
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PMID:Identification of lymphomyeloid primitive progenitor cells in fresh human cord blood and in the marrow of nonobese diabetic-severe combined immunodeficient (NOD-SCID) mice transplanted with human CD34(+) cord blood cells. 1033 Apr 39

Most in vitro studies in the CNS require pure cultures of astrocytes. Astrocytes from the human optic nerve head (ONH, type 1B) represent a specialized population of astrocytes. Primary cells grown from human optic nerve head explants were cultured for 3-4 weeks. To select astrocytes by immunopanning, cell suspensions were placed on a P100 panning dish coated with C5 anti-neuroepithelial antibody and allowed to attach for 30 min. Nonadherent cells were plated on a second dish coated with anti-Thy1.1 antibody to deplete microglia and meningeal cells. Finally, remnant nonadherent cells were plated on a noncoated dish. Purified cells were immunostained with astrocyte markers: GFAP, vimentin, Pax2, A2B5, nestin and NCAM. Other cell types were characterized by HLA-DR for microglia and smooth muscle actin for vascular smooth muscle. The proportion of GFAP+ astrocytes in the cultures was determined by flow cytometry. About 95% of the cells that adhered to the C5 dish were GFAP+ astrocytes. GFAP+ astrocytes expressed vimentin, Pax2, nestin and NCAM, but not A2B5. From the Thy1.1 dish, 60-75% cells were GFAP+ astrocytes and the remainder cells were GFAP- cells. Using cloning rings, we eliminated fibroblast-like cells, smooth muscle and meningeal cells from astrocyte cultures. Smooth muscle cells and fibroblasts grew on the noncoated dish. In conclusion, immunopanning is an efficient method to get high yields of viable type 1B astrocytes from adult human ONH. The current described culture system may provide a valuable tool in studying human optic nerve head biology and disease.
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PMID:Purification of astrocytes from adult human optic nerve heads by immunopanning. 1461 7

Hepatoblastoma is a pediatric liver tumor with epithelial components resembling embryonal and fetal liver cells. The existence of teratoid hepatoblastoma suggests the presence of stem cells in hepatoblastoma. The aim of this study was to analyze the expression of stem cell markers in hepatoblastomas. We studied specimens from 10 hepatoblastomas. Five of the hepatoblastomas were of epithelial and five of mixed type. Immunohistochemistry (IHC) for the stem cell markers CD34, Thy1, c-kit, and the hepatic or biliary lineage markers CK-18, OCH, CK-7, and CD56 was performed. Double IHC for stem cell and lineage markers was used to identify putative liver stem cells. The different markers showed distinct distributions on the tumor cells. Cells in atypical ducts were found to express simultaneously stem cell markers and hepatocytic or biliary lineage markers. Other cells in connective tissue showed c-kit expression, but not hepatic or biliary marker expression. The data show the presence of different cell populations bearing stem cell markers in human hepatoblastoma. Ductal cells co-expressing stem cell markers and hepatic lineage markers phenotypically resemble hepatic stem-like cells. These findings support the thesis that stem cells play a role in the histogenesis of hepatoblastoma.
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PMID:Stem-like cells in human hepatoblastoma. 1550 44