|Title:||Epithelial cell adhesion molecule (EpCAM) complex proteins promote transcription factor-mediated pluripotency reprogramming||Authors:||HSIANG-PO HUANG
|Issue Date:||2011||Journal Volume:||286||Journal Issue:||38||Start page/Pages:||33520-33532||Source:||Journal of Biological Chemistry||Abstract:||
Epithelial cell adhesion molecule (EpCAM) is a transmembrane glycoprotein that is highly expressed in embryonic stem cells (ESCs) and its role in maintenance of pluripotency has been suggested previously. In epithelial cancer cells, activation of the EpCAM surface-to-nucleus signaling transduction pathway involves a number of membrane proteins. However, their role in somatic cell reprogramming is still unknown. Here we demonstrate that EpCAM and its associated protein, Cldn7, play a critical role in reprogramming. Quantitative RT-PCR analysis of Oct4, Sox2, Klf4, and c-Myc (OSKM) infected mouse embryonic fibroblasts (MEFs) indicated that EpCAM and Cldn7 were upregulated during reprogramming. Analysis of numbers of alkaline phosphatase- and Nanog-positive clones, and the expression level of pluripotency-related genes demonstrated that inhibition of either EpCAM or Cldn7 expression resulted in impairment in reprogramming efficiency, whereas overexpression of EpCAM, EpCAM plus Cldn7, or EpCAM intercellular domain (EpICD) significantly enhanced reprogramming efficiency in MEFs. Furthermore, overexpression of EpCAM or EpICD significantly repressed the expression of p53 and p21 in the reprogramming MEFs, and both EpCAM and EpICD activated the promoter activity of Oct4. These observations suggest that EpCAM signaling may enhance reprogramming through up-regulation of Oct4 and possible suppression of the p53-p21 pathway. In vitro and in vivo characterization indicated that the EpCAM-reprogrammed iPSCs exhibited similar molecular and functional features to the mouse ESCs. In summary, our studies provide additional insight into the molecular mechanisms of reprogramming and suggest a more effective means of induced pluripotent stem cell generation. ? 2011 by The American Society for Biochemistry and Molecular Biology, Inc.
|ISSN:||0021-9258||DOI:||10.1074/jbc.M111.256164||SDG/Keyword:||ALkaline phosphatase; Embryonic stem cells; Epithelial cancer cells; Epithelial cell adhesion molecules; Expression levels; Functional features; In-vitro; Membrane proteins; Molecular mechanism; Mouse embryonic fibroblasts; Over-expression; P53 and p21; Pluripotency; Pluripotent stem cells; Promoter activities; Quantitative RT-PCR; Signaling transduction; Somatic cells; Transmembrane glycoproteins; Up-regulation; Biological membranes; Biomolecules; Cell adhesion; Cell culture; Genes; Mammals; Phosphatases; Stem cells; Transcription; Transcription factors; Adhesion; alkaline phosphatase; claudin 7; epithelial cell adhesion molecule; protein p21; protein p53; transcription factor; transcription factor NANOG; animal cell; article; Cldn7 gene; controlled study; cytology; embryo; embryo cell; EpCAM gene; fibroblast; gene; gene activity; gene control; gene expression regulation; gene overexpression; human; human cell; in vitro study; in vivo study; Klf4 gene; mouse; nonhuman; Oct4 gene; oncogene c myc; p21 gene; p53 gene; pluripotent stem cell; priority journal; promoter region; protein domain; protein expression; protein function; protein protein interaction; quantitative analysis; reverse transcription polymerase chain reaction; signal transduction; sox2 gene; transcription regulation; upregulation; Animals; Antigens, Neoplasm; Cell Adhesion Molecules; Claudins; Embryo, Mammalian; Embryonic Stem Cells; Fibroblasts; Humans; Induced Pluripotent Stem Cells; Mice; Models, Biological; Nuclear Reprogramming; Pluripotent Stem Cells; Protein Structure, Tertiary; Signal Transduction; Transcription Factors; Tumor Suppressor Protein p53
|Appears in Collections:||基因體暨蛋白體醫學研究所|
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