Identification of Human Embryonic Stem Cell Surface Markers by Combined Membrane-Polysome Translation State Array Analysis and Immunotranscriptional Profiling§

Authors


  • Author contributions: G.K.: conception and design, collection and assembly of data, data analysis and interpretation, manuscript writing; S.H.M.H. and I.B.: collection and assembly of data, data analysis and interpretation; Q.Z., H.S.C., S.H.M.H., K.K., and N.C.: collection and/or assembly of data; A.L.L. and S.M.G.: conception and design, financial support, data analysis and interpretation, manuscript writing, final approval of manuscript.

  • Disclosure of potential conflicts of interest is found at the end of this article.

  • §

    First published online in STEM CELLS EXPRESS July 30, 2009.

Abstract

Surface marker expression forms the basis for characterization and isolation of human embryonic stem cells (hESCs). Currently, there are few well-defined protein epitopes that definitively mark hESCs. Here we combine immunotranscriptional profiling of hESC lines with membrane-polysome translation state array analysis (TSAA) to determine the full set of genes encoding potential hESC surface marker proteins. Three independently isolated hESC lines (HES2, H9, and MEL1) grown under feeder and feeder-free conditions were sorted into subpopulations by fluorescence-activated cell sorting based on coimmunoreactivity to the hESC surface markers GCTM-2 and CD9. Colony-forming assays confirmed that cells displaying high coimmunoreactivity to GCTM-2 and CD9 constitute an enriched subpopulation displaying multiple stem cell properties. Following microarray profiling, 820 genes were identified that were common to the GCTM-2high/CD9high stem cell-like subpopulation. Membrane-polysome TSAA analysis of hESCs identified 1,492 mRNAs encoding actively translated plasma membrane and secreted proteins. Combining these data sets, 88 genes encode proteins that mark the pluripotent subpopulation, of which only four had been previously reported. Cell surface immunoreactivity was confirmed for two of these markers: TACSTD1/EPCAM and CDH3/P-Cadherin, with antibodies for EPCAM able to enrich for pluripotent hESCs. This comprehensive listing of both hESCs and spontaneous differentiation-associated transcripts and survey of translated membrane-bound and secreted proteins provides a valuable resource for future study into the role of the extracellular environment in both the maintenance of pluripotency and directed differentiation. STEM CELLS 2009;27:2446–2456

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