Characterization of Epithelial Cell Adhesion Molecule as a Surface Marker on Undifferentiated Human Embryonic Stem Cells

• DOI: 10.1002/stem.221
• Publication Date: 2009-09-25T20:27:07Z
• Authors: Valerie Y. Ng; Sheu Ngo Ang; Jia Xin Chan; Andre B.H. Choo
• Keywords: Embryoid body; Lineage markers; Germ layer

Abstract Human embryonic stem cells (hESCs) have the capacity to remain pluripotent and self-renew indefinitely. To discover novel players in maintenance of hESCs, we previously reported generation monoclonal antibodies that bind cell surface markers on not mouse or differentiated embryoid bodies. In this study, identified antigen target one such antibody as epithelial adhesion molecule (EpCAM). undifferentiated EpCAM is localized Octamer 4 (OCT4)-positive cells, its expression down-regulated upon differentiation. further understand biological function endogenous was silenced using small interfering RNA. knockdown had marginal negative effects OCT4 TRA-1-60 expression, however proliferation decreased by >40%. Examination lineage marker showed marked upregulation endoderm mesoderm genes EpCAM-silenced under both differentiating conditions. These results were validated a hESC line whose has been stably knocked down. Data from stable confirmed downregulation decreases growth increases gene lineages. vivo, hESCs lacking able form teratomas containing tissues representing three germ layers, analysis yielded increase alpha fetoprotein compared with control. Together these data demonstrate plays functional roles