First published online November 21, 2007
Stem Cells
Vol. 26 No.
2
February 2008, pp.
525
-533
doi:10.1634/stemcells.2007-0710; www.StemCells.com
© 2008 AlphaMed Press
In Vitro- and In Vivo-Induced Transgene Expression in Human Embryonic Stem Cells and Derivatives
Xiaofeng Xiaa,
Melvin Ayalab,
Benjamin R. Thiedeb,
Su-Chun Zhanga,b
aWiCell Research Institute, Madison, Wisconsin, USA;
bDepartments of Anatomy and Neurology, School of Medicine and Public Health, Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
Key Words. Human embryonic stem cell • Gene modification • Gene delivery systems in vivo or in vitro • Inducible gene expression
Correspondence: Su-Chun Zhang, M.D., Ph.D., Waisman Center, University of Wisconsin, Madison, 1500 Highland Avenue, Madison, Wisconsin 53705, USA. Telephone: 608-265-2543; Fax: 608-263-5267; e-mail: Zhang{at}waisman.wisc.edu
Received August 26, 2007;
accepted for publication November 13, 2007.
First published online in STEM CELLS EXPRESS November 21, 2007.
The use of human embryonic stem cells (hESCs) as a research and therapeutic tool will be facilitated by conditional gene expression. Here, we report drug-induced transgene expression, both in vitro and in vivo, from a tet-on hESC line with >95% purity. Using green fluorescent protein as an indicator, we demonstrated that the tet-on system allowed a tight control of the gene expression in both undifferentiated hESCs and differentiated cells of the three germ layers. More importantly, after the cells were transplanted into animals, the gene expression remained to be regulated by an orally administered drug. These results provide a technical basis for regulation of gene expression in hESCs and derivatives in vitro and in vivo.
Disclosure of potential conflicts of interest is found at the end of this article.

Copyright © 2008 by AlphaMed Press.