Result by researchers of the Institute of Health published on-line in the journal of Stem Cell

Embryonic stem cells possess the trait of limitless proliferation, self-renewal, and multidirectional differentiation. Whether in vitro or in vivo, embryonic stem cells can be induced to differentiate into almost all types of cells, making themselves an important source of cells in the therapy of cell transplantation. But a major problem remains to be solved, that is, the risk of tumor formation. The undifferentiated embryonic stem cells existing in the cells for transplantation may form tumors in the recipients. Thus it has become a matter of primary importance in the research on embryonic stem cell therapy to remove the undifferentiated embryonic stem cells existing in the cells for transplantation.

Under the supervision of Research Fellow Le Weidong, doctoral student Wang Yi with the Institute of Health Sciences, who works on neural genes, found by establishing a GeneSwitch system in mouse embryonic stem cells that inducible caspase-1 expression does not influence the potential for embryonic stem cell differentiation; in addition, it has the capacity to specifically kill

the undifferentiated embryonic stem cells existing in the cells for transplantation, but to leave the differentiated neuroblasts unaffected. Further research found that the introduction of differentiated and undifferentiated into the mouse brain can eliminate tumor formation in the brain through inducible caspase-1 over-expression. For the first time, the research gives a detailed explanation of how to solve the problem of tumor formation in cell transplantation by killing undifferentiated embryonic stem cells through induced over-expression of the suicidal caspase-1. The research shows immense value in application and bright prospects in that it not only provides a very important theoretical basis for lowering the risk of tumor formation in the clinical use of embryonic stem cells in the treatment of disease, but also a very important experimental basis for the cellular treatment of degenerative nervous diseases such as Parkinson‘s disease, as well as other diseases whose treatment requires cell therapy based on embryonic stem cells.

The research result was published on-line in the authoritative journal of Stem Cell on Nov.30, 2011. (Mifepristone Inducible Caspase-1 Expression in Mouse Embryonic Stem Cells Eliminates Tumor Formation but Spares Differentiated Cells in vitro and in vivo.)The study was funded by the National Foundation of Natural Sciences, 973 project fund of the Ministry of Science and Technology, and the special grant for doctoral students of SJTU.