SEOUL NATIONAL UNIVERSITY HOSPITAL

- The team led by Young-Bae Park, HyoSoo Kim, and Hyun-Jai Cho of SNU Hospital safely cultured pluripotent stem cells, equivalent to embryonic stem cells from somatic cells and achieved competitiveness in this area.

- In the future, somatic cells taken from patients will be dedifferentiated into pluripotent stem cells and differentiated into heart, blood vessel, and nerve cell for autologous cell therapy. 

  A local research team succeeded in inducing pluripotent stem cells that can be differentiated into heart, skin, or blood vessel in an innovative way, attracting attention from the world. With this success, we are much closer to the age of autologous cell therapy. In the near future, patients suffering from organ damages will be treated with somatic cells taken from their own cells. 

 The team led by Young-Bae Park, HyoSoo Kim, and Hyun-Jai Cho of the Cardiovascular Center, SNU Hospital, succeeded in culturing pluripotent stem cells by exposing the fibroblasts of adult mouse skin and heart to the lysate protein of mouse embryonic stem cells on. The cultured pluripotent stem cells were equivalent to the mouse embryonic stem cells in terms of stemness gene expression and the capability to differentiate into various cells of three germ layers.

 In particular, they could differentiate into cardiomyocytes in a certaincondition and showed "heartbeats." Furthermore, when the cultured pluripotent stem cells are transplanted in blastocyst, it is possible to make adult chimeric mice. Through the tetraploid complementation experiment, it was possible to make a fetus whose whole body was derived from iPS cells. 
  
 This observation was published in the July issue of Blood (impact factor 10.5), the most prestigious journal of hematology in the world. The patent-application for the novel protocol was completed at home and abroad. The research was supported by the grant from innovative research institute for cell therapy (IRICT president: Young-Base Park) sponsored by the Ministry of Health and Welfare, Korea. 

The history of stem cell research is short, which offers a great opportunity to Korea. In particular, the history of dedifferentiation research is only a couple of years old and its potential for development is endless.

However, the establishment of customized stem cells without immune rejection while minimizing religious and ethical issues is a long task to be accomplished for the realization of stem cell therapy.

The strategy to transfer somatic cell nucleus to the enucleated ovum was abandoned due to ethical controversy and a slim possibility of scientific realization. Meanwhile, in 2006, Doctor Yamanaka of Kyoto University, Japan,succeeded in making the induced pluripotent stem cells (iPS cells), almost equivalent to embryonic stem cells, through transfecting four transcription factors to adult somatic cells. 

However, the methodology pursued by researchers at home and abroad raised an issue of safety that pluripotent stem cells cause tumors in chimeric mice as it was based on genetic manipulation. However, the methodology developed by the research team of SNU Hospital did not use genetic manipulation. Also, by verifying that tumors were not generated in chimeric mice, the team showed off the excellence of the method in terms of safety. 

Based on this result, these new type of stem cells may get spotlight as the source of good alternative to ESCs.

This study suggests that autologous cell therapy will be possible, in which somatic cells taken from patients can be dedifferentiated into pluripotent stem cells, equivalent to embryonic stem cells, and then can be re-differentiated into heart, blood vessel, or nerve cells to regenerate damaged organs with patients own cells. 

"As this is a method to make stem cells out of patients cells, it is meaningful that the foundation of next-generation cell therapy with no immune rejection was established. However, continuous research in the future should verify reproduction in human cells and develop the technology for differentiation into specific cells for safety," said Professor HyoSoo Kim.