At a time when researchers investigating the potential of embryonic stem cells focused on controlling cellular differentiation, Yamanaka took a different approach returning differentiated adult cells to the embryonic state. In 2006 his team reported discovering that inducing the activation of four transcription factors in adult skin cells converted them into cells displaying many properties of embryonic stem cells, which he named induced pluripotent stem cells (iPSCs). In subsequent work, Yamanaka's team confirmed that iPSCs can give rise to any type of mammalian tissue and refined the technology in order to reduce potential hazards associated with the cells.
Long a leader in studies of the regulation of gene expression, Jaenisch was one of the first to replicate and expand on Yamanaka's work. In 2007 both he and Yamanaka reported generating live mice from iPSCs, and Jaenisch went on to show that iPSCs could be used to correct the genetic defect in an animal model of sickle cell disease. He also has used the cells to treat an animal model of Parkinson's disease and earlier this year reprogrammed cells from human blood samples into iPSCs. Jaenisch's group also is investigating ways to overcome the technical limitations of human embryonic stem (ES) cells, which are much harder to work with than mouse ES cells.
Joseph Goldstein, MD, the Regental Professor and chairman of Molecular Genetics at the University of Texas Southwestern Medical Center, a member of the Warren Prize Selection Committee, says, "Yamanaka's development of iPSC technology and Jaenisch's pioneering work demonstrating the use of reprogrammed cells to treat models of human disease have pushed stem cell research to the forefront of biomedical science." Goldstein is also chairman of the MGH Sc
|Contact: Sue McGreevey|
Massachusetts General Hospital