Our general goal is to better understand the differences and similarities between cancer cells and embryonic stem cells, to prevent tumor formation following stem cell transplantation but also to gain novel insights into the mechanisms of tumorigenesis and into the biology of embryonic stem cells. To this end, we have been studying how a tumor suppressor named Rb controls the dedifferentiation (or “reprogramming”) of cells into induced pluripotent stem cells (iPS cells), which are similar to embryonic stem cells. (ES cells).
We have found that, similar to other tumor suppressors such as p53, Rb normally restricts the reprogramming process, both in human and mouse cells. We have also found that loss of RB does not change the proliferation rate of cells during reprogramming, suggesting that the enhanced efficiency of reprogramming observed in the absence of Rb is not due to a simple increase cell number. We are currently investigating the mechanisms by which Rb normally restricts the reprogramming process.