NEW YORK (Aug. 1, 2013) -- The enormous promise of regenerative medicine is matched by equally enormous challenges. But a new finding by a team of researchers led by Weill Cornell Medical College has the potential to improve both the safety and performance of reprogrammed cells.
The researchers' study, published in today's issue of the journal Nature, found that an enzyme, activation-induced cytidine deaminase (AID), helps in the process that changes an adult human cell into an induced pluripotent stem cell (iPS cell). These iPS cells can then be developed into any kind of cell needed to therapeutically restore tissues and organs.
The finding settles an ongoing controversy regarding use of AID to reprogram cells, says the study's senior investigator, Dr. Todd Evans, vice chair for research and professor of cell and developmental biology in the Department of Surgery at Weill Cornell Medical College.
"The dispute was whether AID is required to make iPS cells, and we found that the enzyme does make reprogramming very efficient, although it is not absolutely necessary," says Dr. Evans, an internationally-recognized authority on regenerative medicine. "In fact, we plan to test if reprogramming iPS cells without AID may even be helpful."
One reason is that AID can cause genetic mutations that can lead to cancer. AID is best known as a master regulator of antibody diversity in B cells, and in order to create varied types of beneficial antibodies, it routinely mutates antibody genes. But sometimes the process goes awry, resulting in development of B cell lymphoma, Dr. Evans says. "That leads us to believe that if you can reprogram cells without AID, it could reduce risk of potential mutations, and thus be safer."
iPS Cells Without AID Remember What They Once Were
In order to push a cell, such as a fibroblast, to revert to an iPS cell, the epigenetic "markers" that define an adult cell must be removed.
|Contact: John Rodgers|
Weill Cornell Medical College