Scientists Discover Genetic Abnormalities After Creation of Stem Cells


ScienceDaily (Mar. 14, 2011) — Dr. Andras Nagy's laboratory at the Samuel Lunenfeld Research Institute of Mount Sinai Hospital and Dr. Timo Otonkoski's laboratory at Biomedicum Stem Cell Center (University of Helsinki), as well as collaborators in Europe and Canada have identified genetic abnormalities associated with reprogramming adult cells to induced pluripotent stem (iPS) cells. The findings give researchers new insights into the reprogramming process, and will help make future applications of stem cell creation and subsequent use safer.

The study was published online March 2 in Nature.

The team showed that the reprogramming process for generating iPS cells (i.e., cells that can then be 'coaxed' to become a variety of cell types for use in regenerative medicine) is associated with inherent DNA damage.

This damage is detected in the form of genetic rearrangements and 'copy number variations,' which are alterations of DNA in which a region of the genome is either deleted or amplified on certain chromosomes. The variability may either be inherited, or caused by de novo mutation.

"Our analysis shows that these genetic changes are a result of the reprogramming process itself, which raises the concern that the resultant cell lines are mutant or defective," said Dr. Nagy, a Senior Investigator at the Lunenfeld. "These mutations could alter the properties of the stem cells, affecting their applications in studying degenerative conditions and screening for drugs to treat diseases. In the longer term, this discovery has important implications in the use of these cells for replacement therapies in regenerative medicine."

read....

http://www.sciencedaily.com/releases...0302131847.htm