Bad News for Stem Cells
Considerable promise matched with equally considerable hype surround the subject of stem cells. This is due to the ability of stem cells to differentiate into any specialized type of cell and thus replace injured or diseased tissues. Possibilities include treatments for Parkinson’s disease, Alzheimer’s dementia, heart ailments, and spinal cord injuries.
Adult stem cells are less capable than the embryonic variety but avoid the ethical and religious objections inherent in obtaining embryonic cells. In both cases, however, culturing and induction of the pluripotent state that is capable of wide-ranging differentiation may lead to mutations or other chromosomal aberrations that could be deleterious for human use.
A series of three papers in Nature (471 [March 3, 2011], 58–73) confirm these worries. A slew of different experiments all show that cellular reprogramming leads to both genetic and epigenetic abnormalities that could undermine the safety of stem cell use in human medicine. This does not doom stem cell therapy, but it does mean that much more research will be needed before the promise of regenerative medicine is realized.