Stem Cell Reprogramming as a Means to Attenuate Aging I've found more support for my idea of stem cell reprogramming as a possible means to attenuate aging. Researchers at the University of Kentucky have found that longer-lived mouse strains have stem cells in their bone marrow that are especially good at repairing DNA. This suggests, but does not prove, that DNA damage accumulating in stem cells increases mortality and is a marker of aging. If this is so, then preserving stem cells DNA integrity might lead to increased longevity. Another dimension of possible stem cell reprogramming involves telomeres. There seems to be a unique dichotomy between the ability of cells to continually divide and their resistance to becoming carcinogenic. When the tumor-suppressing p53 gene is overactive in mice, the mice are less likely to develop cancer, but they die young. These p53-related premature deaths were due to the mice having stem cells that wear out too quickly. A requisite for a cell to be carcinogenic is that the telomerase gene which is normally dormant must become activated. But if telomerase is never activated our cells eventually are incapable of dividing and enter a senescent phase, and this is thought by some to be a central impetus of the aging process. Although manipulation of telomeres in vivo and in vitro is extremely complicated, it might be possible to use stem cells as a vector for increasing cell populations with longer telomeres. While stimulating the activity of the telomerase gene in vivo is usually a recipe for cancer, the activation of telomerase in stem cells in vitro is another matter. If telomeres could be elongated in vitro and then transplanted in vivo with normal telomerase activity, more cell divisions could be possible without increasing significantly the risk of carcinogenesis. While the role of stem cell technology may not be the fountain of youth in the next year, its potential to push the bounds of human longevity and physiology go beyond the transplantation of neurons in Parkinson's patients and blood cells in the bone marrow of chemotherapy patients; research in this area may very well address the fundamental facets of aging itself.