The Biological Clock for Some Tissues May Be Ticking Faster than for Others

       Popular Science recently posted an article about Steve Hovarth, a geneticist at UCLA’s medical school, who has developed a new technique for identifying the exact biological age of human tissue. His research suggests that not all tissues of the body follow the same biological clock. The process involves the observation of DNA methylation, which has been suggested to be a biomarker for the age of a cell. As hypothesized, cancerous tissues age far faster than healthy tissue. However, it was also displayed that even some healthy tissues age faster than the rest of the body; in Hovarth’s study, breast tissue was examined. While completely healthy breast tissue is two to three years older than the rest of the female body, it was also shown that tumors aged the tissue an additional 36 years, and healthy breast tissue that was near a tumor was about 12 years older than tissue in other parts of the body.

Hovarth’s study highlighted over 8,000 healthy samples of 51 different types of tissues. He then went even further to study 6,000 samples of cancerous tissue. For each sample, Hovarth examined the DNA methylation levels of the given tissue. Once the biological age of the tissue was determined through the observation of DNA methylation levels, Hovarth compared the biological age of the tissue to the chronological age of the issue donor. His method was virtually completely successful. Not only did Hovarth’s study find a method of effectively calculating the age of various tissues, but he was also able to transform adult human cells into pluripotent stem cells. This transformation essentially rearranges the cells so that they act as if they were embryonic stem cells; Hovarth commented that this transformation “resets the cells’ clock to zero.”

I found this article particularly interesting not only because it explains how some tissues are biologically older than the rest of the body, but also because it proposes a way to essentially reverse that aging process. Looking at this article from a health perspective, it is fascinating how some parts of the body can age faster than others; this increased age of certain tissues definitely makes them more susceptible to acquire different diseases and illnesses. If Hovarth’s method of reprogramming cells to make them act as embryonic stem cells proves to be effective, then not only can the medical community use this method to combat different diseases, but it can also be utilized as a new weapon in the ongoing war against aging. I am a gerontology minor, so I have been learning a lot about the downside of aging as well as the biological aspects of aging. It is exciting to think that in the near future, this method can be perfected and used to improve the health of the population of individuals who are experiencing difficulty or discomfort when aging.

Aging Changes all Tissues