Telomeres are essential caps that occupy each end of a chromosome. They are made of nonessential bits of DNA. Since cell division results in the loss of a bit of DNA during each replication, these caps shorten every time the cell divides. This prevents essential DNA from being deleted. Eventually, the telomere will be too short to do its function. At this point, the cell will die.
How Telomeres Affect Cell Life
As stated above, a cell will die once its telomeres are too short to prevent the destruction of the important parts of the chromosomes they protect when the cell divides. Therefore, both the amount of divisions the cell can do and the lifespan of the cell itself are dependent on the starting length of the telomere.
In some cases, a cell can replenish the length of its telomeres. Unfortunately, this is a characteristic of some types of cancer. One of the reasons tumors can grow so prolifically is that each cancer cell can divide infinitely while keeping itself alive as well. They can do this because their telomeres never get too short to support further divisions. When every cell in a tumor has this trait, growth can be exponential.
Thanks to this association, some researchers have been wary about lengthening the telomeres of healthy cells. Others, however, believe these fears are unfounded. They argue that lengthening telomeres can slow aging and reduce the incidence of disease. Of course, there’s no way to know until scientists develop a suitable way to test this theory without causing serious adverse effects or injuring the test subjects. As cancers can sometimes grow very slowly, it may be some time before a cancer that is caused by therapy is detected.
How Telomerase Can Slow Aging in Healthy Cells
Telomerase is the enzyme responsible for lengthening telomeres. In healthy cells, its presence can increase the lifespan of cells by allowing them to successfully divide for a longer period of time. It can also reduce the incidence of cancer since the initiation of cancerous states is associated with shortened telomeres and DNA damage.
In normal adult humans, some cells have a high amount of telomerase to protect their DNA while others do not. Anti-aging researchers believe that increasing the amount of telomerase in more cells will bring improvements to human lifespan. The unfortunate challenge with this approach is that currently, researchers have little idea about how they are going to increase intracellular concentrations of the telomerase enzyme. There are a number of pharmaceutical and supplement companies that are attacking this problem, so a solution is expected within the next few years.
Is Telomerase Gene Therapy the Solution to Aging?
Tests in mice indicate that the administration of a telomerase-lengthening drug reverses certain types of tissue damage associated with aging. Current studies indicate that certain populations of humans naturally contain a mutation that causes some to live much longer than their peers. This mutation causes increased expression of the genes responsible for telomerase production.
Thanks to these observed effects, much research is being conducted on the effects of using drugs or gene-based therapies to increase the amount of telomerase in healthy cells of various species. So far, the results have been mixed. Increased telomerase has improved the health of mice with a deficiency in the enzyme. On the other hand, some healthy mice have developed cancer after their telomerase was artificially increased.
Overall, telomerase gene therapy and its variants looks very promising, but it’s clear that it will require much refinement before it is medically predictable and useful. The connection between telomere length and aging is almost indisputable. The difficulty will lie in making sure that therapy benefits healthy cells without also aiding malignant ones.
Research into this and other anti-aging therapies is only growing. People are realizing that aging is not something to accept and live with. Instead, it is a condition to be controlled and finally eliminated. It’s just a matter of time before this or another solution is developed that will get rid of humanity’s oldest problem: age-related decline and death.