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Did You Know? Cancer cells are known to express telomerase, which is why they multiply so rapidly and are so difficult to destroy.Human beings have sought immortality since the beginning of time! From posthumous and fanciful accounts of Nicolas Flamel's achievements as an alchemist to Lord Voldemort's machinations in the Harry Potter series, the pursuit of immortality has often been explored in fiction. But in real life, its secrets have remained elusive. Until now.
Recent discoveries in the field of genetics suggest that one of the keys to unlocking the secret of immortality lies within each and every one of us. And it can be summed up in a single word: telomere.
A telomere is the capped end of a chromosome, a bit like the plastic tip on the end of a shoelace. Humans have 46 chromosomes containing important genetic information related to things like eye colour, hair type, and height. You inherit 23 chromosomes from your father, and 23 chromosomes from your mother. Telomeres, like the other parts of a chromosome, are made up of DNA sequences that include the four nucleic acid bases (Adenine, Cytosine, Thymine, Guanine). However, unlike the rest of a chromosome, telomeres do not contain genes, which are specific DNA sequences that act as “chemical codes,” providing essential genetic information.
Did You Know? Glycation occurs when sugars from the food we eat binds to proteins and lipids, causing permanent damage to body tissues.Rather than providing genetic information, telomeres help protect the information in the rest of the chromosome. Cells in your body constantly divide to produce new cells, and each time this happens small bits of chromosome are lost. But because these bits are lost from the telomeres—they get shorter each time a cell divides—cells are able to divide without losing genetic information. But when telomeres get too short, cells can no longer divide and they subsequently die.
So what do telomeres have to do with immortality? The answer lies in an enzyme called telomerase. A fetus consists of embryonic stem cells. Within each of these cells, there is a high amount of telomerase. By adding bases (ACTG) to the ends of telomeres, telomerase allows the embryonic stem cells to continuously divide over and over again, allowing the foetus to grow. This means that telomerase could potentially reverse the effects of aging by preventing telomeres from shortening. As a young child, you probably had a lot of telomerase. However, as you grow older, you automatically begin to lose the enzyme, resulting in decreased production of cells.
University of Utah geneticist Richard Cawthon has shown that shorter telomeres are associated with shorter lives. Numerous studies have proven that shorter telomeres play an important role in human disease and mortality. So telomerase is likely one secret to drastically increasing the human life span, since it lengthens the telomere.
Did You Know? More than 20 studies have shown an association between shorter telomere length and different types of cardiovascular disease.However, there are other biological processes that contribute to aging, including oxidative stress, glycation, and chronological aging. In fact, only 37% of the aging process is caused by shrinking telomeres and chronological aging. The other 63% is caused by oxidative stress, the damage caused to protein, lipids, and DNA by oxidants (highly reactive compounds containing oxygen). Cawthon claims that if all processes of aging are eliminated, it might be possible to live to be 1000!
By understanding the role played by telomeres, we’ve taken an important step in our quest to achieve immortality. However, even if telomere elongation techniques are successfully developed, we will still need to find ways of mitigating oxidative stress. But who knows, with the rapid progress of scientific research in the 21st century, your great grandchildren may just live to be a 1000!
Are Telomeres the Key to Aging and Cancer? (Lee J. Siegel, University of Utah) Telomeres, Telomerase and Cancer (Carol W. Greider and Elizabeth H. Blackburn, Scientific American)