Telomere and telomerase research is leading to an understanding of the mechanisms of cellular aging and cancer development, which in turn is leading to breakthrough medical approaches aimed at anti-aging and cancer treatment.
Aging and cancer are two of the most pressing issues in the medical community today. Mankind has long dreamed of slowing down aging and conquering cancer, and it remains one of the most important goals of modern medicine. In particular, scientists are now pointing to telomeres, the ends of DNA, as an important factor involved in cellular aging. Telomeres are responsible for preventing the loss of genetic information during cell division, and harnessing the power of telomerase, the enzyme that makes telomeres, could lead to the development of new drugs or new treatments for aging and cancer. These discoveries have deepened our understanding of the mechanisms of aging and cancer and are opening the door to medical breakthroughs.
To understand telomeres, we first need to understand the structure of DNA and how it is replicated. DNA is a double helix structure that contains the genetic information of an organism, consisting of two strands of nucleic acids that are joined together in a helix to form a long chain. Each of these nucleic acids contains one of the following bases: adenine (A), guanine (G), cytosine (C), and thymine (T). Nucleic acids with adenine on one strand bind complementarily to nucleic acids with thymine on the other strand, and nucleic acids with guanine bind complementarily to nucleic acids with cytosine. These complementary bonds make up the genetic information, and the order of the sequence of bases determines the various inherited traits.
When DNA is replicated, one end of the helix opens, spreading the two strands apart. The enzymes that synthesize DNA pass through the open strands and weave a new DNA chain from nucleic acids with complementary bases that match the sequence of bases arranged. The problem is that when replicating a DNA chain, the nucleic acids at the end are not replicated. Replication enzymes pass by the nucleic acid being replicated and replicate the nucleic acid they have passed when they reach the next nucleic acid. Therefore, the nucleic acid at the end cannot be passed by the enzyme because there is no next nucleic acid, and it is not replicated. This causes the nucleic acid at the end of the DNA chain to disappear with each replication, and the genetic information in the disappearing section is lost.
To solve this problem, DNA evolved a way to attach short lengths of chain at each end that don’t contain genetic information. These short chains are called telomeres. Telomeres play an important role in preventing the loss of genetic information during cell division, and their sequence and length vary between different species of organisms. For example, the telomeres on human chromosomes are made up of repeats of the sequence TAGGG. This telomere is attached to the part of the chain that contains genetic information, allowing replication enzymes to pass through and preventing the loss of information. However, telomeres also get shorter with each cell division (DNA replication). That’s because telomeres don’t prevent the last nucleic acid from being replicated.
The number of cell divisions is tissue-specific, and the number of divisions is determined by the length of the telomeres. When telomeres shorten below a certain length (the senescence point), senescence occurs, and eventually the cell dies. This process is directly linked to aging, and it is believed that a decrease in telomere length causes aging and decreased function in living tissue.
However, not all cells lose telomeres; cancer cells have telomeres that do not shorten as the cell divides, meaning that they do not age as the number of divisions increases, and they are able to proliferate indefinitely. This happens because telomerase, the enzyme that makes telomeres, is active. Telomerase is responsible for synthesizing telomeres and then attaching them to the ends of DNA, increasing the overall length of the telomere. Although this enzyme is present in all cells, it is inactive in most normal cells in normal people. However, in some cells that need to divide actively, such as the progenitor cells that make eggs and the hematopoietic stem cells that make blood cells, it is active, so that the telomeres in those cells do not shorten.
Currently, scientists are trying to develop ways to modulate the function of telomerase, so that telomeres can be intentionally shortened or, conversely, prevented from shortening. If successfully developed, this could be a game-changer in cancer treatment and anti-aging. It opens up the possibility of conquering cancer by preventing cancer cells from multiplying unrestrictedly, while at the same time making the dream of living longer a reality by slowing or stopping aging. This would be a major scientific breakthrough that could fulfill humanity’s long-standing desire for a healthy life and longevity.
