By Loret Haas-Hanser
Biological immortality is humankind's firmest grasp on the concept of living forever. Immortality has been sought after since the dawn of time. Living forever, unlimited growth and knowledge are all wonderful things to strive for. Up until recently, immortality has remained an intangible dream, but recent scientific breakthroughs are pushing humanity closer towards the goal of infinite life. Biological immortality, or cellular immortality, is a recent concept that illuminated the ideology that some cells are immortal or may have infinite growth and division capacity. A recent breakthrough in the research on cellular immortality is the discovery of the role that telomeres play in lengthening the life of a cell. Telomeres are repetitive DNA sequences at the end of chromosomes that depict the age and functionality of cells. Telomeres inhibit fusion-based degradation when in contact with other chromosomes. Telomeres shorten after each time a cell divides, and each time a telomere shortens, a cell’s genome becomes more unstable. Recent studies by Alexander Sobinoff and Hilda Pickett examine telomeres role in cancerous cells and DNA repair to decrease cellular senescence to elongate the lifespan of cells.
Cells that are immortal use a multitude of certain enzymes that are integral to helping stop or slow down telomeric damage. The most common enzyme, telomerase (used in 80-90% of telomeric scientific experiments) is an enzyme containing RNA that extends telomeres by adding DNA back into the telomere. ALTs (alternative lengthening telomeres) are being studied to find out if extending the size of telomeres can also extend the lifespan of cells . The human genome is subjected to constant stress both internally and externally, and telomeres can be a make or break factor to healing genomic damage in the future.
Telomeres are extremely difficult regions to lengthen as they are associated with replication, and replicating something that has a sole purpose of replication can get a bit tricky. The structure of telomeres includes various loops and quadruplexes, which can eventually lead to a breakage in a replication fork. Pickett and Sobinoff observed through inducing stress and alternative replication synthesis in telomeres that replication fork regression could be an important detail towards ALTs. By dissecting where the degradation begins occurring as telomeres come into contact with other chromosomes, it is possible to use DNA agents, binding proteins or other enzymes to decrease damage in replication forks before telomeres begin to compress.
Beauty magazines, cookbooks, newspapers and other forms of media are obsessed with anti-aging and immortality. The lifespan of telomeres plays a huge roll in the functioning capacity of cells. If telomeres remained at their full capacity forever- it is possible that cells could too. ALTs are a more recent observed factor in DNA synthesis and replication. Although continuing to study cellular immortality would be a colossal breakthrough in furthering the quest for immortality, it is important to remember that telomeres naturally are an integral factor in cells. Anti-aging and immortality are cool things to strive for: no wrinkles, no gray hair, cells continuing to replicate at a healthy rate, etc. But more importantly, focusing on the lives we already lead should not be taken for granted. Gray hair and wrinkles show that the body has exuded strength and time in replicating and synthesizing. Aging is a healthy, beautiful process that shows that your body is working. Accepting our vulnerability to time as human beings is the first step to celebrating all stages of life to the fullest.
References:
Sobinoff, A. P., & Pickett, H. A. (2017). Alternative Lengthening of Telomeres: DNA Repair Pathways Converge. Trends in Genetics. Chicago