Medical Sample [Genetics]

Are Telomeres the Key to Aging and Cancer?

Telomeres are sections of repetitive DNA located at the end of a chromosome – the structure housing the genes crucial for life – meant to help prevent deterioration. Over the course of a cell’s life it will replicate anywhere from 50-70 times, during which telomeres become increasingly shorter.  Without these telomeres the endings of chromosomes would fuse together and destroy the chromosome’s genetic information, causing it to die or become cancerous.

Studies have begun to show that shortened telomeres are often related to many types of cancers. Cancer cells divide much more frequently and must consequently counteract their rapid telomere shortening by introducing an enzyme named telomerase. As a cancerous cell approaches the end of its telomere it activates this enzyme which continually adds nucleic bases to the telomere’s end essentially making the cell ‘immortal’. If researchers can figure out a method that effectively inhibits telomerase, they could successfully make cancer cells age and die. In recent experiments, scientists have been able to block telomerase in breast cancer cells in the laboratory leading to the cells’ death.

However, there are other questions regarding the enzyme and its functions that must be answered before any major steps may be taken by pharmaceutical companies. How does telomerase decide on the number of genetic subunits to attach to the end of a telomere? Would altering binding proteins disrupt elongation? How exactly does the enzyme attach itself to DNA? The scientific community is relentlessly researching the answers to these questions.

Though telomere shortening has been linked to our aging process, but it is not currently known whether the length of telomeres is a sign of aging or actively contributes to the actual process of aging itself. With the idea that telomerase can make cancerous cells immortal, scientists have been able to successfully use telomerase to allow human cells to divide far beyond the normal limit without being considered cancerous.

Just how large of a role do telomeres play in aging though? Research has shown that some species with long lifespans have telomeres that are much shorter than other species that only live several years. 

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