Telomerase and Cancer: The Chemical Fountain of Youth?

Telomerase is an enzyme in the human body. You can always tell if something is an enzyme if it ends in "ase." But telomerase is a very interesting enzyme due to its function. Although telomerase presents an opportunity to be instrumental in reversing the aging process, it also has been implicated in causing cancer if used for such a purpose.

Telomerase functions in DNA replication, adding specific nucleotide sequences to a replicating strand of DNA. It adds these sequences to the end of the DNA strand which is designated as the 3' (three prime) end of the chromosome. To those who haven't studied biology since high school, chromosomes are found in human cells and contain all of our genetic information. Telomerase belongs to a class of enzymes known as the reverse transcriptases, and uses a strand of RNA as a template to create new segments of DNA on the existing DNA strand. Telomerase is needed because in order for cells to divide and replicated, the genetic material must also be replicated exactly. Telomerase's potential at reducing aging derives from its action on special chromosomal regions called telomeres.

Telomeres are the ends of DNA strands, and after each subsequent DNA replication, they shorten to a certain degree. To explain the full mechanism of telomerase and DNA replication would be time-consuming and difficult to explain to those who are not versed in intermediate biology, so I will refrain. Telomeres are like ticking age clocks. When they shorten, cells become less hardy, and effects of aging begin to manifest themselves increasingly. Although it is unknown to what extent telomere shortening causes aging, the correlation has been supported with clinical data. Since telomerase works by adding new segments of DNA to shortened telomeres, one would think that people could prolong their life indefinitely with it. Is it that simple?