Telomeres and Telomerase in Cancer: Overview and Therapeutic Potential

Abstract

Telomeres are specialized structures of eukaryotic chromosomes that protect the tips of the chromosomes. Telomeres prevent chromosomes from losing base pair sequences at their ends, and also stop chromosomes from fusing together. Telomerase is an enzyme that rebuilds telomeres and maintains genomic stability by extending telomeres after each cell division. Telomerase activity prevents cellular aging, also known as senescence. Immortal cell lines can be created by inducing expression of telomerase in cells that normally lack telomerase. Cells need to maintain genomic integrity to prevent mutations that can lead to cancer. Such activation of telomerase mentioned above can often lead to cancer development by preserving genomic stability in rapidly dividing cells. If a cell keeps dividing and overcomes the limitations of telomeres, a cancerous tumor can form. In healthy cells, telomeres achieve the healthy balance between limiting cellular lifespan and keeping cancer growth at bay.
 It has been established that telomerase activity is a biomarker of cancer and tumorigenesis. This makes telomerase an attractive target for cancer therapy, and studies indicate that methods of treatment such as oligonucleotides, immunotherapies, and stabilization of G-quadruplexes all hold immense possibilities in the field of oncology. Such discoveries provide insight on the potential of telomeres to play a significant role in the prevention of cancer before tumorigenesis, or the treatment of cancer after diagnosis. Therefore, telomerase is a viable cancer biomarker and a therapeutic target, and an area of interest in the field of cancer study.