Telomere and Its Role in Diseases

Abstract

Telomeres are highly conservative repeated nucleotide sequences at the ends of linear chromosomes. Allowing effective DNA replication to keep the integrity of gene structure and the stability of chromosomes, telomeres protect the ends of the chromosome from deterioration or from fusion with neighboring chromosomes. Reduction in the telomere length leads to the cessation of cell division and thus cellular senescence. On the other hand, telomerase is a ribonucleoprotein complex with reverse transcriptase activity, protecting the telomere from being shortened. Thus, it is inactivated by synthesis and adds the repeated sequences onto the telomeres. Telomerase plays an important role in cell senescence and tumor formation. Telomere length and telomerase activity may be mediated by immune, endocrine, and metabolic pathways and accelerate cellular dysfunction, ageing, and even induce cancer over one’s lifespan. Significant attainment of telomerase to maintain telomere length could stop the cell senescence and aging related disease and also is required for the evolution of malignancy. This review discusses the role of telomeres and telomerase in humans during senescence and cancer. The evidence indicates that telomerase-induced telomere length manipulations could be targeted for anti-aging and anti-cancer therapy in the future.