The Role of Telomere in Cell; Telomere Dysfunction and Tumorigenesis

Telomeres consist of repetitive DNA sequences and a variety of non-nucleosomal proteins which are essential to survive chromosome. Telomeres protect the ends of chromosomes, but can also inhibit the expression of nearby genes, called telomere position effect. The telomeric cap is a dynamic structure between a fully capped closed and a partially uncapped or open conformation. The protection of chromosome termini from being sensed by the cell as broken DNA is an important function of the telomeres as the capping function. Functional telomeres have a special role in response to DNA damage. The presence of telomere and the length of telomere are two important determinants for binding of chromosomes to the nuclear envelope in meiosis. Future studies about the characteristics of epigenetic factors in telomere length will lead to a better understanding of telomere regulation and its role in human cancers. It seems that telomere dysfunction, rather than telomere length alone, may create insights not only into the pathogenesis, but could also have significant impact on the diagnosis of cancer.