Telomeres

Telomeres are DNA portions, particularly rich in guanine, that protect the end of chromosomes and avoid chromosome fusion and other genetic alterations that could compromise cellular life. In tissue, shortened telomeres can cause problems to injury repair and an acceleration of ageing. Furthermore, short telomeres are associated to cancer predisposition, bone marrow failure and pulmonary fibrosis These functions of telomeres, as a tumor suppressor, have been identified in mammals and in other animals with a long life span while this mechanism doesn’t exist in short-lived organisms.

In several studies about familial heritance of telomeres abnormalities, it has been demonstrated that haplo-insufficiency of telomeres can determine a broad range of diseases, often different between members of the same family. This could mean that phenotype of human heritable telomerase deficiencies is influenced by additional environmental, stochastic and genetic factors: a Darwinian explanation of the role of telomeres has been proposed in July 2009 in the Embo Journal. This new perspective could be useful to explain what happens in stem cells that can be submitted to several stimuli to differentiation or replication and loss the ability of self renewal. Otherwise in cancer epidemiology it could be useful to identify the factors above to better explain cancer susceptibility linked to telomere and telomerase activity.