Cellular Senescence, Telomerase, and Cancer in Human Cells

Alternative telomere maintenance mechanism in Alligator sinensis provides insights into aging evolution

“…Similar results were also reported in Mus musculus and humans; whereas the telomere shortening rate was 100-fold higher in M. musculus than in humans, 20 , 22 no expression of TERT could be detected in the adult stage of the latter. 23 , 28 , 29 Telomerase is active during early human development, but transcriptional silencing occurs between 12 and 18 weeks of gestation. 30 , 31 ATM could play an essential role in long-living species and was found to experience positive selection in A. sinensis and many long-living taxa (longevity > 61 years).…”

“… 25 , 26 , 27 In the somatic cells of adult mice, telomerase activity is often high, whereas corresponding TERT expression levels are absent in somatic cells of humans. 28 , 29 , 30 , 31 TERT expression appears to be inactivated in long-living species such as humans with slow telomere shortening. 30 , 31 In contrast, active telomerase is associated with fast telomere shortening in mice.…”