Vitamin C Forum

In the adult human, the activity of telomerase is mostly restricted to the stem cells and is absent from the vast majority of human cells. In the absence of telomerase, telomere shortening limits cellular life span and prevents tumorigenesis. However, cells with too short telomeres can lose capping function leading to a cellular catastrophe and genetic instability: the origin of many cancer types. In this scenario, telomerase activity is protecting from tumor formation that can be initiated by these dysfunctional telomeres.