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  1. 'The phenomenon Hayflick observed is known as replicative senescence [senesce = shit gets old and dies]. The truly intriguing thing about the process is that it has survived more than a billion years of evolution; it works in yeast in exactly the same wasy as it does in some human cells. Remove some of your fibroblast cells, for example, which are involved in creating the scaffolds on which new tissues grow, and you can culture them in a Petri Dish Then, suddenly, they just stop dividing and die.
  2. Why should this be? It seems to be associated with damage to the DNA packed into the chromsomes of the cell nucleus. The counting mechanism, the ticking clock for senescence in our cells, is the telomere, a string of repetitive DNA sequences that cap the end of every chromosome. Telomeres stop the chromosomes from sticking together, but when the cell divides, the telomeres are not fully reproduced and become shorter on each division. Eventually, cells with enough depleted telomeres die. No one knows for sure how this mechanism progresses, but it has become central to the fight against cancer.
  3. The tantalizing thing is, we know how to stop cells from dying. Cancer cells contain an enzyme called telomerase that restores the telomeres to their full length on each division. It is this that enables them to go into the runaway replication that causes tumors to grow so fast. We could avoid the shortening if our cells produce telomerase. and they can.
  4. In early 1998 a group of researchers led by Andrea Bodnar of the Geron Corporation in Menlo Park, California, announced they had put a gene that activates telomerase into normal human cells, and the cells HAD LIVED TWICE AS LONG AS UNTREATED CELLS - AND THEY WERE STILL GOING STRONG AT THE TIME OF PUBLICATION IN SCIENCE (magazine). The cells looked good; they had the characteristics of young cells. The activated telomeres meant they had avoided the curse of replicate senescence. They were, to all intents and purposes, immortal.
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  6. - "13 things that don't make sense. The most Baffling scientific mysteries of our time." page 128, Michael Brooks
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