Yet More on Aging, Stem Cells and Cancer
Chris Patil has been rolling out the good posts of late, here continuing the general theme of the week: stem cells, aging and cancer. "The rate of aging may be evolutionarily determined as a balancing act between maintenance of regenerative capacity and prevention of cancer ... The idea is that the same mechanisms that stop our cells from proliferating out of control might also prevent them from dividing in order to repair damage. Like all theories of aging, this one has its advocates (of which I am one) and its detractors (whom I'm certainly willing to hear out). ... On the 'pro' side is an article by Christian Beausejour, who's worked in the field of cellular senescence for quite some time. He reviews evidence that senescence, which evolved as a tumor suppressor function, may contribute to age-related decline in the hematopoetic stem cell (HSC) compartment. ... In the other corner we have a review from Aranda-Anzaldo and Dent, who propose that the evolutionary history of p53 makes it unlikely that it's even an important tumor suppressor gene in short-lived species like the mouse, much less an antagonistically pleiotropic gerontogene."