Telomeres and senescence: ending the debate.

Abstract

DNA, the genetic material, is arranged in chromosomes, linear structures in the nucleus capped with a long series of repeated sequences called telomeres. As de Lange describes in her commentary, in 1986 the telomere theory of senescence was put forward, in which progressive loss of bits of the telomere with each cell division serves as a sort of clock, with the cell reaching the end of its life as it runs out of telomere. The corollary--that tumor cells can maintain their telomeres at a young length and so escape death--suggested an attractive site for cancer therapeutics. But the theory had come under fire since its introduction and had fallen out of favor with much of the scientific community. Now in a research article in this issue, the telomeric theory of aging is dramatically resuscitated. [ Bodnar et al ][1]. transfect adult differentiated human cells with a critical subunit of telomerase and rescue them from senescent death. [1]: http://www.sciencemag.org/cgi/content/short/279/5349/349