New telomere discovery could help explain why cancer cells never sto...( Lausanne Switzerland October 4 2007 ...),Health

Lausanne, Switzerland, October 4, 2007 A group working at the Swiss Institute for Experimental Cancer Research (ISREC) in collaboration with the University of Pavia has discovered that telomeres, the repeated DNA-protein complexes at the end of chromosomes that progressively shorten every time a cell divides, also contain RNA. This discovery, published online October 4 in Science Express, calls into question our understanding of how telomeres function, and may provide a new avenue of attack for stopping telomere renewal in cancer cells.

Inside the cell nucleus, all our genetic information is located on twisted, double stranded molecules of DNA which are packaged into chromosomes. At the end of these chromosomes are telomeres, zones of repeated chains of DNA that are often compared to the plastic tips on shoelaces because they prevent chromosomes from fraying, and thus genetic information from getting scrambled when cells divide. The telomere is like a cellular clock, because every time a cell divides, the telomere shortens. After a cell has grown and divided a few dozen times, the telomeres turn on an alarm system that prevents further division. If this clock doesnt function right, cells either end up with damaged chromosomes or they become immortal and continue dividing endlessly either way its bad news and leads to cancer or disease. Understanding how telomeres function, and how this function can potentially be manipulated, is thus extremely important.

The DNA in the chromosome acts like a sort of instruction manual for the cell. Genetic information is transcribed into segments of RNA that then go out into the cell and carry out a variety of tasks such as making proteins, catalyzing chemical reactions, or fulfilling structural roles. It was thought that telomeres were silent that their DNA was not transcribed into strands of RNA. The researchers have turned this theory on its head by discovering telomeric RNA and showing that this RNA
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