Growing Old Gracefully

While immortality is considered to be the reserve of gods and superheroes, it is also a property of cancer cells. Normal healthy cells, however, can only copy themselves about fifty times. Biologists describe cells that have reached the end of their ability to divide as senescent. The cell nucleus pictured comes from a recently senescent human skin cell. Its DNA is coiled around structural proteins like rope around a capstan. Regions managing active processes (shown in blue) are loosely coiled and ‘open for business’. In contrast DNA in the green sections is tightly wound and inoperative. As the cell reaches the end of its life, DNA directing cell division (highlighted in red) also starts to coil tightly causing all business to stop as the cell approaches senescence. Understanding this process could also help scientists to steer cancer cells to an early end.

Written by Julie Webb

Julie Webb

Writer

Julie began her career as a researcher in genetics. In 2000 she won a Wellcome Trust award for her work on a collaborative science drama, staged at the Edinburgh Festival. She now works as a freelance science writer and communicator.

• Masashi Narita
• Cancer Research UK Cambridge Research Institute, UK
• Copyright Elsevier 2012
• Published in Molecular Cell 47(2): 203-214