Researchers at the University of Montreal, Canada, have used novel microscopy techniques to visualize in living cells the behavior of the enzyme responsible for keeping cell replication in check, the enzyme telomerase. Telomerase snips the ends of the telomeres at the ends of DNA at each cell replication so that a cell can only replicate a limited number of times. In cancer this process goes awry allowing uncontrolled cell replication. Pascal Chartrand and colleagues have now homed in on precisely what happens when telomerase is active. They have now identified regulatory factors that restrain the activity of telomerase within a narrow time window when the cell is dividing. Such insights might ultimately allow medicinal chemists to target those factors or telomerase itself to block cancerous replication.
The cancer enzyme