The study, funded by Cancer Research UK and Wellcome Trust and published in Science on [11 February], found that, when epithelial cells are damaged, the damage activates a molecular program that turns cells into migratory leader cells so that the breach can be repaired quickly. The same molecular program also makes sure that these highly migratory cells are removed when the breach is closed, so that the tissue restores its normal epithelial tissue structure. 

Using a simplified model of a wound, epithelial sheets that were scratched in vitro to injure the epithelial monolayer, the researchers identified the molecular signal that makes leader cells emerge. 

The study found that, following injury, cells at the border of the epithelial gap elevate p53 and p21, suggesting that the injury triggers the migratory program.  Once the breach was repaired, leader cells were eliminated from the population by their healthy epithelial neighbours. The cells damaged by the wound were able to cause wound closure, but are then sacrificed to maintain a functional tissue with normal epithelial morphology. 

Read the full University of Bristol press release

Paper: p53 directs leader cell behavior, migration and clearance during epithelial repair by Kasia Kozyrska, Giulia Pilia, Eugenia Piddini et al. in Science