Absent gene heals mice without scarring
Mice lacking the p21 gene can be healed scar free, a study has shown.
Scientists believe gene p21, known to protect against cancer, plays a key role in the regeneration of damaged tissues. They have now shown that switching the gene off allows adult cells in mice to turn into stem cells which assist the healing process.
Researchers studied mice without the p21 gene and found they were able to regenerate tissue which had been removed from the ear. Within a few weeks the ears had re-grown healthy tissue, fully healing the damage with no signs of scarring.
It is thought that most mammals lost the ability to regenerate limbs and organs as a result of evolution. The newt and flatworm are among the few species left that can grow limbs or demonstrate a similar regenerative action after damage. The study on mice has proven that the ability to heal scar-free may still lie dormant in mammals, and scientists suggest that switching off p21 may reactivate the healing pathway.
The problem with switching p21 off is that, when active, it protects against cancer by halting the division of cells with damaged DNA. Despite this anti-cancer role, researchers found mice reverted to a fallback pathway when p21 was not present. This means that it could be possible to exploit the regenerative potential of p21 without encouraging tumour growth as a result.