Two research reports offer novel approaches to the age-old dream of regenerating the body from its own cells.
Animals like newts and zebra fish can regenerate limbs, fins, even part of the heart. But humans have very little regenerative capacity, probably because of an evolutionary trade-off: suppressing cell growth reduced the risk of cancer, enabling us to live longer. A person can renew his liver to some extent, and regrow a fingertip while very young, but not much more.
In the first of the two new approaches, a research group at Stanford University inactivated two genes that work to suppress tumors, and got mouse muscle cells to revert to a younger state, start dividing and help repair tissue.
What is true of mice is often true of humans, and although scientists are a long way from being able to cause limbs to regenerate, the research is attracting attention.
A second, quite different approach is reported in the journal Cell. Researchers have developed a way of reprogramming the ordinary tissue cells of the heart into heart muscle cells, the type that is irretrievably lost in a heart attack.
Here too researchers have a lot of work before they can make clinical use of the discovery.