Lop off a newt’s leg or tail, and it will grow a new one. The creature’s cells can regenerate thanks to built-in time machines that revert cells to early versions of themselves in a process called dedifferentiation.
Researchers who study this mechanism hope one day to learn how to induce the same “cell time travel” in humans. If the cells go back far enough, they become stem cells, which researchers believe hold promise for treating many diseases. Stem cells, which are often taken from embryos, are unformed and have the ability to become many different types of cells. If researchers succeed in inducing this cell time travel, they will also eliminate the ethical issues surrounding embryonic stem-cell research, because no embryos would be destroyed to obtain the cells.
The research is in its infancy, but a 2001 discovery jump-started the field of study. Mark Keating, Christopher McGann and Shannon Odelberg applied a protein extract derived from newts to mouse muscle cells. To their surprise, the protein extract transformed those muscle cells into stem cells in just 48 hours, which means the mouse cells would have the ability to regenerate.
No one expected the experiment to work. Previously, scientists believed that once mammalian cells became muscle, bone or any other type of cells, that was their fate for life — and if those cells were injured, they didn’t regenerate, but grew scar tissue.
But Keating’s experiment introduced the possibility that, under the right circumstances, humans — who are 99 percent genetically similar to mice — might one day be able to regenerate their own cells. Those regenerated cells could be used to treat disease.
“For those of us who want to understand what happens in dedifferentiation, our ultimate goal is to be able to form a pool of stem-cell-like cells that would be able to repopulate the organ or tissue you’re trying to repair,” said Catherine Tsilfidis, a scientist at the Ottawa Health Research Institute who has reproduced Keating’s findings, which she describes as “beautiful.”
