Karen Weintraub

Special for USA TODAY

Stem cells can turn into virtually any cell in the body

New research upends dogma that once a cell matures%2C it can never go back to a less mature state

Advance is a first step%3B many questions remain unresolved

The future of medicine got a giant step closer Wednesday with the publication of new research showing what may be a much easier way to turn regular cells into flexible stem cells, without destroying embryos.

Stem cells have long been looked at as the future of medical care, offering the possibility of mending a damaged heart, replacing brain cells lost to Alzheimer's or repairing the spinal cord of someone who's been paralyzed. But that potential has been limited — first by the controversial need to destroy embryos for the research, and more recently by the expensive and cumbersome techniques used to make stem cells without embryos.

In two papers published Wednesday in the journal Nature, researchers from Japan and Harvard showed they could make stem cells cheaply and easily, simply by damaging mature cells with acid.

"If this pans out, that means (for) almost any person who has a medical problem, researchers could easily make stem cells from that person's skin or blood, and those cells could be a really powerful therapy," said Paul Knoepfler, a stem cell biologist and associate professor at the University of California-Davis, who was not involved in the work.

In theory, a doctor could, say, scrape some cells off the arm of a heart attack patient and turn the cells into stem cells, which could then become healthy heart cells. Eventually the healthy heart cells could be implanted into the heart where they could take over for the damaged ones.

To date, the benefits of stem cells are mostly theoretical. Bone marrow transplants are the primary use of stem cells in therapy today, although clinical trials are underway for other uses.

The new research also suggests that the body has a previously unrecognized ability to heal itself, and upends our understanding of biology by suggesting that adult cells may be able to revert to stem cells after they've been damaged, said Charles Vacanti, the Harvard Medical School stem cell and tissue engineering biologist who led the new research.

Researchers might someday be able to capitalize on this healing ability to create effective treatments and even battle cancer, said Vacanti, also of Brigham and Women's Hospital in Boston.

In the new research, Vacanti and colleagues produced cells they call STAP cells (for stimulus-triggered acquisition of pluripotency) by putting mouse white blood cells under various stressors, such as a low-pH, acidic solution. Vacanti said he has since made STAP cells from human skin cells.

Rudolf Jaenisch, a stem cell biologist at the Whitehead Institute at the Massachusetts Institute of Technology, said he found the team's results quite surprising and cautions that more research is needed before the potential of this new approach can be understood. "I think it's a first step," he said. "Quite a lot of questions were unresolved."

Other researchers not involved in the work said they have no reason to question the results, but science requires replication.

"This is Day One. We'll have to see how this goes," Knoepfler said.