Harvard scientists have discovered that they can transform one cell directly into another without an intermediate stage as an embryonic stem cell. This news of this "feat of biological prestidigitation" was immediately lauded as an ethical way to achieve the cures touted by embryonic stem cell scientists. "One day, this may allow the doctor to replace the scalpel with a sort of genetic surgery," a leading embryonic stem cell scientist, Robert Lanza said excitedly. "If this can be perfected, it would represent one of the holy grails of medicine."

What the Harvard biologists did was to identify three crucial molecular switches which, when flipped, completely convert a common cell in a mouse pancreas into the more precious insulin-producing ones that diabetics need to survive. This raises the possibility that people suffering from diabetes, heart disease, strokes and other ailments could be cured without the need for drugs, transplants or other therapies.

"I see no moral problem in this basic technique," said Richard Doerflinger of the US Conference of Catholic Bishops, a leading American opponent of embryonic stem cell research. "This is a 'win-win' situation for medicine and ethics."

The experiments, which were reported in the journal Nature, were performed upon mice, but Douglas Melton, the lead researcher, is confident that the technique will work in humans as well.

The most remarkable feature of this latest advance in stem cell technology is that, if successful, it completely bypasses the need for embryonic stem cells. For several years, scientists have insisted that the way forward was the creation of clones from which they would derive embryonic stem cells. These would be nudged into becoming other cell types. Even last year’s advance by Japanese scientist Shinya Yamanaka involved reprogramming a skin cells so that they become embryonic-like stem cells. The Harvard technique may make either strategy unnecessary.

As is the case with all work thus far with reprogrammed cells, Melton's experiments involve using viruses to flip the switches. Because of the risks that approach would pose to humans, the team is looking for chemicals that might effectively and safely replace the viruses. Stay tuned for further developments. ~ Harvard Stem Cell Institute, Aug 27; Washington Post, Aug 28