Scientists trick cells into switching identities

November 29, 2010 By MALCOLM RITTER , AP Science Writer
Graphic explains new method of changing one type of human cell into another




The concept is two steps beyond the familiar story of , versatile entities that can be coaxed to become cells of all types, like brain and blood. Scientists are learning to guide those transformations, which someday may provide transplant tissue for treating diseases like Parkinson's or diabetes.

It's still experimental. But at its root, it's really just harnessing and speeding up what happens in nature: a versatile but immature cell matures into a more specialized one.

The first step beyond that came in 2007, when researchers reversed the process. They got skin cells to revert to a state resembling embryonic . That opened the door to a two-part strategy: turn skin cells from a patient back into stem cells, and then run the clock forward again to get whatever specialized cell you want.



And there's no satisfactory way yet to make mature insulin-producing cells of the pancreas, which might be useful for treating , says George Daley of Children's Hospital Boston and the Harvard Stem Cell Institute.



But far more dramatic changes have been reported in the past year in lab dishes, with scientists converting mouse skin cells into nerve cells and . And just this month came success with human cells, turning into early stage blood cells.

The secret to these transformations is the fact that all cells of a person's body carry the same DNA code. But not all the genes are active at any one time. In fact, a cell's identity depends on its lineup of active genes. So, to convert a cell, scientists alter that combination by inserting chemical signals to activate particular genes.

"This is something that's really caught fire because it's an easy strategy to use," Gearhart said. "Everyone's out there trying their different combinations (of chemical signals) to see if they can succeed."

But success is not so easy. "There's a lot of experiments failing," Daley said. "A lot of people are just taking a trial-and-error approach, and that's fundamentally inefficient. And yet, it may create a breakthrough."





In any case, he and Daley said, scientists will still work with embryonic stem cells and the man-made versions first produced in 2007, called iPS cells. Those technologies clearly have places in various kinds of research, and it's not yet clear whether they or direct conversion will eventually prove best for manufacturing replacement cells for people.


Explore further: Study: Skin cells turned into stem cells


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5 / 5 (1) Nov 29, 2010
embryotic stem cell research would go much much faster, smoother, and ethically if the scientific community would spend more time and money promoting the donation of umbilical cords. no embryo's are harmed, and heck we just throw it away anyway.
not rated yet Dec 06, 2010
Whether or not it's ethical is completely irrelevant. It's an ethical MINEFIELD. Other sources are more reliable and faster (and probably cheaper!) because of this. I've heard that embryonic stem cells have even shown a distressing habit of turning into cancer cells and others do not. Finally, other types already match someone they'll have to be tested against and embryonic ones match nobody. Really, it seems to be a no-brainer to me.


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