Tuesday, May 06, 2008

Good News for Embryos

The end may be in sight for the debate over "harvesting" human embryos for their stem-cells in the pursuit of possible medical cures. Apparently adult stem cells--those cells gotten from human body tissues and not embryos--have the potential to be just as versatile for medical research as ESCs--but without the need to kill nascent human life. An article in Newsweek:

In June 2006, a Japanese group led by Shinya Yamanaka reported the first successful result with mouse skin cells, and between November 2007 and January 2008, Yamanaka's group and two American groups led by James Thomson and George Daley at Harvard University all reported the successful reprogramming of human skin cells into a state that is indistinguishable from human embryonic cells. Over the last several months, progress made along this new scientific path has been breathtaking. The laboratory of Rudolf Jaenisch at MIT has taken in the lead in developing therapies with this new technique in mice, demonstrating a cure for a mouse version of sickle cell anemia and alleviating the symptoms of Parkinson's disease in mice.

What these scientists can now do is essentially to take any type of cell and turn it into the equivalent of an embryonic stem cell—without needing embryos or egg cells. So what exactly are these new cells? Cells are fundamentally defined not by where they come from, but by their program of gene activity. In this sense, the new cells should be called embryonic stem cells. And since they are genetically identical to the person who provided the original sample, they are technically embryonic cell clones of that person. But scientists have discovered the power of words to elicit positive or negative emotional responses. "Clone" and "embryo" are words to be avoided. And so by consensus, the new cells are being called induced pluripotent stem cells.

Researchers say more work must be done on the promising technique.


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