SEATTLE, WA--New research published by Science Magazine within the Science Express Web site and released today at the 2004 AAAS Annual Meeting -- may be a first step toward methods for treating diabetes, osteoarthritis, Parkinson's and other diseases, by producing replacement cells unlikely to trigger immune-system rejection.

Transplantation medicine based on stem cells remains a distant hope for now, Science editors cautioned. But, the Science study describes intriguing early results:

For the first time, researchers have reported the development of versatile "pluripotent" human embryonic stem cells, potentially capable of becoming any cell in the body, from a cloned human blastocyst. The stem cells were harvested from a blastocyst produced by transferring the nucleus of a non-reproductive ("somatic") cell, containing a woman's genetic blueprint, into a nucleus-free egg from the same donor.

Following this transfer, factors within the host egg's exterior, or cytoplasm, reprogrammed its new nuclear contents by activating versatile embryonic genes, while silencing the more limited adult somatic cell genes. Researchers were then able to collect embryonic stem cells from the resulting cell mass inside the cloned blastocysts.

In theory: "Because these cells carry the nuclear genome of the individual, after differentiation they could be expected to be transplanted without immune rejection for treatment of degenerative disorders," reported Woo Suk Hwang of Seoul National University in Korea. "Our approach opens the door for the use of these specially developed cells in transplantation medicine."

Embryonic stem cells have previously been produced with cells from mice using the same method, called "somatic cell nuclear transfer." But, achieving this trick with human cells posed unique challenges, said Donald Kennedy, Science's Ed
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Contact: Ginger Pinholster
gpinhols@aaas.org
206-774-6330
American Association for the Advancement of Science
11-Feb-2004