The development, published online by the journal Science, takes doctors an important step closer to creating custom stem-cell treatments for everything from Alzheimer's disease to severed spinal cords.
Hwang's methods are controversial, howeverparticularly in the U.S.and the White House immediately criticized the experiment. The process is called somatic cell nuclear transfer (SCNT), but most people know it colloquially as therapeutic cloning. "I am very concerned about cloning," President Bush said in response to the news. "I worry about a world in which cloning becomes accepted." If Congress manages to pass a bill it is considering that would lift some of the restrictions on stem-cell research in the U.S., the President promised to veto it.
Scientists, for their part, were singing a different tune. "It's a tremendous advance," says Paul Berg, a Nobel laureate from Stanford University and a major backer of California's independent stem-cell initiative. "The Koreans' work is incredibly impressive," says Stephen Minger, director of the stem-cell biology laboratory at King's College, London. "It is fantastica major, major breakthrough."
The crux of that breakthrough is this: each of the newly created stem-cell lines is genetically identical to one of Hwang's patients.
That means any new tissue derived from that patient's cell line can be injected into that individual without triggering an immune reaction. If researchers can figure out how to fix the original defect, they may someday be able to generate replacement tissue that is custom designed to treat the patient's condition. Or at least that's the dream. No one knows yet whether those stem cells can be safely used in people.