Scientists have moved a step closer to the goal of creating stem cells perfectly matched to a patient's DNA in order to treat diseases, they announced on Thursday, creating patient-specific cell lines out of the skin cells of two adult men.
The advance, described online in the journal Cell Stem Cell, is the first time researchers have achieved "therapeutic cloning" of adults. Technically called somatic-cell nuclear transfer, therapeutic cloning means producing embryonic cells genetically identical to a donor, usually for the purpose of using those cells to treat disease.
But nuclear transfer is also the first step in reproductive cloning, or producing a genetic duplicate of someone - a technique that has sparked controversy since the 1997 announcement that it was used to create Dolly, the clone of a ewe. In 2005, the United Nations called on countries to ban it, and the United States prohibits the use of federal funds for either reproductive or therapeutic cloning.
The new study was funded by a foundation and the South Korean government.