The world of stem-cell research was set reeling two years ago when its most successful practitioner, the South Korean scientist Hwang Woo-suk, was found to have fabricated much of his work. But according to a new post-mortem of his research, he did achieve a scientific first, though not the one he claimed.
Hwang said he had derived embryonic stem cells from the adult cells of a patient, but the claim was discredited after parts of his research were found to have been faked. A team of Boston scientists has re-examined stocks of Hwang's purported embryonic stem cells and arrived at another conclusion bound to make waves among research worldwide: Hwang's embryonic stem cells were the product of parthenogenesis, or virgin birth, meaning they were derived from an unfertilized egg.
A team led by Kitai Kim and George Daley of Children's Hospital Boston reported this conclusion yesterday in the journal Cell Stem Cell.
Embryonic stem cells derived through parthenogenesis cannot develop normally, so they are free of ethical objections. The cells could perhaps help treat degenerative diseases in women capable of supplying eggs, should effective treatments ever be developed.
Other researchers have since developed embryonic stem cells from parthenogenetic eggs, but Hwang's team would have been the first to do so if its members had recognized what they had done.
John Gearhart, a stem-cell expert at Johns Hopkins University who had a ringside view of the Hwang affair as a member of the journal Science's advisory board, said parthenogenesis had always been a possibility.
"I'm delighted there was an explanation that didn't involve fraud," Gearhart said.
Hwang soared to prominence after asserting in a report in Science in 2004 that he had developed embryonic stem cells from a patient, the first hurdle in the idea of rebuilding patients' tissues with their own cells.
He said he had removed the nucleus from an unfertilized human egg and inserted a new nucleus from the adult cell of the patient. The egg developed into an embryo, from which his team claimed to have developed embryonic stem cells.
The editors of Science, the journal that published his claim, later retracted the article because the South Korean committee that investigated Hwang's work found that the supporting data had been faked.
As to the source of Hwang's embryonic stem cells, the South Korean committee said parthenogenesis was possible. But this could not be proved with the methods then available.
Hwang seems unlikely to get much scientific credit for developing embryonic cells via parthenogenesis because he lied in his 2004 article.
"It becomes an historic irony that Hwang was the first to produce the parthenogenetic stem cell but didn't appreciate what he had," Daley said.