SEOUL — South Korean scientist Hwang Woo Suk, who rose to international prominence for his breakthrough research creating the first embryonic stem cells tailored to individual patients, was accused by collaborators Thursday of fabricating results in his landmark study.
Dr. Roh Sung Il, the chairman of Seoul's MizMedi Hospital, told South Korea's KBS television that Hwang had admitted to him that some of the published research was faked.
Hwang responded today by insisting that his results were real. However, the beleaguered researcher told a packed auditorium that the stem cells described in his study were no longer available because they had been contaminated and died.
He apologized to the nation and his fellow researchers for the controversy surrounding his work and pledged to authenticate his results by creating new stem cells lines within two weeks.
In the meantime, Hwang said, he asked the journal Science, which published his research in May, to retract his 11-page study because it was so tarnished.
But Hwang's statements seemed to ensure that the uncertainty would continue.
"If it's true, it's going to go down as probably the biggest scandal in science," said Insoo Hyun, a bioethicist at Case Western Reserve University in Cleveland, who spent this summer in Hwang's lab.
The accusations may be a setback for those who had hoped Hwang's work would lead to cures for patients suffering from spinal cord injuries, strokes and such diseases as Alzheimer's, Parkinson's and diabetes.
It is also considered an embarrassment to South Korea, where Hwang is regarded as a national hero for propelling the country to the forefront of stem cell research.
Hwang's paper purported to show the creation of 11 human embryo clones using DNA from injured or sick patients.
According to the paper, the embryos were used to create individualized stem cell lines -- an achievement that offered the possibility of creating personalized stem cell therapies for anyone.
Scientists around the world flocked to Hwang's laboratory at Seoul National University.
The South Korean government agreed to bankroll his research to the tune of millions of dollars, and thousands of women volunteered to contribute to Hwang's research by donating their eggs.
But on Thursday night, Lee Wang Jae, the university's associate dean for research affairs, told the South Korean media that nine of the 11 cell lines did not exist and that the validity of the other two was in doubt.
"We can declare today a day of national infamy," Lee said, according to the Korea Times.
Hwang has been hospitalized for stress over much of the last week. He returned to his laboratory this morning to meet with colleagues before defending his work to the public.
"There have been serious mistakes, but what is for sure is that our research team has produced a stem cell," he said at the news conference, projecting confidence that his name would be cleared.
Some people in the auditorium had tears in their eyes as Hwang spoke. Supporters in wheelchairs listened outside the door.
Hwang, 53, rose to prominence in February 2004, when he published a paper describing the creation of the first cloned human embryo.
The delicate procedure involves squeezing the genetic material out of a human egg and replacing it with DNA from an adult cell.
Then the egg is treated with a chemical and bathed in nutrients to encourage it to divide as if it were fertilized naturally. After several days, the embryo is destroyed to harvest stem cells, which are prized for their ability to become any type of cell in the body.
That achievement paved the way for the study in May, which appeared to show that it was possible to clone embryos from patients who suffered from ailments that potentially could be treated with stem cell therapies.
None of the work has been replicated by other researchers, though many have been trying.
Hwang previously attributed his success to the Korean custom of using metal chopsticks, which fosters the manual dexterity needed to carry out the delicate experiments. Hwang is also well-known for rising at 5 a.m. and keeping his lab running seven days a week.
In another scientific coup, his research team in August unveiled the first cloned dog, a frisky Afghan hound puppy. The animal -- named Snuppy, for Seoul National University puppy -- was featured last month on the cover of Time Magazine as the 2005 Invention of the Year.
None of the current criticism involves Hwang's dog-cloning work.
Accusations of misconduct first surfaced last month, when Hwang's American collaborator, University of Pittsburgh biomedical researcher Gerald Schatten, raised ethics questions about the procurement of eggs used in the initial research.
Hwang later acknowledged that one of his associates paid women $1,400 each to provide eggs and that other eggs were donated by women who worked in his lab. Though the actions weren't illegal, they go against international norms of ethics.