Deeper and Deeper into the Murky Abyss

The headline in News & Nature.com gives the reader a sense of the seriousness of the situation. "Stem-cell scientist asks for retraction: US partner urges Korean cloner to retract landmark paper."

Seemingly, the situation with Woo Suk Hwang grows messier and more tangled by the hour. For those who have not followed the mercurial fortunes of a man said to have become a national hero in South Korea, Hwang achieved instant international stardom for allegedly extracting stem cells from cloned human embryos.

His troubles are two-fold: the ethically dubious source of the eggs used in the cloning experiments, and the results themselves, which are under fire.

According to the New York Times's Nicolas Wade, "In February 2004 Dr. Hwang reported in Science online that he had established a line of human embryonic stem cells by transferring the nucleus of adult cells to a human egg whose own nucleus had been removed. In June 2005 he said he had done the same procedure with 11 patients, using far fewer human eggs." Wade added, "The report was hailed as the first step toward the goal of treating people with their own tissues, generated through embryonic cells."

Hwang had already confessed to ethical lapses in procuring the eggs. The latest turn of events challenges the work itself.

SOURCE OF EGGS

In 2004, Hwang was asked by the British science journal Nature whether two of his junior researchers donated their eggs as part of the cloning experiment. At the time Hwang told Nature that the report was false, even though--as he admitted at the press conference announcing his resignation from the World Stem Cell Hub--Hwang had asked the women if it was true, and they confirmed it. Until his November 24 resignation he continued to assert that the eggs were not improperly donated.

"I am very sorry that I have to tell the public words that are too shameful and horrible," Hwang said, according to the AP. "The responsibility for all disputes and controversy lies on me. I will not make any excuse."

In addition, Hwang's colleague Roh Sung-il of MizMedi Women's Hospital in Seoul admitted November 21 that he paid more than 20 women about $1,500 for their eggs, which were also used in Hwang's research. Roh said that Hwang was unaware of the payments.

"I made the decision on my own without the knowledge of Hwang," Roh told Korea Times. "He would get to know things only after announcing cloned human stem cells in early 2004."

Neither using employees' eggs nor paying for them was illegal under South Korean law until January 2005. However, international standards for research strongly warn against both practices, since they could lead to coercion.

It has gone from bad to worse for Hwang, a veterinary researcher at Seoul National University. University of Pittsburgh biologist and senior author Gerald Schatten asked his former collaborator to remove his name from a paper that he co-authored with Hwang which was published last May in Science.

"My careful re-evaluations of published figures and tables, along with new problematic information, now casts substantial doubts about the paper's accuracy," Schatten said in a December 12 letter sent to Science and his fellow authors, and released by the University of Pittsburgh,

"Over the weekend, I received allegations from someone involved with the experiments that certain elements of the report may be fabricated," Schatten wrote. No one was named, but according to Wade, "Korean press accounts have quoted Kim Sun Jong, a member of Dr. Hwang's laboratory who now works at the University of Pittsburgh, as saying in an interview with MBC-TV in South Korea on the program "PD Diary" that he was told by Dr. Hwang to make 11 or so cell lines out of the two or three he had in his possession."

Schatten, who is director of the Pittsburgh Development Center, added in his letter, "I request retraction of my co-authorship on Hwang et al. (2005) and have recommended to first author Dr. Woo-Suk Hwang and all other co-authors that the report should now be retracted." [Schatten previously sent a correction to Science, "saying that his only role in the paper had been to analyze data and prepare the paper for publication," according to Wade.]

For its part Science said in an editorial statement issued December 13, "No single author, having declared at the time of submission his full and complete confidence in the contents of the paper, can retract his name unilaterally, after publication, and while inquiries are still underway by the Korean authors." In other words it said it had no mechanism to satisfy Schatten's request.

That same day Science published a letter on its website from a number of scientists prominent in cloning technology. The eight included Ian Wilmut of the University of Edinburgh, who cloned "Dolly" the sheep.

The letter asked Hwang "to resolve the matter by cooperating with independent investigators to confirm the results of the DNA tests," according to Reuters. (Wilmut submitted DNA from Dolly to be independently tested, according to Reuters.)

"Accusations made in the press about the validity of the experiments published in South Korea are, in our opinion, best resolved within the scientific community," the scientists wrote.

Wade did an excellent job outlining the chain of events that culminated with Schatten's letter. He wrote, "[T]he paper has come under increasing criticism from Korean scientists. Their accusations, posted anonymously on Korean Web sites, first showed that some of the photographs of the 11 cell colonies were duplicates. Science acknowledged that the accusation was correct but said the duplication occurred when originals were replaced with photographs of higher resolution.

"The critics then showed that several of the photographs overlapped, even though they were supposed to be of different cell colonies," Wade wrote. "Indeed, they said it seemed that as few as two cell colonies had been used to generate photographs.

"The critics also noticed a strange feature in the DNA fingerprints taken of the cell colonies and the donors from whom they were supposedly derived. In several cases the pairs of fingerprints seemed to be identical, lacking any of the subtle differences expected in two independent tests.  "If this were true, critics say, the paper would not have any evidence that the cell colonies came from the donors or that Dr. Hwang ever performed any successful nuclear transfer experiments."

One scientist told Wade that should the article turn out to be "fabricated," it would "give a black eye to science in general."