送交者: 注册笔 于 2005-12-15, 17:48:55:
SEOUL AND TOKYO--Embattled Korean stem cell scientist Woo Suk Hwang and his university have bowed to pressure for an investigation into a growing list of questions about a landmark paper he and colleagues published in Science in June 2005 (17 June, p. 1777). On 12 December, Seoul National University (SNU), where Hwang works, announced it will conduct an investigation at the scientist's request. This follows a 7 December petition for an investigation from 30 SNU faculty members to university president Un Chan Chung. Prompted initially by anonymous allegations made on a public Web site about irregularities in the paper, scientists in Korea and elsewhere are calling for the paper's key DNA fingerprinting tests to be redone by an independent researcher.
(As Science went to press, one of Hwang's co-authors, Gerald Schatten of the University of Pittsburgh in Pennsylvania, asked Science to remove his name from the paper.)
Back to work. Cloning researcher Woo Suk Hwang returned to his lab on 12 December. He had been hospitalized for several days suffering from symptoms of stress and fatigue.
CREDIT: AHN YOUNG-JOON/AP PHOTO
Meanwhile, stem cell researchers elsewhere are worried about the possible fallout. The lab's as-yet-unreplicated feat of creating human embryonic stem (ES) cell lines that match the DNA of patients inspired a global ramp-up in stem cell efforts. Such ES cell lines might one day provide replacement cells genetically matched to a patient suffering from Parkinson's disease or diabetes. Hwang's team not only showed that producing such ES cell lines was possible but also that it could be done efficiently, with relatively few donated oocytes per cell line. Alan Colman, head of Singapore-based ES Cell International and a member of the team that produced Dolly the sheep, the first cloned mammal, says, "I'd still like to believe this is a case of sloppy presentation but good science." If the results of the paper do not hold up, he says it could set the field back to a time when many thought the research "was too difficult and inefficient to pursue." It would also provide ammunition to opponents of the research, he says.
The latest revelations center on the DNA fingerprinting in the paper's supplementary online material first posted on 19 May 2005; the fingerprinting data purportedly show that the ES cells are genetically identical to the patients. There are also new allegations about another set of images in the online material that Hwang last week told editors at Science had been erroneously duplicated (Science, 9 December, p. 1595). All the scientific questions can apparently be traced to anonymous observations about the paper posted on an Internet message board hosted by the Biological Research Information Center (BRIC) (bric.postech.ac.kr). BRIC officials declined to comment, but a senior Korean scientist who has followed the postings agreed to discuss the issue provided he not be identified. (The Korean scientists contacted for this article requested anonymity because they fear a backlash against what are perceived to be attacks on Hwang, who has become a national icon. "This issue is now completely beyond the realm of science," one laments.)
The senior scientist says the message board writer, who claims to be a life science researcher, first pointed out the possibility of duplicated images early on 5 December Korea time. Hwang's e-mailed notice of problems with duplicate images arrived at Science's editorial offices on 4 December at 11:29 p.m. Eastern Standard Time, which would have been 1:29 p.m. on 5 December in Korea, or several hours after the images were posted on the message board.
On 7 December, a critique of the DNA fingerprinting results appeared on the BRIC site. DNA fingerprinting shows a genetic match between two samples when peaks in the traces line up. But because the height and shapes of peaks are influenced by random factors, they should not be identical. The anonymous poster pointed out that the traces for several cell lines appear to be identical to the traces from the respective patients. In other cases, the background noise on the two traces looks very similar.
Alec Jeffreys, a genetic fingerprinting expert at the University of Leicester, U.K., said in an e-mail that "some of the traces do look unusually similar in peak shape and background noise." He declined to comment further without seeing the original data.
The anonymous poster also notes that Hwang's admission of duplicated images does not include other images that appear to have been duplicated.
The postings have elicited a flurry of responses. The consensus, says the senior scientist following the BRIC postings, seems to be that if Korean scientists don't take the lead in reviewing the paper, "the integrity of the Korean scientific community might be questioned by the world community."
Two of the 30 SNU professors who signed the petition asking for an investigation told Science the group first learned of the questions surrounding the paper from the BRIC discussion. One of the two professors contacted by Science says that they are not trying to discredit Hwang. "Dr. Hwang is a pioneer researcher in the field, and his studies should be pursued. We just see a serious need for a review."
The investigation comes amid a flurry of claims and counterclaims in the Korean media. On 10 December, a Korean news Web site called Pressian reported that it had seen a transcript from an unaired documentary by the Korean Munhwa Broadcasting Corp. MBC pulled the documentary, prepared for a weekly TV show called PD Notebook, in response to public outcry over allegations that the investigative team had coerced its sources; MBC later apologized for the investigative team's transgressions. Pressian claimed that in an interview for the unaired segment, a member of Hwang's team alleged that Hwang had directed him to manipulate photographs of stem cells. The lab member had previously said that the interview was coerced. On 11 December, Hwang's team issued a statement dismissing the allegations.
In this charged atmosphere, SNU held a press conference on 12 December to announce its investigation. Jung Hye Roe, SNU's dean of research affairs, said SNU would form an investigative committee of experts from within and outside the university. They will not be publicly identified and will not respond to press inquiries. Roe said SNU may cooperate with the University of Pittsburgh, which started its own investigation at Schatten's request. One of the two SNU professors contacted by Science says the announcement of the investigation is welcome. But this professor added that because the details have not yet been set, "we need to keep an eye on how the investigation goes." On 9 December, Science Editor-in-Chief Donald Kennedy wrote to Hwang encouraging him to cooperate with efforts to verify his findings.
Colman thinks the only way to prove whether and how many of the ES cell lines match the donors is a new genetic analysis. "There is an absolute necessity now to have an independent investigator redo the fingerprinting," he says. But this could be problematic. Fresh samples might have to be taken from the donors, and that would entail again gaining informed consent. The university has not yet set any timeline for its investigation.