Korean scientist defends work

Researcher says he will duplicate stem cell studies to prove they're legitimate


A prominent South Korean scientist accused of falsifying breakthroughs in stem cell research stood by his conclusions yesterday but asked a scientific journal to retract the paper on his findings because of technical errors.

Hwang Woo Suck, lead author of an article in the journal Science reporting that his team had created stem cells from 11 patients through cloning, said at a news conference yesterday that he would duplicate the results to prove that the process works.

Though he denied allegations that most of the cells didn't exist, he asked for the retraction because the same photographs were used in some cases to represent different patient stem cells. He also acknowledged problems with DNA fingerprints used to match cloned cells with specific patients.

"What I can say clearly is that we have produced patient-specific stem cells, and we have the technology to do so," Hwang said.

He was responding to allegations by co-author Sung Il Roh, an administrator at MizMedi Hospital where some of the research was done, that at least nine of the 11 stem cell lines did not exist.

In the paper, researchers reported that they injected a volunteer's nuclear DNA - his genetic data - into donated eggs from which the original DNA had been removed. The resulting cells behaved much like embryos, producing stem cells that could be harvested and used for treatments. Embryonic stem cells are the master cells that generate all specialized tissues in the human body.

Hwang said that six of the original 11 stem cell lines died because of contamination, while five others were viable and stored in a freezer. In the next 10 days, they will be thawed and used to validate his results, he said.

But Roh later told reporters that Hwang acknowledged to him this week that all of the stem cell lines had died in the lab.

In the United States, Pittsburgh researcher Gerald Schatten asked Monday that Science remove him as the senior author of the report, questioning its accuracy.

Investigations are under way at Seoul National University, where the research was conducted, and at the University of Pittsburgh, where Schatten is based.

Editors at Science said they could not explain how the errors slipped through the internal peer review process, which is designed to ensure the quality of the research the journal reports.

"I just have no explanation other than it was an easy thing to miss," said Dr. Donald Kennedy, the journal's editor in chief.

The publication's policy is to print retractions only if all of the authors listed on a paper agree to it. There were 25 listed on the stem cell article, and Hwang is contacting them to ask their permission for a retraction, Kennedy said.

Science will issue a retraction if the authors agree. Otherwise, the editors might print an article addressing the issue.

As with all scientific papers, the findings were reviewed by outside experts before publication. Kennedy also said that there was nothing wrong with the two-month review and that there is no need to alter the review process.

Reviewers' identities are never disclosed, according to Science.

Some scientists said peer review is generally incapable of detecting fraud. "If you read a paper, you do not go there with the eye of a criminal investigator," said Rudolph Jaenisch, a stem cell researcher at the Whitehead Institute for Biomedical Research in Cambridge, Mass. "We don't do that because of the honesty and trust you have in science."

Instead, reviewers make sure that investigators followed proper scientific methods and that the conclusions are supported by data. They also scrutinize the use of statistics.

Stem cell scientists acknowledged yesterday that a scandal could set back the research, or at least its image. But they defended the process used to vet scientific publications.

"We're trying to advance the field, and we didn't need this," said Michael West, a stem cell researcher who is president and chief scientific officer of Advanced Cell Technology.

Of requiring a scientist reviewing a paper to visit researchers' labs and check their findings before publication, West said: "Thousands of papers are published every year, and allowing access to labs and finding someone willing to take all those steps, it's just an impractical thing to add on."

Dr. John D. Gearhart, a stem cell biologist at the Johns Hopkins School of Medicine, said outside reviewers see only the data that's before them.

"You don't vet their lab notebooks," he said. "You're not in the lab. You don't have access to the raw data."



The Associated Press contributed to this article.

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