3 Harvard Researchers Retract a Claim on the Aging of Stem Cells

3 Harvard Researchers Retract a Claim on the Aging of Stem Cells
By NICHOLAS WADE
Copyright by The New York Times
Published: October 14, 2010
http://www.nytimes.com/2010/10/15/science/15retract.html?hpw



Harvard researchers have retracted a far-reaching claim they made in January that the aging of stem cells might be reversible.

The retraction was published in Thursday’s issue of Nature and is signed by the senior author, Amy J. Wagers, and two others. They say that serious concerns, which they did not specify, have undermined their confidence in the original report.

A fourth author, Shane R. Mayack, maintained that the results were still valid and refused to sign the retraction. All four scientists are affiliated with Harvard University and the Joslin Diabetes Center, a Harvard affiliate.

The original article, published by Nature in January, asserted that there was a rejuvenating factor in the blood of young mice that could reverse symptoms of aging in the blood-forming stem cells of elderly mice. The therapeutic use of such a factor would be “to extend the youthful function of the aging blood system,” Dr. Wagers and her colleagues wrote.

The article states that Dr. Wagers designed and interpreted the experiments and that Dr. Mayack, a post-doctoral student, performed and analyzed them.

Dr. Wagers issued a statement saying that she had immediately brought the disturbing information to the attention of Nature and the Harvard Medical School, and that she was working to repeat the experiments. She said by e-mail that the information came to light in the course of studies in her laboratory, prompting her to re-examine the reported data.

Press officers at Harvard Medical School, Joslin and the Harvard Stem Cell Institute said the matter was being reviewed but declined to comment further. Rachel Twinn, a Nature press officer, said she could not comment.

Dr. Wagers has expressed her doubts about a second paper co-authored with Dr. Mayack and published in the journal Blood in August 2008. In a statement issued today, the journal said it was posting a “Notice of Concern” about the paper pending further review.

The two retracted papers follow the withdrawal of two other stem cell papers noted by the blog Retraction Watch, which began only in August.

The blog has recorded other high-profile retractions in its short lifetime. Linda Buck, a Nobel winner, retracted two papers, and Savio Wu, an expert in gene therapy, retracted four papers while firing two post-doctoral students from his laboratory.

“We wondered if we’d have enough material,” said Adam Marcus, one of the two authors of Retraction Watch. Both of them are medical journalists.

His co-author, Ivan Oransky, said many of the retractions involved post-doctoral students who produced unreliable data. It is not clear whether the competitive nature of science puts pressure on the students to cut corners, or whether the laboratory chief creates an atmosphere that induces cheating, Dr. Oransky said.

Over all, the retractions are “a sign that things are going well,” Dr. Oransky said, meaning that science is cleansing itself of error.