Friday, November 5, 2010

Harvard stem cell researcher retracts two papers

Stem cell researcher Amy Wagers from the Joslin Diabetes Center (JDC) at Harvard Medical School (HMS) has issued a retraction notice for a 2010 paper, as well as a statement of concern with the intent to review a second paper from 2008. Shane Mayack, a former postdoc in Wagers’ lab, was the first author on both papers and maintains the validity of the results.

In a notice published online 13 Oct. 2010 in Nature, Wagers and two other authors retracted their January 2010 paper “Systemic signals regulate ageing and rejuvenation of blood stem cell niches.” The paper claimed that the stem cell aging process may be reversible but the notice references “serious concerns” with the data that led to that hypothesis, prompting a retraction. In a statement, Wagers said that she immediately notifiedNature, JDC, and HMS upon reviewing the data and has begun working to repeat the experiments.

A point of concern for Wager is the appearance of very similar figures in both papers; Figure S3b (top) from the Nature paper and Figure 6c (bottom) from the Blood paper chart the frequency of blood stem cells but result from very different protocols. Source: Nature News.

A day later, Wagers published a notice of concern in Blood, stating that a 2008 paper that she coauthored with Mayack is also under review for possible misreported data. No further information has yet been published concerning the study, “Osteolineage niche cells initiate hematopoietic stem cell mobilization,” which features a figure that is similar to one published in the retracted Nature paper.

Although Mayack has not personally commented on the retractions, her lawyer issued a statement saying that although Mayack realizes the data presentation was improperly handled, she believes the underlying research remains conclusive. Accordingly, Mayack did not sign the retraction notice. Further examination is ongoing to determine if the conclusions presented in either paper are still viable

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