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Stem-cell researcher guilty of falsifying data
14:27 07 October 2008
NewScientist.com news service

Peter Aldhous and Eugenie Samuel Reich
A former member of one of the highest-profile teams in stem-cell biology has been found guilty of falsifying results, after New Scientist questioned the findings.

Last year, the work of researchers led by Catherine Verfaillie of the University of Minnesota in Minneapolis became mired in controversy, after New Scientist pointed to irregularities in their published results.

Now an expert panel called in by the university to investigate has ruled that a PhD student on the team, Morayma Reyes, falsified data.

Verfaillie's group shot to prominence in 2002, after publishing a paper in Nature (vol 418, p 41) suggesting that a rare type of adult stem cell from bone marrow – first isolated by Reyes – could give rise to all of the body's tissues. Such astonishing versatility had previously been seen only in embryonic stem cells (ESCs).

The findings attracted huge scientific attention, and were seized upon as an ethical alternative to ESCs by self-styled "pro-life" activists – who oppose the destruction of human embryos to isolate stem cell lines. But over the years that followed, other researchers were unable to repeat the results.

The verdict of falsification relates to an earlier paper on the cells, published in the journal Blood (vol 98, p 2615) in 2001. Less well known than the Nature paper, the Blood paper is significant because it describes cells isolated from the bone marrow of humans rather than experimental mice.

Flipped images
Last year, New Scientist revealed that figures in that paper documenting the presence of proteins in the stem cells as they developed into cells, including those normally found in cartilage and bone, also appeared in US patent 7015037, where they were supposed to describe different experiments.

In the most disturbing case, the same image, flipped through 180° and slightly altered, was used twice in the Blood paper to represent the results of two different experiments.

An expert panel of three scientists has now concluded that the problems ran deeper still.

According to a summary of the panel's findings released by the university, parts of four figures in the Blood paper were falsified by manipulating the original images. For another image, the panel was unable to find the raw data. The university has now asked for the paper to be retracted.

While deciding that figures in the patent were "seriously flawed", the panel said there was insufficient evidence of misconduct in their preparation.

'Inadequate supervision'
The panel also found duplicated figures in both the Blood paper and another publication in the Journal of Clinical Investigation (vol 109, p 337) , but ruled that these errors were not misconduct. The Journal of Clinical Investigation has been informed of the problems, but the university has not asked for the second paper to be withdrawn.

The problems with this paper were drawn to the panel's attention by Verfaillie herself, who is now at the Catholic University of Leuven in Belgium.

The panel cleared Verfaillie of misconduct along with the other authors of both papers. Still, Verfaillie is criticised heavily by the panel for inadequate training and oversight of Reyes.

"I have initiated a number of additional oversight measures designed to further enhance the integrity of research and scientific publications coming from my lab," says Verfaillie. "I am confident that these measures will avoid the recurrence of a similar problem in the future."

Reyes' punishment is unknown, as the university is not allowed by Minnesota law to reveal disciplinary action against a former student. She is now at the University of Washington in Seattle, which may also review the matter. "We would have to gather all the relevant information and look at our policies," says spokesman Norm Arkans.

Reyes disputes the finding that she misrepresented data. "These were honest errors in part due to inexperience, poor training and lack of clear standards about digital image handling and proper presentation," she told New Scientist.

Earlier inquiry
The finding against Reyes follows an earlier inquiry into the Nature paper and another publication in Experimental Hematology (vol 30, p 896) – again triggered by questions raised by New Scientist.

In that case, six plots prepared by another junior member of the team were duplicated between the two papers. An earlier panel concluded that there was no evidence of deliberate misconduct, but pointed out that the experiments were flawed, because the controls were not carried out correctly.

The problems surrounding the Minnesota team's work followed news of fraud in research on cloned human ESCs by South Korea's Woo Suk Hwang. Biologists contacted by New Scientist worry that the intense competition in stem-cell biology may tempt others into misrepresenting data.

"My concern is that this sort of thing will happen again," says Arnold Kriegstein, who heads the Institute for Regeneration Medicine at the University of California, San Francisco.

Today, most of the excitement surrounds the ability to "reprogram" adult cells back to an ESC-like state. Unlike the Minnesota team's work, this process has been repeated by several groups. But some biologists worry that problems may emerge as other scientists jump onto the bandwagon.

"When a topic is of great interest – not just to scientists but also to the public – it's certainly more likely that someone will get ahead of themselves and not be as scrupulous as scientists have to be," says Jeanne Loring, a stem-cell biologist at the Scripps Research Institute in La Jolla, California.

Stem Cells - Learn more about the promise and the controversy in our cutting edge special report .

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http://www.newscientist.com/article....mg19426084.700
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http://www.newscientist.com/article....mg19325973.600
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http://www.newscientist.com/article....mg19325964.600
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Weblinks
Morayma Reyes (now at University of Washington)
http://www.med.umn.edu/mdphd/alumni/...gradReyes.html
Catherine Verfaillie, University of Minnesota
http://www.stemcell.umn.edu/stemcell...llie/home.html
University of Minnesota Stem Cell Institute
http://www.stemcell.umn.edu/