Adult stem-cell study flawed, panel says

MINNEAPOLIS — Five years ago, a University of Minnesota study found that a type of adult stem cell in mice could have as much potential to treat disease as stem cells taken from embryos. The research made headlines around the world.

But the university and the lead scientist, Dr. Catherine Verfaillie, now acknowledge part of the study was flawed.

Her study had concluded adult stem cells taken from the bone marrow of mice could grow into an array of biological tissues, including brain, heart, lung and liver.

So far, only embryonic stem cells, which are commonly retrieved by destroying embryos at an early stage of development, are known to hold such regenerative promise.

The university took the unusual step of conducting an inquiry into the 2002 study last summer after questions were raised by a British magazine, New Scientist, about some of the published data. The magazine disclosed the questions in an article published last week.

An expert panel convened by the university concluded a process used to identify the cells was "significantly flawed and that the interpretations based on these data, expressed in the manuscript, are potentially incorrect."

Verfaillie called the problem "an honest mistake" and said it did not affect the study's conclusions about the potential of adult stem cells.

But the disclosure comes at a time of growing skepticism among scientists about the power of this kind of adult stem cell, in part because others have had only limited success replicating her study.

Verfaillie's research was heralded by social conservatives who have pinned their hopes on adult stem cells as an alternative to using embryonic cells, which they oppose on moral grounds.

Verfaillie, 49, ran the University of Minnesota's stem-cell institute from 1999-2006 and now heads stem-cell research at Catholic University in Leuven, Belgium, while remaining on the University of Minnesota faculty.

"We believe we did everything appropriately," said Tim Mulcahy, vice president of research at the university, who oversaw the inquiry.

Verfaillie said she requested the inquiry as soon as problems were brought to her attention.

Answering questions by e-mail, she wrote: "I knew that this was an 'honest mistake,' but that given the profile of the paper, of my work, and the political climate, that it could be construed otherwise."

Material from The Associated Press is included in this report.