Posted on 02/27/2007 10:42:31 AM PST by neverdem
Associated Press
Promise of adult cells now in doubt
MINNEAPOLIS - A scientific panel says a 2002 study that suggested adult stem cells might be as useful as embryonic ones was flawed and its conclusions may be wrong, a finding that raises questions about the promise of a less controversial source for stem cells. The research by Catherine Verfaillie at the University of Minnesota concluded that 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. Many scientists believe they might one day be used to treat diseases.
Opponents of stem cell research seized on the 2002 findings as evidence that stem cell science could move forward without destroying embryos. But Verfaillie has acknowledged flaws in parts of the study after inquiries from the British magazine New Scientist, which first publicized the questions last week.
A panel of experts commissioned by the university concluded that the process used to identify tissue derived from the adult stem cells was "significantly flawed, and that the interpretations based on these data, expressed in the manuscript, are potentially incorrect," according to a portion of the panel's findings released by the university.
The panel concluded that it was not clear whether the flaws mean Verfaillie's conclusions were wrong. It also determined that the flaws were mistakes, not falsifications.
Tim Mulcahy, vice president of research at the university, said it would be up to the scientific community to decide whether Verfaillie's study still stands up.
"From her perspective, the findings stand. I think the scientific community will have to make their own opinion," he said.
Other researchers have been unable to duplicate Verfaillie's results since the 2002 publications, increasing their skepticism about her claims. But that may only be an indication of how difficult the cells are to work with, said Amy Wagers, a Harvard University stem cell researcher who was not involved in the investigation.
Verfaillie did not respond to a phone message left with her current employer, the Catholic University of Leuven in Belgium. She told the Star Tribune of Minneapolis in a story published Friday that the problem was "an honest mistake" that did not affect the study's conclusions about the potential of adult stem cells.
Her research was scrutinized after a writer for New Scientist noticed that some data from the original 2002 article in the journal Nature duplicated data in a second paper by Verfaillie about the same time in a different journal, even though they supposedly referred to different cells. Verfaillie told the Star Tribune that the duplication was an oversight and said she notified the University of Minnesota, which convened the panel to take a closer look at the research.
The editor of the London-based scientific journal Nature said in a statement, "We are in touch with the author and investigating the problems that have been mentioned. We have no further comment."
Dr. Diane Krause of Yale University, who also has studied using bone marrow as an alternative to embryonic stem cells, said she believes Verfaillie's research will hold up, despite being hard to repeat.
"When it comes to Catherine, she's impeccable. She's one of the most careful scientists I know," Krause said.
I find that hard to believe. IMHO, the Associated Press is just pushing its agenda. Just enter adult stem cells into PubMed.
Exactly. How many cures have been produced by embryonic stem cells? Adult stem cells? I believe the current ratio is 0/72.
The suggestion here isn't that adult stem cells aren't good for anything -- no serious scientist believes that -- but that they aren't capable of producing the full array of tissues and organs that would be needed for various treatments.
Stem Cell Ping
Such promise of cancer, I assume...
I guess the 72 confirmed treatments by adult stem cells is an mirage then... -sarc
Many researchers are unable even to isolate them. “They’re very testy cells,” observes Amy Wagers of Harvard University, who spent a week in Verfaillie’s lab trying in vain to learn the technique. The problems with the marker profiles may help explain these difficulties. “If I had been following this recipe since 2002, I’d be extremely angry,” says Jeanne Loring, a stem cell biologist at the Burnham Institute for Medical Research in La Jolla, California. "In her most recent paper, Verfaillie and Irving Weissman, a stem cell biologist at Stanford University in California, showed that MAPCs can give rise to all the cell types found in blood, but it is still unclear whether MAPCs are as versatile as she claimed in the original Nature paper."
A follow up study published in Journal of Experimental Medicine (I don't have link) and reported on in Science,that included doubter Irving Weissman proved multipotency, if not pleuripotency.
"A lot of people have lost interest in MAP cells by this point," says Weissman. "What our paper will help do is get everybody to look at it again." Others agree. "I'm sure it will revive interest in MAP cells," says stem cell researcher Paul Schiller of the University of Miami, Florida." "The work has impressed one skeptic, Stanford blood stem cell researcher Irving Weissman, who collaborated on the new work. Weissman calls the result "remarkable." His skepticism, he adds, "makes me a perfect collaborator, because I insisted on very rigorous criteria for the experiments." He emphasizes, as does Verfaillie, that these cells are clearly not as versatile as ES cells. But despite their limitations, they could prove to be useful therapeutically.
Perhaps, now that the "recipe" is corrected, more labs will confirm the original reports.
Different populations and kinds of adult stem cells are indeed very versatile, especially for producing what we really want: stable cells that will only become the exact specialized cells that are needed, where they are needed.
Adult stem cells have yielded more populations of specific progenitor and stem cells than even embryonic stem cells. The only place that embryonic stem cells work to produce "every cell in the body" is in the original container - in the intact embryo. Elsewhere, they produce embryoid bodies or teratomas, or mutate and die out unless first manipulated to become a more specialized stem cell or progenitor cell.
Which sounds like an adult stem cell or progenitor cell, to me.
Part of the problem with all stem cell research is that, as in the press coverage, scientists have also been "shotgunning" with groups of cells as though all samples stem cells are a bunch of homogeneous one size fits all entity. Slowly but surely, we're learning what markers to look for in order to find the most primitive or the exact future lineage we need, the environment, stimulating factors and the epigenetic factors involved.
If we think the progress has been fast before, I don't think it's anything like what will happen in the next 5 years.
(See my post #7, above.)
Thanks for the links.
Good gravy! Over 70 useful treatments for adult stem cells to ZERO for embryonic, and they put THIS on top of the story!?
They can talk about the "promise" all they want. But when it comes to actual "usefulness" it is not even close. Outside of nature's purpose for them, embryonic stem cells are currently useless except to cause cancer, cause tissue rejection, and apparently to scam the public.
Here's another article, from The Scientist http://www.the-scientist.com/news/home/52892/ This one covers queries to scientists about the mistakes and affirm that the research was "good" and verifiable, although there is disagreement about the conclusions.
Thanks for the link back to this thread!
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What diseases or maladies, can we count on to be cured by any stem cells? They claim some have been helped. Well, if some have been helped, why can't everyone with these maladies be helped? I'm getting skeptical of all the claims. For instance, I have family members at risk for HD. Any hope for them?
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