It appears that the Bush administration is ready to proceed with limited federal funding of research on existing lines of embryonic stem cells, despite the fact that an increasing number of scientific studies indicate that adult stem cells have as much promise in developing disease-treating breakthroughs as do those taken from embryos.
Last August, when Bush made his decision to fund the research, many pro-life advocates resigned to a belief that the first Republican president in eight years had sold them out on the issue of when life officially begins.
“The president's decision to allow taxpayer funded research to proceed on 60 existing stem cell lines is troubling,” said Family Research Council President Ken Connor Aug. 9.
Bush's top health official recently confirmed that opinions haven't much changed since last summer.
“Everything is on the table. I think there is an answer there that we are working on that is going to allow research to continue with some moderations,” Health and Human Services Secretary Tommy Thompson said last month, “but one that will be hopefully satisfactory to the various views that are very polarized at this point.”
Ironically, the issue of how extensively to use embryonic stem cells for medical research – even the issue of whether to use them at all – may not have needed to be made. In fact, according to a number of promising new studies, it just could be that a different kind of stem cells – those harvested from live adults – will accomplish most or all of what embryonic stem-cell researchers believe their lines are capable of doing.
Researchers believe that stem cells can mimic the actions and activities of nearly every other cell in the body. Eventually, scientists hope to use them to repair damaged hearts after heart attacks, regenerate livers devastated by cirrhosis or viral disease, reconstruct damaged joints, or seed the brain with fresh neurons to reverse the effects of Parkinson's and Lou Gehrig's disease, according to the November issue of Technology Review, a research magazine published by the Massachusetts Institute of Technology, or MIT.
So-called “excess” embryos – those created by fertility clinics but never implanted in women – contain stem cells that researchers believe can accomplish more of these tasks. However, a number of recent studies show that adult stem cells, which are found in tissues throughout the body – from just below the surface of the skin to the “deep redoubts” of the liver and bone marrow – are increasingly accomplishing tasks once thought unlikely.
Doubts about the overall capability of adult stem cells remain.
“For certain diseases, adult cells appear very promising, for hepatic and cardiac diseases in particular,” Ronald McKay, a researcher at the National Institutes of Health, told Technology Review. “However, if you're asking for a solution to Parkinson's disease or diabetes, I would say the cells that offer the best way are fetal and embryonic.”
In reality, there is no obvious way to verify such statements. Because of the origin of embryonic stem cells, pressure from religious groups, pro-life advocates and lawmakers has slowed funding and research opportunities for such cell lines.
Meanwhile, adult stem cell research has progressed at a brisk pace. And, as MIT's Technology Review concluded, “adult stem cells have quietly been writing a fascinating story of their own – a story that in many ways is more advanced, clinically and commercially, than the embryonic stem-cell story.”
'The dogma was wrong.'
For nearly three years, doctors working with Osiris Therapeutics of Baltimore have been examining the performance of adult stem cells harvested from bone marrow to help cancer victims more quickly recover their immune functions, which can be damaged by chemotherapy. In those studies, the stem cells were intended to enhance traditional bone marrow or umbilical-cord-blood transplants, Technology Review said.
“What we can say so far,” University of Minnesota professor of pediatrics John E. Wagner, who heads one of the studies, told the magazine, “is that we have seen no negative side effects, and we have the impression that it's faster.”
Recent animal studies have also found that adult stem cells are much more versatile than previously thought. For instance, last May a New York University pathologist named Neil Theise, stem-cell biologist Diane Krause of Yale and their colleagues published a report in an industry journal called Cell that claimed adult stem cells from the bone marrow of mice could form multiple tissues, including blood, liver, lung, stomach, esophagus, intestines and skin. The results led Theise to believe that these adult stem cells are as flexible as embryonic cells. The MIT journal said he refers to the bone marrow cells as the “ultimate adult stem cell.”
“There is a cell in the bone marrow that can serve as the stem cell for most, if not all, of the organs in the body,” Theise says. “It had been thought that only embryonic stem cells had such wide-ranging potential. However, this study provides the strongest evidence yet that the adult body harbors stem cells that are as flexible as embryonic stem cells.”
Another research team led by molecular biologist Freda Miller of McGill University in Montreal, Canada, recently published a study concluding that adult stem cells taken out of the skin could develop into fat, muscle and neural (brain) cells. The study also pointed out that because they were found in the skin, they could be accessed easily for harvest.
“They are beautiful neurons,” Miller told the journal Nature Cell Biology. “You kind of look at them and say, 'This can't be true.' But then you go back and do it 10 times, and you realize it is true.”
“Two years ago, I would have said this is a big surprise and I wouldn't have believed it unless it could be widely reproduced,” added Ronald Worton, head of Canada's Stem Cell Network. “But then the dogma used to be that if you were a stem cell in [adult] bone marrow, you could only make blood cells, or if you were a stem cell in skin, you could only make skin. There's now enough lab work to say the dogma was wrong.”
Also, doctors at Singapore's National Hospital and Singapore General Hospital have recently announced a “medical first” involving stem-cell rich umbilical cord blood. In a joint statement, doctors said cord blood from a non-related donor was used to successfully treat a case of thalassaemia – a hereditary blood disorder that often causes severe anemia and is usually fatal in children if untreated.
The statement said that umbilical cord blood is rich in “haemopoietic stem cells” from which the different types of blood cells evolve.
And, scientists at Australia's Walter and Eliza Hall Institute of Medical Research announced in August that they had isolated an “extremely pure batch” of adult neural stem cells from the brains of mice. As reported by the journal Nature, scientists say they have managed to isolate “elusive” neural stem cells with 80 percent purity, compared to a previous rate of 5 percent.
“It proves that embryonic stem cells are not the only stem cells able to develop into new cells,” said the statement, according to Australian press sources. The finding, scientists said, means that adult stem cells could be used to treat Alzheimer's Disease, Parkinson's, “and other neurodegenerative diseases.”
“It's important in the sense that there's been a debate about whether stem cells from adult tissues, whether that be brain or blood or elsewhere, do have the potential to give rise to various tissues,” said Perry Bartlett, a member of the Australian team. “I guess this is one of the very first unequivocal demonstrations that these cells are able to give rise to a larger number of cell types than was previously thought.”
Finally, doctors at Chicago's Northwestern Memorial Hospital say they have had some initial success in utilizing adult stem cells to treat two patients with Crohn's disease, a potentially disabling inflammatory bowel disease. One patient, doctors said, was doing “phenomenally well” nearly three months after undergoing the procedure; the cells were extracted from her own blood. The success led doctors to try the procedure on a second patient. Those results thus far have been characterized as “encouraging.”
Challenging Research Orthodoxy
The results of so much adult stem cell research slowly is beginning to win over doubters and reverse the opinions of former critics. That's because many of the results so far are too overwhelming to ignore.
“In a finding that could offer an entirely new way to treat heart disease within the next few years, scientists working with mice and rats have found that key cells from adult bone marrow can rebuild a damaged heart – actually creating new heart muscle and blood vessels,” Robert Bazell of NBC Nightly News reported March 30.
“Until now, researchers thought that stem cells from embryos offer the best hope for rebuilding damaged organs, but this latest research shows that the embryos, which are politically controversial, may not be necessary,” Bazell said.
“We are currently finding that these adult stem cells can function as well, perhaps even better than, embryonic stem cells,” Dr. Donald Orlic of the National Human Genome Research Institute told NBC.
In a separate interview in Wired magazine, Orlic went on to say that fetal and embryonic stem-cell researchers have not been able to show the regeneration of heart cells, even in animals.
“This study alone gives us tremendous hope that adult stem cells can do more than what embryonic stem cells can do,” he said.
Scientists have even found that fat cells may also contain the right kind of stem cells needed to regenerate tissue.
“With the newest evidence that even cells in fat are capable of being transformed into tissue through the alchemy of biotechnology, some scientists said they are beginning to conclude they'll be able to grow with relative ease all sorts of replacement tissues without resorting to embryo or fetal cells,” the Washington Post reported April 10.
Such results make for “highly provocative work,” said Eric Olson, chairman of molecular biology at the University of Texas Southwestern Medical Center in Dallas, but nevertheless, those scientists “are probably right.”
He added it's encouraging that “every other week there's another interesting finding of adult stem cells turning into neurons or blood cells or heart muscle cells.”
“Apparently our traditional views need to be reevaluated,” he told the Post.
But Gene Tarne, communications director for the Coalition of Americans for Research Ethics, – which supports the use of adult stem cells for research – says that overall, there has not yet been a sea change of attitudes regarding adult stem cell research.
Hearts and minds “among lay people – the interested, informed citizen – are changing,” he said, “as well as some in the media, too.” But in terms of the scientific community, “maybe a little bit,” he added.
“There's this orthodoxy out there [among researchers and scientists] which is that the adult stem cells are not going to be proven good enough. They tend to be more skeptical of claims made on behalf of adult stem cells, but they are almost uncritical of claims involving embryonic stem cells,” Tarne said.
“I think that's an unfair assessment,” he said.
When asked how the scientific community could still pin so much hope on stem-cell research when so little of it has been conducted, Tarne said he believed it was because of an institutionalized way of thinking among many scientists.
“Challenging the orthodoxy is unwelcome,” he said.
(Jon E. Dougherty is a staff reporter and columnist for WorldNetDaily, and author of the special report, Election 2000: How the Military Vote Was Suppressed. This column courtesy of WorldNetDaily.)