072301Hard CellJuly 23, 2001Opinion Journal

By Richard Miniter, an editorial page writer for The Wall Street Journal Europe. His column appears Fridays. This commentary origina;;y appeared on OpinionJournal.com

When President Bush meets the pope today, one of the issues they're sure to discuss is the controversy over embryonic stem-cell research. Mr. Bush is reportedly struggling with the decision of whether to accept a last-minute Clinton decision that would effectively lift the ban on federal funding of such research. During his campaign, Mr. Bush promised to uphold the ban.

Proponents of such research, and the media, frame the issue as one of religion vs. science, arguing that if the president keeps his promise, he will set back new medical advances and sacrifice potential cures for diseases like Parkinson's.

But science isn't on their side, and Mr. Bush doesn't have to choose between convictions and cures. While federal funding for embryo research is banned, the research itself is not. The private sector lavishly funds research on stem cells drawn from both embryos and adults. Yet research on embryonic stem cells is no more developed than the embryos themselves -- while research on adult stem cells is close to delivering miraculous treatments.

Consider these recent advances:

• Surgeons in Taiwan restored vision to patients with severe eye damage by using stem cells from the patients' own eyes. Their vision improved from 20/112 to 20/45, according to results published in the New England Journal of Medicine.

• British scientists found that adult stem cells in bone marrow can turn into liver tissue, a first step toward developing new treatments for liver damage. Their work was reported in the journal Nature.

• Two recent studies show that adult stem cells in bone marrow transplanted into the brain of mice can develop into neurons and have been reprogrammed into healthy brain cells in lab rats. Previous research had shown this transformation was possible in cultured cells, but these studies, one of which was published in the journal Science, show it can happen in living animals.

• Scientists found that adult stem cells in bone marrow injected into a damaged mouse heart could become functional heart muscle cells, and that these new cells partially restored the heart's pumping ability. One of the scientists predicted that after successful follow-up studies, human clinical trials could start in three years. The results were published in Nature.

These findings were all reported within the past year. And they are only a few examples of the breathtaking medical breakthroughs occurring after years of research on adult stem cells -- stroke victims' brains repaired with adult stem cells becoming fully functional neurons connecting with existing brain cells, new cartilage grown to repair damaged knees.

We are on the verge of astounding human applications using adult stem cells. Embryonic stem cells, by contrast, have yet to save a single life.

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Stem cells are unspecialized cells that have the ability to transform themselves, in varying degrees, into many other types of cells. Thus a single stem cell could become a skin cell, a hair cell, a liver cell and so on. All of us were once stem cells, and our bodies still hold many forms of these cells.

It appears that every organ and tissue in the body has undifferentiated stem cells. These cells may exist to repair organs when they are traumatized or damaged, but scientists are still puzzled by how they work and what exactly they are supposed to do. If scientists can improve this natural repair process with adult stem cells, people may be able to grow new livers from stem cells extracted from their own liver. Another source of adult stem cells is body fat. And umbilical cords provide a large supply of stem cells -- without political or moral controversy.

A National Institutes of Health report, released just in time for last week's congressional hearings, argues that stem cells from embryos are better. But on closer examination, the evidence is shaky and speculative, while the unique drawbacks of embryo stem cells are becoming clearer.

The case for the superiority of embryo stem cells rests on three pillars: They are easier to harvest, there are more stem cells in embryos than in adults, and they can be more easily changed into every organ and tissue in the body.

The first two claims are misleading. Harvesting is a nonproblem. Scientists have been extracting some types of human adult stem cells for almost a decade, while human embryo stem cells weren't successfully isolated until 1998. Several biotech companies have developed proprietary methods to make adult-cell isolation and extraction even easier. "We've been here in the background while all the noise was going on, and there's been a pressure on us to provide a solution," John Wong, CEO of MorphoGen Pharmaceuticals, told BioWorld Today last August. "We believe we've provided that solution. The technology has just moved beyond stem cells from embryonic tissue."

While it's true that embryos have a higher ratio of stem to nonstem cells, that doesn't mean much. Scientists have discovered stem cells in adults in virtually every major organ, including the brain and body, and researchers last year identified conditions that would allow for the multiplication of adult stem cells in culture by a billion-fold in a few weeks.

The real argument for using stem cells from embryos is they are more "plastic" -- that is, they are easier to change into other types of cells. This is a hard claim to evaluate because, as last week's NIH report notes, "the field of stem-cell biology is advancing at an incredible pace with new discoveries being reported in the scientific literature on a weekly basis." Any distinguishing advantage from using embryo stem cells today may already have been overtaken by a lab that is waiting for its results to be published.

Indeed, scientists have already proved adept at turning adult stem cells into a variety of seemingly unrelated cells. Jonas Frisen, a scientist working at NeuroNova AB, a Stockholm-based biotech firm, published some exciting work in one of the world's leading scientific journals, Science, in June 2000. "We have demonstrated that the potency of these [adult stem] cells was far greater than expected and what seemed to be a fairly restricted cell type can give rise to many different types of cells. These recent findings may turn some previous concepts upside down," Dr. Frisen said in a press release. Already, human adult stem cells have been transformed into cartilage, muscle, bone, cardiac tissues, neural cells, liver tissues and blood vessels. Research with animal adult stem cells indicate the ability to transform them into kidney, heart, lung, intestine and nervous-system tissues.

While adult stem cells may never be as completely "plastic" as embryo stem cells they will almost certainly be plastic enough for all practical applications. "These adult tissues don't appear to be as restricted in their fate as we thought they were," Dennis Steindler, a professor of neuroscience and neurosurgery at the University of Tennessee-Memphis, told Blood Weekly magazine in May. "In some ways they may not have the same potential as embryonic cells, but once we figure out their molecular genetics, we should be able to coax them into becoming almost anything we want them to be."

Diane Krause of the Yale School of Medicine -- a supporter of embryonic stem-cell research -- says she was "surprised" by her own research on adult stem cells. "It went against our dogma," Dr. Krause says. Stem cells found in the liver were believed to be limited to making liver tissue, stem cells in the skin more skin and so on. "But at least for stem cells found in bone marrow, that is not true." Scientists, who previously underestimated the potential of adult stem cells, are "searching for a new paradigm," she adds.

What's more, new research suggests that embryonic stem cells may be a little too plastic. "The emerging truth in the lab is that pluripotent [embryonic] stem cells are hard to rein in," University of Pennsylvania bioethicist Glenn McGee told MIT's Technology Review. "The potential that they would explode into a cancerous mass after a stem-cell transplant might turn out to be the Pandora's box of stem-cell research." In a recent Weekly Standard article, author Wesley J. Smith, who opposes embryonic stem-cell research on moral grounds, cites a chilling report from China in a study in the May 1996 edition of Neurology, the official journal of the American Academy of Neurology, in which implanted embryonic and fetal stem cells became bone, skin and hair cells -- inside a test subject's brain. He died.

Then there is the problem of rejection. Transplant patients know that they must take antirejection drugs for years and, in some cases, for life. New tissues developed from embryonic stem cells may require a long-term regimen of drugs to suppress the body's immune system. These drugs have side effects, and a suppressed immune systems can increase the risk of infection. This is not a problem of adult stem cells because they can be drawn from the patient's own body.

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Adult stem cells appear to be easier to control than embryonic cells, are closer to commercial application, and have a history of proven benefits -- including bone-marrow applications.

It's easier to transform, say, a pancreatic adult stem cell into pancreatic tissue than to turn an embryonic stem cell into pancreatic tissue. "It is inherently a shorter biological step to make a beta cell from a duct [adult stem] cell than it is from other possible cells, such as embryonic stem cells," according to the British Medical Journal. Human adult pancreatic stem cells have already been grown in culture and differentiated into insulin-producing cells.

Adult stem cells are also being used in human clinical trials and applications to treat multiple sclerosis, leukemia, liver disease, cardiac damage, brain tumors, ovarian cancer, breast cancer, arthritis, lupus and other conditions. French physicians used a patient's own adult muscle stem cells to treat heart disease, with promising results.

Little wonder, then, that the private sector is focusing almost exclusively on adult stem-cell research. Of the 15 U.S. biotech companies solely devoted to developing cures using stem cells, only two focus on embryos. "While the embryonic cells are rumored to have broad potential, so far only adult stem cells have demonstrated wide uses," writes Scott Gottlieb, a physician and staff writer for the British Medical Journal, in The American Spectator.

In the race to cure Parkinson's disease, cancer and other age-old scourges, the private sector is more than a few laps ahead. And perhaps a dozen private-sector projects are within a few years of human trials. StemCells Inc. is using adult stem-cell research to develop methods for regenerating damaged central nervous systems and restoring function to kidneys and livers. Baltimore-based Osiris Therapeutic Inc. has already developed technology for isolating adult stem cells, found adult stem cells in the body's connective tissues and conducted a clinical trial of adult stem-cell infusion for breast cancer patients who'd had chemotherapy. "The practical use of adult stem cells is not 10- to 15 years away but well along in the commercialization process," Osiris president James Burns told Transplant News in March 1999. "We believe that adult stem cells will become a routine treatment for cancer, immune disorders, orthopedic injuries, transplant medicine, congestive heart failure and degenerative diseases."

By contrast embryo stem-cell research is at the drawing-board stage -- not for lack of funds but for lack of promising research to finance. Venture capitalists have no agenda beyond making money; if they see embryo projects that are likely to bear fruit over the next five to seven years -- the usual VC time horizon -- they will fund them.

That the market is speaking so loudly against embryo stem-cell research probably explains why embryo researchers are so eager to reverse the ban on government funding. But medical science will continue to advance even if Mr. Bush keeps his word.

Whatever the president decides, though, the NIH should put more funds into adult stem-cell research. That would give the most promising research a big push -- and isn't that what's most important?