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Politicians Ignore Absolute Importance Of Moving Forward In Parallel With Embryonic And Adult Stem Cell Research... Politicians are using Dr. Catherine Verfaille's successes to promote adult stem cell research only... They should read the whole story... murray * * * The Chicago Tribune http://www.chicagotribune.com/technology/local/chi- 0206210219jun21,0,2592572.story 2 new studies bolster promise of stem cells By Peter Gorner Tribune science reporter June 21, 2002 Scientists on Thursday presented the best evidence yet that both embryonic and adult stem cells can fulfill their promise to treat hopeless diseases that afflict millions of Americans. The advances should add to the debate raging in Congress over therapeutic cloning and stem cell research. In publishing two separate studies it called remarkable, the British journal Nature sponsored an unusual news conference at the University of Minnesota Stem Cell Institute in Minneapolis, where leaders of both research teams explained their findings. In one study, University of Minnesota researchers said they identified an extremely rare adult stem cell found in human and animal bone marrow that functions like an embryonic stem cell and may turn out to be as versatile. The other experiment marked the first time embryonic stem cells have been shown to be functional in an animal and capable of treating a disease--the tremendous promise of stem cell research. Embryonic stem cells are considered to be the most promising because of their dual ability to proliferate and to become any of the body's cells and tissues. But they are ethically contentious because 5-day- old embryos have to be destroyed to derive them. Cells that have already committed to a career path--adult stem cells--show promise as an ethically preferable alternative, but until now scientists have been unable to show they might be as versatile as embryonic stem cells. When the Minnesota researchers transplanted the bone marrow cells into lab animals, the cells seemed to respond to whatever environment they found themselves in and went to work making those kinds of cells. Bone marrow cells that migrated to the liver, for example, started making liver cells. Significantly, when the stem cells differentiated in the animals' bodies, they did not start dividing uncontrollably, which would have made them cancerous, said lead researcher Dr. Catherine Verfaillie, who in the last decade has earned respect for her pioneering studies of stem cells. She and her colleagues cultured adult bone marrow stem cells from rats and humans that normally differentiate only into tissues such as bone, muscle and fat. From these cultures, they isolated what they call "multipotent" stem cells that can proliferate indefinitely in tissue culture. Injected into mouse embryos, the rat cells differentiated into most if not all of the cell types in the body. (They had been tagged with genes that made them identifiable later.) "These bone marrow cells--which we call multipotent adult progenitor cells, or MAPCs--might be used as undifferentiated cells to repair organs," Verfaillie said. They could become whatever type of cell was needed to heal a heart, liver or kidney, for example. "Alternatively, they could be programmed to become specific types of cells prior to transplantation. Finally, they may be useful for medical testing or as a source of differentiated cells for drug development and toxicology studies." The other experiment, by Ron McKay and colleagues at the National Institute of Neurological Disorders and Stroke in Bethesda, Md., showed that embryonic stem cells can be used in cell replacement therapy for an animal model of Parkinson's disease. A brain researcher who has pioneered stem cell biology, McKay was the first to coax the stem cells from very early embryos of lab animals into becoming pancreatic islet cells that produce the hormone insulin. These "organs in a dish," as McKay called them, didn't work very well, but conceivably could be used someday against diabetes. Islets regulate the body's use of sugar from food, and mammals can't survive without them. In the recent experiment, the government researchers generated a large supply of dopamine neurons from cultured mouse embryonic stem cells. Dopamine is the neurotransmitter that controls movement and is missing from the brains of Parkinson's patients. When transplanted into laboratory rats with damaged dopamine neurons (modeling Parkinson's disease), the neurons functioned normally and the rats showed signs of recovery in behavioral tests. "Both studies are absolutely fascinating and offer proof of principle," said Dr. Jayesh Mehta, director of the stem cell transplant program at Northwestern Memorial Hospital, whose team is researching ways to use bone marrow stem cells to treat cancer, mend diseased hearts and cure autoimmune diseases. "The researchers themselves have highlighted the problems with their research," Mehta said. "For example, we don't know how long the beneficial effects will last. In the McKay study, the embryonic stem cells were implanted in the brain. What if they were to start dividing and give rise to a tumor? And of course the entire issue of embryonic stem cell research must be resolved. "But despite such caveats, the studies demonstrate that this approach can work. That will have profound implications for how treatments will evolve over the next several years." McKay pointed out that scientists already knew that if they implanted fetal tissue containing dopamine-producing cells into the brains of Parkinson's patients, many of them enjoyed a benefit. The fetal cells were not stem cells, however, which have the capacity to endlessly duplicate themselves, so the beneficial effect was limited. "But that was the first evidence that cell therapy might be therapeutic," McKay said. "Over the last two years, we've learned to manipulate mouse embryonic stem cells so they will produce neurons that make the right kind of dopamine in the right place when we transplant them into the animal brain. We're absolutely confident that we have the right type of cell and we can clearly show it affects the behavior of the animal." The nervous system uses the dopamine receptor for many things, McKay said. "When it's damaged on purpose in laboratory animals, they can only move in a circle, as if rowing a boat with one oar," he said. "When we put in these cells, they go back to normal. But if we put in too many, they start circling the other way. What this means is that the transplants don't cure the animals' problem, but provide absolute proof that these cells work in the brain." Dr. Irving Weissman , Stanford University cancer biologist and stem cell pioneer, called the Verfaillie study "intriguing. Nothing like it has been published before, and the work is amazingly clean. But this researcher is too good to maintain that her interpretation is the only correct one. "We need independent verification of the findings. The study has the potential to be landmark work. As for now it looks like a good hit, but we don't know yet if it's a homer or a single." Dr. Ira Black, the New Jersey researcher who was first to show that stem cells in the blood can be transformed into brain cells, called the McKay study "an important advance. Both studies show the absolute importance of moving forward in parallel with embryonic and adult stem cell research. "The journey will be fascinating scientifically and should absolutely overturn the way we treat sick patients." ---------- For more on stem cell research, chicagotribune.com. SOURCE: The Chicago Tribune http://www.chicagotribune.com/templates/misc/printstory.jsp?slug=chi%2 D0206210219jun21§ion=/printstory * * * ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn