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Stem cells' promise collides with politics By Tina Hesman Of the Post-Dispatch 04/21/2001 Joseph Zahner and Asutosh Sharda, former St. Louis University professors, have a patent pending for a process that might allow them to grow human liver tissue from ordinary skin cells. The possibility that researchers someday could grow replacement parts for people has turned stem cell research into one of the most exciting fields of science. These versatile cells might well be prodded into growing into new human organs, replacing brain tissue to treat strokes, Alzheimer's and Parkinson's diseases and even helping paralyzed people regain some movement by healing injuries to the spinal cord. Yet, stem cell research also has become one of the most divisive and political areas in science today. The reason: Some of the most promising research so far centers on stem cells that come from human embryos. And that has raised ethical questions - especially among anti-abortion groups. The stem cell debate could take center stage as soon this week in Jefferson City as the Missouri House and Senate discuss pending life- science funding bills. And it already has become a hot-button issue in Washington, where the National Institutes of Health has quietly canceled this week's planned review of grants for human embryonic research pending a White House review of its research guidelines. At the heart of the issue is a type of powerful cell known as an embryonic stem cell, which scientists say could revolutionize medicine. The body's raw material Stem cells are the raw material for building bodies. Embryonic stem cells are taken from a tiny raspberry-shaped ball of cells called the blastocyst about four days after sperm and egg collide at fertilization. The cells have the ability to grow and divide virtually forever and can become any type of cell in the body. Embryonic stem cells "have the capacity to be coaxed into becoming whatever kinds of cells you want them to be," said Dr. William Peck, dean of the Washington University School of Medicine. "It's just phenomenal what can be done." In August, the NIH unveiled new guidelines that would allow scientists to conduct research on stem cells derived from human embryos, as long as the cells were made according to strict restrictions. However, President George W. Bush has said that he does not support research on human embryo or fetal tissue. Bush also expressed doubts about the agency's interpretation of a law banning work on human embryos. Abortion opponents oppose research with stem cells from embryonic tissue because they believe life begins at conception - when the sperm fertilizes the egg. Bush asked Health and Human Services Secretary Tommy Thompson to review the guidelines and rule on the legal interpretation of the embryo research ban. Thompson's ruling is expected this summer. The NIH's Human Pluripotent Stem Cell Review Group was to have met Wednesday to assess applications for federal money to do research on embryonic cells. The meeting was postponed indefinitely until Thompson decides whether the research can go forward, NIH officials said. The power of nature The excitement over stem cells is not merely hype, researchers say. "One of the reasons for being so optimistic is that (with embryonic cells), you're not asking nature to do anything it doesn't normally do," said David Gottlieb, a developmental biologist at Washington University. Gottlieb and his colleagues were the first to coax mouse embryonic stem cells to make neurons and repair spinal cords in paralyzed rats - a feat they hope to repeat with human cells. The "uninteresting" appearance of the stem cells with their average-size nucleus and small bodies belies their power, Gottlieb said. "They're small, but they're smart," he said. The cells are just waiting for the right signal to become any type of cell in the body. Stem cells grown in petri dishes spontaneously try out new fates, said developmental biologist Doug Melton of Harvard University. The trick is getting the cells to move down the pathway that scientists choose, he said. Researchers have made great strides in coaxing embryonic stem cells to adopt a desired fate, but clinical applications are still years away - largely because academic researchers have been barred from working with embryonic cells, some scientists say. Controversy and caution Despite the enormous promise of the embryonic cells, only two groups have submitted the necessary paperwork to show that they could comply with NIH guidelines governing stem cell research. A third application was submitted and then withdrawn. But scientists say that shutting off money for embryonic stem cell research would affect the entire scientific community - not just those who apply for the money in an uncertain political climate. "Scientists, like everyone else, follow the politics. They realize all this research could be shut down," said Tim Leshan of the American Society for Cell Biology. Some of the caution may be due to the controversy regarding work with embryo-derived tissue, said Dr. Dennis W. Choi, head of the departments of neurology and neurological surgery at Washington University. But it takes time to put together complicated grant proposals and develop a project worthy of funding, he said. "The green lights are just going on, and it takes awhile to gear up for these," Choi said. Federal restrictions on the type of material that can be used in embryonic stem cell research have severely limited the supply of cells. "There aren't a lot of stem cells out there that would be viable under the guidelines," Leshan said. The line of stem cells developed from aborted fetal tissue by Dr. John Gearhart of Johns Hopkins University may qualify under the new guidelines. But those stem cells isolated from discarded embryos by James Thomson of the University of Wisconsin probably would not, Leshan said. Thomson's stem cells were taken from an embryo created for in vitro fertilization, but the embryo was not frozen - a requirement under the guidelines. Even if Thomson's cells met the requirements, patents on the cells held by Geron Corp., of Menlo Park, Calif., make the cells unavailable to most academic researchers, Melton said. Adult stem cells don't work as well The limitations on embryonic cell research have prompted many scientists to search for adult stem cell alternatives. Recent reports of stem cells isolated from fat, placenta and other sources have been hailed by the news media and embryo-research foes. But scientists in the stem cell field say that the potential of adult stem cells can only be judged against the awesome power of embryonic cells - and so far adult cells are not as flexible. That is because adult cells have already started down a path that leads them to a restricted number of developmental fates, while embryonic cells have not made any decisions and can be pushed down any road. Adult cells are more likely to have accumulated damage to their genetic material and have not been shown to be truly reprogrammable. "If stem cells from adult tissues worked as well, we wouldn't be having this discussion," Peck said. In five to 10 years, the situation could change, but right now, "they don't have the kind of potential that the other cells have." Bill Bell Jr. of the Post-Dispatch Jefferson City bureau contributed information for this article. Reporter Tina Hesman: E-mail: [log in to unmask] Phone: 314-862-2143 http://www.stltoday.com/stltoday/news/stories.nsf/News/FB160BE7DD5 E0F8386256A3500646B1A?OpenDocument&Headline=Stem%20cells'%2 0promise%20collides%20with%20politics%20 ******* ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn