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wisconsin state journal http://www.madison.com/wsj/mad/top/index.php?ntid=67187&ntpid=1 UW scientists reveal stem-cell advance DAVID WAHLBERG [log in to unmask] January 1, 2006 UW-Madison scientists have created two new embryonic stem-cell lines, the first grown without animal products, officials say, removing a major obstacle to their potential use as cell therapies in people. All 22 stem-cell lines available for federal funding, including the five created by UW-Madison researcher James Thomson in 1998, have been grown with animal products such as mouse cells and cow blood proteins. Stem-cell lines developed in recent years with private funding, including 17 lines produced by Harvard professor Doug Melton in 2004, have also relied on animal products. Such cells could transfer animal viruses or other dangerous agents to people, making it unlikely treatments using them could be approved. In the new technique, reported by Thomson and his UW-Madison colleagues Sunday in the journal Nature Biotechnology, only human materials were used. "It's a major step forward," said Dr. James Battey, chairman of the stem-cell task force at the National Institutes of Health. "It moves us closer to optimizing the most useful way to grow the cells." Battey said no other stem cells free of animal products are known to have been developed. But while the new stem cells grew well for seven months before researchers froze them, both lines developed abnormal chromosomes, suggesting more research is needed to understand how useful they are, Battey said. Embryonic stem cells, blank- slate cells believed capable of turning into all of the body's 220 cell types, are found in early-stage embryos. Some of the embryos used in the new research came from UW-Madison's in-vitro fertilization clinic. But the work was funded by and performed at the WiCell Research Institute, a private lab affiliated with the university. The breakthrough gives researchers a new recipe for creating stem cells for studies of basic biology and for possible treatments for Parkinson's disease, diabetes, spinal-cord injury and other conditions. It also raises new questions about President Bush's policy forbidding the use of federal money to study stem-cell lines created after 2001, including the new animal-free lines. The creation of the new lines, or colonies, of stem cells, "makes current public policy in the United States increasingly unsound," the UW-Madison researchers wrote in the paper. "It really does limit what we can do," Thomson said. "If the restrictions were removed, we could use these cells much more broadly." But Battey said the Bush policy stems largely from some people's belief that the destruction of human embryos, required to obtain stem cells, is immoral. "The current breakthrough doesn't change that," he said. To create the new lines, researchers first developed a new way to grow them. Previously, cells from mouse embryos were placed on the bottom of petri dishes to help the stem cells attach to the dish. The stem cells were then bathed in a liquid mixture of nutrients, called culture medium. Cow blood proteins were among several ingredients used in the culture medium to keep the stem cells in their primordial state. In the new technique, scientists replaced the mouse feeder layer with four human proteins purified from plasma or placental tissue, said Tenneille Ludwig, lead author of the paper. Scientists had tried to grow stem cells on many human proteins individually before, but none worked well enough on its own, Ludwig said. "This time, we took our top four contenders and put them together," she said. The researchers also replaced all of the animal ingredients in the culture medium with human products, adding five factors to improve the mixture. The new bottom layer and culture medium, containing no animal products, enabled the stem cells to thrive and remain undifferentiated. Researchers then extracted stem cells from five blastocysts, or week-old embryos, said Jeffrey Jones, director of the university's in-vitro laboratory and another author of the paper. They placed the cells in the dish containing the four human proteins and the new culture medium. Although three groups of cells didn't grow well in the new system, the other two did, Jones said. One of the lines developed an abnormal chromosome often seen in other stem-cell lines, Jones said, but the other had an abnormality never before seen in stem cells. "We think it could have been present in the embryo from the very beginning," he said. A patent has been filed on the discovery, but the new recipe for growing stem cells is being made available to other scientists without charge, Ludwig said. ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn