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Stem Cells Taken In Human Cloning Seoul study: Focus on disease treatment -- not making babies By GINA KOLATA THE NEW YORK TIMES Thursday, February 12, 2004 Scientists in South Korea report that they have created human embryos through cloning and have extracted embryonic stem cells, the universal cells that hold great promise for medical research. Their goal, they say, is not to clone humans but to advance understanding of the causes and treatment of disease. But the work makes the birth of a cloned baby suddenly more feasible. For that reason, it probably will reignite a fierce debate over the ethics of human cloning. The work was led by Dr. Woo Suk Hwang and Dr. Shin Yong Moon of Seoul National University and will be published in tomorrow's edition of Science magazine, which is published by the American Association for the Advancement of Science. Hwang will discuss the report in Seattle today at the academy's annual meeting. The paper provides a detailed description of how to create human embryos by cloning. Experts said they found the paper persuasive. "You now have the cookbook, you have a methodology that's publicly available," said Dr. Robert Lanza, the medical director of Advanced Cell Technology in Worcester, Mass., which tried without success to do what the South Koreans did. The researchers placed human genetic material into a human egg cell and coaxed it to develop into a blastocyst, a cluster of about 100 cells that is substantially more advanced than any embryo previously known to have been created in a human cloning experiment. The researchers' paper is written in dense jargon, summarizing it by saying, "We report the derivation of a pluripotent embryonic stem cell line (SCNT-hES-1) from a cloned human blastocyst." But its import was clear to researchers. "My reaction is, basically, Wow!" said Dr. Richard Rawlins, an embryologist who is director of the assisted reproduction laboratories at Rush University Medical Center in Chicago. "It's a landmark paper." It was what patients with diseases such as Parkinson's and diabetes had been waiting for, the start of so-called therapeutic cloning. The idea is to clone a patient's cells to make embryonic stem cells that are an exact genetic match of the patient. Then those cells, patients hope, could be turned into replacement tissue to treat or cure their disease. Even though the new work clears a significant hurdle, scientists caution that it could take years of research before stem cell science turns into actual therapies. Even before the paper's publication -- reported last night by a South Korean newspaper, one day ahead of the embargo imposed by Science -- the research was being assailed by opponents of cloning. Dr. Leon Kass, chairman of the President's Council on Bioethics, called for federal legislation to stop any human cloning. "The age of human cloning has apparently arrived: today, cloned blastocysts for research, tomorrow cloned blastocysts for babymaking," he wrote in an e-mail message. The House has twice passed legislation that would ban all human cloning experiments, most recently in February 2003. But the bills have foundered in the Senate, where many members who oppose reproductive cloning do not want to ban it for medical research. Richard Doerflinger, deputy director for abortion foe activities at the U.S. Conference of Catholic Bishops, termed cloning "the ultimate way of treating life as an object, as an instrument to an end." Hwang said that he knew the work would elicit strong responses but said he thought the research was so important that it should be done anyway. He added that there was strict oversight by an ethics committee. "As scientists, we think it is our obligation to do this," he said. The paper describes the researchers' successful cloning process in detail, with precise information on how to start the embryos growing and what solutions are best for nourishing them. That recipe appears to advance the likelihood of reproductive cloning: When fertility laboratories grow embryos to the same developmental stage as the embryo clones and implant them in women, 40 to 60 percent end up as babies. The scientists emphasize that all the research took place in the laboratory, in petri dishes. No embryo was implanted in a woman. The women who provided unfertilized eggs, needed to start the cloning process, were not paid. The research was financed by the government of South Korea, where cloning to create a baby is illegal. Hwang is an expert in animal cloning and Moon is a medical doctor who trained in the late 1980s at a leading U.S. fertility center, the Jones Institute for Reproductive Medicine at Eastern Virginia Medical School in Norfolk. That is one of the very few places where researchers have extracted human stem cells from embryos that were made the usual way, by using sperm to fertilize eggs. Until now, no one had even come close to using cloning to create a human embryo, or even a monkey embryo, to say nothing of extracting stem cells from one. And it is stem cells that are the research prize. They appear after an embryo has grown for five or six days, its cells subdividing within the hard casing of the egg. Although the embryo at this stage contains about 100 cells, it is no bigger than the original egg. At this blastocyst stage, the inner mass consists of cells that are not yet committed to becoming any cell type. They are the stem cells, which can in theory develop into any of the body's tissues and organs. Stem cells from a clone would be genetically identical to the person who contributed cells to make the embryo. Scientists were particularly surprised that the researchers had managed to assemble so many unfertilized human eggs, more than 200 in all. Advanced Cell Technology, the only U.S. company that has attempted similar research, paid egg donors and wound up with just 19 eggs. In South Korea, Moon said in a telephone interview that there were no payments. The 16 women who donated eggs were "personal contacts," he said, declining to elaborate. The abundance of eggs enabled the scientists to experiment with various ways of getting the egg cells to start to divide and of growing the embryos in the laboratory. The resulting method yielded blastocysts 26 percent of the time. Eventually, Hwang, Moon and their colleagues ended up with 30 blastocysts from which they were able to extract 20 inner cell masses. One grew into a line of stem cells. Dr. Ron McKay, a stem cell scientist at the National Institute of Neurological Disorders and Stroke, said the work suggested that it might be easier than anyone thought to make cloned human embryos and extract stem cells. "The next question takes you to the heart of the whole discussion," he said. "Why do it anyway?" McKay said that for him, the point is that such cells can provide a unique opportunity to study human disease. He spoke of a scientist who died in her 40s from breast cancer. What if her cells had been cloned to make embryonic stem cells, and those cells directed to turn into breast tissue? That might give scientists the chance to examine how the cancer developed in the first place. "I owe her that explanation," McKay said, "even though this seems so complicated and fraught with politics." SOURCE: The New York Times / The Seattle Post Intelligencer, WA http://seattlepi.nwsource.com/national/160355_clone12.html * * * ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn