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Costly Cloning Isn't a Cure-All By Kristen Philipkoski Story location: http://www.wired.com/news/medtech/0,1286,65883,00.html 02:00 AM Dec. 01, 2004 PT Of the small number of Americans who have any idea what therapeutic cloning is, the majority likely believes it essential for stem-cell therapies to succeed. That is not necessarily true. Therapeutic cloning, also known as somatic cell nuclear transfer, will not be the route to successful stem-cell therapies, many scientists say. In fact, if therapeutic cloning were vital, it would make stem-cell therapies prohibitively expensive. But that would mean a custom-made clone for every patient. Not only would that be exorbitant for already cash-strapped hospitals (especially when you consider treatments would likely cost up to $200,000), but it could also create a big demand for donor eggs. That prospect led to protest from feminist organizations, such as the Boston Women's Health Book Collective, which worried that underprivileged women would bear the brunt of the demand. But now, most stem-cell researchers have given up on the idea of custom-made clones. "Not only would it be expensive, but logistically it could be impossible because you will have to have every single hospital in the world set up to do therapeutic cloning and prepared to do the different protocols," said Jose Cibelli, a cloning researcher at Michigan State University in East Lansing. While immune rejection is a big hurdle for stem-cell therapies, excluding therapeutic cloning as the solution is a bit of a weight off researchers' shoulders. It means therapeutic cloning bans, which have been in the works in the United States and the United Nations for years but are unlikely to pass in their present forms, might not throw a wrench in California's stem-cell initiative (or other states' plans), at least when it comes to deriving stem-cell therapies. Researchers hope, nevertheless, that some of the $3 billion awarded to embryonic stem-cell research by California's Proposition 71 will go toward cloning studies that could act as drug-development tools and eventually lead to new pharmaceuticals. While researchers aren't certain the cloning-for-research approach will point to drugs, Rudolf Jaenisch, a biology professor at the Massachusetts Institute of Technology, has cloned mice with severe combined immunodeficiency, then derived stem cells to watch the disease develop, setting a precedent for further studies. "Producing such lines would make available to the biomedical research community a fantastic set of tools for studying and understanding how each correlated gene plays a role in disease development, a prelude to testing therapies," said Irv Weissman, a developmental professor at Stanford University in Palo Alto, California. If the federal government did pass a therapeutic cloning ban, it could overrule states' efforts, depending on the language of the legislation, said R. Alta Charo, a bioethics and law professor at the University of Wisconsin law and medical schools. But states would likely challenge the law in federal court, she added. A way around immune rejection remains an enigma for stem-cell scientists. Researchers like Weissman and Okarma believe perhaps scientists will one day make therapeutic cloning practical by, for example, figuring out a way to develop human eggs from stem cells. Others are working on different solutions altogether. Advanced Cell Technology scientists are focusing on a pseudo-cloning technique called parthenogenesis, which involves creating an embryo using only eggs. Clones produced using parthenogenesis would be less likely to cause immune rejection, said Robert Lanza, vice president of medical and scientific development at Advanced Cell Technology, who has spent his 25-year career dealing with transplantation-induced immune rejection. His company published research in Science in February 2002 showing it could achieve parthenogenesis in monkeys. "With a few dozen or a few hundred stem-cell lines we could create a bank that would match most of the U.S. population," Lanza said. Okarma of Geron suggested worrying about immune rejection might be moot, because the immune activity caused by embryonic stem cells may be insignificant, much like a mother does not reject an embryo that implants in her uterus. But other researchers say the data on this theory is conflicting, and the outcome might depend on how many cells are implanted. Another approach could be to build up tolerance in a patient by slowly introducing small amounts of cells so the patient does not reject them, Okarma said. Because scientists don't know which, if any, methods will work, they hope they will be free to explore all of them. "I think there is hope out there," Lanza said. "But the problem is we've been fooled in the past over and over with promising technologies." -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.289 / Virus Database: 265.4.5 - Release Date: 12/3/2004 ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn