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Flawed embryos seen as source for stem cells By Colin Nickerson Globe Staff / January 28, 2008 From what is now considered medical waste might be fashioned bio-treasure: stem cells able to form into any of the body's 220 cell types, including blood, nerves, bone, and skin tissue, new research suggests. Scientists at Children's Hospital Boston have forged stem cells from the "flawed" and "poor quality" early-stage embryos that in vitro fertilization clinics discard by the hundreds of thousands every year, according to research published yesterday in the journal Nature Biotechnology. These are embryos created by IVF technicians but culled because abnormalities make them unsuitable for implantation into the wombs of women unable to conceive naturally. The embryos, usually containing no more than a few score cells, are deemed medical waste and simply tossed away. Such embryos can "provide a reliable source for embryonic stem derivation," said Dr. Paul H. Lerou, lead author of the study and a neonatologist at Children's and Brigham & Women's Hospital. Stem cells are thought to represent medicine's single best hope for healing damaged heart cells, mending shattered spinal cords, and curing or treating an array of other horrendous afflictions. The cells derived from low-quality embryos may be limited to use in general stem cell research because they might carry tiny abnormalities making them too risky for direct patient therapy, said George Q. Daley, a stem cell scientist at Children's and the study's senior author. Meanwhile, he said in an interview, the procedure represents "an ethically acceptable source" for the generation of embryonic stem cell lines, or self-renewing colonies, urgently needed by researchers exploring the potential benefits of stem cells. "These embryos are destined to be waste, they are defective, and would not be even considered for use in [inducing IVF] pregnancy," he said. "This way they serve a beneficial use." Religious conservatives sharply dispute the idea that using any embryos is ethically acceptable. They oppose most research involving embryos on the grounds that embryos are humans and it is immoral to destroy them, even for medicine. The conservatives have a powerful arrow in their quiver: Late last year, researchers in Japan and the United States stunned the world by creating human embryonic-like stem cells from adult skin tissue, without any use of embryos. No ethical issues are associated with these stem cells, which have already started receiving tens of millions of dollars in research funds from the federal government. Nonetheless, it may be years before such so-called "induced" cells can be used in treatment, if ever - the cells contain gene-altered viruses that may be too dangerous to use in human therapy. Meanwhile, many front rank stem cell scientists, including Daley, believe stem cells derived from human embryos remain critical for research and near-term therapies. The researchers at Children's scored their best success rate in creating stem cell lines from flawed IVF embryos that had reached the "blastocyst" stage, an entity about five days old and containing 50 to 200 cells. This appears to refute earlier studies suggesting that flawed or poor quality IVF embryos could not be consistently cultivated into healthy stem cell lines. "We have shown that blastocyst stage embryos are a robust source of stem cells," said Daley, who is also a professor of biology at Harvard and president of the International Society for Stem Cell Research. "We have taken chromosomally abnormal embryos and used them to derive stem cells that are normal." The study put a damper, however, on the notion proposed by the President's Council of Bioethics that stem cells might be ethically harvested from so-called "early arrested" embryos - two- or three-day old entities so hopelessly defective that their state is roughly equivalent to adults determined brain dead. These are so defective they rarely reach even the blastocyst stage. The Children's researchers were able to harvest stem cells from such embryos at a rate "too inefficient for science," in Daley's words. © Copyright 2008 Globe Newspaper Company. The poor quality embryos are "an ethically acceptable source" for the creation of stem cell lines. Scientist George Q. Daley Rayilyn Brown Director AZNPF Arizona Chapter National Parkinson Foundation [log in to unmask] ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn