printable versionGuidelines issued for embryonic stem cell research
BY AMY ADAMS
A panel convened by the National Academy of Sciences released on Tuesday ethical guidelines for carrying out human embryonic stem cell research and recommended that all institutions engaging in such research establish oversight committees to ensure that researchers adhere to these guidelines.
The panel's report outlines a nationwide system for monitoring stem cell work, which closely mirrors guidelines already laid out by the California Institute for Regenerative Medicine, the state agency established by Proposition 71 to support stem cell research. Stanford also has already moved toward putting in place policies that resemble those in the report.
Under the recommendations from the 10-member panel, which included top scientists and ethicists, institutions would form their own oversight committees to review all research proposals involving human embryonic stem cells, track the research carried out by investigators and maintain a list of stem cell lines that exist at the institution. The report also calls for establishing a national panel to update the guidelines as research progresses.
"This is a quickly moving field," said Richard O. Hynes, the panel's co-chair and the Daniel K. Ludwig Professor of Cancer Research at the Massachusetts Institute of Technology. "It isn't possible to anticipate everything that will need to be covered by these guidelines in the future."
Irving Weissman, MD, the Karel and Avice Beekhuis Professor of Cancer Biology, said he was pleased that the panel recognized the need for institutional oversight. The School of Medicine had already begun establishing such an oversight committee as part of the Institute for Cancer/Stem Cell Biology and Medicine, which he directs.
Weissman and Linda Giudice, MD, PhD, the Stanley McCormick Memorial Professor, both agreed that having consistent guidelines would allow researchers at different institutions and in different states to collaborate under a single set of guidelines. "I think this gives structure and uniformity across institutions and across state boundaries," said Giudice, who reviewed an early draft of the recommendations. Until now, research that was conducted in different states and funded by public (as opposed to private) sources fell under different regulations. In some instances colleagues could not share stem cell lines to reproduce research findings.
Weissman noted that one difficulty for other institutions will be finding experts to serve on the oversight committees. "We're lucky at Stanford where we have researchers, lawyers and ethicists who have taken an interest in the work and can make up a committee," he said. Other institutions may have only a few researchers interested in working with embryonic stem cells and no knowledgeable experts to serve on such committees.
Although the report recommends that each institution establish its own committee to review research proposals, the report does suggest some guidelines to ensure that the various committees act in a consistent fashion. Most importantly, it recommends a complete ban on cloning for reproductive purposes, suggesting that human blastocysts—the source of embryonic stem cells—should not be cultured any longer than 14 days. "This is exactly what we have been saying should be done all along," Weissman said.
This limitation on reproductive cloning follows a similar ban for research funded by California's stem cell institute, which has a 12-day limit on culturing blastocysts.
The report also recommends against transferring human embryonic stem cells into non-human primates such as chimpanzees and urges caution in transferring the cells into other mammals. Although mammals carrying human stem cells—called chimeras—could be useful for scientific purposes, the report recommends that such animals never be allowed to reproduce.
These guidelines for chimeric animals closely mirror recommendations made by an ad hoc committee at Stanford assembled by Hank Greely, JD, the C. Wendell and Edith M. Carlsmith Professor in Law, in response to a request by Weissman. Both groups caution that work with chimeras should proceed slowly to ensure these animals don't take on human characteristics.
With the NAS recommendations in hand and Greely's report almost complete, Weissman said he can now think about moving forward with his proposed experiment to insert human neural stem cells into the brains of mice, though he added that he has no immediate plans to do so.
An additional ethical issue the report tackles is how human eggs should be procured for creating new embryonic stem cell lines. The report recommends that egg and sperm donors give full consent before their tissues can be used to create human embryonic stem cells and that donors be compensated only for expenses rather than being paid directly for their eggs or sperm.
David Magnus, PhD, director of the Stanford Center for Biomedical Ethics, noted that the state stem cell institute's policy is even stricter, prohibiting egg donors from receiving any money in compensation. "This report is vague about how much money a donor can receive," he said, adding that it could open up concerns about poor women being bribed to donate eggs for stem cell research.
Giudice, who oversees a committee for the Program in Regenerative Medicine at Stanford examining ethical ways of procuring eggs, acknowledged that the loophole does exist. But, she added, the guidelines do give comprehensive protections for donor privacy and informed consent, both of which have been concerns the general public has had about this research.
