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Re: Moving Forward Ethically



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Kathryn, it is definitely always encouraging to see stem-cell researchers making efforts to move forward ethically, i.e. to get pluripotent cells without harming human embryos. But as you say, I’m not sure this particular effort has succeeded in doing that in the way the article you linked to suggests. Details below the fold.

This team took 43 embryos created by in vitro fertilization, grew each to the 8-cell stage, and then removed a cell or two from each of the embryos. This is a technique sometimes used in IVF to run genetic tests on the embryos produced—the remaining embryo is then allowed to continue developing, and in many cases, though far from all, does survive and continue to grow (in this case 34 of the post-biopsy embryos survived, and 9 died). In this experiment, rather than use the removed (or biopsied) cells for testing, they tried to produce embryonic stem cell lines from them, using three different methods of culturing the biopsied cells. They ended up producing 5 lines successfully.

The case they make is that since this kind of embryo biopsy is done anyway in the course of some IVF procedures (so parents can find out about any genetic condition, or the sex of the child, etc. and, to put it as frankly as it ought to be put, eliminate the undesirables) this procedure is no more dangerous or harmful to the embryos than that, and so should be supported by federal dollars.

Again, the effort to find ethical ways to produce these kinds of stem cells is laudable, but there are a lot of problems with the case these guys are trying to make. First of all, embryo biopsy does seem to significantly increase the risk of harm to the embryos involved.

Second, federal funding for embryo research is limited by statute (not by the Bush policy) in a way that prohibits the use of taxpayer funds for “research in which a human embryo or embryos are destroyed, discarded, or knowingly subjected to risk of injury or death greater than that allowed for research on fetuses in utero.” (That language is from the so-called Dickey Amendment, passed by Congress each year since 1995.) The standard for “research on fetuses in utero” is set by federal regulations, and this new technique does not even come close to meeting the “risk of injury or death” standard. So the notion—put forward in the article you linked, Kathryn, and in others today—that it’s just up to President Bush to decide if this work will be funded, is not true. By law it’s hard to see how it could be. The researchers are right that this technique probably doesn’t pose greater harm than the one used for genetic screening in IVF, but that IVF technique is not funded by the federal government either, and for the same reason. So this doesn’t work as an argument for funding.

Back in 2005, the President’s Council on Bioethics released a report looking at some possible ways to get pluripotent stem cells without harming human embryos. They were enthusiastic about some of these possible techniques (especially reprogramming adult cells, as was done successfully in November), but they also looked at the potential of the technique being talked about today, embryo biopsy. Their unanimous conclusion about it was:

We find this proposal to be ethically unacceptable in humans, owing to the reasons given in the ethical analysis: we should not impose risks on living embryos destined to become children for the sake of getting stem cells for research. This approach could, of course, be attempted in animals, but we do not yet see how results from animal experimentation could alter this assessment of ethical propriety in humans. We do not expect this method to become ethically acceptable for human trials in the future.

The results published today don’t seem to me to change the reasons behind that conclusion. We have seen in the past few months that ethical and uncontroversial ways to get these kinds of cells are not only possible but are being actively and successfully developed. But this particular technique seems like it’s probably not one of them.



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