WASHINGTON (BP)–One of two new techniques aimed at producing stem cells without harming a human embryo is worthy of further study through research on animals, some pro-life bioethicists are cautiously saying.
In one study, a team from the Massachusetts Institute of Technology used a version of cloning known as altered nuclear transfer (ANT). In the process, a gene in a mouse skin cell is turned off before the nucleus is placed in a fertilized egg, which develops to a stage in which stem cells can be extracted. By switching off the gene, however, the researchers make the embryo incapable of implantation in the uterus. The question in this procedure appears to be whether an embryo has truly been produced.
Pro-life bioethicists are not as inclined to endorse another new method reported on by a team from Advanced Cell Technology in Worchester, Mass. The researchers took single cells from eight-cell mouse embryos. They derived stem cell lines from those individual cells, and the embryos seemingly developed into healthy mice. The procedure is similar to preimplantation genetic diagnosis (PGD), a technique utilized in in vitro fertilization. In PGD, an individual cell is removed from an eight-cell embryo for genetic testing before the tiny human being is implanted.
The new techniques were outlined Oct. 16 in the online version of Nature, a science journal.
While some ethicists said both methods pass ethical scrutiny, others who have led the opposition to destructive embryonic research offered qualified support only for experiments using the ANT technique.
“The quest for ethical ways to retrieve stem cells is genuinely encouraging, and animal studies should certainly go forward expeditiously,” bioethicist C. Ben Mitchell told Baptist Press, “but it’s too early to tell whether the [ANT] technique can be applied to human embryos without harm to the embryos. We should remain open to the possibility.”
Even so, one thing that must be avoided “is the view that human beings — whether embryos or adults — are natural resources we can strip mine,” said Mitchell, associate professor of bioethics at Trinity Evangelical Divinity School in suburban Chicago and a consultant for the Southern Baptist Ethics & Religious Liberty Commission. “Human beings deserve respect, not commodification.”
There were questions about each of the methods from two members of the President’s Council on Bioethics.
William Hurlbut, a consulting professor at Stanford University and a proponent of the ANT technique, told Nature concerning the PGD-like method that removes a single cell, “You are getting a live birth, but are you getting the same child you would otherwise get? It is uncomfortable to me to endorse such a strategy.”
Meanwhile, Robert George, a professor of jurisprudence at Princeton University, questioned the ANT approach, telling The Washington Post, “Nobody should be speaking too quickly here on either side. The way to find out is to do the careful studies to figure out exactly what you’ve got here. It’s not a spiritual question. We’re not looking for a soul. The question is, ‘Does it have the [biological basis] for self-construction and self-organization, or is it a fundamentally disordered growth?’”
George, however, joined Mitchell, Hurlbut and about 30 other pro-lifers in endorsing an Oct. 17 joint statement in favor of research for a form of ANT that produces a cell “[i]ncapable of being or becoming an embryo.” (The statement on oocyte assisted reprogramming is available at www.westchesterinstitute.net.)
While answers to the ethical questions await further animal experiments using the new techniques, supporters and foes of destructive embryonic stem cell research endorse different measures.
“As [the two research teams’] work continues to develop, it is even more important that our nation fully support what is currently the most promising form of this research -– that involving human embryonic stem cells derived from excess fertilized eggs and somatic cell nuclear transfer techniques,” said Daniel Perry, president of the Coalition for the Advancement of Medical Research, a leading supporter of destructive embryonic research.
“It is important,” Perry said in a written statement, “that our best scientists are free to do their work using the best materials and methods available…. It is imperative to expand the current federal stem cell policy and ensure that somatic cell nuclear transfer remains legal in the United States.”
Somatic cell nuclear transfer is another term for cloning.
Mitchell, meanwhile, disagreed, saying, “[W]e must continue to vigorously expand adult stem cell research. Adult stem cells are effective, with more than 65 treatments or cures. Adult stem cells are morally uncontroversial; no one objects to their use. Adult stem cells are plentiful; they are even found in human fat.”
President Bush’s policy bars federal funds for stem cell research that destroys embryos. It permits grants for embryonic stem cell lines in existence when he announced his policy in 2001. The federal government also funds stem cell research on adult and other non-embryonic stem cells.
So far, embryonic stem cells have produced no treatments for human beings, while non-embryonic stem cells have provided therapies for such ailments as spinal cord injuries, rheumatoid arthritis, lupus, multiple sclerosis and sickle cell anemia. Taking stem cells from non-embryonic sources –- such as fat, bone marrow and umbilical cord blood -– does not harm the donor.
Research seeking ethically defensible means of extracting stem cells is ongoing on a number of fronts and has produced promising results in some cases. The following reports on such experiments were announced in August alone:
— Harvard University scientists revealed they have transformed skin cells into embryonic-like stem cells without the use of human eggs or the creation of embryos, The Washington Post reported Aug. 22.
— A team of Texas and British researchers revealed they have generated what appear to be embryonic stem cells from umbilical cord blood, according to the Aug. 19 issue of the Houston Chronicle.
— University of Pittsburgh scientists said they have discovered embryonic-like stem cells in the placenta, the Pittsburgh Tribune-Review reported Aug. 5.
The Nature article describing the two new techniques for deriving embryonic stem cells may be accessed at http://www.nature.com/news/2005/051010/full/4371072b.html.
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