Stem Cells without EmbryosREV. TADEUSZ PACHOLCZYK
Two years ago, a letter was released on the Ethics and Public Policy website that dealt with making embryonic stem cells without destroying human embryos.
The central objection to embryonic stem cell research is that it requires the destruction of embryonic humans who are about 5 days old, in order to procure their stem cells. OAR might provide scientists with a way to make embryonic stem cells directly, without creating or destroying human embryos. Because no embryos would be involved, the stem cells you would get out of the OAR procedure really shouldn’t be called embryonicat all, but rather pluripotent. They would be pluripotent because they would be very flexible, as flexible as the stem cells you get from embryos.
So how do you use OAR to make pluripotent stem cells? OAR makes use of a woman’s egg to carry out a procedure that, on first glance, looks very similar to cloning.
Suppose for a moment that a police officer suffering from diabetes were to donate a skin cell from his arm, and we took the nucleus of that skin cell (which contains his DNA) and placed it inside a woman’s egg, after we had taken out her egg’s own nucleus. In other words, a kind of “nucleus swap”. The expression that scientists use is “nuclear transfer”. This is what cloning is all about. Even though no sperm is involved, the egg-with-a-new-nucleus now divides and grows normally as a human embryo, a new human being. This embryo is special, however, because it would have the same genes, and be the identical twin brother of the police officer. It would be a very young clone of the officer, and if that embryo were implanted into a woman’s uterus, it could become a live-born cloned baby. But if that tiny little embryo at the beginning were denied the safe harbor of a woman’s uterus to grow in, and the embryo was instead destroyed to extract its stem cells, scientists could get immune-matched cells for the potential benefit of treating the police officer’s diabetes. The reason they would be immune-matched cells, tailored to the police officer, would be that they came from his own identical twin brother. It turns out that identical twins can exchange organs (like kidneys) between each other without rejecting those organs. So the stem cells from his embryonic twin brother, in theory, could be introduced into his body without being rejected.
The moral problem here, of course, is that you create your own twin brother (or twin sister if you are a woman) precisely in order to kill them when they are very young for their desired stem cells. If OAR were successful, it would avoid this moral problem. Instead of creating your own identical twin brother (or sister) for the purposes of strip-mining their stem cells, OAR would propose to directly make pluripotent stem cells through the same series of steps as cloning. The big difference would happen at the very beginning of the process, when special genetic changes would be made in the DNA of the police officer’s skin cell. These changes involve turning on special master genes that direct a cell to be pluripotent, or highly flexible, like a stem cell, rather than totipotent, or completely flexible, like an embryo.
So when the “nucleus swap” would occur, the new cell would now become a kind of stem cell, rather than an embryo. In other words, the woman’s egg would never be activated to form a human being. If the resulting cells made by OAR were put into a uterus, nothing would happen, no pregnancy would be possible, since they would be stem cells, not embryos. Only embryos are capable of implanting into the wall of the uterus in making a woman pregnant. Since OAR stem cells are not derived from embryos, and are not embryos themselves, it would be morally permissible to culture and grow them or manipulate them in the lab as needed, in an attempt to come up with new therapies for patients.
Rev. Tadeusz Pacholczyk. "Stem Cells without Embryos." Making Sense Out of Bioethics (July 1, 2005).
Father Tad Pacholczyk, Ph.D. writes a monthly column, Making Sense out of Bioethics, which appears in various diocesan newspapers across the country. This article is reprinted with permission of the author, Rev. Tadeusz Pacholczyk, Ph.D.
The National Catholic Bioethics Center (NCBC) has a long history of addressing ethical issues in the life sciences and medicine. Established in 1972, the Center is engaged in education, research, consultation, and publishing to promote and safeguard the dignity of the human person in health care and the life sciences. The Center is unique among bioethics organizations in that its message derives from the official teaching of the Catholic Church: drawing on the unique Catholic moral tradition that acknowledges the unity of faith and reason and builds on the solid foundation of natural law.
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Father Tadeusz Pacholczyk earned a Ph.D. in Neuroscience from Yale University. Father Tad did post-doctoral research at Massachusetts General Hospital/ Harvard Medical School. He subsequently studied in Rome where he did advanced studies in theology and in bioethics. He is a priest of the diocese of Fall River, MA, and serves as the Director of Education at The National Catholic Bioethics Center in Philadelphia. Father Tadeusz Pacholczyk is a member of the advisory board of the Catholic Education Resource Center.
Copyright © 2007 Rev. Tadeusz Pacholczyk, Ph.D.
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