Is a cloned embryo a human person?

Psychiatrist Paul McHugh has argued that embryos made by means of somatic cell transfer (SCNT) are not human persons even though those made by fertilization are. According to McHugh, SCNT is a “biological manufacturing process” that is used to make, not babies, but embryonic stem cell lines, and “resembles tissue culture” more than fertilization. McHugh has even fashioned the name “clonotes” for SCNT-derived embryos to distinguish them from embryo made by fertilization with sperm.

What is the substantive difference between embryos made by fertilization and those made by SCNT? McHugh’s main argument is as follows:

…If one used the notion of “potential” to protect cells developed through SCNT because with further manipulation they might become a living clone, then every somatic cell would deserve some protection because it has the potential to follow the same path (Paul R. McHugh, “Zygote and ‘Clonote’ – The Ethical Use of Embryonic Stem Cells,” New England Journal of Medicine 351 (2004): 209-11).

In other words, because nuclei from almost any somatic cell can be used to form a clonote, almost any somatic cell has the potential to become a clonote. It is absurd to regard all the somatic cells of our bodies as human persons. As Robert Lanza of Advanced Cell Technologies stated, “research advances are making all cells embryonic, but if you consider these cells human life, then 100 souls are lost every time I sneeze” (Joannie Fischer, “The First Clone,” U.S. News and World Report (3 December, 2001). Since it is untenable to regard somatic cells, which have the ability to form clonotes, as human persons, it is equally untenable to regard clonotes as human persons.

McHugh’s second argument notes that the vast majority of clonotes are grossly abnormal and die very early during development. Thus clonotes are not human persons, which make the production of ESCs from them morally justifiable.

McHugh’s second point is overstated. While many cloned animals develop into animals with a variety of developmental abnormalities, not all of then do. To classify cloned animals as a distinct kind of creature because they possess abnormalities ignores those cloned animals that either do not possess such abnormalities or whose health overlaps with animals that were not made by the process of cloning. If the abnormalities are part of the reason for assigning cloned animals into a different category, then that classification fails for normal cloned animals.

Secondly, molecular comparisons of cloned embryos with embryos made from in vitro fertilization have revealed extensive similarities. The abnormalities only arise later, once the embryo implants into the uterus. Thus the abnormalities that McHugh uses to disqualify cloned embryos as human persons have yet to arise.

Thirdly, if cloned embryos differ in kind from embryos made by fertilization, then what of those cloned animals that survived to term: Are such animals a different kind of animal? Consider Dolly, the cloned sheep. Was she so different as to not be considered a Suffolk Blackface sheep? This seems patently absurd. If relegating the cloned adult to a lower status is fallacious, then it is just as fallacious to demote cloned embryos to a similar status.

Finally, even if cloned embryos have abnormalities, so what? Do we really want to dismiss the humanity of an individual because they carry some sort of handicap? Dismissing the humanity of cloned embryos because of their potential abnormalities is tantamount to dismissing abnormal children and allowing medical research on them since their death is immanent (Robert P. George and Christopher Tollefson, Embryo: A Defense of Human Life (New York: Doubleday, 2008): 184-9). We should find such a proposal revolting.

What of McHugh’s first point; that is, nuclei from any somatic cell can produce a cloned embryo, and therefore, all somatic cells are potential embryos and deserve protection, which is absurd? On this point, the analogy of somatic cells with embryos seems hopelessly flawed. In fact, the entire category of “potential embryos” is simply nonsensical (Robert P. George and Patrick Lee, “Acorns and Embryos,” The New Atlantis (Fall 2004/Winter 2005): 90-100). The term embryo refers to a very specific entity in the life of an organism. Something is either an embryo or not. Secondly, somatic cells are not similar to embryos. Instead they are similar to sperm and eggs, the cells that are used to make embryos. Once the sperm and the egg fuse and complete conception, they no longer exist. Instead a new entity, the embryo, which did not exist before hand, begins it existence. The embryo is a “distinct, complete, self-integrating organism.” Somatic cells are no such thing, but are, instead, part of an organism. SCNT or fertilization makes an embryo. Thus McHugh’s first point also fails.

More Women are Donating Eggs for Money

According to a story in the Boston Globe and a CBS piece, the recession is influencing more women to donate their oocytes (eggs) to biotechnology. Men are also donating more sperm to sperm banks. The main motivation behind the increased donation rates seems to be money.

Because egg donation poses definite risks to the health of women, such an upswing makes many women nervous.  Two women (one in London and one in Dublin) are known to have died recently from complications associated with egg extraction.  In fact this web site, has more a few things to say about egg donation.

Also, formerly, bioethics panels firmly asserted that egg donations had to come from women who were not being financially compensated for anything other than expenses (see Science 312, 16 June,  2006, 1548; also see 312, 21 April, 2006, 366-367; 313, 14 July 2006, 155; and 316, 20 April, 2007, 368-370).  However, because egg donation is difficult, and because there was such a large shortage of human eggs for research, people made many arguments in favor of paying women for egg donations.  Critics complained that this would lead to exploitation of lower-income women.  The proponents guffawed at this, but now we are reaping the worldwind.

Harvesting Embryonic Stem Cells from Deceased Human Embryos

Maureen L. Condic, an associate professor of neurobiology and anatomy at the University of Utah, and Edward J. Furton, Ph.D., an ethicist and the director of publications at The National Catholic Bioethics Center in Philadelphia, Pennsylvania, have written this very useful article on the derivation of embryonic stem cells from dead embryos. Their article can be found here.

Oocyte-Assisted Reprogramming, Scientific Concerns

Dr. William Hurlburt, a member of the President’s Council on Bioethics, has proposed two possible techniques for the production of embryonic stem cells that, according to him, bypass the necessity of destroying human embryos to make embryonic stem cells. His two techniques are altered nuclear transfer (ANT) and oocyte nuclear reprogramming (OAR).

ANT proposes to inhibit a gene or group of genes that are necessary for the formation of the trophectoderm in an egg before a nucleus from an adult cell in inserted into it. Once the embryo develops, it will become a cluster of inner cell mass cell that can be directly cultured to make an embryonic stem cell line. Hurlburt recommends using techniques that temporarily inhibit the Cdx2 gene. The Cdx2 gene is required for embryos to form the outer layer of trophoblast cells (trophectoderm). Without functional Cdx2, the embryo defaults to a mass of inner cell mass cells.

Animal experiments have demonstrated the plausibility of this proposal. Experiments with mouse embryos in the laboratory of Rudolph Jaenisch at MIT used nuclei from tail-tip fibroblasts (a cell commonly found in connective tissue) as the sources for the nuclear replacement. Prior to nuclear replacement, the Cdx2 gene was conditionally inhibited by a procedure called RNA interference. Replacement of the egg nucleus with a pretreated nucleus from fibroblasts, followed by artificial stimulation of the egg produced abnormal embryos that failed to implant in the uterus, and when cultured in the laboratory, they formed embryonic stem cell cultures (Nature 439, (2006): 212–15).

OAR proposes the overexpression of the Nanos gene in the egg, and then after the transfer of a new nucleus, the embryo will form pluripotent stem cells that can be cultured to form embryonic stem cell cultures.  This website gives a clear presentation of OAR.

There are no animal experiments to support the feasibility of OAR. In fact, there are reasons to suspect that OAR would not work. The conversion of cells into pluripotent stem cells requires a network of genes of which Nanos is one (Critical Reviews in Eukaryotic Gene Expression, 16 (2006): 211-31; Stem Cell Reviews, 1 (2005): 111-8; Current Opinion in Genetics and Development, 16 (2006): 455-62; Stem Cells, 25 (2007): 2-9). Thus when it comes to the conversion of cells into pluripotent stem cells, Nanos does not work alone (Nature Genetics 38 (2006): 431-40; Cell 122 (2005): 947-56; Journal of Biological Chemistry 280 (2005): 24731-7; FASEB Journal 20 (2006): E1-E9). Thus there are good reasons to suspect that OAR, as proposed, will not work.  While these are not the only problems with OAR, it seems scientificallt dubious to endorse an alternative means of deriving embryonic stem cells that is rather unlikely to work.

Stem Cells and The Oprah Winfrey Show

Oprah had a show dedicated to stem cells. Her guests were Michael J. Fox, who suffers from Parkinson’s Disease and is an enthusiastic advocate for embryonic stem cell research, and Dr. Oz who seems to think that adult stem cells might be able to do all the heavy lifting for regenerative treatments.  He actually brought a brain to the show and showed the midbrain to demonstrate the cells that die off during Parkinson’s disease.

Unfortunately, something Dr. Oz does not mention is that cells introduced into the brain tend to be shielded from the immune system and any embryonic stem cell derivatives that were introduced into the brains of patients with Parkinson’s disease are protected from the immune system by the blood-brain barrier.  Thus, Dr. Oz’s concern about immunological rejection probably does not apply to the brain, unless the blood-brain barrier is damaged.

See the exchange here.