Was La Jolla company right to clone?
On Jan. 17, Stemagen, a La Jolla company devoted to stem cell research, announced that it had produced “human blastocyst stage embryos” using a method of cloning. The news, which was published in the peer-reviewed journal “Stem Cells,” was received with sharply mixed reactions around the world.
Because the process carries enormous potential to heal even as it produces and destroys embryonic human life, it is fraught with ethical questions.
In an attempt to wrestle with the world-wide ethical questions raised by this local work, the Light asked two ethics professionals to write essays exploring and clarifying the moral issues involved in Stemagen’s work.
By Mary DevereauxStemagen’s recently announced success with human embryonic cloning provides scientists with a new tool in advancing stem cell research. It also confronts us with some important biological and ethical questions. What is it that cloning creates? How should we think about this newly created thing? And what responsibilities do we have as scientists, healthcare providers, patients and citizens to think through the social, ethical and legal implications of this work?
The usual source of pluripotent stem cells is the inner mass of the four to five-day-old embryo or, more precisely, a “blastocyst,” the hollow ball of cells no bigger than the period at the end of this sentence. Stem cell research has made use of excess blastocysts produced by couples undergoing fertility treatment.
Stemagen has succeeded in developing human blastocysts in a new way. Technically known as somatic cell nuclear transfer (SCNT), this process involves taking a donor egg or “oocyte,” removing its nucleus, then inserting the nucleus of an ordinary body cell (a skin cell, for example). With a little help from scientists, the donor nucleus and the remaining or enucleated egg will fuse. This new unity will go on to divide and form the hollow ball of the blastocyst, again providing a source of pluripotent stem cells.
Compared to the IVF-generated blastocyst, this process (SCNT) has two major advantages. The first is that this new technique moves us one step further towards the possibility of generating stem cell lines that “match” a person’s own genes. Therapies based on such customized cells would overcome the significant problem of immune rejection, a large factor in the difficulties of organ transplants. The second advantage is that SCNT-produced blastocysts make it possible to expand the genetic diversity of the cell lines studied.
Nobody would object to the aim of curing human disease. What is at issue ethically are the means used to reach this goal. Many, although not all, of the methods used to derive pluripotent stem cells, including SCNT, require disaggregating, or taking apart, the embryo, resulting in its death.
Dr. McGoldrick believes that this is equivalent to murder. Disaggregating the blastocyst is, he argues, like bulldozing an abandoned building with a homeless man living inside. The killing isn’t the aim of the bulldozing, but the man inside ends up dead nonetheless.
But the analogy between the early embryo and the homeless man begs the very question we need to answer. Does the five-day-old blastocyst have the moral status of an adult human being? The question “What is it we have in the dish?” is precisely a question about the status of the entity found there. McGoldrick’s answer to the status question rests on a controversial, specifically religious, premise held by a particular Christian denomination. This premise is the Roman Catholic Church’s comparatively recent doctrine that the embryo becomes “ensouled” at conception. It is worth noting that the Catholic position on the time of ensoulment has changed over history. So Thomas Aquinas, following Aristotle, held the view that a male fetus became ensouled only at 40 days past conception; female fetuses at 90 days. The Church’s doctrine was changed to accommodate scientific discoveries about gestation. While we owe respect to those who hold such beliefs, it is important to note that many religious groups, including Christian ones, hold developmental views on which moral personhood is fully acquired only at birth or even after. There is also the question whether the religious doctrines of particular denominations should determine public policy in a pluralistic society.
The point of Dr. McGoldrick’s homeless man analogy is that precisely because of disagreements over what SCNT produces, we should exercise caution.
The idea that we should presume that what we create in the Petri dish possesses the status of an adult human being is a way of avoiding the need to make moral judgments about the moral status of biologically new forms of entities. The argument that any biological entity that has the potential to become an adult human being should be regarded as one may, moreover, lead to an absurdly broad definition of moral personhood in a future where cell reprogramming becomes commonplace. The future aside, what the moral status of the SCNT-produced blastocyst is is something we have to decide. Somatic cell nuclear transfer, like IVF before it, takes us into new ethical territory. The specific ways in which this new approach produces blastocysts puts the very idea that the cloned entity is an embryo in question. IVF allowed fertilization to take place outside the uterus. SCNT removes the sperm. The result is something quite different in origin from what we’ve traditionally understood by conception, a process involving the fertilization of egg and sperm in utero. With SCNT, we have only the enucleated egg and a donor nucleus, neither of which constitute anything like what we ordinarily mean by “parents.” Of even greater moral significance, a blastocyst produced in this “new” way is not on a path towards becoming a full fledged human being. The biological limitations of reproductive cloning (cloning aimed at producing babies not cell lines) have led to a near unanimous scientific agreement that efforts at implanting such blastocysts would be unsafe and highly unethical.
What ethical commitment calls for in the case of the SCNT or clonal blastocyst then is reflection on hard moral questions. Answering these fundamental questions is the responsibility not only of bioethicists, theologians, or scientists, but of all of us.
Mary Devereaux, Ph.D. is the Director of Biomedical Ethics Seminars in the Research Ethics Program at UCSD.