This article appears in the November 2002 edition of the Catholic Medical Quarterly
ETHICAL ISSUES RAISED BY STEM CELL RESEARCH
Lecture to the Polish Medical Association, June 30th 2002
Medical advances have brought our society extraordinary benefits, but what is technically possible is not for that reason alone morally acceptable. The end does not justify the means, nor does a good intention permit anything to be undertaken. To claim that to ban human cloning would unnecessarily prevent the development of specific types of stem cells, or to say the use of therapeutic cloning is inevitable, does not constitute a moral argument. Instead, the method itself must be examined as scientific evidence shows that human somatic cell transfer is fraught with many difficulties and may well be impossible. As the whole area is one of claim and counter claim it is necessary to examine carefully the science of therapeutic cloning. Only then can there be an impartial look at the ethical problems in this area.
Stem cells are those capable of automatically renewing body tissues. Recently permission has been sought in several countries to experiment on stem cells as a way to produce organ-determined stem cells. To make this possible, stem cells have to be collected either from embryonic cells when they are pluripotent, or from adult stems and tweaked to become pluripotent, and then genetically altered to grow, for example, liver cells. Researchers prefer using embryonic cells. To achieve a regular supply of such cells, somatic cell transfer or therapeutic cloning is involved; and the cell is grown on to the blastocyst stage. Finally, the aim is to produce a line of eternal stem cells. All this raises fundamental ethical and religious questions about what it means to be human and what restrictions, if any, should be placed on research in this area. The importance of such questions for society cannot simply be ignored in favour of commerce, the advance of human knowledge, or the possible cure of many genetic disorders. It must be emphasised that these concerns are not about whether medicine should advance, but how it should advance.
The Science of Therapeutic Cloning
Cell replication in higher animals takes place by mitosis, a process characterised by a series of complex changes in the nucleus leading to its subdivision; after the nucleus has divided the cell protoplasm divides. From the nuclear genes come the body (soma) and the gametes (sperm and oocytes). Yet the nuclear genes need the mitochondrial genes in the oocyte to work, as they are the powerhouses of cell life. So in the initial stages of embryogenesis following fertilisation, there is a period of so called "genetic silence" where the somatic genes are not operational and the cell depends on its mitochondrial genes for its development. At this early stage of zygotic division cells are totipotent, as each cell is considered to have the potential to make all the cells in the body. Three days later totipotent cells become pluripotent. These are embryonic stem cells.
Stem cells also exist in the adult body. Organs, like the liver, bone and skin, can repair. Other tissues are continually replaced. The gut relines every two days, white cell defences turn over every week, and the red blood cells change every hundred and twenty days. This is the work of stem cells. However, researchers do not favour this supply of stem cells. Instead, they wish to use embryonic stem cells by using somatic cell transfer which involves enucleating a cell and replacing it with a donor nucleus. This raises two basic ethical dilemmas.
Enucleating the Cell
Enucleating a cell involves removing the genetic information of the somatic genes. The uniqueness of an individual s genetic material and the special link that there is between it and the identity of the person, together with the importance anci centrality of reproduction in the life plan of a person or couple, indicate the value that is destroyed. It is this connec tion between life and the person that is removed. That is the point in emphasizing that human life is sacred from its beginning. To argue that the nucleus is mere genetic information, a DNA among mil lions, misses the point. The way that everyone prizes their family lineage and keep detailed docu ments of their forebears shows the respect that is due for an individual s genetic material. However, to argue that because the DNA controls develop ment, personal life begins at conception, is flawed because the delayed action of the somatic genes, the lack of individualisation, and the natural loss of so many oocytes, point to the zygote as a potential person. This is why the Pontifical Academy of Life in a statement of June 24th 1997 said:
Human cloning is an extreme form of manipulation that would destroy the complementary and personalist nature of human reproduction. It turns it into an industrial process.
Human cloning violates the human right of equal dignity by selective reproduction.
Human cloning would radically exploit women reducing their role to the strictly biological function of the provider of ova and a uterus.
Human cloning would destroy natural family relationships of parenthood and blood relations.
Human cloning would create a context of psycho logical suffering for the cloned subject who is simply a copy of somebody else.
Replacing the Cell with a Donor Nucleus
Enucleating a cell and replacing this with a donor nucleus means the mitochondria of one cell are used by the donor nucleus to grow. This is because mitochondrial organelles are the powerhouses of the cell. They provide four essential pathways for energy transformation. Damage to any of these essential pathways accelerates aging in children and adults.2 Humans breathe down the female line. A cloned animal may look like its father, but its genetic structure is not the same because it uses different mitochondria from the father.
Unfortunately, given the range of problems that cloned animals have, there can be no doubt that somatic cell nuclear transfer damages the mitochondrial genes in the female egg. For example, the New Scientist (19th May 2001) reports that no matter what tests scientists do, they cannot predict which cloned calves will be born healthy. In fact, only 5 to 10 percent of implanted cloned embryos become live calves and around 75 percent of the cloned calves die in the first two months of pregnancy. Every fourth clone born is either stillborn or sufferers from a lethal defect. Even worse, the idea of screening cloned embryos for chromosome abnormalities, and using imaging to keep tabs on the foetus, is sheer nonsense. Foetuses that look robust at 60 days may die at 61. And a clone that dies after five days of life can have normal chromosomes and genes while still in the womb3. Hence it must be concluded that the present process of therapeutic cloning presents serious risks and, at best, can only be described as highly experimental. This means the ethics of non-beneficial experimentation, as the subject of the experiment does not benefit from this research, must be applied.
The subject of the experiment must not be treated as an object to be manipulated - respect and consent are fundamental;
The research must be well-planned, risks fore seen and avoided if possible,
The knowledge gained should be freely available to the whole of humankind, only new developments should be patented No harm should be done either to the subject of the research or those who use this research.4
The surprising fact is that none of these basic ethical rules will be kept by the proposed research on stem cells:
Because somatic cell transfer treats the cell to be enucleated as an object to be manipulated whose only purpose is to provide mitochondria.
Consent to use blastocysts to be enucleated is not possible, neither is the consent of the owners of such blastocysts really possible, as a blanket consent to use such cells for research does not include sufficient information about the possibil ity of cloning.
The risks in this process are exceptionally high.
The purpose of this research is to patent the human embryonic stem cells created and recoup the costs involved by charging for those stem cells. This is in spite of the fact that human embryonic stem cells occur naturally.
Harm is certainly done both personally and to society by therapeutic cloning because it lessens the respect for life in society.
Destroying the Blastocyst to Remove its Stem Cells
The final stage of making embryonic stem cells is destruction of the blastocyst created. This is a more serious act than enucleating a cell, as it is certain the cell is now organised by its DNA and its biological potentiality is clear. Prudence would suggest that proceeding with such destruction is at best morally very doubtful, and most probably immoral.5 The Declaration of the Pontifical Academy for Life on the Production and Use of Embryonic Stem Cells for Scientific or Therapeutic Research argues that this is clear from the encyclical Evangelium Vitae and the Instruction Donum Vitae, which teach that the fruit of human generation must be respected from the very first moment of its existence. Likewise, Pope John Paul II declared that therapeutic cloning is not morally acceptable precisely because it involves the manipulation and destruction of human embryos.6
Using Adult Stem Cells
However, there are other methods that avoid these difficulties. These are the collection of stem cells from the umbilical cord, and altering adult stem cells.
The blood contained in the baby's umbilical cord is rich in haematopoietic stem cells, the master cells of the blood and the immune system. These have already been used to cure blood and immune disorders following cancer treatment: they are particularly useful as they are immature and so avoid rejection problems. Already cord blood banks, that charge no fees, exist in North America.
Adult stem cells have been collected and then nurtured into becoming another stem cell type, for example stem cells from the blood have been tweaked to become muscle stem cells. This is only the beginning. Researchers are finding adult stem cells incredibly plastic. The difficulty over the age of such cells has recently been overcome, and such cells are widely available in the patient s own body, thus avoiding rejection.
Obviously neither of these methods would lead to such significant problems as arise in therapeutic cloning.
However, the use of adult stem cells presents significant risks to the recipients of such cells. The damage caused in collecting, preserving and tweaking adult stem cells is unknown and the results of their use could be unpredictable. Likewise, the mechanism that restricts the growth of new tissue or cells is only now being understood, and the failure of such a mechanism to control adult stem cells could also give unfortunate results. Hence in every sense to claim cure for many conditions at present incurable is premature and cruel to those who suffer from such diseases. There is a need to moderate the hopes of stem cell research.
Thus, while the aim of scientists seeking to clone stem cells to produce a life saving technique for various illnesses is most laudable: it cannot justify bringing it about through immoral means.
Although this is a very common opinion, some argue that the energy derived from the mitochondrial activity which causes cell division could also mean there is some interaction between the nuclear and mitochondrial genes.
The cycles are the citric acid and respiratory cycles as well as oxidative phosphorylation and fatty acid oxidation, page 136, Encyclopaedia of Gerontology. Age, Ageing and the Aged. Volume 2. Academic Press 1999.
Cloning Special Report. "The Awful Truth: Why would anyone in their right mind want to clone a baby when animal cloning can go disastrously wrong?". Philip Cohen and David Concar. New Scientist 19th May 2001, pages 14-154
Reich W T, edit. Encyclopaediaof Bioethics, The Free Press, New York, 1978. pp. 694-695.
For example Dr Norman Ford in the Tablet argued that the status of the human embryo is not settled in Catholic theology. Ford N. 9th December 2000.
Address to 18th International Congress of the Transplant Society, Rome 29th August 2000.
Fr. Peter Jeffery CSSP, STL, STD is a Holy Ghost Father at Northwood, Middlesex.