Stem cellsThe ethical issues of deriving stem cells from human embryos have been discussed in great depth and passion since their first isolation in 1998. Dr Bruce has played signficant roles in the development of ethical thinking and regulation in both these fields in the UK and Europe in the context of his previous work for the Church of Scotland SRT Project and the Bioethics Working Group of the Conference of European Churches.
The acceptability of such research depends on what is believed about the moral status of the human embryo. There are three main positions.
Church of Scotland Study on Human Stem Cell Research and Embryology
In 2006 Dr Bruce set up a multi-disciplinary working group, comprising adult and embryonic stem cell researchers, clinicians, theologians and ethicists, to examine in depth the issues for a report to the 2006 General Assembly of the Church of Scotland. The report assessed the scientific developments in adult and embryonic stem cells and cell nuclear transfer cloning. Three case studies assessed their potential use to provide clinical therapies to treat Parkinson's, Huntington's and and motor neurone diseases, diabetes and blood disorders. It then re-examined the complex issue of the moral status of the human embryo. It looked at the stages of embryo development from fertilisation to implantation and asked what ethical and theological signficance each stage had and at what stage we should consider it should be given the protection of a human person. It recognising the differences of view within the Church.
In Edinethics we take the intermediate position of the status of the human embryo. We would see validity in using using surplus IVF of PGD embryos up to the UK legal limit of 14 days for certain types of research, but only for good reasons, and there remains an obligation to seek for alternatives, and to use these in preference once a scientific and clinical case can be made to do so. The creation of embryos for research, either by IVF or cloning is unacceptably instrumental towards the embryo. We would alsooppose the use of animal-human hybrid and parthenogenetic embryos.
New Developments in Stem Cells - Deriving Human GametesAs the science of stem cells has developed into new areas, at Edinethics we are seeking to keep pace with ethical assessment.
ESNATS Project : Stem Cells to test Pharmacueticals
Up till now, the ethical debate over human embryonic stem cells has focused on their direct therapeutic uses. Indeed, the justification for using human embryonic stem cells has been made almost entirely on the basis of their potential to provide unlimited qualtities of replacement cells for the treatment of a range of degenerative diseases, as well as heart conditions, and spinal injuries. But the clinical realisation of these aims remains considerably in the future. In the meantime, the most immediate application of these cells is likely to be in a quite different field, of testing potential pharmaceuticals for toxicity, but hardly any ethical discussion has made of this. Edinethics is examining the issues involved in the EC FP7 ESNATS project (Embryonic Stem cell-based Novel Alternative Testing Strategies) on the use of human embryonic stem cells to test pharmaceuticals for toxicity and as alternatives to animal testing, which raises several searching new ethical issues.
We have also created a Democs card games to help people explore the issues in small groups. Democs Card Game on Human Embryonic Stem Cells to Test Medicines for Toxicity
Culturing Gametes from Stem CellsExperiments have demonstrated that mouse ESCs can make sperm cells and sperm. This is seen as the 'proof of principle' for making human sperm from human ESCs. Experiments at Newcastle in the UK have derived human sperm cells to a quite late stage of development. Although it is not clear that it would be possible to make fully functional sperm, it raises some important ethical questions. Analogous work to make human oocytes (eggs) from hESCs is at a very much earlier stage. It may prove too difficult because the egg is very much more complex than sperm.
Why is such work being done? One reason is to research into understanding why reproductive development goes wrong. Second some think it might offer potential solutions to some causes of male infertility, for example rare conditions where a man cannot produce sperm at all, or more commonly sperm of very low quality or quantity. To produce his own sperm, however, he could not use stem cells from 'surplus' IVF embryo, because they would be his, but cells from some other genetic individual. To make his own sperm, would require a nuclear transfer cloning process.
Skin cells could be taken from the man, added to the enucleated egg of his wife and fused to create a cloned embryo of the man. So far no one has made functional embryonic stem cells from a nuclear transfer cloned human embryo, but if it was one day possible to do this and also to differentiate them to become sperm cells, it might be possible to make the man's 'own' human sperm by this means. The couple may then be able to have their own genetic child by IVF.
Some Ethical issues in Culturing Gametes from Stem Cells
This and some other developments lead me to express a general concern for our societies of being enchanted by the impersonal logic of techne, in so far as it is primarily interested in 'what works' for a particular medical or personal goal, expressed as a technical problem, without sufficient regard for wider values, except perhaps efficacy and safety. There is a reductionism in the progressive ability to access and separate the parts and processes of reproduction from their natural biological context (and their wider human contexts), and rearrange them. Such an engineering understanding lacks an adequate ethical framework to know which manipulations would be deemed morally right or wrong. Whilst this is recognised by many, the churches have a special role to play in identifying what values are crucially important.
If sperm were generated via cells from a spare IVF embryo, and a child was born, the biological father of the child would be the destroyed embryo. I suggest that this is ethically unacceptable, like the suggestion in 1994 to derive human eggs for assisted reproduction from aborted foetuses, which was ruled as impermissible in the UK.
If a child were created using sperm from somatic cell nuclear transfer, strictly speaking the child would also not be that of the intending father, but of the cloned embryo, which is his unborn cloned twin brother. There is also a profound inconsistency in using a reproductive process that entails creating an intermediate embryo that will be destroyed, in order to obtain one's 'own' sperm to make a sperm-egg embryo of your own.
It might be possible to do this using iPS cells. A skin sample would be taken from the man, the cells would be taken back to the pluripotent stage, and then redirected to create sperm. In this case, the sperm would be truly the man's own, and no intermediate embryo would be created.
There are also significant risks of deformity to the child because of the nature of the procedures. Thus, mouse pups born using sperm from mouse iPS cells died soon after birth. It is one thing to have a laboratory experiment, quite another to make a safe and reliable clinical therapy. It is hard to see what experiments could be done to establish this so unequivocally, that one would be sure of getting it right first time and every time. It seems likely that the first attempt would, in effect, treat the child to be as an experimental subject, which would be contrary to normal medical ethics. Pressures to proceed before establishing due safety, or to use such technologies before the underlying science is understood, should be resisted.
There are also very serious ethical issues if both sperm and eggs could be made in unlimited quantities, and according to particular specifications, from either human embryonic stem cells or induced pluripotent stem cells.
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