The ethical cell

The ethical cell ... Research breakthrough

David Albert Jones - 20 October 2012

Professor David Albert Jones with Archbishop Vincent Nichols

For many decades, scientists working in the field of generative medicine sought ways of finding a ready and plentiful supply of human stem cells in the hope that these could be used to treat a range of degenerative diseases. Last week, the Cambridge scientist, Sir John Gurdon, and Professor Shinya Yamanaka of Japan were jointly awarded the Nobel Prize for Medicine for bringing this dream a step nearer. Forty years before Dolly the sheep, Sir John cloned a frog by a similar cloning technique, and Professor Yamanaka conducted experiments in 2005 that showed that it was possible to re-programme a skin cell to turn it into a stem cell.

What are stem cells? All (or almost all) of the tens of million of cells in the human body are similar in structure, having a nucleus with the same DNA containing the same information that gives you your inherited characteristics and gives me mine. However, blood cells do not do the same job as nerve cells, which do not do the same job as muscle cells, and so on.

All the cells in the body are descendants of the original cell, the zygote or single-cell human embryo, but over time the cells have specialised to perform different functions in the body.

In contrast, a stem cell is a cell that remains flexible in what it can do. It can both reproduce itself and give rise to different kinds of specialist cells. For some time, scientists have hoped that stem cells might be useful in medicine, helping to replace or repair damaged tissue.

Stem cells are found in bone marrow, the cornea and the blood in a baby's umbilical cord, and these have been extracted for use in a variety of treatments. However, the most controversial and ethically problematic source of stem cells is the human embryo. In 1998, a line of stem cells was created by destroying a human embryo, and since that time many hundreds of embryos have been destroyed in attempts to create more stem-cell lines. For anyone who accepts (or even suspects) that a human life begins at fertilisation, it is clearly unethical to kill an embryonic human being simply to "harvest" his or her cells.

The controversy over destroying human embryos for their stem cells is the background to Yamanaka's work in Japan and the US. He was able to take ordinary adult cells (not adult stem cells, but ordinary skin cells) and turn them into cells which behave very like embryonic stem cells. This is the biological equivalent of turning base metal into gold.

From a humble skin cell, by switching on certain genes, Yamanaka was able to create a stem cell. This cell seems to have the advantages of embryonic stem cells (for example, being able to multiply easily) together with some of the ethical and practical advantages of adult stem cells (being taken from an adult). His experiment was both elegant science and ethical science.

In a New York Times interview, Yamanaka recounted an experience that changed his career - a glimpse down the microscope, at a friend's fertility clinic, of one of the embryos stored there. He commented: "When I saw the embryo, I suddenly realised there was such a small difference between it and my daughters. I thought, we can't keep destroying embryos for our research. There must be another way." Although he did not oppose all embryo research, Yamanaka was motivated, at least in part, by a desire to find "another way", and not just by political pressures, such as the restriction on funding embryo research imposed by President George W. Bush.

In the United Kingdom, there has never been any restriction on funding destructive embryo experimentation. Indeed, as each new and unethical form of experimentation has been suggested, the Government has rushed to permit it, including the creation of part-human part-non-human embryos, hybrids and also chimeras, made from the nucleus of a human being and the cytoplasm of a cow or a rabbit. Nothing came of these bizarre experiments, despite the exaggerated claims made about them at the time.

In contrast, Yamanaka's experiment has been the basis of a whole new area of research, not with adult stem cells or embryonic stem cells, but with what are called iPS cells or "induced pluripotent stem cells". These are stem cells created from ordinary adult cells, such as skin cells. This research is increasingly attracting funding both in this country and abroad. It is exciting science.

Are there, nevertheless, some ethical problems with iPS cells? Should we be cautious before welcoming this Nobel Prize? As with any technology, especially one that is potentially very powerful, the issue of iPS cells does raise ethical issues. Already they have been used to clone mice and create artificial sperm and eggs for use in mouse IVF. As human cloning, and other forms of in vitro manufacture of human lives, contradicts the dignity of procreation, it would clearly be wrong to use iPS cells for such purposes.

Another more immediate ethical problem with iPS research is that many scientists who are working with iPS cells are, at the same time, working with embryonic cells. There can be an inertia among scientists, and professional and personal attachments to older ways of doing things, even if they are unethical.

So a strongly ethical young scientist who wishes to work on iPS cells might find themselves in difficulties because of being asked to cooperate with embryonic stem-cell research. It is also true that stem-cell research is still a very young area of science, and we should not exaggerate the prospect of immediate treatments.

Adult stem cells are already used successfully in both established and experimental treatments, but the revolution in treatment for which many are hoping is still some way off.

It is the job of a bioethicist to make qualifications and to point out potential difficulties, but none of these should obscure the fundamentally positive contribution of Yamanaka's work. This Nobel Prize recognises a great scientific breakthrough, but it is equally an achievement of great ethical significance. It offers a new and promising approach to stem-cell research which need not involve the destruction of human embryos.

The occasional conflicts of scientists and ethicists, and the adoption of unethical practices in the name of science, should not be allowed to obscure the fundamentally ethical character of the scientific endeavour and the positive contribution that religion has had in sustaining the search for knowledge through the centuries. This Nobel Prize shows science as it can be, science at its best: both beautiful and ethical.

Professor David Albert Jones is director of the Anscombe Bioethics Centre in Oxford.