Slippery slope or uphill struggle?

Last week, scientists in Newcastle received the first UK licence granting  permission to isolate stem cells from cloned early human embryos. Team leaders Alison Murdoch and Miodrag Stojkovic hope that the work will eventually lead to new treatments for diabetes, and a range of other diseases caused by the loss of a specific type of cell. This exciting news triggered a media frenzy, with most reports focussing on the potential medical benefits of the research.

Inevitably, however, pressure groups against any research on human embryos raised concerns that the development would lead straight to cloned human babies. But given the scientific and legal background to last week's announcement, the Newcastle group may well feel that they face an uphill struggle with their work, rather than any slippery slopes. Their project is a technically-demanding one, and could face further regulatory challenges.

The one-year licence will allow the researchers to try and derive stem cells from cloned human embryos, using eggs left over from IVF treatment. The work is permitted for basic research purposes only, and will not directly lead to any new treatments. But even getting this far represents a landmark for UK stem cell scientists, who have waited since 1998 to begin work in this promising area of research. It was then that 'therapeutic cloning' was first considered as a potential way of treating many diseases.

The idea followed the successful development of cloning technology by UK scientists to produce Dolly the sheep, unveiled in 1997. This was followed by the isolation of stem cells from human embryos, by a US team a year later. By combining these technologies, scientists proposed, it might be possible to produce any type of body cell, genetically identical to the patient requiring treatment. In reality, it took a further six years before a team of Korean scientists managed to produce the world's first cloned human embryo stem cells: an achievement that the Newcastle team now hopes to match.

The regulatory hurdles facing the researchers must, at times, have seemed as challenging as the scientific ones. Before research on human embryo stem cells could begin in the UK, an amendment to the Human Fertilisation and Embryology Act of 1990 was required. After much parliamentary debate, the legislation was passed in December 2000, only to face a successful legal challenge by an alliance of pro-life groups. This ruling was overturned in January 2002, and a House of Lords select committee eventually gave the green light to embryo stem cell research two months later.

Last week, pro-life campaigners in the UK were again considering legal action aimed at stalling work in this crucial area of research. There are also ongoing efforts to ban research on cloned human embryos at the European and international levels. Parents of children with diabetes, and people affected by conditions such as motor neurone and Parkinson's disease must hope that these efforts are unsuccessful, leaving committed scientists to continue their pioneering work towards new medical treatments.