'Reprogrammed' stem cells excite opponents of embryo research

Last week's announcement that two teams of researchers, led by Dr Shinya Yamanaka at Japan's Kyoto University and Professor James Thompson at the University of Wisconsin in the US, had managed to 'reprogram' human skin cells into what they term iPS (induced pluripotent stem) cell has re-ignited the debate over the ethics and value of research using embryos.

Opponents of embryonic stem cell (ES cell) research have hailed the news that a similar state of pluripotency - the unique aspect of ES cells that some scientists claim makes these cells an invaluable research source - as a triumph of 'non-destructive' research over other methods that entail the destruction of a human embryo. Some even declare the stem cell 'war' to be over with iPS cells rendering embryo research and SCNT - therapeutic cloning - unnecessary. However, many stem cell researchers have been at pains to highlight that the creation of iPS cells actually demonstrates the worth of pursuing all avenues of research. Even Cell, the journal in which the findings were published, ran a commentary accompanying the news items maintaining that ES cell research is 'more important that ever'.

The ethical appeal of iPS cells for some lie in the way in which they are created: reprogramming human skin cells into a pluripotent state. This absolves the need to use or create (as in SCNT) an embryo to source the cells from in a process where the embryo would ultimately be destroyed. Many bioethicists and institutions, such as the Catholic Church, as well as the Bush administration, oppose the destruction of what they consider nascent human life and have welcomed the new findings. Tony Fratto, spokesman for the White House, reported that President Bush was 'very pleased' on hearing the news. 'By avoiding techniques that destroy life, while vigorously supporting alternative approaches, President Bush is encouraging scientific advancement within ethical boundaries,' Fratto said in a statement.

Bioethicist Leon Kass, who is a member and a former chair of the conservative President's Council on Bioethics, which advises Bush on ethical issues surrounding biotechnology, commented that these findings were 'an enormously significant achievement, one that boosters of medical progress and defenders of human dignity can celebrate without qualification'. Kass claimed that the news makes the 'alleged need for so-called therapeutic cloning - cloning embryos for research - now passe'. 'We can therefore disentangle the 'life issue' of embryo-destruction from the 'dignity issue' of baby manufacture, and enact a legislative ban on cloning and other degrading forms of baby-making,' he said.

The US public interest organisation, the Center for Genetics and Society, in their opposition to therapeutic cloning, have called on SCNT research to be put on hold whilst the value of iPS cells is explored further. 'Cloning-based stem cell research lays the technical groundwork for the reproductive cloning of humans, and it requires enormous numbers of fresh eggs, whose extraction poses health risks to women', said Jesse Reynolds, a policy analyst at the organisation. The Center also points out that 'after years of work, no researcher has created a cloned human embryo viable enough to yield stem cells'. However, whilst there are indeed no therapies at trial stage based on ES cell research as of yet, it has been reported that two US biotechnology firms, Geron and Advanced Cell Technology, have plans to begin the first trials using treatments derived from embryonic cells next year.

Meanwhile, Dr Shinya Yamanaka and Professor James Thompson themselves have put a dampener on the furore surrounding the discovery of iPS cells raising concerns that mitigate the immediate potential of the new type of stem cell, calling for ES cell research to continue. Dr Yamanaka said that whilst the discovery 'was a breakthrough', in terms of utilising the findings 'the goal is far off in the distance'. 'Scientists have to continue embryonic stem cell research as it would take some time for us - at least a year, I would say - to prove its safety in research on monkey cells', he said. Since both techniques rely on the use of viruses to introduce the crucial genes, they are not suitable for clinical applications. Professor James Thomson, the first person to isolate ES cells in 1998, was similarly sober about his discovery: 'Even though we have this nice new source of cells, it doesn't solve all the downstream problems of getting them into the body in useful form'. It therefore appears that it may be too early to write off ES cell research and its potential to produce groundbreaking medical discoveries.