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Stem Cell Researchers Win Nobel Prize

By Michael Cook

The development of induced pluripotent stem cells overturned conventional thinking and removed the ethical issues associated with the destruction of embryos.

Two stem cell researchers shared the Nobel Prize in Medicine for 2012, Britain’s John B. Gurdon and Japan’s Shinya Yamanaka. By a serendipitous coincidence, Gurdon made his discovery in 1962 – the year of Yamanaka’s birth.

Fifty years of stem cell research have brought cures for intractable diseases within reach but they have also generated controversy. Between 2001 and 2008, stem cell research vied with climate change as the stormiest issue in science.

But the gale has subsided – basically because of Yamanaka. In fact, Tom Douglas of the Uehiro Centre for Practical Ethics at Oxford University describes Yamanaka’s work as “a rare example of a scientific discovery that may solve more ethical problems than it creates”.

What happened in those 50 years?

In a classic experiment at the University of Cambridge, Gurdon discovered cloning. The conventional wisdom was that cells could never change once they had specialised. He proved that this was wrong by replacing the nucleus of a frog egg cell with a nucleus from a mature intestinal cell. This modified cell developed into a normal tadpole.

This astonishing development eventually led to the cloning of Dolly the sheep in 1996. But while the technique clearly worked, no one understood why.

The obvious target for investigation was the embryo. In 1998 James Thomson of the University of Wisconsin–Madison isolated and cultivated human embryonic stem cells.

But using embryos left stem cell science hostage to ethics. Even Thomson admitted to the New York Times that “if human embryonic stem cell research does not make you at least a little bit uncomfortable, you have not thought about it enough”.

Still, it seemed the only way forward. Desperate patient advocates, backed by a supporting chorus of bioethicists, scientists and doctors, argued tearfully that miracle cures had to trump ethics.

But in 2006 there came astonishing news from the University of Kyoto. An orthopaedic surgeon turned stem cell scientist, Shinya Yamanaka, had discovered that skin cells from mature mice could be reprogrammed to become immature stem cells.

It was an amazingly imaginative step. Instead of mimicking natural development from embryo to adult, he wound the clock back from adult to embryo. Like Gurdon, Yamanaka had skittled the conventional wisdom.

This was electrifying news. It was as if commuters on a pot-holed, terrorist-infested road could suddenly detour down a six-lane autobahn. Famous scientists dropped human embryonic stem cells almost immediately and began work on “induced pluri­potent stem cells”. A year later, in November 2007, both Yamanaka and Thomson, in separate papers, confirmed that human cells could also be reprogrammed.

The rest is history.

What immunised Yamanaka against the group-think that had led others into the swamp of human embryonic stem cell research?

Nowadays, the fever over human embryonic stem cells in the early Noughties seems faintly ridiculous. Leading journals were depicting it as a battle between the Enlightenment and the Endarkenment. An editorial in the New England Journal of Medicine – the world’s leading medical journal – concluded with this cringeworthy hyperbole: “The Promethean prospect of eternal regeneration awaits us, while time’s vulture looks on.”

It never mentioned cell reprogramming.

Yamanaka’s originality may have sprung from his ethical sensitivities. Even Julian Savulescu, the director of the Oxford Uehiro Centre for Practical Ethics, recognises this. “Yamanaka has taken people’s ethical concerns seriously about embryo research and modified the trajectory of research into a path that is acceptable for all,” he said. “He deserves not only a Nobel Prize for Medicine, but a Nobel Prize for Ethics.”

In an interview with the New York Times in 2007, Yamanaka reminisced about a visit he once made to a friend’s IVF clinic. There, he peered through a microscope. “When I saw the embryo, I suddenly realised there was such a small difference between it and my daughters,” said the father of two. “I thought, we can’t keep destroying embryos for our research. There must be another way.”

Furthermore, he believes that scientists should not set the ethical boundaries. “These are very difficult decisions, and I think that society should make them,” he told New Scientist in 2007. “It should not be scientists. They can find it difficult to think like the person on the street, and instead may see it simply as a good opportunity.”

Once again, experience shows that good science is ethical science.

Michael Cook is editor of the online bioethics newsletter BioEdge.