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A way to sidestep biotech's ethical impasse

Financial Times, August 24th, 2006

Stem cell research needed a boost, a fter a year that brought US President George W. Bush's veto on federal funding and the fiasco of Hwang Woo-suk's scientific fraud in South Korea. It comes on Thursday, with the publication of experiments showing human embryonic stem cells can be created without destroying embryos.

The work by Advanced Cell Technology, a US biotechnology company, will be a scientific landmark if it removes the biggest ethical objection to stem cell research: the inevitable destruction of potential human life. "It appears to be a way out of the current political impasse in the US and elsewhere," says Ronald Green, who chairs ACT's ethics board.

Scientists at ACT's Massachusetts laboratory generated stem cell "lines" – self-replicating cultures – by plucking individual cells from newly fertilised human embryos, which are not harmed in the process. The breakthrough is based on a single-cell biopsy, known as pre-implantation genet ic diagnosis (PGD), which fertility clinics use to detect gene defects in their in-vitro fertilisation (IVF) embryos. Conventional stem cell production instead involves extracting the "inner cell mass" of embryos that are about a week old.

"I think ACT's single-cell derivation will become the method of choice for producing human embryonic stem cells," says Prof Green, who is also director of Dartmouth College's Ethics Institute, "assuming that the experiments are replicated by others."

His proviso is understandable, after Prof Hwang's human cloning experiments turned out largely to be fabricated. But Nature, the journal carrying the ACT studies, subjected them to thorough review in an effort to avoid the embarrassment suffered by its rival, Science, which published Prof Hwang's work.

Advocates of "regenerative medicine" pin their hopes on embryonic stem cells because these hav e the potential to become any specialised cell or tissue in the body. By directing this differentiation, scientists hope to develop treatments for a range of degenerative diseases, from diabetes and heart failure to Parkinson's and Alzheimer's.

Independent stem cell scientists admire ACT's technical achievement, which comes only a few months after the company's researchers first carried out the procedure in mouse embryos. (It often takes several years to transfer biological procedures from animals to humans.) But some experts doubt whether the advance will be very useful in countries where the conventional method of deriving embryonic stem cells is acceptable.

Robin Lovell-Badge, head of developmental genetics at the National Institute for Medical Research in London, points out that the technique will need to be refined to make it efficient enough for widespread use. The ACT scientists obtained only two stable lines of embryonic stem cells from the 91 cells they extracted from human embryos – about a 2 per cent success rate.

In response Robert Lanza, head of ACT's research team, says it is unfair to judge the ultimate success rate from the first test, adding: "I think we can greatly improve the efficiency."

Others say the work obscures the real ethical issue – that the world's IVF clinics are storing hundreds of thousands of embryos created for fertility treatment but no longer wanted by their "parents". The vast majority of these spare embryos will have to be destroyed anyway, so some might as well be used for research that might benefit humanity.

But the method could help research and at the same time benefit couples undergoing PGD at IVF clinics, Dr Lanza argues. "Overnight culture of a single cell obtained through biopsy allows both PGD and the development of stem cell lines, wi thout affecting the subsequent chances of having a child," he says. "To date, over 1,500 healthy children have been born following the use of PGD."

David Macauley, chief executive of the UK Stem Cell Foundation, an advisory and fund-raising group, says the achievement "addresses one of the major constraints to advancing research – the provision of reliable sources of clinical-grade embryonic stem cells", adding: "ACT is a prime example of the vital role that the private sector can play in realising the commercial potential in stem cells for the benefit of all."

So far, few biotechnology companies have invested heavily in human embryonic stem cell research, because any commercial payback is still many years away. Although large drugs groups could take a longer-term view, they remain wary of moving into a field that is so controversial.

ACT, a small company with 35 scientists, h as raised $25m since early last year and is engaged in an $11m funding round. But Dr Lanza says it aims to move its first stem cell therapy – for the eyes – into the clinic late next year: "Only with success in patients will we be able to persuade a pharmaceutical company to spend hundreds of millions of dollars on a commercial development programme."

Clive Cookson