To its advocates, including British Prime Minister Tony Blair and Californian Governor Arnold Schwarzenegger, stem cell therapies promise a medical revolution that will enable all of us to live longer, healthier lives.
This week Blair was in San Francisco to foster closer ties between British scientists and U.S. biotechnology firms after California announced a massive 10-year investment in stem cell research.
But to its critics — notably U.S. President George W. Bush — stem cell research threatens to undermine what it means to be human. Announcing a presidential veto on federal funding last month, Bush said that experimental studies involving embryonic cells "crossed a moral boundary that our decent society needs to respect."
The debate may already be under way, but the likely clinical benefits of stem cell research are at least a decade away, according to scientists.
Professor Colin McGuckin, a specialist in regenerative medicine at the UK’s Newcastle University, said the prospect of imminent treatments for conditions affecting the nervous system such as Alzheimer’s and Parkinson’s disease had been exaggerated.
But he said stem cell therapies for degenerative disorders afflicting major organs such as the heart and liver could be available within 10 years.
"What we’re going to see is one or two patients being helped in some way and people are going to hail it as the end of Parkinson’s and Alzheimer’s," McGuckin told CNN.
"But it’s going to be a slow process. We hear an awful lot of hype about what stem cells can do but in reality there’s still a lot of work to do."
Dr. Stephen Minger, Director of the Stem Cell Biology Laboratory at King’s College in London, said existing cell therapy treatments for diseases such as Parkinson’s and diabetes already provided a model for possible stem cell therapies.
But he said the pace of progress would depend on increasing the number of suitable cells made available to scientists — and warned that a great deal of "fundamental research" still had to be done before stem cell applications were ready for clinical trial.
"This is a very, very young field," Minger told CNN. "Most people in the world have only been working with these cells for two to three years. Prior to 2002 if you wanted to do human embryonic stem cell research it was almost impossible to gain access to cells. We don’t want to create false expectations that these therapies are just around the corner."
Minger, who moved his research program from Kentucky to the UK in 1996, said the U.S. presidential veto on federal funding for embryonic research would have a detrimental effect on the progress of research worldwide.
"It has had a very chilling effect," he said. "The U.S. funds more biomedical research than any other country and for them not to be involved in this is a setback to the entire field. The rest of us will push on anyway but clearly the field is not going to advance as quickly. I think U.S. scientists have done a poor job of articulating what this field is about."
McGuckin said the most disappointing aspect of the controversy had been the failure of both critics and advocates to engage in a constructive debate on the future benefits of stem cell therapy.
"If you look at the five years over which they’ve been working towards getting this bill on the books and ultimately getting it vetoed there was really very little proper scientific debate about what the issues were," he said.
"It was really all about religion and ethics but there was nothing about whether this was the right thing to put money into. The thing that kills lots of people in the Third World is infection — and putting millions into stem cell research isn’t necessarily going to help us treat infectious diseases which kill millions of people."
Stem cell research has also been thrown into disrepute in recent months by the revelation that South Korean scientist Hwang Woo-suk, formerly the head of one of the world’s leading stem cell laboratories, had faked results in landmark research papers concerning the alleged successful cloning of human embryos.
But Minger dismissed concerns that Hwang’s exposure had set back wider stem cell research, claiming the revelations would have a "minimal effect" on scientific work in other laboratories.
"The main body of stem cell research is people working on embryonic stem cells, adult stem cells or cord blood and all of us are trying to find out the best way to use these cells for clinical applications. Hwang’s work was spectacular but cloning and stem cell cloning is really a fringe element," he said.
