Scientists make stem cells without destroying embryo
Scientists have found a way to make human embryonic stem cells without destroying embryos, a breakthrough that could overcome intense ethical objections to the research.
Religious groups, “pro-life” organisations and the Bush administration have all condemned embryonic stem-cell science because embryos must be cannibalised to harvest stem cells from them. Last month, United States President George Bush used his first veto to defeat a bill that would have expanded federal funding for embryonic stem cell research.
But scientists in the US claim their technique sidesteps objections by not harming embryos, and so gives researchers an ethical way to create valuable stockpiles of stem cells for the first time.
British experts applauded the discovery on Wednesday, but raised questions about its success rate and the practical benefits it would bring to patients.
Embryonic stem cells are widely tipped to usher in a new age of medicine because they can grow into any tissue in the body. Researchers believe the cells will give them unprecedented insight into diseases, and ultimately lead to radical new therapies for some of the most intractable medical conditions, such as Parkinson’s disease, diabetes and even spinal cord injuries.
Scientists led by Robert Lanza at Advanced Cell Technology in Massachusetts created the stem cells by adapting a technique called pre-implantation genetic diagnosis (PGD), which is already used in fertility clinics to check IVF embryos for genetic defects.
In PGD, a single cell is plucked from an embryo when it is a three-day-old ball of only eight cells.
The cell is then tested for defects such as cystic fibrosis, and if it is healthy, the embryo is implanted. More than 2 000 babies have been born worldwide following PGD.
Dr Lanza’s group showed that the single cell removed from an embryo can be grown into many cells overnight, and some of those can then be turned into embryonic stem cells. In tests, the team took 91 clumps of cells from 16 embryos and created two sets of embryonic stem cells, according to Natureon Thursday.
Lanza said: “Many people, including President Bush, are concerned about destroying life in order to save lives. We now have a technique to generate stem cells without destroying the embryo, and we think that with the right resources we have the capacity to create as many stem cells as the scientific community needs without harming any embryos whatsoever.
“Hopefully this takes away the president’s last excuse to oppose this research. We hope it solves the current political impasse.”
However, the research has raised concerns among scientists and lobby groups. Josephine Quintavalle, of Comment on Reproductive Ethics, said: “We still don’t know the dangers of taking a biopsy from an early stage embryo, whether it has any effect on the baby’s future development. On paper it looks like an ethical solution, but that requires the biopsy to be completely harmless.”
Robin Lovell-Badge, a stem-cell expert at the National Institute for Medical Research in London, said that while the work was important, it was inefficient and unlikely to lead to plentiful stocks of embryonic stem cells. “It requires couples having IVF to give permission to have cells taken from their embryos and it’s extremely unlikely a couple would want to do that,” he said.
Ian Wilmut, whose team at Edinburgh University is hoping to use stem cells to unravel the mysteries of motor neurone disease, warned people not to seize on the new technique as the only way to create stem cells. “It would be very unfortunate if this became seen as the only route to derive human embryonic stem cells. We still need more and we need more research on how to derive them,” he said.
Other scientists said the research was merely an attempt to circumvent strict laws on stem-cell research in the US. Peter Braude, professor of obstetrics and gynaecology at King’s College London, said: “This is a way of trying to get around legislation, not practise science. The bottom line is if you believe there is a future in stem-cell research, one has to pursue all sorts of ways of growing them.”
Professor Braude said he doubted whether the controversy could be avoided by the US breakthrough. “We don’t undertake embryo biopsy willy-nilly, as it is better not to remove a cell from a developing embryo unless one really has to,” he said. “I certainly cannot see why one would wish to try and remove a cell from a healthy embryo with such low odds of developing a stem line from it when many thousands of useful cells are harvested from a baby’s placenta at birth, if one needed to do it. Equally, I’m not persuaded by arguments that this is a more ethical way of getting stem-cell lines, as it is not impossible that biopsy compromises the developing embryo from which one removes the cell.”
Bush made clear his feelings on the matter when he vetoed the Bill to expand US government funding for stem-cell research, saying the law would have supported “the taking of innocent human life in the hope of finding medical benefits for others. It crosses a real moral boundary that our society needs to respect”.
Last month, scientists in the north-east of England were granted permission to offer cheap IVF treatment to women willing to donate eggs for therapeutic cloning and stem-cell research. The eggs were to be used to create cloned embryos from which stem cells could be extracted. The decision was attacked by groups opposed to embryo research, and some scientists, for in effect inviting women to “sell” their eggs. - Guardian Unlimited Â