UK and Canadian researchers have taken a revolutionary step towards creating stem cells without having to use and destroy human embryos. The breakthrough may have huge implications for the development of ‘ethical’ science. The two teams of scientists found a way of reprogramming skin cells taken from adults, effectively winding the clock back on the cells until they were in an embryonic form. Working together, the teams gave skin cells embryonic powers while avoiding pitfalls that would normally lead to cancer or genetic abnormalities in patients. In essence, they combined ideas to devise a safer technique for reprogramming skin cells so that they become ‘pluripotent’ stem cells – fundamental cells that then grow into specialised organs.
The research, led by Dr Keisuke Kaji, from the Medical Research Council (MRC) Centre for Regenerative Medicine at the University of Edinburgh, and Dr Andras Nagy, from the University of Toronto, combined their separate knowledge of cell programming to make the new breakthrough.
‘It is a step towards the practical use of reprogrammed cells in medicine, perhaps even eliminating the need for human embryos as a source of stem cells’, says Dr Kaji. He adds saying that nobody, including himself, had thought it was really possible.
'This new method of generating stem cells does not require embryos as starting points and could be used to generate cells from many adult tissues, such as a patient's own skin cells' said Dr Nagy.
‘We hope that these stem cells will form the basis for treatment for many diseases and conditions that are currently considered incurable. We have found a highly efficient and safe way to create new cells for the human body which avoids the challenge of immune rejection’, he added.
Many scientists are confident that stem cells are key to curing a number of previously fatal conditions due to their ability to be grown into any other kind of cell in the body. However, the problem has been that the ‘master cells’ could only be taken from embryos and this created a number of ethical and practical difficulties. In addition, previously it was only possible to create these ‘induced pluripotent stem’ (iPS) cells using viruses to insert the four genes that carry out the reprogramming. But the viruses modified the cells’ DNA in such a way that it greatly increased the risk of cancer, making the technique too risky for human patients. Another danger was that further changes caused by the genes might lead to developmental abnormalities. The new approach not only avoids the use of viruses, but allows the transformational genes to be removed after their job is done to prevent them causing future damage.
‘Because we succeeded in recovering the chromosomes, the risk of cancer [in the iPS cells] was significantly reduced. It will also be possible to remove the four chromosomes in human iPS cells’, Dr Kaji said.
(http://www.yomiuri.co.jp/dy/features/science/20090302TDY01304.htm)
Ian Wilmut, head of the MRC centre and one of the scientists who cloned the first mammal, Dolly the sheep, said it would take time before the new iPS cells could be given to patients, but the new technique was an important step forward.
‘Combining this work with that of other scientists working on stem cell differentiation, there is hope that the promise of regenerative medicine could soon be met’, he said.
A number of other scientists working in this area of science commented on the breakthrough:
‘What’s critical about this work is that it makes it much, much easier for labs around the world to create these special cells and it will accelerate discovery’, commented Dr Jim Woodgett, the Director of Research for the Samuel Lunenfeld Institute.
Dr Michael Rudnicki, who works for the Stem Cell Network of Canada, finds the discovery fascinating and exciting.
‘We now have the technology to derive these cells readily and in a way that will facilitate their use clinically. This is an important finding and is really a breakthrough. This discovery is going to be widely used’, he said. ‘I think it will prove to be the routine method used internationally.’
This development builds on an award-winning breakthrough in 2007 by Shinya Yamanaka of Kyoto University. It has been hailed as a major step forward by scientists and welcomed by pro-life organisations, who called on researchers to halt other experiments which use stem cells collected from embryos made at IVF clinics.
Josephine Quintavalle, of Comment on Reproductive Ethics, said: ‘This is ethical stem cell research at its best, with embryonic-type stem cells derived successfully from adult tissue without involving human embryos.’
‘There are some scientists who like to hold on to what they’ve got, but I do not think people are going to waste time on embryonic stem cells any more. Half of Europe is opposed to embryonic stem cell research. Ideally you want something that everybody can use without any problems. This is definitely a very, very promising way forward and a very promising solution to the embryonic stem cell battle.’
BBC News
http://news.bbc.co.uk/1/hi/health/7914976.stm
Guardian
http://www.guardian.co.uk/science/2009/mar/01/stem-cells-breakthrough
Daily Telegraph
Daily Mail
CTV (Canada)
The Tech Herald