MOST of the excitement surrounding stem cells has been over their potential for treating diseases directly. Now stem cells obtained from human embryos with genetic defects are opening up a new way of studying inherited diseases and testing potential treatments.
At a meeting of the International Society for Stem Cell Research in Boston last week, two groups revealed that they have obtained such stem cells. One team, at the Reproductive Genetics Institute in Chicago, has created 13 embryonic stem cell lines from human embryos with different genetic diseases, including fragile X, beta thalassaemia and Becker muscular dystrophy. The cell lines were obtained from IVF embryos discarded after genetic screening revealed they had the disease-causing mutations.
Another group, at the Technion-Israel Institute of Technology and the Rambam Medical Center in Haifa, Israel, announced it has created five cell lines with disease-causing mutations. And in the UK, a team led by Stephen Minger of King鈥檚 College London is preparing to publish details of a cell line with one of the mutations that causes cystic fibrosis. Minger says the group also plans to create a line for Huntington鈥檚 disease.
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The idea is to maintain stocks of the embryonic stem cells bearing the disease-causing mutations and use them to derive cells of the types affected by the various diseases 鈥� lung and gut cells in the case of cystic fibrosis, for instance. Just a few ESCs could provide a virtually unlimited supply of cells for research. 鈥淭his is a significant advance for the field,鈥� Leonard Zon, president of the stem cell society, told reporters. 鈥淲e may learn a lot about the biology of basic diseases by having those lines available.鈥�
At the moment, most research on inherited diseases involves looking at animals with similar mutations. But the animal disease is often not exactly the same as the human one. Being able to study human cells directly and use them to test the safety and efficacy of potential drugs and other therapies should help ensure results are relevant to people. It might save years of wasted effort 鈥� for instance, by revealing at an early stage if a drug that works in animals will not work in humans. The technique will be especially useful for neurological diseases where taking samples of living tissue for research would harm patients.
ESC lines could be derived for any genetic disease that can be identified in embryos using pre-implantation genetic diagnosis. In the future, it should also be possible to derive stem cells from living patients, using therapeutic cloning. This would should help researchers identify the genetic roots of less-understood disorders.
For instance, Ian Wilmut鈥檚 team at the Roslin Institute near Edinburgh, UK, hopes to clone cells from people with the motor neuron disease ALS (快猫短视频, 21 February, p 16). The cause of most cases remains a mystery. But so far only one team, in South Korea, has managed to derive ESCs from cloned human embryos.
