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Embryo-free stem cell method means treatments are nearer By Roger Highfield, Science Editor Last Updated: 7:01pm BST 25/09/2008 A safer way to turn one kind of cell into another has been developed that could make it much easier to develop revolutionary new treatments based on stem cells. Stem cell technology may make blood donations thing of the past Treatment could mean diabetics produce their own insulin Scientists use 'biological alchemy' to convert one cell type into another A recently-developed embryo-free method overcomes key practical and ethical issues in obtaining embryo-like cells - the most potent kind of stem cells - that potentially capable of generating all cell types for treating a wide range of diseases, from degenerative brain disease to heart disease. But that method, pioneered in Japan, required a virus to genetically alter adult cells, such as skin cells, to convert them into embryo-like cells and there were safety concerns. Now a team led by Prof Konrad Hochedlinger at Massachusetts General Hospital Cancer Centre and Harvard Stem Cell Institute has developed a safer approach. His team's work, published in Science, deals with one of the major drawbacks of the technique developed by Japanese researcher Prof Shinya Yamanaka to reprogram cells. Prof Yamanaka used a so called retrovirus - one from the same family as the Human Immunodeficiency Virus - to introduce four genes into, say, skin cells to turn back the clock, so they became more embryo like. However, there are safety worries because a virus usually parachutes the new genes into the genetic code and this can cause damage or disruption, potentially triggering cancer. "There is already evidence that one in five mice generated with such induced pluripotent stem cells (iPS cells) develops cancer," says Prof Hochedlinger. Now Prof Hochedlinger and his team say that they have developed a method for generating these cells using a type of common cold virus, called an adenovirus, that does not knit the new genes into the genetic code, or genome. This new finding represents a major step forward in the future use of the cells in the hospital and clinic, though it is less efficient. Prof Hochedlinger, Dr Matthias Stadtfeld and colleagues grew their stem cells, which show potential for growing into a variety of other specialised cells including lung, brain, and heart cells, and they say that they have not observed any unwanted side effects yet. In the past, similar reprogrammed cells have been shown to alleviate the symptoms of Parkinson's disease and sickle cell anaemia in mice, so this new discovery could lead to advances in cell therapy and treatments of human disease as well. However, the researchers say that it will be important to determine if human cells generated in the future using this kind of virus are as potent as human embryonic stem cells for potential clinical applications. "It remains unclear how long it will take until 'safer" iPS cells can be used to treat patients. Our work rather provided a conceptual advance showing that IPS cells in general can be produced without permanent genetic alterations of the genome, a pre-requisite for any therapeutic application of this technology," said Prof Hochedlinger. Rayilyn Brown Director AZNPF Arizona Chapter National Parkinson Foundation [log in to unmask] ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn