Pioneering work by Japanese stem-cell researchers two years ago has taken a major step forward, helping the quest for versatile, grow-in-a-dish transplant tissue.

Two teams have combined ideas to devise a safer technique for reprogramming skin cells so that they become "pluripoten" stem cells - fundamental cells that then grow into specialized organs.

Their effort builds on an award-winning breakthrough in 2007 by Shinya Yamanaka of Kyoto University

He and his team introduced four genes into skin cells, reprogramming them so that they became indistinguishable from embryonic stem cells.

Reprogramming cells using a virus modified their DNA in such a way that they cannot be given to patients without boosting the risk of cancer.

In th new studies, published by the British-based journal Nature, two squads of researchers from Britain and Canada recount a method by which the four genes are delivered into the cell without using a virus and then are remove after the reprogramming is done.

The insertion is carried out using "piggybac," a tried-and-tested technique in genetically modified crops in which mobile genetic sequences called transposons are slotted into the genome.

In the IPS work, it has been tested successfully on mouse and human skin cells. Test on the reprogrammed cells lines show they faithfully reproduce the behavior of embroyonic stem cells.

In a press release issued by Britain's Medical Research Council, Ian Wilmut father of Dolly the cloned sheep, stressed that the new IPS cells would have to be tested thoroughly for safety before being used in any human trials. Stem cells have excited huge interest over the past decade. Promoters say this material could reverse cancer, diabetes, alzheimer's and other regenerative disease.

March 9, 2009 President Barack Obama signed an executive order lifting restrictions on federal funding for medical research involving embryonic stem cells.

Obama signed the executive order on the divisive stem cell issue and a memo addressing what he called scientific integrity before an East Room audience packed with scientists. He laced his remarks with several jabs at the way science was handled by former President George W. Bush.

"Promoting science isn't just about providing resources, it is also about protecting free and open inquiry," Obama said. "It is about letting scientists like those here today do their jobs, free from manipulation or coercion, and listening to what they tell us, even when it's inconvenient especially when it's inconvenient. It is about ensuring that scientific data is never distorted or concealed to serve a political agenda and that we make scientific decisions based on facts, not ideology."


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