STOCKHOLM, Sweden - Two American scientists and a Briton won the 2007 in medicine on Monday for groundbreaking discoveries that led to a powerful technique for manipulating mouse genes.
The widely used process has helped scientists use mice to study heart disease, diabetes, cancer, cystic fibrosis and other diseases.
The prize is shared by Mario R. Capecchi, 70, of the University of Utah in Salt Lake City; Oliver Smithies, 82, a native of Britain now at University of North Carolina in Chapel Hill, and Sir Martin J. Evans, 66, of Cardiff University in Wales.
The Nobel is a particularly striking achievement for Capecchi, a native of Italy who at the age of 4 was separated from his mother when the Gestapo took her to the Dachau concentration camp during World War II.
Capecchi lived on the streets for more than four years, fending for himself by begging and stealing, until reuniting with his mother at age 9. They soon moved to the United States, where he started elementary school without knowing how to read or write, nor how to speak English.
The three scientists were honored for a technique called gene targeting, which lets scientists inactivate or modify particular genes in mice. That in turn lets them study how those genes affect health and disease.
To use this technique, researchers introduce a genetic change into mouse embryonic stem cells. These cells are then injected into mouse embryos. The mice born from these embryos are bred with others, to produce offspring with altered genes.
The first mice with genes manipulated in this way were announced in 1989. More than 10,000 different genes in mice have been studied with the technique, the Nobel committee said. That's about half the genes the rodents have.
"Gene targeting has pervaded all fields of biomedicine. Its impact on the understanding of gene function and its benefits to mankind will continue to increase over many years to come," said the citation for the US$1.54 million prize.
Steve Brown, director of the mammalian genetics unit at the Medical Research Council in London, said the three researchers have "given us the toolkit to understand how genes function" in mice and so, by extension, in humans. As a result, of their work, he said, "we're on the cusp of having a much better understanding of the relationship between genes and disease."
In a telephone interview from Salt Lake City, Capecchi called the award "a fantastic surprise."
He said he was deep asleep when he got the phone call from the Nobel committee at 3 a.m. local time. "He sounded very serious," Capecchi said, "so the first reaction was, `This must be real.'"
Smithies told The Associated Press getting the award was "very gratifying." After working on the research for more than 20 years, he said it's "rather enjoyable being recognized at this level."
Smithies said he hopes winning the prize will make it easier to secure funding for other work.
Although gene targeting uses embryonic stem cells from mice, it is different from how stem cells would be used to treat disease in humans. In people, stem cells would be prodded to become replacement tissue like nerve cells for transplant into patients.
Capecchi's work has uncovered the roles of genes involved in organ development in mammals, the committee said. Evans has developed strains of gene-altered mice to study cystic fibrosis, and Smithies has created strains to study such conditions as high blood pressure and heart disease.
The medicine prize was the first of the six prestigious awards to be announced this year. The others are chemistry, physics, literature, peace and economics.
The prizes are handed out every year on Dec. 10, the anniversary of award founder Alfred Nobel's death in 1896.
Last year, the Nobel Prize in medicine went to Americans Andrew Z. Fire and Craig C. Mello for discovering RNA interference, a process that can silence specific genes.
