Stockholm_Two American scientists and a Briton won the 2007 Nobel Prize 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, (pronounced kuh-PEK'-ee). A native of Italy, he was separated from his mother at age 4 when she was taken to the Dachau concentration camp as a political prisoner during World War II.
For four years, Capecchi lived on the street or in orphanages, "and most of the time hungry," he recalled in a University of Utah publication in 1997. Malnutrition sent him to a hospital where his mother found him on his ninth birthday. Within two weeks they left for the United States, where he went to school for the first time, starting in third grade despite not knowing English.
The three scientists were honored for a technique called gene targeting, which lets scientists deactivate 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 $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.'"
Evans, reached while visiting his daughter in Cambridge, England, said "I haven't come to terms with it yet. In many ways it is the boyhood aspiration of science, isn't it? And here I am unexpectedly with it. It's amazing."
After working on the research for more than 20 years, Smithies told The Associated Press, 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.
The three scientists mostly worked separately, although they exchanged information about their research. Evans identified embryonic stem cells in mice, while the gene-targeting technique used on those cells came from work by Capecchi and Smithies.
Scientists are also attempting to do this genetic manipulation in human embryonic cells to create a basic research tool, said John Gearhart, a stem cell expert at the Johns Hopkins School of Medicine.
The idea is to make cells with disease-related gene mutations so they can be studied in the laboratory. That could give clues about how the disease develops, and serve as a screening tool for potential therapies, he said.
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.
Since the medicine prize was first awarded in 1901, 90 Americans and 29 Britons have received it.