Stockholm: Three Americans won the Nobel prize for medicine on Monday for revealing the existence and nature of telomerase, an enzyme which helps prevent the fraying of chromosomes that underlies aging and cancer.
Australian-born Elizabeth Blackburn, British-born Jack Szostak and Carol Greider won the prize of 10 million Swedish crowns ($1.42 million), Sweden's Karolinska Institute said.
"The discoveries ... have added a new dimension to our understanding of the cell, shed light on disease mechanisms, and stimulated the development of potential new therapies," it said.
The trio's work laid the foundation for studies that have linked telomerase and telomeres -- the small caps on the end of chromosomes -- to cancer and age-related conditions.
Work on the enzyme has become a hot area of drug research, particularly in cancer, as it is thought to play a key role in allowing tumor cells to reproduce out of control.
One example, a so-called therapeutic vaccine that targets telomerase, in trials since last year by drug and biotech firms Merck and Geron, could yield a treatment for patients with tumors including lung and prostate cancer.
The Chief Executive of Britain's Medical Research Council said the discovery of telomerase had spawned research of "huge importance" to the world of science and medicine.
"Their research on chromosomes helped lay the foundations of future work on cancer, stem cells and even human aging, areas that continue to be of huge importance," Sir Leszek Borysiewicz said in a statement.
"Follow your nose"
Blackburn, a molecular biologist and biochemist known for her work on DNA and cell division, said she had not stayed waiting for a call from the Nobel Prize Committee, even though her name topped many Nobel prediction lists.
"I was surprised. It is always a surprise when something like this happens," she told Reuters in a telephone interview. "I was woken up and (it) took me a while to take it in."
Blackburn said she had been in Southern California the previous day for her mother-in-law's 95th birthday. "The phone rang and I sort of groped around in the dark for it," she said.
An outspoken researcher, Blackburn was fired in 2004 from then-President George W. Bush's Council on Bioethics for her criticism of his policy on embryonic stem cell research.
In earlier interviews, she has said she knew that something like telomerase must exist from working with Szostak on telomeres, which help keep the ends of chromosomes together.
"We didn't stumble over it," she said. "The molecular behavior of the ends of the chromosomes was screaming out that there was something going on, some hitherto unknown enzyme."
"Carol and I hunted it down," she added.
Carol Greier, 48, who grew up in Davis, California, where her father was a physicist, said winning the Nobel prize was especially significant because it recognized the value of discoveries driven by pure curiosity.
"We had no idea when we started this work that telomerase would be involved in cancer, but were simply curious about how chromosomes stayed intact," she said in a statement.
"Our approach shows that while you can do research that tries to answer specific questions about a disease, you can also just follow your nose," she said.
Greider started research on telomerase in the late 1970s with Blackburn, her academic adviser. The three were among those considered likely winners in a Thomson Reuters forecast.
Dr Jeremy Berg of the US National Institute of General Medical Sciences, which funded some of the research, said this year's prize was not a surprise.
"It was at the top of all lists this year," Berg said in a telephone interview. "The work on telomeres and telomerase is a classic in curiosity-driven discovery in a fundamental biological process."
Berg said Szostak, 56, had moved along since his work on telomerase.
"He is trying to figure out how he can make proto-cells and get them to copy their genetic material. That's almost literally creating life in a test tube."
Blackburn is with the University of California, San Francisco, Greider is with the Johns Hopkins School of Medicine in Baltimore. Szostak, at Harvard Medical School since 1979, is currently at the Massachusetts General Hospital in Boston and the Howard Hughes Medical Institute.
Medicine is traditionally the first of the Nobel prizes awarded each year. The prizes for achievement in science, literature and peace were first awarded in 1901 accordance with the will of dynamite inventor and businessman Alfred Nobel.