* 3 Americans win prize for discovery of telomerase enzyme
* Blackburn, Szostak, Greider shed light on aging process
* Institute says work solved a major problem in biology
(Adds Szostak quotes, detail)
By Nicholas Vinocur
STOCKHOLM, Oct 5 (Reuters) - Three Americans won the Nobel prize for medicine on Monday for revealing the existence and nature of telomerase, an enzyme that 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 understanding how telomerase and telomeres -- the small caps on the end of chromosomes that carry the DNA -- affect 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 (MRK.N) and Geron (GERN.O), could yield a treatment for patients with tumors including lung and prostate cancer.
“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,” said Sir Leszek Borysiewicz, chief executive of Britain’s Medical Research Council.
“FOLLOW YOUR NOSE”
Blackburn, a molecular biologist and biochemist at the University of California San Francisco known for her work on DNA and cell division, said she had not stayed awake 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.”
She 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 President George W. Bush’s Council on Bioethics in what many scientists believed was her criticism of his policy on human embryonic stem cell research.
She said she knew that something like telomerase must exist from working with Szostak on telomeres, which help keep the ends of chromosomes together.
“Carol and I hunted it down,” she said. “We didn’t stumble over it. The molecular behavior of the ends of the chromosomes was screaming out that there was something going on, some hitherto unknown enzyme.”
Greider, 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.”
Greider, now at the Johns Hopkins School of Medicine in Baltimore, started research on telomerase in the late 1970s with Blackburn, her academic adviser.
Szostak, 56, also said he started on the work without knowing what if any practical benefit it would bring. “Eventually its role in aging and cancer emerged from the work,” he said.
Asked what he planned to do with the prize money, Szostak said he would be putting his children through college.
Dr. Jeremy Berg of the U.S. 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.
Berg said Szostak, who works at Harvard Medical School in Boston, Massachusetts General Hospital and the Howard Hughes Medical Institute, 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.”
All three new Nobel laureates were among those considered likely winners in a Thomson Reuters forecast.
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. (Additional Reporting by Mia Shanley, Scott Malone, Peter Henderson and Ben Hirschler, editing by Maggie Fox and Chris Wilson)