STOCKHOLM, Sweden - American scientists who discovered an enzyme that broke new ground in research on cancer and aging are among potential winners of this year's Nobel Prize in medicine, the first of six prestigious awards being announced by the Nobel committees.
Another possible winner of Monday's US$1.54 million prize in medicine is a British researcher who discovered genetic fingerprinting that has helped solve crimes and settle paternity disputes.
The secretive Nobel committee at Stockholm's Karolinska Institute will announce the winner after a final vote Monday morning, but won't even say who's on the short list before then.
"We have been working on this since February," said Hans Jornvall, secretary of the Nobel committee that reviews research nominated for the award.
Last year, the Nobel Prize in medicine went to Americans Andrew Fire and Craig Mello for discovering RNA interference, a process that can silence specific genes.
American researchers Elizabeth Blackburn, Carol Greider and Jack Szostak have figured prominently in Nobel speculation in recent years for predicting and discovering an enzyme called telomerase.
Their work set the stage for research suggesting that cancer cells use telomerase to sustain their uncontrolled growth. Scientists are studying whether drugs that block the enzyme can fight the disease.
In addition, scientists believe that the DNA erosion the enzyme repairs might play a role in age-related illnesses.
Sir Alec Jeffreys of the University of Leicester also is often mentioned by experts as a possible candidate. Jeffreys found in 1984 that a DNA sample could be linked to the person it came from -- a finding that has come into play in court cases in which DNA evidence has exonerated convicted murderers.
It has also been used to help identify the victims of mass disasters, such as the Sept. 11, 2001, terror attacks in New York and Washington.
Karin Bojs, science editor at the Swedish newspaper Dagens Nyheter -- who correctly guessed two of last year's Nobel Prizes -- predicted that the medicine award would go to American David Julius and Israeli Baruch Minke for research on how the human body reacts to heat and pain.
Thomson Scientific, a unit of the U.S.-based Thomson Corp., singled out five possible candidates, including neuroscientist Fred Gage, who discovered that humans can develop new brain cells as adults.
Alfred Nobel, the Swedish inventor of dynamite, established the prizes in his will in the categories of medicine, physics, chemistry, literature and peace. The Nobel Memorial Prize in Economic Science is technically not a Nobel but a 1968 creation of Sweden's central bank.
The prizes are handed out every year on Dec. 10, the anniversary of Nobel's death in 1896.
Nobel left few instructions on how to select winners, only that the prizes should honour those who "shall have conferred the greatest benefit on mankind."
Jornvall said medicine winners must have made an important discovery - they are not awarded for a body of research.
"If it's not possible to define what the discovery is, then it's going to be hard," he said.
Recent winners of the Nobel Prize in physiology or medicine, and their research, according to the Nobel Foundation:
- 2006: Andrew Fire and Craig Mello of the United States for their work in controlling the flow of genetic information.
- 2005: Barry Marshall and Robin Warren of Australia for their work in how the bacterium Helicobacter pylori plays a role in gastritis and peptic ulcer disease.
- 2004: Richard Axel and Linda Buck of the United States for their work in studying odorant receptors and the organization of the olfactory system in humans.
- 2003: Paul Lauterbur, United States, and Sir Peter Mansfield, Britain, for discoveries in magnetic resonance imaging, a technique that reveals the brain and inner organs in breathtaking detail.
- 2002: Sydney Brenner and John Sulston, Britain, and H. Robert Horvitz, United States, for discoveries concerning how genes regulate organ development and a process of programmed cell death.
- 2001: Leland Hartwell, United States, R. Timothy (Tim) Hunt and Sir Paul Nurse, Britain, for the discovery of key regulators of the process that lets cells divide, which is expected to lead to new cancer treatments.
- 2000: Arvid Carlsson, Sweden, Paul Greengard and Eric Kandel, United States, for research on how brain cells transmit signals to each other, thus increasing understanding on how the brain functions and how neurological and psychiatric disorders may be better treated.
- 1999: Guenter Blobel, United States, for protein research that shed new light on diseases, including cystic fibrosis and early development of kidney stones.
- 1998: Robert Furchgott, Louis Ignarro and Ferid Murad, United States, for the discovery of properties of nitric oxide, a common air pollutant but also a lifesaver because of its capacity to dilate blood vessels.
- 1997: Stanley Prusiner, United States, for the discovery of prions, an infectious agent at the heart of several forms of brain-wasting disease.
