GLOBAL HEALTH | Addressing the world’s health challenges
10 October 2008
Four Americans Share in Nobel Science Prizes
Honored for discovery of fluorescent protein, advances in particle physics
Washington — Four Americans are among the nine recipients of the 2008 Nobel Prizes in chemistry, physics, and medicine or physiology, the Royal Swedish Academy of Sciences and the Karolinska Institute in Stockholm announced during the week of October 5.
Americans Martin Chalfie and Roger Tsien and Japanese-American Osamu Shimomura won the chemistry prize for the discovery and development of a fluorescent protein whose use has revolutionized biological imaging.
The medicine or physiology prize honored French scientists Françoise Barré-Sinoussi and Luc Montagnier for the discovery of HIV, the virus that causes AIDS, and German scientist Harald zur Hausen for showing that human papillomavirus causes cervical cancer.
Two Japanese scientists, Makoto Kobayashi and Toshihide Maskawa, and Japanese American Yoichiro Nambu won the physics prize for discovery of the origin and mechanism of broken symmetry. Their work is important for elementary particle physics and led to the discovery of three new families of subatomic particles, according to the Royal Swedish Academy of Sciences.
GLOWING PROTEINS
The discovery and development of the green fluorescent protein (GFP) has enabled biologists to watch previously invisible processes inside cells and tissues, such as how proteins move from one part of a cell to another or how cells grow and divide in living animals.
"GFP rapidly became an essential piece of the scientific toolbox, paving the way for an explosion of groundbreaking studies that significantly advanced our understanding of health and disease,” said Jeremy M. Berg, director of the National Institute of General Medical Sciences at the National Institutes of Health, which funded some of this research. “It is impossible to understate the impact of these investigators' work on scientific progress."
In 1962 Osamu Shimomura and colleagues isolated GFP from the jellyfish Aequorea victoria and characterized its fluorescent properties. When exposed to ultraviolet light, GFP glows green.
Shimomura’s discovery remained a biological curiosity until Martin Chalfie realized that GFP could be used to monitor when particular genes are turned on or off in a cell as well as the location of proteins in living animals.
In 1994 Chalfie demonstrated that GFP could be used to tag a restricted population of nerve cells in the roundworm Caenorhabditis elegans. The worm has about 300 nerve cells that are difficult to distinguish from one another. Chalfie genetically modified worms to produce GFP in only six of these cells, the ones involved in sensing touch, which glowed green and were readily visible in live worms.
Roger Tsien expanded the fluorescent-protein color palette by creating variants that glow in colors such as orange and cherry red. Scientists now routinely tag cells and proteins with different colors and are able to monitor multiple biological processes simultaneously. In 2007, Jeff Lichtman and colleagues genetically engineered mice to display dozens of colors in discrete cells in the brain. Animal models such as these “brainbow” mice will allow scientists to trace brain circuitry — the connections made between cells in the brain — at unparalleled levels of detail.
GFP and its variants have proven to be generally nontoxic and active in a variety of experimental organisms, including bacteria, yeast, flies, worms, mice and fish. GFP has even crossed over into science fiction: In the 2003 film Hulk, the title character’s green skin is allegedly due to the effects of GFP.
VIRUSES AND CANCER
Cervical cancer is the second most common form of cancer among women: about 500,000 are diagnosed annually and nearly 250,000 die from it.
In the 1970s, Harald zur Hausen bucked prevailing thinking by postulating that a human papillomavirus — not a herpes virus — caused sexually transmitted cervical cancer.
Zur Hausen and colleagues discovered dozens of strains of human papillomavirus (HPV) and found two, types 16 and 18, present in cervical tumors. Subsequent work showed that HPV types 16 and 18 are responsible for about 70 percent of cervical cancers.
More than 5 percent of all cancers worldwide are caused by persistent infection with HPV, according to the Nobel Assembly at the Karolinska Institute in Sweden. Zur Hausen’s work led to the development of two vaccines currently used to prevent HPV infection.
Eighty percent of deaths from cervical cancer occur in developing countries, according to doctors Jan Agosti and Sue Goldie, writing in the New England Journal of Medicine in 2007. United States aid organizations and private companies are helping to make HPV vaccines accessible in the developing world. Pharmaceutical manufacturer Merck & Co. is making its vaccine available at reduced prices in the developing world, according to a company spokeswoman.
PATH, an international nonprofit organization based in Seattle, is working with industry and local governments in India, Peru, Uganda and Vietnam to explore the most effective and acceptable strategies for vaccinating young girls against HPV. Data from these pilot programs will be distributed freely to allow governments to adopt appropriate vaccination policies.
Between 50,000 and 70,000 girls will receive free doses of the HPV vaccine during the pilot programs, according to Scott Wittet, director of advocacy and communication for PATH’s cervical cancer prevention programs.
“I see a lot of excitement around the HPV vaccine,” Wittet said. “It could be an opportunity to expand health services to this underserved population.”
Additional information about the Nobel prizes is available from the Nobel Web site.
More information about HPV vaccine distribution projects is available from PATH.
Additional information about the “brainbow” mouse can be found in the November 1, 2007, issue of the journal Nature.
