January 14, 2005

Salk Scientist who discovered cancer 'switch' awarded the Wolf Prize in Medicine

Salk News

Salk Scientist who discovered cancer ‘switch’ awarded the Wolf Prize in Medicine

La Jolla, CA – Salk Institute scientist Tony Hunter has been awarded the 2005 Wolf Prize in Medicine, Israel’s top recognition for achievements in the interest of mankind, for his key discoveries in cell regulation and cancer research.

Dr. Hunter, an American Cancer Society professor of molecular and cell biology at the Salk Institute for Biological Studies in La Jolla, shared the award with Anthony Pawson of Mount Sinai Hospital, Toronto, Canada, and Alexander Levitzki of the Hebrew University of Jerusalem. The three recipients will share the $100,000 Prize, in equal parts, for their work in cancer medicine. The prize will be presented by the President of the State of Israel, Mr. Moshe Katsav, at a special ceremony, at the Knesset (parliament) in Jerusalem, on Sunday, May 22, 2005.

In 1979, Hunter discovered that a process called tyrosine phosphorylation was a chemical ‘on-off’ switch that can tell cells to multiply in an uncontrolled fashion, i.e., become cancerous. Discovery of this important signaling mechanism, which proved to be the underlying cause of many types of human cancer, revolutionized cancer medicine and, ultimately, led to the development of several innovative cancer therapies (e.g., Gleevec®, Iressa® and Tarceva®) as researchers found ways to inhibit the special proteins called tyrosine kinases that are responsible for tyrosine phosphorylation.

The human genome encodes 90 different tyrosine kinases and over half of these have been implicated in cancer. Tyrosine kinase research, said Hunter, continues to yield huge dividends as researchers pinpoint the damaged tyrosine kinase genes (mutations) that lead cells down the road to cancer. “In the long run it should be possible to develop diagnostics for those mutations,” said Hunter, “Then you’ll know that this particular cancer should be susceptible to that particular kinase inhibitor. This could, ultimately, lead to personalized medicine where everyone will have their own cancer drug regimen, which may include drugs that act as targeted tyrosine kinase inhibitors.”


Since the mid-twentieth century, medical scientists have worked intensively to find explanations of how different kinds of cancers arise, in hope that by understanding the basic underlying science, new drugs can be developed to combat these cancers. Two of the winners of the 2005 Wolf Foundation Prize for Medicine, Hunter and Pawson, have explained how a basic mechanism for transmitting information can break down and lead to malignancy. The third winner, Levitzki, has created drugs that block the disrupted signaling route, thus preventing the development of some cancers. By targeting cancer cells specifically, without damaging normal cells, the unpleasant side-effects associated with traditional chemotherapy and radiotherapy, are avoided.

British-born Tony Hunter, 61, is recognized for “the discovery of protein kinases that phosphorylate tyrosine residues in proteins, critical for the regulation of a wide variety of cellular events, including malignant transformation. His contributions lie at the heart of signaling pathways and their disorders,” the Jury stated. Fellow of the Royal Society of London, and Foreign Associate of the National Academy of Sciences, USA, Hunter, received his Ph.D. in 1969, from the University of Cambridge. He has been associated with the Salk Institute since 1971, and was appointed Professor of Biology in 1982. Since 1983, Hunter has been Adjunct Professor at the University of California, San Diego.

Anthony James Pawson, 52, is cited for “his discovery of protein domains essential for mediating protein-protein interactions in cellular signaling pathways, and the insights this research has provided into cancer,” said the Jury. Born in the U.K., Pawson received his B.A. in Biochemistry, from Cambridge University, in 1973, and his Ph.D. in Molecular Biology, from London University, in 1976. From 1981 to 1985, he was Assistant Professor at the University of British Columbia, Canada. Since 1985, Pawson has been a Senior Scientist at the Samuel Lunenfeld Research Institute, Mount Sinai Hospital, in Toronto, Canada. He is a Fellow of the Royal Society of London and Foreign Associate of the National Academy of Sciences, USA. Since 1985, Pawson has been a Full Professor, at the Department of Medical Genetics, University of Toronto.

Alexander Levitzki, 64, is recognized “for pioneering signal transduction therapy and for developing tyrosine kinase inhibitors as effective agents against cancer and a range of other diseases. He demonstrated that such an inhibitor to Bcr-Abl kinase induces death of chronic myeloid leukemia cells. This is currently used, with great success, in the therapy of patients afflicted by the disease,” the Jury said. Born in Israel, Levitzki received his Ph.D. in Biochemistry and Biophysics from the Hebrew University of Jerusalem and the Weizmann Institute of Science, in 1968. In 1976, Levitzki was appointed Professor of Biochemistry at the Hebrew University of Jerusalem. He has been Visiting Scientist at the National Cancer Institute, NIH, Bethesda, Maryland, and Visiting Scholar at Stanford University, California, USA. Professor Levitzki is a Member of the Israel Academy of Sciences and Humanities.


The Israel-based Wolf Foundation was established by the late German-born inventor, diplomat and philanthropist, Dr. Ricardo Wolf. A resident of Cuba for many years, Wolf became Fidel Castro’s ambassador to Israel, where he lived until his death in 1981. Five annual Wolf Prizes have been awarded since 1978, to outstanding scientists and artists, “for achievements in the interest of mankind and friendly relations among peoples, irrespective of nationality, race, color, religion, sex, or political view.” The prizes of $100,000 in each area, are given every year in four out of five scientific fields, in rotation: Agriculture, Chemistry, Mathematics, Medicine and Physics. In the Arts, the Prize rotates among Architecture, Music, Painting and Sculpture. To date, a total of 224 scientists and artists from 21 countries have been honored.

The Salk Institute for Biological Studies in La Jolla, California, is an independent nonprofit organization dedicated to fundamental discoveries in the life sciences, the improvement of human health and the training of future generations of researchers. Jonas Salk, M.D., whose polio vaccine all but eradicated the crippling disease poliomyelitis in 1955, opened the Institute in 1965 with a gift of land from the City of San Diego and the financial support of the March of Dimes.

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