The awardees are Tony Hunter, American Cancer Society professor of molecular and cell biology at the Salk Institute for Biological Studies in San Diego, and Anthony Pawson, senior investigator and director of research at the Samuel Lunenfeld Research Institute of Mount Sinai Hospital, Toronto, and university professor of medical genetics and microbiology at the University of Toronto.
The researchers will receive the award in February 2005 in recognition of their discoveries in understanding protein-tyrosine phosphorylation. This process of molecular signals within and between cells has led to the development of drugs for halting cancer cell proliferation and has potential for other significant therapies.
"This creative work by Hunter and Pawson has given us new insight into cell metabolism that goes beyond the original and historical concepts of the role of phosphate," said David Hirsh, executive vice president for research at Columbia University. "It is most appropriate that they will receive the Horwitz Prize, an award known for its prescience in recognizing major scientific contributions."
Gerald Fischbach, executive vice president and dean of Columbia University Medical Center, said, "Drs. Hunter and Pawson have laid the foundation for an extraordinarily important field of study that is now leading to new breakthroughs in clinical treatment of disease."
Awarded annually since its inception in 1967, the Louisa Gross Horwitz Prize recognizes exceptional accomplishments in biological and biochemical research. The prize was named after the mother of Columbia benefactor S. Gross Horwitz. Mrs. Horwitz was the daughter of former American Medical Association President and surgery textbook author Samuel David Gross.
Protein phosphorylation is the addition of a phosphate group to a protein, in order to provide an on-off switch for molecular signals within and between cells. For example, many enzymes and receptors are turned "on" or "off" through phosphorylation and dephosphorylation. These signals are crucial in the development of tissues, immune system responses and hormone action.
Tyrosine is one of the 20 amino acids found in proteins. In 1979, Hunter discovered that a phosphate could be attached to tyrosine in proteins, a significant advancement in understanding how cell growth is regulated. Tyrosine kinases - the enzymes that add phosphates to proteins - tell cells when to multiply in a controlled manner; when overactive, however, they can drive the continuous proliferation of cancer cells.
This discovery, a major advance in the field of signal transduction, opened the door to further study of cell growth in a variety of diseases. The research ultimately led to the development of a new generation of targeted drugs that block the action of tyrosine kinases and can stop the proliferation of some types of cancer cells. Gleevec®, a groundbreaking oral treatment for one form of leukemia, is successful because it blocks the wayward tyrosine kinase that drives this particular cancer.
Pawson's work has provided essential insight into how cells signal each other, and has had a broad impact throughout biomedical research. In 1986, he identified protein modules that recognize specific phosphorylated tyrosine residues and established that molecular protein interactions control signal transduction.
Columbia University in the City of New York, founded in 1754 as King's College by royal charter of King George II of England, is the oldest institution of higher learning in the state of New York and the fifth oldest in the United States.