The Prize Committee for Medicine has unanimously decided that the 2005 Wolf Prize will be jointly awarded, in equal parts, to three scientists:
Anthony R. Hunter
The Salk Institute
La Jolla, California, USA
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;
Anthony J. Pawson
The Samuel Lunenfeld Research Institute of Mount Sinai Hospital
Toronto, Canada
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;
Alexander Levitzki
The Silberman Institute of Life Sciences
The Hebrew University, Jerusalem, Israel
for pioneering signal transduction therapy and for developing tyrosine kinase inhibitors as effective agents against cancer and a range of other diseases.
Over recent decades, an understanding of the biological bases of cancers and the provision of rational therapies to combat them, has proved a major challenge for medical science. Two recipients of the 2005 Wolf Prize for Medicine, Professors Hunter and Pawson, have each independently contributed to an understanding of the tyrosine kinase signaling pathways in biology and the effect of their disruption on the development of certain cancers. The third recipient, Professor Levitzki, has pioneered the development of small molecule inhibitors of tyrosine phosphorylation that block the disrupted pathways associated with cancer and thus provide effective therapies.
Anthony R. Hunter´s contributions lie at the heart of signaling pathways and their disorders. He discovered that tyrosine phosphorylation is a fundamental mechanism for transmembrane-signal transduction in response to growth factor stimulation and that disregulation of such tyrosine phosphorylation, by activated oncogenic protein tyrosine kinases, is a pivotal mechanism utilized in the malignant transformation of cells.
Anthony J. Pawson demonstrated that a conserved sequence domain is required for an oncogene to transform, as it directs the cellular activity of the kinase domain. He showed that the SH2 domain binds specifically to phosphotyrosine, leading to a completely new way of connecting signal transduction to cell transformation.
Alexander Levitzki developed specific chemical inhibitors of cancer-induced protein kinases. He demonstrated that such an inhibitor to Bcr-Abl kinase induces death of chronic myeloid leukemia cells. This is currently used, with great success, for therapy of patients afflicted by this disease. Levitzki is in the process of developing additional tyrosine kinase inhibitors for treatment of other malignant disorders.