Two Hebrew University of Jerusalem researchers, Prof. Howard Cedar and Prof. Aharon Razin, have been awarded the 2008 Wolf Prize in Medicine for their fundamental contributions to the control of gene expression and cancer research.

Minister of Education Prof. Yuli Tamir, chairperson of the Wolf Foundation Council, announced that the $100,000 prize, often referred to as Israel’s “Nobel Prize,” will be awarded to Professors Cedar and Razin of the Hebrew University-Hadassah Medical School ''for their fundamental contributions to our understanding of the role of DNA methylation in the biological function of higher organisms, with widespread impact on studies of development, control of gene expression and cancer research.''

DNA methylation (chemical changes in the DNA molecule) is a very basic aspect of animal cell biology involved in the regulation of a large number of physiological, developmental and pathological processes. The foundations of this field were laid, almost exclusively, through the work of Cedar and Razin.

Born in the US in 1943, Howard Cedar received his Ph.D. from New York University in 1970. From 1971 to 1973, he was a research associate at the National Institutes of Health in the US. Prof. Cedar has been associated with the Hebrew University of Jerusalem since 1973 in the Department of Cellular Biochemistry and Human Genetics at the Hebrew University-Hadassah Medical School. He is the incumbent of the Harry and Helen L. Brenner Chair in Molecular Biology and is a member of the Israel Academy of Sciences and Humanities. He is a member of the European Molecular Biology Organization (EMBO) and the Human Genome Organization (HUGO).

Dr. Howard Cedar, recipient of the first ICRF Professorship, which he has held since 1987, as well as The Israel Prize in Biology, Israel's highest civilian honor, is world renowned for his pioneering research in DNA Methylation, a molecular process that turns genes on and off.

He noted that tumors result from an imbalance in the gene regulation machinery of the cell. The objective of his study of the regulation of gene expression in animal cells is to understand the process whereby genes in living organisms are turned on and off during development.

He led a team of researchers at Hebrew University/Hadassah Medical School that took an important step in comprehending this process, which has significant consequences for advancing the use of medical genetic engineering -- growing new tissue to replace damaged or defective organs, or halting the growth of undesirable tumors. The achievement took nearly five years of research to attain.

These new findings provide information fundamental to understanding how an embryo develops and for deciphering the genetic defects that lead to cancer. This data will also aid scientists in developing better methods for therapeutic genetic engineering.

Dr. Cedar, Professor in the Department of Cellular Biochemistry at Hebrew University/Hadassah Medical School, explained that in general there are two kinds of genes in every cell -- those that control the "housekeeping" duties necessary to keep all cells functioning, and those that give each tissue its unique properties. Since a complete set of genes exists in every cell, no matter where it is located in a given organism, most tissue-specific genes are actually in a dormant, unexpressed state. Only those genes needed for a particular cell type (such as liver, heart, or brain) are activated, along with the housekeeping genes.

How are some genes kept on while others are turned off? Dr. Cedar's new studies suggest that this occurs during the process of gene duplication which occurs before cell division. Housekeeping genes get copied early during a unique "window of opportunity" that activates them, while other genes are copied later. The latter, as a result, are mostly doomed to inactivity.

He drew an analogy. "If you try to do something when a timer clock is off, you won't be able to do anything; you can do it only when the timer is on." Thus, in a sense, each cell knows how to pass on to the next generation both the genes themselves and the instructions for setting up their state of activity or inactivity -- their timer mechanism.

Source: Israel Cancer Research Fund