Stanley Cohen American biochemist and zoologist, Nobel Prize in Physiology or Medicine, 1986 (shared with Rita Levi-Montalcini). Date of Birth: 17.11.1922 Country: USA

Biography of Stanley Cohen

Stanley Cohen is an American biochemist and zoologist who won the Nobel Prize in Physiology or Medicine in 1986, jointly with Rita Levi-Montalcini. He was born to Russian-Jewish immigrants Louis Cohen and Fannie Cohen (Feitel). He grew up in a family with four children and developed a passion for scientific research during his time at James Madison High School. Cohen described his youth as a time when his "primary driving force was the desire to understand, to the best of my abilities and talents, the world around me."

After completing high school, Cohen pursued studies in chemistry and zoology at Brooklyn College. He obtained his bachelor's degree in 1943 and received a scholarship to study at Oberlin College in Ohio, where he earned his master's degree in zoology in 1946. He then moved to Ann Arbor and became a biochemistry instructor at the University of Michigan. In 1948, he obtained his doctoral degree by defending a dissertation on the metabolism of earthworms.

For the next four years, Cohen worked as a faculty member in the Departments of Biochemistry and Pediatrics at the University of Colorado School of Medicine in Denver. During this time, he collaborated with American pediatrician Harry Gordon on important research on the metabolism of creatinine in premature and newborn infants.

In 1952, Cohen relocated to St. Louis, where he spent a year as a postdoctoral fellow at the Washington University School of Medicine's Radiology Department, sponsored by the American Cancer Society. He then became an adjunct professor in the Department of Zoology for the next six years. It was in St. Louis where Cohen, along with Victor Hamburger and Rita Levi-Montalcini, made significant discoveries in the field of biochemistry of growth processes.

In 1953, Levi-Montalcini discovered that substances found in certain mouse tumors could cause an excessive growth of specific parts of the nervous system in chicken embryos. The active factor responsible for this growth was named nerve growth factor (NGF). In 1956, Cohen joined a research group at Washington University and embarked on the challenging task of purifying and identifying NGF. After three years of work, Cohen and his colleagues obtained a concentrated extract from mouse tumors that promoted tissue growth. This extract consisted of proteins and nucleic acids and was very viscous and difficult to separate. To isolate the active component, Cohen added snake venom containing an enzyme that could break down nucleic acids. This venom was found to have greater NGF-like activity than the extract itself. This discovery stimulated the search for NGF in other tissues, leading to the detection of high NGF activity in the salivary glands of adult mice. Cohen was able to purify NGF and obtain antibodies to it. The chemical structure of NGF was later decoded, revealing it to be a protein with a chain of 118 amino acids. When two such chains came together, they formed a biologically active factor. Cohen's achievement was significant in neurobiological research, as scientists now had a well-defined chemical agent that stimulated nerve growth, as well as another that inhibited it.

In 1959, Cohen joined the Vanderbilt University School of Medicine in Nashville, Tennessee, where he studied endocrinology and the action of hormones. At Vanderbilt, he continued his research on growth factors, starting as an assistant professor of biochemistry and eventually becoming a full professor in 1967. In 1976, he assumed the position of the American Cancer Society Professor of Biochemistry.

During his time at Vanderbilt, Cohen also discovered a second substance that he noticed while studying NGF. This substance, which he named epidermal growth factor (EGF), stimulated the growth of skin and corneal cells. EGF became a valuable tool in the study of biochemical signals regulating cell division and differentiation. Cohen and his team were able to unravel the mechanism of EGF binding to its receptors and entry into the cell. He developed a simple and elegant method to isolate and purify mouse EGF in relatively large quantities. In 1972, he and his colleagues determined the amino acid sequence of this polypeptide (a chain of 53 amino acids) and identified three regions where the chain formed loops. Cohen also obtained antibodies to EGF. In 1975, he isolated EGF from the urine of pregnant women and determined its amino acid sequence. EGF proved to be a crucial tool for studying biochemical signals that regulate cell division and differentiation. It was found to stimulate the growth of many types of cells and enhance various biological processes.

Using a radioactive labeling method that allowed tracking the interaction between EGF and its receptors, Cohen and his team revealed the mechanism of EGF-receptor binding and the penetration of this complex into the cell. They discovered that a universal enzymatic system, shared by other growth factors, hormones, and oncogenic viruses, was involved in this process. This work played a significant role in uncovering previously unknown growth factors and shed light on the actions of viruses and tumor formation. In 1986, Cohen and Levi-Montalcini were awarded the Nobel Prize "for their discoveries of growth factors, which have important implications for understanding the regulation of cell growth and organ development." Cohen's research on the sequence of molecular events stimulated by the interaction between EGF and its receptor, as well as his discovery of new principles applicable to a wide range of hormone-cell interactions, were noted as part of the award.

Cohen has received numerous awards in recognition of his contributions to science, including the Earl Sutherland Prize for Achievement in Scientific Research (Vanderbilt University, 1978), the Robertson Memorial Award (National Academy of Sciences, 1981), the Lewis S. Rosenstiel Award for Distinguished Work in Basic Medical Research (Brandeis University, 1982), the Louisa Gross Horwitz Prize (Columbia University), the International Gardner Foundation Award (1985), the National Medal of Science (National Science Foundation), and the Albert Lasker Basic Medical Research Award (1986). He is a member of the American Society of Biochemists, the International Institute of Embryology, the National Academy of Sciences, and the American Academy of Arts and Sciences. Cohen has also been awarded an honorary degree from the University of Chicago.