03/19/2010 - Carol W. Greider, Ph.D., a 1990 Pew scholar in the biomedical sciences and now professor of molecular biology and genetics at the Johns Hopkins University School of Medicine, received the 2009 Nobel Prize in Physiology or Medicine, sharing the award with Jack W. Szostak of Massachusetts General Hospital and Elizabeth H. Blackburn of the University of California at San Francisco.
The three scientists solved the biology question of how chromosomes, which contain DNA molecules, can be copied in a complete way during cell division and how they are protected against degradation. They showed, as the Nobel Assembly put it, that “the solution is to be found in the ends of the chromosomes—the telomeres—and in an enzyme that forms them—telomerase.”
Blackburn and Szostak “discovered that a unique DNA sequence in the telomeres protects the chromosomes” and then Greider and Blackburn “identified telomerase, the enzyme that makes telomere DNA. These discoveries explained how the ends of the chromosomes are protected by the telomeres and that they are built by telomerase,” the assembly noted.
“If the telomeres are shortened, cells age. Conversely, if telomerase activity is high, telomere length is maintained, and cellular senescence is delayed. This is the case in cancer cells, which can be considered to have eternal life. Certain inherited diseases, in contrast, are characterized by a defective telomerase, resulting in damaged cells. The award of the Nobel Prize recognizes the discovery of a fundamental mechanism in the cell, a discovery that has stimulated the development of new therapeutic strategies.”
More remains to be known, Greider says—for instance, how the telomeres maintain their length, or “length equilibrium,” since telomeres that are either too long or too short can cause damage.
Following the early-morning notice (she was folding laundry and getting her two children off to school when the Nobel Committee called), the editor-in-chief of Nobelprize.org asked Greider what attracted her to the telomerase question, “Curiosity,” she said, “drove me there.”
“Was it a difficult question to answer?”
“It was really unknown. It wasn’t clear whether it was going to be difficult or not,” she said, adding, “It was just, you know, diving into the unknown.”
The Pew Scholars Program in the Biomedical Sciences provides support that enables scientists in health fields to take calculated risks and follow unanticipated leads to maximize the benefits of their research for society. Begun in 1985, the program has invested more than $125 million to fund more than 460 individuals. Scholars have won three Nobel Prizes as well as MacArthur fellowships, Albert Lasker Medical Research Awards and other honors.
Greider was featured in the summer 2007 issue of Trust, which also contained an article on the biomedical scholars program as a whole. For more about the Pew Scholars Program in the Biomedical Sciences, visit the Emerging Science section of pewtrusts.org.
This article appeared in the Spring 2010 issue of Trust magazine.