January 18, 2008

Discovery lecturer lands Vanderbilt Prize

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Steven Gabbe, M.D., presents Elizabeth Blackburn, Ph.D., with the Vanderbilt Prize in Biomedical Science. (photo by Dana Johnson)

Discovery lecturer lands Vanderbilt Prize

Many of us are concerned about aging. But while some people ignore their worries and others slap on wrinkle cream, Elizabeth H. Blackburn, Ph.D., is performing groundbreaking research on the role of telomeres and telomerase — a facet of the aging process that may play a role in age-related diseases such as cancer.

Blackburn explained the promise of her research on telomeres and telomerase at the Jan. 10 Discovery Lecture, where she was introduced as the second winner of the Vanderbilt Prize in Biomedical Science.

Blackburn is professor of Biology and Physiology at the University of California, San Francisco. After her widely publicized 2004 dismissal on political grounds from the President's Council on Bioethics, she became an outspoken advocate for stem cell research. In 2007, she was listed among Time magazine's 100 Most Influential People in The World.

The Vanderbilt Prize in Biomedical Science was established by Vanderbilt University School of Medicine to honor women who have made significant advances in the biological and biomedical sciences and have contributed positively to the mentorship of other women in science.

Telomeres are DNA-protein complexes that cap the ends of chromosomes. They keep the ends of chromosomes from “fraying,” Blackburn explained, much like the plastic tip on a shoelace. If a chromosome's telomere cap gets too short, the chromosome loses DNA during replication. This leads to loss of vital genetic information and cell senescence, or aging.

Telomeres are aided and protected by telomerase, an enzyme that adds back lost DNA with each round of cell division. In humans, telomerase is found in stem cells and in 90 percent of tumor cells.

Blackburn co-discovered telomerase in 1984 in the model organism Tetrahymena thermophila, a single-celled microbe with characteristics similar to animal cells and the ability to divide forever, which essentially makes it immortal. She demonstrated that when Tetrahymena telomerase is inactivated, proper cell division stops and the organism becomes “mortal.”

This discovery led Blackburn to look at the role of telomeres and telomerase in human aging.

Her research on live, cultured human cells over a long time span showed that telomerase is essential to normal cell functioning, while mutations in telomerase lead to age-related diseases, such as bone marrow failure.

She concluded that a full and healthy human lifespan requires properly functioning telomeres and telomerase.

For a complete schedule of the Discovery Lecture series and archived video of previous lectures, go to www.mc.vanderbilt.edu/discoveryseries.