[The following is an exact transcript of this podcast.]

The 2009 Nobel Prize in physiology or medicine goes to Harvard’s Jack Szostak, Johns Hopkins’s Carol Greider and Elizabeth Blackburn at U.C. San Francisco for their work on how chromosomes are protected by telomeres and the enzyme telomerase.

The Nobel laureates’ research helped explain how an organism’s DNA is successfully copied when cells divide. Telomeres are genetic sequences that act like little protective caps at the end of chromosomes—think of the sealed tips of your shoelaces. Telomerase is the enzyme that builds telomeres.

Blackburn and Szostak determined that it was a specific DNA sequence in the telomeres that kept chromosomes from fraying whenever they were copied when a cell splits in two. Blackburn and Greider discovered telomerase. The findings have implications for the understanding of aging and cancer. Because if the enzyme keeps the telomeres robust, the chromosomes stay protected and the cell’s aging is slowed. And in cancer cells, which unfortunately do not seem to age, telomere length is maintained virtually indefinitely. Szostak, Greider and Blackburn thus revealed one of life’s basic mechanisms, and paved the way for new medical strategies.

—Steve Mirsky

For more Nobel Prize coverage, see Nobel Prize in Medicine shared by three U.S. genetic researchers

Carol Greider and Elizabeth Blackburn co-authored the article "Telomeres, Telomerase and Cancer" for the February, 1996, issue of Scientific American magazine. It’s available in our digital archive at www.sciamdigital.com

Jack Szostak co-authored the article "The Origin of Life on Earth" in the September 2009 issue of Scientific American magazine, available on our website. And to hear an archived interview with new Nobel Laureate Jack Szostak, go to the May 7, 2008, episode of Science Talk, available at www.scientificamerican.com/podcast