Advances in Research
Killing Cells to Save Lives
Every day, millions of cells in the human body die through a process called apoptosis, or programmed cell death. Barbara Conradt, PhD, studies apoptosis in Caenorhabditis elegans, a tiny roundworm that has taught scientists much of what they know about the way cell death works in humans.
In a recent study, Conradt examined two "sister" cells that result from the division of one larger "mother" cell. Usually, one of these sister cells will survive and the other will die. Their fates are determined by a pro-apoptotic gene called egl-1. In the cell that dies, egl-1 is turned on. In the cell that survives, a protein called CES-1 suppresses egl-1, preventing apoptosis. But in some genetically mutated worms, both sister cells have CES-1, and in those cases neither one dies.
In humans, mutations that prevent apoptosis can result in uncontrolled cell growth, potentially leading to a tumor. "So apoptosis is really critical for cancer," says Conradt. Figuring out how to turn on apoptosis in mutated cells in C. elegans may someday provide scientists with a way to do the same in humans, helping to stop tumor growth before it starts.
Small Molecules Have Big Implications
Short strands of RNA called microRNAs could prove to be of vast importance in human disease. Discovered in 2001, microRNAs are known to be involved in the translation of genes into specific proteins. Now it seems that examining these tiny molecules could help doctors to understand how breast cancer develops-and to detect it as early as possible.
Lorenzo Sempere, PhD, studies the use of microRNAs as a type of biomarker—an indicator of biological processes. While working in the lab of Charles Cole, PhD, Sempere found that the levels of some microRNAs change as breast cancer progresses. "This might be potentially useful as a biomarker for early detection," Sempere says. The amount of microRNA miR-145, for example, decreases in the cells surrounding a tumor. The expression of another microRNA, miR-21, increases in cancer cells. Some day doctors might be able to examine these molecules to know whether a patient is developing cancer.
Communicating about Cancer
It's not always easy to make long-term health risks seem relevant to a teenager. But Meg Gerrard, PhD, and her husband, Fredrick Gibbons, PhD, say that it is possible to help young people make good choices when it comes to behaviors that can lead to cancer. Gerrard recently became director of the Cancer Control Research Program at Norris Cotton Cancer Center and Gibbons has joined the Psychology and Brain Sciences Department at Dartmouth College. They study how people, particularly adolescents and young adults, make decisions that can be harmful to their future health.
In one study, Gerrard and Gibbons designed an intervention to deter college students from sunbathing. Simply warning the students about the risk of skin cancer is not very effective, they say. Using a camera equipped with a special filter, they showed the students photographs that revealed the hidden damage done to their skin by prolonged sun exposure. This technique, Gerrard says, "was very successful in changing people's behaviors." The goal, both in this study and other interventions, is to help young people become wise beyond their years.
January 25, 2009
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