AMHERST, Mass. - University of Massachusetts biology professor Lawrence M. Schwartz will speak on cell death in his upcoming Distinguished Faculty Lecture, "Programmed Cell Death: Of Moths and Men." The presentation is scheduled for 4 p.m. on Wed. March 10 in Memorial Hall, and is the third in this year’s Distinguished Faculty Lecture series.
Schwartz studies cell death, a carefully orchestrated process that is essential for normal development, but which can also carry grave results if the process goes awry.
"Cell death is a double-edged sword," he said. "It can result in essential, healthy changes, or in disabling or devastating illnesses." For example, human fetuses have webbing between their fingers; cell death eradicates this webbing by the time a baby is born, so that the child will have functional fingers. On the other hand, cells that are needed by the body are sometimes inappropriately killed off. Alzheimer’s disease is essentially the result of necessary neurons being killed; AIDS is made more complicated by the loss of T-cells that would otherwise protect the immune systems of people who are HIV-positive. "Lose those cells and you have devastating effects," Schwartz said.
Intriguingly, the cells don’t just die. According to scientists, cells commit suicide. "Every cell knows how to commit suicide, and every cell thinks about it at some point, and they either decide to go ahead with it, or to back away from it," he said. Those decisions are based on a biochemical cascade of hormones, which is not toxic itself, but which carries a message to the cell. Defective cells, for instance, are told to die. "The message is either interpreted as ‘You’re a valuable cell and you should stick around,’ or ‘It’s time for you to commit cell death.’"
Understanding how the process of cell death works could have serious ramifications in treating an array of diseases, Schwartz said. If scientists could determine how to save cells that are bent on self-destruction, it could become possible to stave off disorders such as Alzheimer’s disease or multiple sclerosis, in which the protective sheath around the spinal cord erodes. Conversely, the ability to induce unwanted cells to die could offer new options in the treatment of cancer. "If we could instruct tumor cells to die, we could treat a patient without creating the uncomfortable side affects often associated with chemotherapy," Schwartz said.
Cell death is also a common phenomenon in the animal kingdom, according to Schwartz. For example, tadpoles undergo an increase in thyroid hormone; most of the body cells ignore the message carried by the hormone, but the cells in the tail are instructed to die off, enabling the tadpole to grow into a frog.
The moth provides another excellent example of cell death, Schwartz said. "To start, they are fat little caterpillars; then they become completely different animals built from the same genome," he said. Schwartz has done extensive research on the caterpillar’s abdomen muscles, which are used to inch along, and eventually push it from its cuticle, a protective covering, when it emerges as an insect.
"Thirty hours later, those muscles are gone; here today and gone tomorrow, without a trace, in response to a hormonal signal," he said. "No one murders them. They really commit suicide."
Schwartz’s work is unusual in that it has included not just the study of specific organisms, but also the study of individual genes. He has conducted genetics experiments on fruitflies, and has cloned the mouse and human genes that correspond to the moth genes in his study of abdomen muscles. He considers what the consequences are if an animal lacks a certain gene, or if that gene is misregulated, or in the wrong place. "What we’re really looking at," he said, "is when and where the genes are expressed."
He joined the University’s faculty in 1988. Schwartz was educated at Northwestern University, where he earned a bachelor’s degree in biology, and the University of Washington, where he received his doctorate in zoology. He held postdoctoral fellowships at the University of North Carolina and the University of Washington, and served as a visiting scientist at the Whitehead Institute at the Massachusetts Institute of Technology, where he studied mouse transgenics.
Schwartz has worked to bring undergraduates into the research lab, and his honors include awards from the National Institutes of Health, the American Cancer Society, the Muscular Dystrophy Association, the Spinal Cord Research Foundation, and the American Heart Association.
He served on a National Science Foundation panel for developmental neuroscience, and has presented seminars at a number of institutions, including Tufts University, the University of Pennsylvania, Yale University, and Massachusetts General Hospital. His research has been published in such respected journals as Science, Cell, the Proceedings of the National Academy of Sciences, and Molecular and Cellular Biology.