Web Exclusives: Systems
Why Cells Make Different Decisions
One of biology's mysteries is how cells with the same genetic instruction book can respond in dramatically different ways to the signals around them, including to medicines. Figuring out why could lead to new treatments for diseases like cancer or inflammation, which involve cells growing and responding incorrectly to their environments.
Peter Sorger, a systems biologist at Harvard Medical School, uses mathematical modeling along with experiments to study cellular behaviors and why cells make different choices. Mathematics and computation, he says, make it possible to understand these complicated processes in time and space.
To better understand the processes governing cellular activities, Sorger and his research group studied how cells respond to an investigational cancer drug called TRAIL. When exposed to TRAIL, some human cells died within an hour while others died after 12 hours or survived apparently unscathed. Why did these cells vary so much in their response to the drug? Sorger's team considered an assortment of possible factors—modifications to the genome, flukes in biochemical responses, temporary differences in cellular components. All of these factors turned out to be important, causing both consistency and variation in cell behavior.
In investigating cell behavior, Sorger says he is trying to model how individual cells make life-death decisions. He also hopes that understanding those decisions will help cure disease.