In the cell nucleus, DNA is wrapped around proteins called histones. Together they form chromatin.
Chromatin's job is to package the genetic code neatly into the cell's nucleus. Chromatin can also regulate which genes are switched on and off. In cancer cells, however, chromatin helps them to evolve and adapt to cancer therapies, thereby allowing them to survive.
"If you think of genetics as hardware," explains study co-author Vadim Backman, of the McCormick School of Engineering at Northwestern University in Evanston, IL, "then chromatin is the software."
"Complex diseases such as cancer," he adds, "do not depend on the behavior of individual genes, but on the complex interplay among tens of thousands of genes."
So, Backman and his colleagues set their sights on chromatin as the key to combating cancer drug resistance, and an imaging technique they developed last year helped them to learn more about this intricate set of macromolecules.