Narrator:       This is Science Today. A discovery by researchers at the University of California, San Francisco, is shedding new light on how some cancers develop resistance to drug therapy. Oncologist Pamela Munster explains that changes in gene expression, called epigenetic modification, play a major role in allowing tumors to escape therapy.

Munster:        The tumors don't have to have a genetic mutation to develop resistance. They can actually develop a method to up-regulate or down-regulate genes.

Narrator:       Munster's team has shown that epigenetic modification in some breast cancers affects a certain protein involved in glucose metabolism called AKT. This protein plays an essential role in allowing cancer cells to survive even the harshest of environments. In the future, Munster hopes to use AKT as a biomarker to detect genetic changes to cancer cells early enough to stop drug resistance from happening in the first place.

Munster:       We feel pretty confident that we can reverse resistance. The question is, can we prevent it?

Narrator:       For Science Today, I'm Larissa Branin.