A team of scientists from Johns Hopkins and the biotechnology company Genitope has unlocked the 3-D structure of a receptor, called HER2, that goes awry in 20 to 30 percent of breast cancers.

The scientists reported in the journal Nature that they also figured out how the HER2 receptor interacts with an antibody, sold as Herceptin, that is used to treat thousands of breast cancer patients.

"Now we know exactly which building blocks of the Herceptin antibody interact with which building blocks of HER2," says Dan Leahy, Ph.D., professor of biophysics at Johns Hopkins. "When you understand the properties of receptors and antibodies in terms of their structural interaction, you can begin to explain their effects and use the information to design better drugs."

Herceptin, which kills cancer cells carrying excess HER2, was approved by the U.S. Food and Drug Administration as a breast cancer treatment in 1998 but until now it wasn't clear precisely how Herceptin interacted with HER2.

Other sources: Journal of Clinical Oncology