Herceptin has been touted as a wonder drug for women with HER2-positive breast cancer, an aggressive form of the disease that is fueled by excess production of the HER2 protein. Not all women respond to the drug, however, and many who do respond eventually acquire resistance.

Researchers at Mayo Clinic found a promising way to circumvent this obstacle: They identified a small site in the HER2 protein that enables it to pair up, forming a molecular switch that sets off a cascade of events that turn normal cells cancerous. Research showed that disrupting this site can stem the growth of breast cancer cells more effectively than drugs currently in use.

The study, Blockade of a key Region in the Extracellular Domain Inhibits HER2 Dimerization and Signaling, was published in the Journal of the National Cancer Institute in April 2015. Ruth Lupu, Ph.D., Laboratory Medicine and Pathology, at Mayo Clinic's campus in Rochester, Minnesota, and the study's senior author, comment.