New Combination Treatment Helps Combat Aggressive Forms Of Breast Cancer

New findings published in the journal Proceedings of the National Academy of Sciences (PNAS) show that a novel treatment for aggressive breast cancers may be on the way.

"The findings point toward a new therapeutic target for aggressive breast cancer and potentially an adjunct for women who become resistant to Herceptin, or trastuzumab, the drug commonly given to ErbB2-positive patients. Erbin could be a diagnostic biomarker that physicians look for in breast tissue biopsies," said corresponding study author, Dr. Lin Mei, in a news release.

For the study, researchers examined the interaction between the oncogene ErbB2 and the protein Erbin, which can be stabilized and reduce proliferation of aggressive ErbB2 positive breast cancer when binded together. They did this by studying overexpression of the gene in 171 aggressive forms of human breast cancer that is present both inside and outside of tumor cells.

"Breast cancer cells can mutate so they no longer have an external protrusion of ErbB2, leaving Herceptin and other breast cancer medication without a place to bind. While getting inside the cells can be more difficult, the ability to target intracellular Erbin could one day make a difference for these patients," Mei added.

Researchers believe that disrupting the interaction of Erbin and ErbB2 could help to prevent further cancer proliferation.

"Erbin itself could be a novel target: you disrupt the interaction, and it will be therapeutic," Mei concluded. "Secondly, when a patient becomes Herceptin-resistant because the extracellular domain of ErbB2 is lost, this approach should still be effective because of the critical interaction of the two."