Mayo Clinic study finds a potential Achilles' heel for HER2-positive cancer

Mayo Clinic's Ruth Lupu

The HER2 protein plays a well-understood role in driving a particularly aggressive type of breast cancer, and drugs like Herceptin have pioneered new--but limited--approaches to HER2-positive cancer that can help about 20% of all breast cancer patients. Now a team of investigators at the Mayo Clinic says they may have found the key to taking this approach one big step forward, with implications for a range of cancers.

Starting with the observation that excessive levels of HER2 triggers a protein pairing process which signals for rapid cell proliferation, driving the cancer, the investigators zeroed in on a "functional site" they believed played a big role in promoting the pairing and then set out to block it.

Eventually they focused on a segment of 16 amino acids and concluded that without the "short stretch" normal cells could not be transformed into cancerous cells.

"Our study demonstrates that this protein sequence is a druggable target," says Ruth Lupu, a professor of experimental pathology and laboratory medicine and biochemistry and molecular biology at the Mayo Clinic. "Targeting this sequence could have a much broader impact than other drugs that are currently available because it does not just disrupt HER2, but it actually gets in the way of HER2's dimerization to itself and other family members. As a result, this approach could block many of the different pathways by which cancer-causing signals get sent into the cell."

The next step is to test this approach in animals while looking for the best kind of drug for it. The study is published in the Journal of the National Cancer Institute.

- here's the release
- get the research abstract