New Hope For People With Advanced Breast Cancer

A surprising discovery by Queen's University researchers that happened when their work took an unexpected turn may help women with advanced breast cancer respond better to conventional drug treatments.

The Queen's team's findings, to be published on-line today in the international journal Cancer Research, show that a newly discovered "peptide" molecule (a chain of amino acids smaller than a protein) increases the effectiveness by 350 per cent of drugs used to kill breast cancer cells.

Drs. Zongchao Jia and Vinay Singh, of the Queen's Department of Biochemistry, initially intended to study the structure of a protein called SNCG which is implicated in drug resistance in breast cancer. When unraveling the structure proved more difficult than expected, the research team looked to a similar protein associated with Alzheimer's Disease.

They were looking for "binding partners" of the Alzheimr's protein, hoping to learn how the structures of the Alzheimer protein and SNCG were held together. From this information, they were able to design a completely new peptide, which blocked SNCG's interaction with another protein, counteracting the resistance to cancer drugs. "We were excited to find that it actually can reduce anti-cancer drug resistance by three-and-a-half times," says Dr. Jia, Canada Research Chair in Structural Biology.

Noting that the peptide itself is not a drug, Dr. Jia likens it to an ingredient in the kind of "drug cocktails" used to treat HIV/AIDS. "It has to be used in combination with a drug to be effective," he says. "In the same way that cream flavors coffee to make it taste better, the peptide enhances the effectiveness of the most widely-used breast cancer drugs today."

"We greatly hope this will not only increase the positive response from patients but also will make the current drug more useful by extending its impact to a wider range of people, particularly those with a resistance problem," says Dr. Jia.

"The whole discovery 'morphed' from something entirely different. In a basic research lab like ours, this is as close as we get to treatment for a disease," says Dr. Jia, whose mother has breast cancer. "It just shows that once in a while basic science leads to discoveries that are useful in everyday life!" he adds.

Also on the research team are Drs. Yue Zhou and Jingwen Liu (Palo Alto Health Care System); Joseph Marsh and Julie Forman-Kay (University of Toronto); and Vladimir Uversky (Indiana University). The study was partially funded by the Canadian Institutes of Health Research (CIHR) and the Natural Sciences and Engineering Research Council (NSERC).

Next, Dr. Jia hopes to team up with other researchers to advance the work to the point where they can transform the peptide, called ANK, into a suitable form for "drug cocktail" therapy. A U.S. patent application has been filed for this discovery through PARTEQ Innovations, the university's technology transfer office.