Potential target for triple-negative breast cancer found

Investigators have hit on a potential target for triple-negative breast cancer, a disease that is notoriously impervious to some of the most effective therapies available for breast cancer and has attracted significant interest from drug developers.

Triple-negative breast cancer, an aggressive form of the disease that represents between 12% and 17% of all breast cancers, is treated with a combination of therapies such as surgery, radiation therapy, and chemotherapy, but these have varying success rates.

On the hunt for more effective therapies, researchers from the University of Kansas School of Medicine turned their attention to a member of a family of protein kinase enzymes. In recent years, atypical protein kinase C signaling has been found in the tissue invasion and metastasis of multiple tumors.

Examining samples of breast cancer that had spread to the liver, lung and other organs, the research team found that atypical protein kinase c lambda/iota, which is known to influence cell growth, was highly expressed in metastatic breast cancers.

To further test this connection, the researchers depleted the protein in mice with a type of triple-negative breast cancer known to be highly invasive and metastatic. Reducing this protein significantly slowed the breast tumor growth in the mice.

Previous studies have associated the atypical protein kinase c lambda/iota with other cancers, but no prior study had revealed its possible role in breast cancer metastasis.

"We have been able to show that this protein is highly expressed in metastatic triple-negative breast cancer, and when we are depleting it from triple-negative breast cancer cells, we found that the cancer cells are not metastasizing," associate professor and study author Dr. Soumen Paul said in a statement. "The tumor growth is slowing down. This is giving us an opportunity for a targeted therapy."

- read the press release