Possible: A New Treatment for Aggressive Breast Cancer

By Jane Farrell

Experts have found a process that fuels triple negative breast cancer, the most aggressive form of the illness, and that could lead to new treatments.

The researchers, from the University of Michigan Comprehensive Cancer Center and Georgia Regents University, discovered that a protein that fuels an inflammatory pathway does not turn off in breast cancer. The failure to turn off leads to an increase in cancer stem cells.

The protein, SOCS3, is highly expressed in normal cells but until now has been undetectable in triple-negative breast cancer.

The study showed that in cancers, SOCS3 blocks the “off switch” of the inflammatory protein interleukin 6, or IL6.  When the switch does not get turned off, it enables cancer stem cells to grow.

“We have known for a long time known that there are important links between inflammation and cancer, including similar pathways that regulate normal and cancer stem cells," says study author Max S. Wicha, M.D., distinguished professor of oncology and director of the U-M Comprehensive Cancer Center.

"This work helps explain why these pathways shut off in normal tissues after injury but remain active in cancers, resulting in an increase in cancer stem cells. Furthermore, they suggest that blocking these inflammatory loops may be a means of targeting cancer stem cells, improving patient outcome," he says.

The study appears in the journal Oncogene.

Currently, there are no molecularly targeted therapies aimed at triple-negative breast cancer.

The researchers tested a drug, bortezomib, in mouse models of triple-negative breast cancer and found that it stops the process that leads to an increase in metastatic cells. Bortezomib is currently approved for treatment of the blood cancer multiple myeloma.

This team is designing a clinical trial which uses an IL6 blocker. The new research suggests that adding bortezomib to the IL6 inhibitor may be a way to target stem cells in triple-negative breast cancer.

The researchers also suspect that this pathway may apply to other cancers as well and are investigating that further.