ANN ARBOR, Mich. New research from the University of Michigan Comprehensive Cancer Center and Georgia Regents University finds that a protein that fuels an inflammatory pathway does not turn off in breast cancer, resulting in an increase in cancer stem cells. This provides a potential target for treating triple negative breast cancer, the most aggressive form of the disease.
The researchers identified a protein, SOCS3, that is highly expressed in normal cells but undetectable in triple-negative breast cancer. They showed that this protein is degraded in cancers, blocking the cellular off-switch of a feedback loop involving the inflammatory protein interleukin 6, 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 Nature journal Oncogene.
Currently, there are no molecularly targeted therapies aimed at triple-negative breast cancer, which is a type of cancer negative for estrogen receptor, progesterone receptor and the HER2 protein all key targets for current therapies. Patients with this form of disease tend to have worse outcomes.
The researchers tested a drug, bortezomib, in mouse models of triple-negative breast cancer and found that it stops the protein degradation, resulting in the inflammatory loop shutting off, which reduces
|Contact: Nicole Fawcett|
University of Michigan Health System