Scientists discovered a new way breast cancer cells dodge the immune system and promote tumor growth, providing a fresh treatment target in the fight against the disease. While comparable mechanisms to avoid the immune system have been identified in mice with breast and other cancers, the study tested human breast tumor cells, putting researchers closer to understanding how the disease progresses in real patients.
The study, published in the journal Cancer Research, found high levels of the protein Hsp27 (heat shock protein 27) are released from human breast cancer cells and may not only render immune cells unresponsive to the tumor, but increase blood flow to the tumor as well, both of which fuel tumor growth.
"Our study is very unique because we used human breast cancer cells, which are extremely difficult to get," said Asit De, Ph.D., lead author and research associate professor in the Department of Surgery at the University of Rochester Medical Center, who worked closely with physicians at the Wilmot Cancer Center. "The way tumor cells operate in mice is not identical to humans, so we need to do more of these types of human studies to confirm or reject cancer-related discoveries in mice."
Past research reports Hsp27 is present in high levels inside breast tumor cells and is associated with resistance to chemo and radiation therapy. De and his team discovered Hsp27 is also released, or pushed out of breast tumor cells, into the area surrounding the tumor, known as the breast tumor microenvironment.
Once outside the cells, Hsp27 may transform circulating white blood cells called monocytes that enter the tumor into cells known as macrophages, which do the opposite of what they are meant to do. Usually, macrophages work to wipe out tumor cells, but in this case they help, rather than hurt, tumor cells. These particular macrophages may make human T cells the main immune cells that attack and kill foreign invaders,
|Contact: Emily Boynton|
University of Rochester Medical Center