Researchers have uncovered a surprising way triple-negative breast cancer may turn the body against itself. Tumors appear to recruit macrophages—immune cells normally involved in healing and fighting infection—and use them to release a protein called BDNF that draws nerves into the tumor. Those nerves may then help the cancer grow, resist treatment, and potentially spread.
New research from the University of Oklahoma has revealed how an aggressive type of breast cancer can manipulate the immune system to draw nerves into tumors, creating conditions that may help the cancer grow.
Scientists have known for years that many solid tumors contain extensive nerve networks. What has been less clear is how those nerves enter the tumor in the first place. The new study, published in Cell Death & Differentiation, provides an explanation for this process in triple-negative breast cancer, a particularly difficult form of the disease to treat.
The researchers discovered that tumors attract macrophages, a type of immune cell that normally helps the body fight infections and repair damaged tissue. After entering the tumor, these macrophages release brain-derived neurotrophic factor (BDNF), a protein that encourages nearby nerves to grow toward and into the cancer.
BDNF is most widely known for supporting the growth and survival of nerve cells in the brain. In breast cancer, however, the researchers found that tumors can take advantage of this same biological signal. By prompting nerve growth inside the tumor, the process may contribute to cancer progression and resistance to treatment.
“Macrophages are the critical source for drawing nerves into the tumor. Although macrophages typically play a positive role in the body, they are facilitating a negative function in this scenario of breast cancer,” said Maureen Cox, Ph.D., an assistant professor in the Department of Microbiology and Immunology at the OU College of Medicine and a research member of OU Health Stephenson Cancer Center.
https://www.sciencedaily.com/releases/2026/08/260814011038.htm
