Researchers from Buffalo, N.Y.-based Roswell Park Comprehensive Cancer Center found immunosuppressive cells become more sensitive to stress signals as tumors grow, according to a Nov. 4 press release.
The study, published Oct. 26 in Cell Reports, used a preclinical model of triple-negative breast cancer. Scientists learned that as tumors grow, they become more sensitive to stress signals coming from the nervous system. Researchers discovered a population of immune cells known as myeloid derived suppressor cells show an increase in the expression of β2 adrenergic receptors, molecules that control the function of key immune cells.
"This increase in β-AR expression on myeloid-derived suppressor cells allows these cells to be stimulated by the stress hormone norepinephrine, which fosters an immunosuppressed environment that promotes tumor growth by increasing MDSCs' ability to generate and process energy and suppress anti-tumor immune response," Hemn Mohammadpour, PhD, the paper’s first author, said in the press release. "This study provides some very important clues that help explain the specific mechanisms by which prolonged stress stimulates tumor growth and decreases lifespan."