Stress hormones and immune cells called neutrophils may contribute to the reappearance of tumors years after treatment by awakening dormant cancer cells, suggests a study of mice and data from 80 lung cancer patients, published in the journal ‘ Science Translational Medicine ‘.
The study helps answer the lifelong question of why cancers can come back long after they have apparently been cured with chemotherapy or surgery. The results therefore also suggest that targeting stress hormones with approved drugs known as beta-blockers could help prevent tumors from coming back.
Tumor recurrence is one of the leading causes of death in cancer patients, but it is unclear exactly what biological mechanisms cause the recurrence of tumors.
However, studies have suggested that recurrence develops when dormant tumor cells, which initially spread during the early stages of cancer, become active once again.
Researchers at the Wistar Institute in Philadelphia Michela Perego and her colleagues found that stress hormones, such as norepinephrine, reactivate dormant ovarian, and lung cancer cells in mice.
Specifically, the scientists found that exposing mice to stressful situations raised levels of stress hormones, causing neutrophils to release S100A8 / A9 proteins and fat molecules that, in turn, caused tumor cells to wake up again. inactivity. However, tumor cells remained dormant in stressed mice that received an experimental beta-blocker.
The team also studied serum samples from 80 patients who had lung cancer surgically removed and found that patients harboring higher concentrations of S100A8 / A9 were more likely to have experienced a recurrence 33 months after surgery.
Perego and his team state that beta-blockers or compounds that target the S100A8 / A9 proteins should be evaluated as potential therapies to disrupt the reactivation process, but they underscore the need for more sophisticated models of tumor cell inactivity.