New York, June 5
Aerobic exercise, which includes brisk walking, swimming, running or cycling, can help reprogram the immune system to reduce tumor growth and amplify the effects of immunotherapy, a new study has found.
Published online in Cancer Cell, the study, which focused on pancreatic cancer, provides new insights into how the mammalian immune system, designed to attack foreign invaders like bacteria, can also recognize cancer cells as abnormal.
According to New York University researchers, exercise-induced increases in adrenaline levels lead to changes in the immune system.
It includes the activity of cells that respond to the signaling protein interleukin-15 (IL-15).
The study found that exercise promotes the survival of IL-15-sensitive CD8 T cells and doubles the number of them that go to pancreatic ductal adenocarcinoma (PDAC) tumors in mice.
Such “effector” T cells have been shown by other studies to be able to kill cancer cells. Further tests revealed that aerobic exercise for 30 minutes five times a week reduced the rate of cancer formation by 50% in a mouse model of PDAC and reduced tumor weight by 25% in another model, in which mice ran on treadmills for three weeks.
Working with the University of Texas MD Anderson Cancer Center, the study authors then found that human patients who exercised before surgery to remove their pancreatic tumors had more CD8 effector T cells that expressed a protein called granzyme B, which confers the ability to kill tumor cells. .
Patients who exercised and had more of these cell types had a 50% better five-year overall survival than patients who had fewer.
“Our results show, for the first time, how aerobic exercise affects the immune microenvironment in pancreatic tumors,” said first author Emma Kurz, graduate student at NYU Grossman School of Medicine.
“The work revealed that activation of IL-15 signaling in pancreatic cancer could be an important therapeutic approach in the future.” IANS