Effects of Aerobic Exercise on Cytokine Expression in a Breast Cancer Mouse Model

Background: Regular physical activity lowers or prevents the risk of heart disease, diabetes, some cancers, the development of hypertension, and death from these diseases through a reduction in inflammation. Cytokines, such as interleukin (IL)-6, IL-18, tumor necrosis factor-alpha (TNF-alpha), and C-reactive protein (CRP) are major markers representing the inflammatory process. This study aimed to investigate cytokine mRNA expression levels of IL-6, IL-18, TNF-alpha, and CRP in hepatocytes from breast cancer xenograft mice with or without moderate exercise. Methods: Each of the 5 mice at SP Korea Company, Seoul, Korea in 2015 were randomly divided into 3 groups: control (CTL), breast cancer (BC), and breast cancer exercise (BCEX). The inflammatory markers were analyzed in 10-week-old female Balb/C nude mice hepatocytes (n = 15; CTL = 5, BC = 5, BCEX = 5). Moderate intensity physical activity in mice was performed on a treadmill at an intensity of 18 m/min for 12 weeks, at 30 min for 5 days per week. Results: IL-6, IL-18, TNF-alpha, and CRP mRNA expression levels of the BCEX group were significantly decreased compared to those of the BC group (P < 0.05), with no difference to the CTL group. Conclusion: There might be a reduced inflammatory process via a reduction in TNF-alpha, IL-6, IL-18, and CRP expression in breast cancer mice that were subjected to moderate intensity exercise.