The Effects of Prophylactic and Adjuvant Therapy of Endurance Training on the Levels of Tissue IL-6 and Tumor Volume in Mice Breast Cancer

Abstract

Background and Objectives: Many studies have shown that the exercise has preventive effects on breast cancer. The objective of this study was assessment the effects of prophylactic and adjuvant therapy of endurance training on tissue IL-6 levels in mice with breast cancer. Material and Methods: Forty female Balb/C mice were randomly assigned to Exercise-Tumor-Exercise (ETE), Exercise-Tumor-Rest (ETR), Rest-Tumor-Exercise (RTE) and Rest-Tumor-Rest (RTR) groups. After adaptation in the environment, two groups of mice performed continuous endurance training (8 weeks; %55-85 VO2max), and cancer cells were injected to all of them. Then, one group of trained and one group of non-trained mice continued the endurance training (6 weeks; %55-70 VO2max). Tumor volume was measured by a digital caliper weekly. Finally, the mice were sacrificed, tumor sample was homogenized and levels of IL-6 were measured by ELISA method. Results: There was significant difference (P=0.0001) in the IL-6 level among the groups performed endurance exercise after malignancy (RTE and ETE) and groups not performed (ETR and RTR). These results had with tumor growth rate (P=0.0001). Conclusions: Intratumoral inflammation reaction leads to the progression and metastasis of cancer cells and the decrease of tumor volume in exercise groups is related to the decrease of inflammatory mediators such as IL-6. Finally the endurance training can be effective as a non-pharmaceutical method in prophylaxis and adjuvant therapy of breast cancer.