The Effects of 4-Week Aerobic Exercise on the Levels of CCl2, CCl5, and their Respective Receptors in Female BALB/C Mice Suffering from Breast Cancer

BACKGROUND: The studies reported that chemokines Chemokine (C-C motif) ligand 2 (CCL2) and Chemokine (C-C motif) ligand 5 (CCL5) have tumor-promoting roles in breast cancer (BC). The aim of the present study was to evaluate the effect of 4 weeks of continuous aerobic exercise (AE) on chemokines CCL2 and CCL5 and their relative receptors in animal model of human BC. MATERIALS AND METHODS: BALB/c mice were divided randomly into four groups included cancer control (CC) and three other groups. The total duration of the experiment was 14 weeks, including 2 weeks of familiarization of mice with treadmills and three of 4-week periods of experiment. Tumor inoculation and formation were performed in the second 4-week period. Group 1 received AE in the first 4-week, Group 2 received AE in the second 4-week and Group 3 in the third 4-week. RESULTS: The CCL2 was reduced significantly in Groups 1, 2, and 3 compared to control (F(3,12)= 4705, P = 0.0001). In terms of CCL5, a significant decrease was seen only between Group 3 and control. Western blot results showed a significant reduction in C-C chemokine receptor Type 2 (CCR2) between Group 1 versus CC and Group 2 versus CC (F(3,20)= 1.812, P = 0.004). In terms of C-C chemokine receptor Type 5 (CCR5) a significant decrease was observed between Group 2 versus control and Group 3 versus control (F(3,20)= 273.3, P = 0.042), (P = 0.004). CONCLUSION: It can be concluded that 4-week AE significantly reduces the chemokines CCL2 and CCL5 and their respective receptors levels CCR5 and CCR2 in different stages, and it may have an inhibitory effect on tumor growth.