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

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.

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.

The CCL2 was reduced significantly in Groups 1, 2, and 3 compared to control (F3,12 = 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 (F3,20 = 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 (F3,20 = 273.3, P = 0.042), (P = 0.004).

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.