endurance training attenuates angiogenesis following breast cancer by regulation of mir126 and mir296 in breast cancer bearing mice

Background: in recent decades, various studies have shown a relationship between exercise and decreased mortality in patients with breast cancer. however, potentially involved molecular mechanisms are yet to be detected.objectives: the goal of this study was to investigate the effect of endurance training on gene expression of mir-126, mir-296, hgs and protein expression of vegf-a, in the tumor tissues of breast cancer bearing mice.methods: twelve laboratory female balb/c mice, weighing 19 ± 1.05 g, were randomly divided into two groups of 6 each; that is, endurance training and control, after inducing cancer by subcutaneous injection with mc4-l2 into their right sides. each session of endurance training involves 60-min of running on a treadmill at an intensity of 60% - 65% vo2max, five days a week for 10 weeks. twenty-four hours after the last exercise session, the mice are sacrificed and the genes expression is measured.results: endurance training caused a significant decrease in mir-296 (p < 0.05) and an increase in the hgs (p < 0.05) and mir-126 (p < 0.05) at mrna level, and a decrease in vegf-a (p < 0.05) at protein level in tumor tissue compared to the controls. decrease in proangiogenic factors and induction of anti-angiogenic factors are associated with decreased growth of tumor volume (p < 0.05) in the endurance training group compared to the control group.conclusions: data from this study demonstrate that endurance training can significantly decreases tumor growth in balb/c mice. endurance training mediates its effects through reduction of level of the vascular endothelial growth factors (vegf) and vegf receptors (vegfr) in tumor tissue.