Gene expression of angiogenesis and apoptotic factors in female BALB/c mice with breast cancer after eight weeks of aerobic training

OBJECTIVE(S): Breast cancer is the most common cancer in women, caused by a disorder in the angiogenesis and apoptosis process. Exercise can affect the process of angiogenesis and apoptosis in the tumor tissue. Thus, the aim of the present study was to investigate the changes in angiogenesis and apoptotic factors in mice with breast cancer after 8 weeks of exercise training. MATERIALS AND METHODS: Sixteen females BALB/c mice (age: 3-5 weeks and weight: 17.1 ± 0.1 g) with breast cancer were randomly divided into two groups of aerobic training and control. The aerobic training included 8 weeks and 5 sessions per week of running with an intensity of 14-20 m.min-1. HIF-1α, VEGF, miR-21 and cytochrome C, Apaf-1, caspase-9, and caspase-3 gene expressions were examined by real-time PCR. Repeated measures ANOVA, Bonferroni’s post hoc test, and independent samples t-test were used to analyze the data (P<0.05). RESULTS: The results showed that aerobic training reduced the growth of tumor volume and significantly reduced miR-21 gene expression. Aerobic training also significantly increased the gene expression of HIF-1α, cytochrome C, Apaf-1, caspase-9, and caspase-3, while changes in VEGF gene expression were not statistically significant. CONCLUSION: It appears that aerobic exercise training reduces tumor size and ameliorates breast cancer by reducing miR-21 gene expression, suppressing the apoptosis process, and reducing angiogenesis.