The effects of 8 weeks aerobic training on HIF-1α, miR-21 and VEGF gene expression in female Balb/c with breast cancer

Background: Breast cancer, which is a major cancer for women, affects the angiogenesis process. Exercise training can decrease the process of angiogenesis in tumor tissue. The aim of present study was to investigate the effects of 8 weeks of aerobic training on HIF-1α, miR-21 and VEGF gene expression in female Balb/c mice with breast cancer. Materials and Methods: 16 female Balb/c mice (age: 3-5 weeks and weight: 17/1 ± 0.1 g) were selected and randomly divided into two groups: aerobic training and control. The aerobic training involved running with intensity of 14-20 m/min for 5 sessions per week over 8 weeks. The gene expression of HIF-1α, miR-21 and VEGF was examined by RT&PCR. The repeated measurement ANOVA, Bonferroni post hoc test and the independent T-test were used to analyse the data, with a significant level set at p<0.05. Results: The results showed that aerobic training induced significant differences in the growth of tumor volume and an increase in HIF-1α. In addition, aerobic training caused a significant decrease in the gene expression of miR-21, whereas the changes in gene expression of VEGF were not significant. Conclusion: It appears that aerobic training caused a reduction in the gene expression of miR-21 and VEGF, which in turn, induced a decrease in the tumor volume and a corresponding improvement in the cancer