The Effect of Aerobic Training on Tumor Growth and Expression of Bcl-2 Gene and Protein in Female Mice with Breast Cancer

Introduction: The aim of this study was to investigate the effect of aerobic exercise with detraining in different phases of prevention on Bcl-2 gene expression and protein. Methods: For this purpose, 32 female BALB-c mice (18-20 g) were purchased and randomly assigned to four groups of primordial prevention (A), primary prevention (B), secondary prevention (C), and control (D). Group A performed aerobic exercise for 4 weeks, followed by injection of 4T1 cells and 8 weeks of detraining after the injection. Group B performed aerobic exercise for 4 weeks immediately after the injection of 4T1 cells and then detrained for 4 weeks. Group C received a 4T1 cell injection and maintained a sedentary life for 4 weeks, followed by 4 weeks of aerobic exercise. The subjects were killed 48 hours after the last training session and detraining courses and tumor tissues were removed. Real-time polymerase chain reaction was used to measure gene expression and western blotting was used to measure protein content.The one-way ANOVA test was used to analyze the data. Results: The mean gene expression due to aerobic exercise was significantly (P<0.001) lower in groups A (0.481), B (0.323), and C (0.035) compared with group D (1.711). Also, aerobic exercise caused a significant decrease in Bcl-2 (P=0.005) protein expression in groups A (0.692), B (0.821), and C (0.670) compared with group D (1.000). It should be noted that tumor growth in experimental groups was not significantly different from the control group (P=0.092). Conclusion: Exercise may be able to reduce anti-apoptotic agents in tumor cells, leading to apoptosis of tumor cells and reduced tumor growth.