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

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.

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.

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).

Exercise may be able to reduce anti-apoptotic agents in tumor cells, leading to apoptosis of tumor cells and reduced tumor growth.