The Effects of Combined Exercises Before and After Breast Cancer Tumor Induction Along with Capecitabine Treatment on the Gene Expression of E2F1 Transcription Factor in Tumor-bearing Female Mice
Oral Presentation
Paper ID : 1170-SSRC
Authors
1بخش علوم ورزشی دانشکده علوم تربیتی و روانشناسی دانشگاه شیراز در شیراز ایران
2استادیار فیزیولوژی پزشکی دانشگاه علوم پزشکی زاهدان زاهدان ایران
Abstract
Introduction & Objective: The lack of physical activity and the side effects of chemotherapy cause cancer patients many problems. Exercise and physical activity seem to have important roles in the prevention and treatment of breast cancer (BC). The aim of this study was to investigate the effects of combined exercises before and after BC tumor induction, with or without capecitabine treatment, on the expression of E2F1 transcription factor in tumor-bearing female mice.
Materials and Methods: Eighty Balb/c mice were divided into eight groups. In the first four groups, mice performed combined (aerobic and resistance) exercises for 12 weeks (five sessions per week). Tumors were created by injecting one million MC4-L2 cells to each mouse. The first, second, fifth, and sixth groups performed modified combined exercises for eight weeks. The mice in the second, third, sixth, and seventh groups were orally fed with capecitabine. Forty-eight hours after the last exercise session, the mice were sacrificed, and the tumor tissue was immediately extracted and stored at -70℃. Then RNA was extracted using TRIZOL reagent, and cDNA was synthesized by a commercial kit according to the manufacturer’s instructions. Finally, real-time PCR was performed to determine E2F1 gene expression.
Results: Breast cancer tumors were successfully induced by MC4-L2 cell line injection to mice. Combined exercises before tumor induction significantly decreased E2F1 gene expression in the tumor tissue (p = 0.001). In addition, combined exercise (p = 0.001), combined exercise+ capecitabine (p = 0.001), and capecitabine treatment (p = 0.001) after tumor induction significantly reduced E2F1 gene expression. Also, combined exercise (p = 0.003), combined exercise+ capecitabine (p = 0.02), and capecitabine treatment (p = 0.001) after tumor induction in association with pre-tumor induction exercises significantly reduced E2F1 gene expression in the tumor tissue.
Conclusion: The greatest reduction in E2F1 gene expression in BC tumor tissues was observed in the "exercise-tumor-exercise + drug" group, indicating the preventive effects of combined exercises before and after tumor induction in association with capecitabine treatment on the expression of this transcription factor in BC tumors in female mice.
Materials and Methods: Eighty Balb/c mice were divided into eight groups. In the first four groups, mice performed combined (aerobic and resistance) exercises for 12 weeks (five sessions per week). Tumors were created by injecting one million MC4-L2 cells to each mouse. The first, second, fifth, and sixth groups performed modified combined exercises for eight weeks. The mice in the second, third, sixth, and seventh groups were orally fed with capecitabine. Forty-eight hours after the last exercise session, the mice were sacrificed, and the tumor tissue was immediately extracted and stored at -70℃. Then RNA was extracted using TRIZOL reagent, and cDNA was synthesized by a commercial kit according to the manufacturer’s instructions. Finally, real-time PCR was performed to determine E2F1 gene expression.
Results: Breast cancer tumors were successfully induced by MC4-L2 cell line injection to mice. Combined exercises before tumor induction significantly decreased E2F1 gene expression in the tumor tissue (p = 0.001). In addition, combined exercise (p = 0.001), combined exercise+ capecitabine (p = 0.001), and capecitabine treatment (p = 0.001) after tumor induction significantly reduced E2F1 gene expression. Also, combined exercise (p = 0.003), combined exercise+ capecitabine (p = 0.02), and capecitabine treatment (p = 0.001) after tumor induction in association with pre-tumor induction exercises significantly reduced E2F1 gene expression in the tumor tissue.
Conclusion: The greatest reduction in E2F1 gene expression in BC tumor tissues was observed in the "exercise-tumor-exercise + drug" group, indicating the preventive effects of combined exercises before and after tumor induction in association with capecitabine treatment on the expression of this transcription factor in BC tumors in female mice.
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