Online Home-Based Physical Activity Counteracts Changes of Redox-Status Biomarkers and Fitness Profiles during Treatment Programs in Postsurgery Female Breast Cancer Patients

The impact of physical activity on promoter-specific methylation of genes involved in the redox-status and disease progression: A longitudinal study on post-surgery female breast cancer patients undergoing medical treatment

Most anticancer treatments act on oxidative-stress pathways by producing reactive oxygen species (ROS) to kill cancer cells, commonly resulting in consequential drug-induced systemic cytotoxicity. Physical activity (PA) has arisen as an integrative cancer therapy, having positive health effects, including in redox-homeostasis. Here, we investigated the impact of an online supervised PA program on promoter-specific DNA methylation, and corresponding gene expression/activity, in 3 antioxidants- (SOD1, SOD2, and CAT) and 3 breast cancer (BC)-related genes (BRCA1, L3MBTL1 and RASSF1A) in a population-based sample of women diagnosed with primary BC, undergoing medical treatment. We further examined mechanisms involved in methylating and demethylating pathways, predicted biological pathways and interactions of exercise-modulated molecules, and the functional relevance of modulated antioxidant markers on parameters related to aerobic capacity/endurance, physical fatigue and quality of life (QoL). PA maintained levels of SOD activity in blood plasma, and at the cellular level significantly increased SOD2 mRNA (≈+77 %), contrary to their depletion due to medical treatment. This change was inversely correlated with DNA methylation in SOD2 promoter (≈-20 %). Similarly, we found a significant effect of PA only on L3MBTL1 promoter methylation (≈-25 %), which was inversely correlated with its mRNA (≈+43 %). Finally, PA increased TET1 mRNA levels (≈+15 %) and decreased expression of DNMT3B mRNA (≈-28 %). Our results suggest that PA-modulated DNA methylation affects several signalling pathways/biological activities involved in the cellular oxidative stress response, chromatin organization/regulation, antioxidant activity and DNA/protein binding. These changes may positively impact clinical outcomes and improve the response to cancer treatment in post-surgery BC patients.

Exercise-induced redox modulation as a mediator of DNA methylation in health maintenance and disease prevention

The evidence for physical activity (PA) as a major public health preventive approach and a potent medical therapy has increased exponentially in the last decades. The biomolecular mechanisms supporting the associations between PA and/or structured exercise training with health maintenance and disease prevention are not completely characterized. However, increasing evidence pointed out the role of epigenetic modifications in exercise adaptation and health-enhancing PA throughout life, DNA methylation being the most intensely studied epigenetic modification induced by acute and chronic exercise. The current data on the modulation of DNA methylation determined by physically active behavior or exercise interventions points out genes related to energy regulation, mitochondrial function, and biosynthesis, as well as muscle regeneration, calcium signaling pathways, and brain plasticity, all consistent with the known exercise-induced redox signaling and/or reactive oxygen species (ROS) unbalance. Thus, the main focus of this review is to discuss the role of ROS and redox-signaling on DNA methylation profile and its impact on exercise-induced health benefits in humans.