Journal of Exercise & Organ Cross Talk

Abstract This study aimed to investigate the effects of high-intensity interval training (HIIT) on Adiponectin receptor 1 (AdipR1) gene expression in breast tumor tissue and serum levels of glutathione peroxidase (GPX) and glutathione reductase (GR) in a murine model of breast cancer. Sixteen female BALB/c mice were inoculated subcutaneously with 4T1 murine mammary carcinoma cells (5 × 10⁵ cells/mouse). One week post-inoculation, mice were randomly assigned to either a tumor-bearing control group (Tumor, n=8) or a tumor-bearing group subjected to HIIT (Tumor+HIIT, n=8). The HIIT protocol was performed on a motor-driven treadmill five days/week for four weeks, consisting of six 2-minute high-intensity intervals (18–25 m/min, 80–90% VO₂max) interspersed with 3-minute active recovery periods (5–9 m/min). Twenty-four hours after the final session, tumor tissues were excised for AdipR1 gene expression analysis via quantitative real-time PCR (2^-ΔΔCT method), and serum samples were collected for assessment of GPX and GR levels using ELISA. Statistical comparisons were performed using independent samples t-tests (p<0.05). HIIT significantly upregulated AdipR1 gene expression in breast tumor tissue compared to the control group (p<0.0001). Serum GPX levels were significantly decreased in the Tumor+HIIT group compared to the Tumor control group (p<0.0001). However, no significant difference was observed in serum GR levels between the two groups (p=0.7499). These findings suggest that HIIT may influence breast cancer progression through adiponectin-mediated pathways and oxidative stress regulation, providing a potential non-pharmacological adjunctive strategy for breast cancer management. Further studies are warranted to elucidate the underlying molecular mechanisms and clinical implications.

Abstract This study investigated the effects of high intensity interval training (HIIT), Nano-selenium supplementation, and their combination on the expression of LDHA, LDHB, and the LDHA/LDHB ratio in mice breast tumor tissue. Female mice (n=32) were inoculated with mammary adenocarcinoma cells (4T1) and randomly assigned to four groups (n=8 each): tumor control (Tu), tumor+HIIT (Tu+Ex), tumor + Nano-selenium (Tu+Nsel, 2 mg/kg/day orally), and tumor+HIIT+Nano-selenium (Tu+Ex+Nsel). HIIT was performed on a treadmill (30 min/day, 5 days/week) for four weeks. One-way ANOVA revealed significant differences among groups for LDHA expression (F=38.66, p<0.0001). Compared to the Tu group, all intervention groups (Tu+Ex,Tu+Nsel, and Tu+Ex+Nsel) showed a significant increase in LDHA expression (p<0.05). The greatest increase was observed in the combined treatment group (Tu+Ex+Nsel), which was significantly higher than both Tu+Ex and Tu+Nsel (p<0.001). For the LDHA/LDHB ratio, a significant overall effect was found (F=163.87, p<0.0001). The Tu+Nsel group exhibited a significant increase in the ratio compared to the Tu group (p<0.05), whereas both Tu+Ex and Tu+Ex+Nsel showed a significant decrease in the ratio (p<0.05). The ratio in the Tu+Nsel group was also significantly higher than in the two exercise containing groups (p<0.05). HIIT and Nano-selenium independently upregulate LDHA expression in breast tumor tissue, with an additive effect when combined. However, only Nano-selenium alone increased the LDHA/LDHB ratio, while exercise-based interventions (with or without Nano-selenium) decreased this ratio. These findings suggest that exercise and Nano-selenium differentially shift the balance between LDHA and LDHB, potentially influencing tumor lactate metabolism and the tumor microenvironment.