Physical Activity and Differential Methylation of Breast Cancer Genes Assayed from Saliva: A Preliminary Investigation

PURPOSE: Individuals who exercise are at lower risk for breast cancer and have better post-diagnosis outcomes. The biological mechanisms behind this association are unclear, but DNA methylation has been suggested. METHODS: We developed a composite measure of DNA methylation across 45 CpG sites on genes selected a priori. We examined the association of this measure to self-reported physical activity and objectively measured cardiovascular fitness in a sample of healthy nonsmoking adults (n = 64) in an exercise promotion intervention. RESULTS: Individuals who were more physically fit and who exercised more minutes per week had lower levels of DNA methylation. Those who increased their minutes of physical activity over 12 months experienced decreases in DNA methylation. CONCLUSIONS: DNA methylation may be a mechanism linking exercise and cancer incidence, and could serve as a biomarker for behavioral intervention trials. Studies with larger samples, objectively measured exercise, and more cancer-related markers are needed

Production and use of two marine zooplanktons, Tigriopus japonicus and Diaphanosoma celebensis, as live food for red sea bream Pagrus major larvae

We evaluated the effectiveness of two representative marine zooplankton, the harpacticoid copepod Tigriopus japonicus and the euryhaline cladoceran Diaphanosoma celebensis, as live food for red sea bream Pagrus major larvae. Chicken-dropping extract (CDE) was applied to both zooplankton cultures to improve population growth. Population growth of both zooplankton was significantly enhanced by CDE supplementation (at 1 or 2 ml/l). The highest amount of docosahexaenoic acid (DHA) and higher DHA/eicosapentaenoic acid ratio were detected in T. japonicus, whereas D. celebensis showed similar values to that of Artemia. Effectiveness of both animals as live food was tested by rearing red sea bream larvae on them for 28 days and comparing the results with those for Artemia. There were no significant differences in total length (8.6 ± 1.1?8.7 ± 0.7 mm) or wet weight (8.2 ± 0.3?9.4 ± 0.1 mg) among fish larvae feeding on the three different zooplankton. Survival rate was significantly higher with T. japonicus (39.4 ± 3.1 %) than with D. celebensis (20.8 ± 3.8 %) and Artemia (16.7 ± 9.8 %). Viability was significantly higher in fish fed with T. japonicus (60.0 ± 27.8 %) and D. celebensis (60.0 ± 32.2 %) than in those fed with Artemia (44.4 ± 12.3 %). Fish fed with T. japonicus contained higher n-3 highly unsaturated fatty acids than those fed with D. celebensis and Artemia. It is concluded that T. japonicus and D. celebensis have high potential as live food in marine fish larviculture