Physical activity and differential methylation of breast cancer genes assayed from saliva: a preliminary investigation.
OBJECTIVE
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.
Department of Psychology and Neuroscience, University of Colorado Boulder, 80309-0345, USA. angela.bryan@colorado.edu
Angela D
AD
Bryan
Renee E
RE
Magnan
Ann E Caldwell
AE
Hooper
Nicole
N
Harlaar
Kent E
KE
Hutchison
D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism; D019175:DNA Methylation / Q000235:genetics*; D015444:Exercise / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000235:genetics*; D010101:Oxygen Consumption / Q000502:physiology; D010809:Physical Fitness / Q000502:physiology; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D012463:Saliva / Q000378:metabolism*; D057566:Self Report
D015415:Biomarkers