Changes in DNA methylation after 6‐week exercise training in colorectal cancer survivors: A preliminary study

• Published in: Asia-Pacific journal of clinical oncology Vol. 18; no. 1; pp. 52 - 60
• Main Authors: Hwang, Seo‐Hyeon, Kang, Dong‐Woo, Lee, Mi‐Kyung, Byeon, Ji Yong, Park, Hanui, Park, Dong‐Hyuk, Kim, Kyung‐Chul, Lee, Seung‐Tae, Chu, Sang Hui, Kim, Nam Kyu, Jeon, Justin Y.
• Format: Journal Article
• Language: English
• Published: Australia Wiley Subscription Services, Inc 01-02-2022
• Subjects: Cancer; cancer survivor; Cancer Survivors; Colorectal cancer; Colorectal carcinoma; Colorectal Neoplasms - genetics; Colorectal Neoplasms - therapy; CpG islands; DNA Methylation; Epigenetics; Exercise; Fitness training programs; Genomes; Humans; Immune response; Immunological diseases; Intervention; Physical training; Survivors; Transcription; DNA methylation; exercise; colorectal cancer; epigenetics; cancer survivor
• ISSN: 1743-7555; 1743-7563
• DOI: 10.1111/ajco.13482

Aim
Behavioral interventions such as exercise may induce epigenetic changes. Only few studies investigated the effects of exercise on epigenetic alterations in colorectal cancer survivors. The aim of this study was to explore the changes of genome‐wide DNA methylation after 6‐week exercise training in colorectal cancer survivors.
Methods
This preliminary study used a subset of data from a randomized controlled trial in 15 colorectal cancer survivors. Participants were randomized either to the 6‐week exercise group or control group. The exercise intervention consisted of a weekly, group‐based, supervised resistance exercise program and a home‐based same resistance exercise plus walking six times per week. Blood samples were collected at baseline and after the intervention and data from eight subjects were analyzed for genome‐wide DNA methylation on 865,918 CpG sites.
Results
Compared to the control group, the exercise group shows notable methylation changes in 756 CpG sites (22.7–25.2%). Gene ontology and disease annotation analysis showed that the genes targeting 81 CpG sites in promoter region with significant group‐difference were linked in biological process such as immune response and transcription and related to metabolic and immune diseases. Also, hypermethylation on genes related to disease prevention seemed to be inhibited in the exercise group compared to the control group, indicating a likelihood of transcriptional activity of these genes.
Conclusion
We found a preliminary evidence of the positive effects of exercise intervention on epigenetic markers in colorectal cancer survivors. Larger scale randomized controlled trials are warranted to further investigate our findings.
Exercise may induce epigenetic changes in genes associated with various disease mechanisms in colorectal cancer survivors. Our preliminary study showed that a 6‐week resistance and aerobic exercise intervention inhibited DNA hypermethylation in genes related to metabolic and immune diseases, suggesting a positive role of exercise on epigenetics in cancer survivors.