DNA Methylome and Transcriptome Alterations and Cancer Prevention by Curcumin in Colitis-accelerated Colon Cancer in Mice

Inflammation is highly associated with colon carcinogenesis. Epigenetic mechanisms could play an important role in the initiation and progression of colon cancer. Curcumin, a dietary phytochemical, shows promising effects in suppressing colitis-associated colon cancer in AOM-DSS mice. However, the potential epigenetic mechanisms of curcumin in colon cancer remain unknown. In this study, the anti-cancer effect of curcumin in suppressing colon cancer in an 18-week AOM-DSS colon cancer mouse model was confirmed. The authors identified lists of differentially expressed and differentially methylated genes in pairwise comparisons and several pathways involved in the potential anti-cancer effect of curcumin. These pathways include LPS/IL-1 mediated inhibition of RXR function, Nrf2-mediated oxidative stress response, production of NO and ROS in macrophages, and IL-6 signalling. Among these genes, Tnf stood out with decreased DNA CpG methylation of Tnf in the AOM-DSS group and reversal of the AOM-DSS induced Tnf demethylation by curcumin. These observations in Tnf methylation correlated with increased and decreased Tnf expression in RNA-seq. The functional role of DNA methylation of Tnf was further confirmed by in vitro luciferase transcriptional activity assay. In addition, the DNA methylation level in a group of inflammatory genes, was decreased in the AOM+DSS group but restored by curcumin and were validated by pyrosequencing. This study shows for the first time epigenomic changes in DNA CpG methylation in the inflammatory response from colitis-associated colon cancer and the reversal of their CpG methylation changes by curcumin. Future clinical epigenetic studies with curcumin in inflammation-associated colon cancer would be warranted.

Authors: Guo Y, Wu R, Gaspar JM, Sargsyan D, Su ZY, Zhang C, Gao L, Cheng D, Li W, Wang C, Yin R, Fang M, Verzi MP, Hart RP, Kong AN. ; Full Source: Carcinogenesis. 2018 Mar 14. doi: 10.1093/carcin/bgy043. [fusion_builder_container hundred_percent=”yes” overflow=”visible”][fusion_builder_row][fusion_builder_column type=”1_1″ background_position=”left top” background_color=”” border_size=”” border_color=”” border_style=”solid” spacing=”yes” background_image=”” background_repeat=”no-repeat” padding=”” margin_top=”0px” margin_bottom=”0px” class=”” id=”” animation_type=”” animation_speed=”0.3″ animation_direction=”left” hide_on_mobile=”no” center_content=”no” min_height=”none”][Epub ahead of print][/fusion_builder_column][/fusion_builder_row][/fusion_builder_container]

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