ETBF colonization enhances CpG island DNA hypermethylation in murine colon tissues expressing BRAFV600E. Mus musculus

Changes in DNA methylation have been associated with both the expression of the BRAFV600Emutation as well as the presence of enterotoxigenic Bacteroides fragilis (ETBF). The BRAFV600E mutation has been associated in DNA hypermethylation in some colon tumors. To better understand this association, we analyzed the methylation patterns in colonic tumors and epithelium from mice bearing the BRAFV600E mutation in the multiple intestinal neoplasia (Min) ETBF model (BRAFV600ELgr5CreMin (BLM) mice).Overall design: We used methylation-binding domain sequencing (MBD-seq) to examine the impact of ETBF on CpG island DNA hypermethylation in BLM and Min mice. Sham tumors, sham epithelium, ETBF-induced tumors, and the surrounding normal ETBF epithelium for both the Min and BLM genotypes were analyzed for changes in CpG island DNA methylation. The addition of BRAFV600E results in distinct ETBF colonization-associated CpG island DNA hypermethylation.