DNA methylation patterns in ulcerative colitis-associated cancer: a systematic review

Background: Evidence points to the role of DNA methylation in ulcerative colitis (UC)-associated cancer (UCC), the most serious complication of ulcerative colitis. A better understanding of the etiology of UCC may facilitate the development of new therapeutic targets and help to identify biomarkers of the disease risk. Methods: A search was performed in three databases following PRISMA protocol. DNA methylation in UCC was compared with sporadic colorectal cancer (SCRC), and individual genes differently methylated in UCC identified. Results: While there were some similarities in the methylation patterns of UCC compared with SCRC, generally lower levels of hypermethylation in promoter regions of individual genes was evident in UCC. Certain individual genes are, however, highly methylated in colitis-associated cancer: RUNX3, MINT1, MYOD and p16 exon1 and the promoter regions of EYA4 and ESR. Conclusion: Patterns of DNA methylation differ between UCC and SCRC. Seven genes appear to be promising putative biomarkers.