Validation of differentially methylated DNA regions in colorectal precancerous lesions.

In this study, we validated 992 previously identified differentially methylated regions (DMRs) in colorectal precancerous lesions compared to adjacent normal mucosa in a new series of 59 prospectively collected lesions and matched normal tissue using targeted bisulfite sequencing. Strong differences in methylation level were observed across the full set of validated DMRs. Based on the mean methylation levels of a panel of 30 selected DMRs tumors could be accurately classified. We thus provide a large list of validated DNA markers to be exploited in the development of noninvasive, colorectal tumor screening assays.