Figure 3

Methylation analysis of regions of GNAS-AS1 (a) and MEG3 (b) that are differentially methylated in adenomas and normal mucosal samples. Both panels include schematic depictions of the imprinted locus (upper left); examples of COBRA (lower left) and BGS results (upper right); and expression levels for miRNAs encoded in the locus measured in adenomas in which the locus was hypermethylated or normally methylated. (Each panel includes representative COBRA results for two adenomas with hypermethylation at the locus and one normally methylated adenoma.) (a) MiR-296-5p expression was significantly downregulated (P=0.0080) in adenomas with hypermethylation of the GNAS-AS1 CpG island. (b) Adenomas whose MEG3 CpG island was hypermethylated displayed significantly downregulated miR-154 expression (P=0.0183) and substantial but nonsignificant downregulation of miR-127-3p expression (P=0.0717). ad, adenoma; nm, normal mucosa.