Non-CpG island promoter hypomethylation and miR-149 regulate the expression of SRPX2 in colorectal cancer

We used Illumina Infinium 27k Human DNA Methylation BeadChip v1.2 to assess genome-wide DNA methylation profiling of normal colon epithelial, adenomas and colorectal adenocarcinomas across approximately 27,000 CpGs in fresh frozen colorectal tissue samples. We found that cancer-associated methylation changes with impact on transcription occur nearly as frequent at non-CpG island as CpG island promoters in colorectal cancer (CRC). Samples included 6 normal colon epithelial tissue samples, 6 adenomas, and 30 colorectal adenocarcinomas. Bisulfite-converted DNA from the 42 samples were hybridised to the Illumina Infinium 27k Human Methylation Beadchip v1.2.