Global methylation analysis of development and progression of colorectal carcinoma

Colorectal tumorigenesis proceedes through well defined clinical stages assoicated with charateristic mutations. Besides genetic alterations, epi-driver genes that are aberrantly expressed in cancers in a fashion that confers a seletive growth advantage can also contribute to tumor evolution. To gain a global view of methylation patterns in normal and maliganant colorectal epithelia, we performed genome-wide DNA methylation analysis on DNAs from 48 fresh frozen CRC samples at different stages of CRC progression. We used IlluminaHumanMethylation450 Beadchip to get a broad view of genome-wide DNA methylationdata during CRC progression and identified significantly differentially methylated genes during CRC progression A total of 48 macro-dissected tissues including normal colon tissue, adenomas, carcinomas and metastases were collected by the Department of Pathology at the University of Virginia under the supervision of an experienced pathologist. DNA was extracted and run on IlluminaHumanMethylation450 Beadchip by Expression Analyisis.