Gene expression analysis of colorectal tumors and matched adjacent non-tumor colorectal tissues.

We performed gene expression profiling of 26 colorectal tumors and matched histologically normal adjacent colonic tissue samples using the Illumina Ref-8 whole-genome expression BeadChip. We performed an integrated analysis of promoter DNA methylation and gene expression data to investigate the effects of DNA hypermethylation on gene expression. Total RNA was isolated from 26 pairs of fresh frozen colorectal tumor and matched adjacent non-tumor tissue samples. Their gene expression profiles were obtained using the Illumina Ref-8 whole-genome expression BeadChip (HumanRef-8 v3.0, 24,526 transcripts).