Project description:Methylation profiling in colorectal cancer : adjacent normal tissue vs colon tumor tissue indirect comparison experiment : CRD(common reference DNA) vs tumor-adjacent normal, CRD vs Colon tumor
Project description:lncRNAs contributes to the development of colorectal cancer (CRC). Analysis of tumor tissues and adjacent non-tumor tissues from 6 colorectal cancer patients was conducted. Results indicate insight into molecular signature of the tumorigenesis of CRC.
Project description: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).
Project description:To identify novel hypermethylated genes in colorectal cancer (CRC) and to test their potential application in CRC early diagnosis, we performed a genome-wide screening of 57,723 CpG dinucleotides covering 4,010 genes in paired DNA samples extracted from 3 fresh frozen CRC tissues and their matching non-tumor adjacent tissues from a cohort of 3 CRC patients undergoing curative surgery using MIRA-based microarray. We also validated candidate hypermethylated genes screened by MIRA-based microarray in independent CRC samples using combined bisulfite restriction analysis. A total of 297 CpG dinucleotides in CRC covering 211 genes were found to be hypermethylated in CRC tissues. From these 211 candidate methylated genes, seven novel methylated genes were picked up for validation and three genes were confirmed to be methylated in cancer samples but not in non-cancer samples.We also compared the methylation levels of these three novel hypermethylated genes with those of Vimentin and SEPT9, well-known hypermethylated genes in CRC, and found that methylated PHOX2B, FGF12 and GAD2 were better than methylated Vimentin and SEPT9 in differentiating CRC cancer tissue from normal tissue. Significant enrichment analysis of GO terms of the hypermethylated genes showed that a high proportion of hypermethylated genes in tumor tissues are involved in regulation of transcription. Paired experiments, colorectal cancer tissue vs. adjacent non-cancer tissue. Biological replicates: 3 cancer replicates, 3 paired non-cancer replicates.