Project description:Colorectal polyp is known a precursor of colorectal cancer (CRC) that holds an increased risk for progression to CRC. Circulating cell-free DNA(cfDNA) methylation has shown favorable performance in the detection and monitoring the malignant progression in a variety of cancers. Here, we conducted a study to discovery cfDNA methylation markers for the diagnosis of CRC. We first performed a genome-wide analysis using the Infinium HumanMethylationEPIC BeadChip array to identify differentially methylated CpGs (DMCs) between 8 CRC and 8 polyp tissues. Then, we validated DMCs in a larger tissue cohort and four methylation markers (cg04486886, cg06712559, cg13539460 and cg27541454) were selected as the methylation markers in tissue by LASSO and random forest models. A diagnosis prediction model was bulit based on the four markers and the methylaion diagnosis score (md-score) can effectively discriminate patients with CRC from polyp tissues. Finally, a single cfDNA methylation marker, cg27541454, was confirmed hypermethylated in CRC in the plasma validation cohort. Together, our findings suggested that the md-score derived from tissue could robustly detect CRC from polpy patients, and cg27541454 may be a promising candidate non-invasive biomarker for CRC early diagnosis.
Project description:Genome wide DNA methylation profiling of tumor and surrounding healthy colonic mucosa from patients with colorectal carcinoma. The Illumina Infinium 27k Human DNA methylation Beadchip v1.2 was used to obtain DNA methylation profiles across 27,578 CpG loci covering 14,475 genes.
Project description:Genome wide DNA methylation profiling of tumor and surrounding healthy colonic mucosa from patients with colorectal carcinoma. The Illumina Infinium 27k Human DNA methylation Beadchip v1.2 was used to obtain DNA methylation profiles across 27,578 CpG loci covering 14,475 genes. Samples included a total of 48 paired normal and tumor samples from 24 patients. The paired samples were put on the same chip.
Project description:Genome-wide DNA methylation of colorectal cancer patients with lymph node metastases showed global loss of DNA methylation in CG-poor, non-CpG island (CGI) regions. Overall CGI methylation was increased in tumour samples. Differential methylation analysis of CGIs identified 60 putative biomarkers, with >20% increase in DNA methylation in both primary tumour and metastasis samples compared to normal adjacent tissue.
Project description:Genome-wide DNA methylation analysis of colorectal tumour samples from 44 FFPE tumour and 15 FFPE normal mucosa samples was performed to invesgitate genome-wide DNA methylation signatures that can distinguish MLH1 epimutation carrier CRCs. This was further applied to resolve clinically challenging CRCs including MLH1 promoter VUS carriers and MLH1 methylated EOCRCs
Project description:Genetic and epigenetic alterations are a fundamental aspect of colorectal cancer formation. There is considerable heterogeneity between colorectal cancers regarding the mutations and methylated genes they carry, and this heterogeneity may arise early in the polyp-cancer sequence. However, our understanding of the epigenetic alterations and gene mutations in colon adenomas and their relation to colorectal cancer is incomplete. Thus, we have assessed the methylome in normal colon mucosa, tubular adenomas, and colorectal adenocarcinomas and have determined the relationship of these findings between adenomas and cancer in the colon. Genome-wide alterations in DNA methylation were found in the normal colon mucosa adjacent to colorectal cancer, tubular adenomas, and colorectal cancer. Three subgroups of CRCs and two subgroups of adenomas were identified on the basis of their DNA methylation patterns. The adenomas separated into a high-frequency methylation class (Adenoma-H) and a low-frequency methylation class. The adenoma-H polyps have a methylated DNA signature similar to non-CIMP CRCs, whereas those of the Adenoma-L class have a similar methylation pattern to normal colon mucosa. The CpGs that account for these signatures are located in intragenic/intergenic regions, which suggests that these two groups of adenomas arise from different stem cell populations. We conducted genome-wide array-based studies and comprehensive data analyses of aberrantly methylated loci in 41 normal colon samples, 42 colon adenomas, and 64 colorectal cancers. Supplementary file 'GSE48684_Matrix_signal_intensities_1.txt.gz': includes the unmethylated and methylated signal intensities from Samples GSM1183439-GSM1183561. Supplementary file 'GSE48684_Matrix_signal_intensities_2.txt.gz': includes the unmethylated and methylated signal intensities from Samples GSM1235135-GSM1235158.
Project description:The current risk stratification system defined by clinicopathological features do not accurately identify the risk of disease recurrence in patients with stage I-II colorectal cancer (CRC). We aimed to investigate whether the CpG sites from newly established genome-wide methylation profiles could serve as biomarkers to improve prognosis prediction.