Identification of genomic methylation markers for colorectal cancer diagnosis and toxicity of capecitabine-based chemotherapy

ABSTRACT: Background: Colorectal cancer (CRC) remains a major concern with high morbidity and mortality worldwide. DNA methylation alteration plays a pivotal role in cancer development. We aimed to screen novel biomarkers for CRC diagnosis and chemotherapy-related adverse event (CRAE) prediction using the advanced Illumina Infinium MethylationEPIC (850K) BeadChip. Methods: We analyzed the methylation profiles of paired tumor and normal tissues from 21 Chinese CRC patients. After normalization by potential confounders, three types of methylation profiles (differentially methylated probes, differentially methylated regions, and gene-function-differentially methylated regions) were further studied by functional annotation and pathway enrichment analysis. At last, integrated-methylation-marker systems for CRC diagnosis and CRAE prediction were developed based on genes within the mostly related pathways and LASSO regression. Findings: Tumor-related methylation was characterized with hypermethylated promoter islands and hypomethylated intragenic openseas. CRAE-related methylation was characterized with hyper- (or hypo-) methylated intragenic (or intergenic) regions. The two most important susceptible factors for various types of CARE were inactive regeneration functions and active immune response. Differentially methylated genes were significantly enriched in neuronal system, metabolism of RNA, and extracellular matrix organization. All of the integrated-methylation-marker systems demonstrated high discriminative accuracy in both CRC diagnosis (AUROC = 1) and CRAE prediction (AUROC = 0.817-1). Interpretation: In this study, we provided new insights on the formation of CRC diagnosis and CRAE based on three types of methylation profile. The integrated-methylation-marker systems combining multiple DMPs were found to have potentially diagnostic and predictive values. Hence, our findings have important clinical implications, and further validation is warranted.

ORGANISM(S): Homo sapiens

PROVIDER: GSE159898 | GEO | 2021/08/01

REPOSITORIES: GEO