Korea Bioinformation Center (KOBIC), Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Korea.
Department of Internal Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul 03080, Korea.
BMB Rep. 2023 Oct;56(10):563-568. doi: 10.5483/BMBRep.2023-0096.
DNA methylation regulates gene expression and contributes to tumorigenesis in the early stages of cancer. In colorectal cancer (CRC), CpG island methylator phenotype (CIMP) is recognized as a distinct subset that is associated with specific molecular and clinical features. In this study, we investigated the genomewide DNA methylation patterns among patients with CRC. The methylation data of 1 unmatched normal, 142 adjacent normal, and 294 tumor samples were analyzed. We identified 40,003 differentially methylated positions with 6,933 (79.8%) hypermethylated and 16,145 (51.6%) hypomethylated probes in the genic region. Hypermethylated probes were predominantly found in promoter-like regions, CpG islands, and N shore sites; hypomethylated probes were enriched in open-sea regions. CRC tumors were categorized into three CIMP subgroups, with 90 (30.6%) in the CIMP-high (CIMP-H), 115 (39.1%) in the CIMP-low (CIMP-L), and 89 (30.3%) in the non-CIMP group. The CIMP-H group was associated with microsatellite instabilityhigh tumors, hypermethylation of MLH1, older age, and rightsided tumors. Our results showed that genome-wide methylation analyses classified patients with CRC into three subgroups according to CIMP levels, with clinical and molecular features consistent with previous data. [BMB Reports 2023; 56(10): 563-568].
DNA 甲基化调控基因表达，并在癌症早期促进肿瘤发生。在结直肠癌（CRC）中，CpG 岛甲基化表型（CIMP）被认为是一个独特的亚组，与特定的分子和临床特征相关。在这项研究中，我们研究了 CRC 患者的全基因组 DNA 甲基化模式。分析了 1 个未配对正常、142 个相邻正常和 294 个肿瘤样本的甲基化数据。我们在基因区域中鉴定出 40003 个差异甲基化位置，其中 6933 个（79.8%）呈高甲基化，16145 个（51.6%）呈低甲基化探针。高甲基化探针主要存在于启动子样区域、CpG 岛和 N 岸位点；低甲基化探针在开阔海域区域富集。CRC 肿瘤被分为三个 CIMP 亚组，其中 CIMP-H 组 90 例（30.6%），CIMP-L 组 115 例（39.1%），非 CIMP 组 89 例（30.3%）。CIMP-H 组与微卫星不稳定高肿瘤、MLH1 高甲基化、年龄较大和右侧肿瘤相关。我们的结果表明，全基因组甲基化分析根据 CIMP 水平将 CRC 患者分为三组，其临床和分子特征与先前的数据一致。[BMB 报告 2023；56(10):563-568]。
