Zhang Weisong, Yang Chaogang, Wang Shuyi, Xiang Zhenxian, Dou Rongzhang, Lin Zaihuan, Zheng Jinsen, Xiong Bin
Department of Gastrointestinal Surgery, Zhongnan Hospital of Wuhan University, Hubei Key Laboratory of Tumor Biological Behaviors & Hubei Cancer Clinical Study Center, Wuhan, 430071, People's Republic of China.
Cancer Manag Res. 2021 Apr 30;13:3601-3617. doi: 10.2147/CMAR.S300861. eCollection 2021.
Detection of aberrant methylated DNA in the stool is an effective early screening method for colorectal cancer (CRC). Previously, reporters identified that syndecan-2 (SDC2) and tissue factor pathway inhibitor 2 (TFPI2) were aberrantly methylated in most CRC tissues. However, the combined diagnostic role of them remains undefined. Our research aimed at probing the role and efficiency of the methylation status of SDC2 and TFPI2 in CRC early screening by using bioinformatics analysis and clinical stool sample validation.
The promoter and CpG site methylation levels of SDC2 and TFPI2 and their correlation with clinicopathological characteristics of CRC were analyzed using UALCAN, Methsurv, and Wanderer. UCSC Xena was used to perform survival analyses. LinkedOmics was used to do functional network analysis. DNA was isolated and purified from stool, and quantitative methylation-specific PCR (qMSP) was applied to detect methylatedSDC2 and TFPI2.
The results showed that promoter and most CpG site methylation levels of SDC2 and TFPI2 were significantly higher in CRC than in normal tissues. Moreover, SDC2 and TFPI2 methylation showed a positive correlation. Functional network analysis suggested that both methylated SDC2 and TFPI2 were involved in tumor cells' metabolic programs. Besides, there was a higher positive integrated detection rate in CRC (n=61) with a sensitivity of 93.4% and in adenoma (Ade) (n=16) with a sensitivity of 81.3% than normal with a specificity of 94.3% in stool samples. What is more, integration of methylated SDC2 and TFPI2 showed a higher sensitivity and Youden index than a single gene in detecting Adeor CRC.
Our data indicate that SDC2 and TFPI2 were hypermethylated in CRC, and integrated detection of methylated SDC2 and TFPI2 in stool has the potential to be an effective and noninvasive tool of CRC early screening.
检测粪便中异常甲基化的DNA是结直肠癌（CRC）有效的早期筛查方法。此前，有报道称在大多数CRC组织中，多配体聚糖-2（SDC2）和组织因子途径抑制物2（TFPI2）存在异常甲基化。然而，它们的联合诊断作用仍不明确。我们的研究旨在通过生物信息学分析和临床粪便样本验证，探究SDC2和TFPI2甲基化状态在CRC早期筛查中的作用和效率。
使用UALCAN、Methsurv和Wanderer分析SDC2和TFPI2的启动子和CpG位点甲基化水平及其与CRC临床病理特征的相关性。使用UCSC Xena进行生存分析。使用LinkedOmics进行功能网络分析。从粪便中分离并纯化DNA，应用定量甲基化特异性PCR（qMSP）检测甲基化的SDC2和TFPI2。
结果显示，CRC中SDC2和TFPI2的启动子及大多数CpG位点甲基化水平显著高于正常组织。此外，SDC2和TFPI2甲基化呈正相关。功能网络分析表明，甲基化的SDC2和TFPI2均参与肿瘤细胞的代谢程序。此外，在CRC（n = 61）中，甲基化SDC2和TFPI2联合检测的阳性率更高，敏感性为93.4%；在腺瘤（Ade）（n = 16）中，敏感性为81.3%，而在粪便样本中，与正常样本相比，特异性为94.3%。此外，在检测Ade或CRC时，甲基化SDC2和TFPI2联合检测比单个基因检测具有更高的敏感性和尤登指数。
我们的数据表明，CRC中SDC2和TFPI2存在高甲基化，粪便中甲基化SDC2和TFPI2的联合检测有可能成为CRC早期筛查的有效且无创工具。
