MRC Cancer Unit, Hutchison/MRC Research Centre, University of Cambridge, Cambridge, UK.
Department of Histopathology, Addenbrooke's Hospital, Cambridge, UK.
Gut. 2018 Nov;67(11):1942-1949. doi: 10.1136/gutjnl-2017-314026. Epub 2017 Oct 30.
Barrett's oesophagus is a premalignant condition that occurs in the context of gastro-oesophageal reflux. However, most Barrett's cases are undiagnosed because of reliance on endoscopy. We have developed a non-endoscopic tool: the Cytosponge, which when combined with trefoil factor 3 immunohistochemistry, can diagnose Barrett's oesophagus. We investigated whether a quantitative methylation test that is not reliant on histopathological analysis could be used to diagnose Barrett's oesophagus.
Differentially methylated genes between Barrett's and normal squamous oesophageal biopsies were identified from whole methylome data and confirmed using MethyLight PCR in biopsy samples of squamous oesophagus, gastric cardia and Barrett's oesophagus. Selected genes were then tested on Cytosponge BEST2 trial samples comprising a pilot cohort (n=20 cases, n=10 controls) and a validation cohort (n=149 cases, n=129 controls).
Eighteen genes were differentially methylated in patients with Barrett'soesophagus compared with squamous controls. Hypermethylation of TFPI2, TWIST1, ZNF345 and ZNF569 was confirmed in Barrett's biopsies compared with biopsies from squamous oesophagus and gastric cardia (p<0.05). When tested in Cytosponge samples, these four genes were hypermethylated in patients with Barrett's oesophagus compared with patients with reflux symptoms (p<0.001). The optimum biomarker to diagnose Barrett's oesophagus was TFPI2 with a sensitivity and specificity of 82.2% and 95.7%, respectively.
TFPI2, TWIST1, ZNF345 and ZNF569 methylation have promise as diagnostic biomarkers for Barrett's oesophagus when used in combination with a simple and cost effective non-endoscopic cell collection device.
巴雷特食管是一种发生在胃食管反流背景下的癌前病变。然而，由于依赖于内镜检查，大多数巴雷特食管病例未被诊断。我们开发了一种非内镜工具：Cytosponge，当与三叶因子 3 免疫组化结合使用时，可以诊断巴雷特食管。我们研究了一种不依赖于组织病理学分析的定量甲基化检测是否可用于诊断巴雷特食管。
从全甲基化组数据中鉴定出巴雷特食管和正常鳞状食管活检之间差异甲基化的基因，并在鳞状食管、胃贲门和巴雷特食管活检样本中使用 MethyLight PCR 进行验证。然后在 Cytosponge BEST2 试验样本上测试选定的基因，该试验样本包括一个试点队列（n=20 例，n=10 例对照）和一个验证队列（n=149 例，n=129 例对照）。
与鳞状对照组相比，巴雷特食管患者有 18 个基因发生甲基化差异。与鳞状食管和胃贲门活检相比，巴雷特活检中 TFPI2、TWIST1、ZNF345 和 ZNF569 的 hypermethylation 得到了确认（p<0.05）。在 Cytosponge 样本中测试时，与反流症状患者相比，巴雷特食管患者这四个基因发生了 hypermethylation（p<0.001）。诊断巴雷特食管的最佳生物标志物是 TFPI2，其敏感性和特异性分别为 82.2%和 95.7%。
当与简单且具有成本效益的非内镜细胞收集装置结合使用时，TFPI2、TWIST1、ZNF345 和 ZNF569 的甲基化具有作为巴雷特食管诊断生物标志物的潜力。
