Determination of the molecular mechanism from reflux oesophagitis to the development of Barrett's oesophagus and oesophageal adenocarcinoma in a mouse model

本研究主要从分子机制的角度探讨胃酸反流对Barrett食管和食管腺癌诱导食管鳞状上皮粘膜的改变。采用球囊扩张胃食管交界处或吻合食管与胃体的方法制备胃食管反流小鼠模型。制作了一种适用于小动物的pH监测器，建立了用pH监测器监测小鼠食道的方法。胃食管反流模型小鼠与对照组小鼠在手术后饲养至50周。每天测量6-12小时小鼠的pH值变化，间隔数天，以研究胃酸反流的程度。在20-60%的测量时间内，所有模型小鼠的pH值均低于4。这些小鼠被用作胃食管反流小鼠模型。分别于第2周、第4周、第6周、第12周、第30周、第40周和第50周7个时间点取食管黏膜标本进行组织病理学检查。甚至在第2周，炎症细胞浸润，腺上皮细胞排列异常，导管部分改变。从12周及以后切除的上皮异常增生标本中提取RNA，采用差异显示法、减法技术和cDNA阵列系统比较其与对照小鼠食管黏膜基因表达的差异。结果，24个标本中有7个标本检测到基因表达差异。

The study was conducted to determine the changes in the squamous epithelial mucosa of oesophagus induced by a reflux of gastric acid to Barrett's oesophagus and oesophageal adenocarcinoma mainly from the viewpoint of the molecular mechanism. A mouse model for gastroesophageal acid reflux was prepared by dilating the gastroesophageal junction with a balloon or by anastomosing the oesophagus and the body of stomach. A pH monitor suitable for small animals was produced to establish a monitoring method using the pH monitor for the esophagus of the mice. Model mice for gastroesophageal reflux were bred with control mice up to 50 weeks after surgery. The pH changes in the mice were measured for 6-12 hours per day at intervals of several days to investigate the degree of gastric acid reflux. The pH of all the model mice was confirmed to be lower than 4 for 20-60% of the period of measurement. These mice were used as mouse models for gastroesophageal reflux. Oesophageal mucosa samples were removed at 7 time points, Week 2, 4, 6, 12, 30, 40 and 50 to examine them histopathologically. Even in Week 2, inflammatory cell infiltrates, abnormal glandular epithelial cell arrangement and a partial change in the duct were noted. RNA was extracted from samples of epithelial dysplasia removed in Week 12 or later and the difference in gene expression was examined in comparison with that of the oesophageal mucosa of the control mice using the differential display method, subtraction technique and cDNA array system. As the result, a difference in gene expression was detected in 7 specimens out of the 24 specimens.