CDX1/2在人Barrett's食管中的表达以及胆酸对CDX2表达的影响

Expression of CDX1/2 in patients with Barrett’s esophagus and the effects of bile acids on CDX2 expression

目的:观察Barrett's食管黏膜组织中CDX mRNA和蛋白表达,观察不同胆汁酸对人食管细胞株Eca-109CDX2 mRNA表达水平的影响.方法:收集内镜下正常食管组织(n=5),反流性食管炎(n=7),Barrett's食管(n=8)标本.采用RT-PCR测定CDX1和CDX2 mRNA表达;实时荧光定量PCR测定CDX2 mRNA表达.用免疫组织化学染色法对CDX2蛋白进行定位.人食管癌细胞株Eca-109分别在100、400、1000μmol/L胆酸(CA),脱氧胆酸(DCA),甘胆酸(GC)中培养,分别在0-24h收取细胞,荧光定量PCR测定CDX2 mRNA表达.结果:CDX2 mRNA在正常食管组织中无表达,在Barrett's食管组、反流性食管炎组表达增高(9.6411±6.6823,3.9156±3.6700),与正常食管组之间比较均存在显著性差异(P=0.006,0.025),但2组之间没有显著性差异(P=0.133),CDX1在所有食管组织中均无表达.免疫组织化学染色在Barrett's食管有CDX2蛋白胞核呈特异性染色阳性反应,反流性食管炎组织CDX2胞质显示细颗粒性染色(假阳性),正常的食管组织未发现特异性染色.CDX2 mRNA在未加药物处理的Eca-109细胞株中没有表达,其表达量对DCA、GC、CA显示出时间和剂量依赖性.结论:CDX2基因异常表达在食管黏膜肠化生过程中可能具有较重要作用,CDX2基因的表达可能是Barrett's食管发生过程的早期事件.胆汁酸在体外实验上调CDX2基因表达,通过调节其表达在Barrett's食管发生中起重要作用.

AIM： To investigate CDX1 and CDX2 expressions in biopsies obtained from patients with reflux esophagitis and Barrett＇s esophagus and to study the effects of various bile acids on CDX2 mRNA expression in human esophageal cell line （Eca-109）. METHODS： Endoscopic biopsies were obtained at the distal esophagus in patients and classified according to histology： normal squamous mucosa （n = 5）, esophagitis mucosa （n = 7）, and Barrett＇s metaplasia （n = 8）. Gene expression of CDX1 and CDX2 were measured using reverse transcription polymerase chain reaction （RTPCR） or quantitative real-time RT-PCR. CDX2 protein expression was assessed immunohistochemically. Human esophageal cell line （Eca-109） was exposed to cell culture for 1-24 h to 100, 400, 1000 μmol/L deoxycholic acid （DCA）, cholicacid （CA）, and glycocholicacids （GC）. CDX2 mRNA expression was determined by quantitative RTPCR. RESULTS： CDX2 mRNA expression was significantly higher in Barrett＇s epithelium （9.6411 ± 6.6823） and reflux esophagitis （3.9156 ± 3.6700）, compared with normal esophagus （P = 0.006, 0.025 respectively）. There was no significant difference between Barrett＇s mucosa and reflux esophagits （P = 0.133）. CDX1 mRNA was not detected in all esophageal mucosa. There was no CDX2 protein expression in normal squamous esophagus, and nuclear immunoreactivity was seen in Barrett＇s epithelium. Perinuclear immunoreactivity for CDX2 was detected in reflux esophagitis. CDX2 mRNA expression was absent before bile acid exposure in all cell lines and increased in a dose- and time-dependent pattern with deoxycholic acid （DCA）, cholicacid （CA）, and glycocholicacids （GC）. CONCLUSION： CDX2 expression is up-regulated in esphagitis and Barrett＇s esophagus, suggesting a possible onset role for CDX2 in esophagitis-Barrett＇s metaplasia sequence. Bile acids can evoke high expression of CDX2 in vitro. Bile acids may play an important role in Barrett＇s metaplasia by influencing the expression of CDX2.