KLF4与Notch1在脱氧胆酸诱导Barrett食管形成过程的作用

Roles of KLF4 and Notch1 in deoxycholic acid-induced Barrett's esophagus

目的探讨Krüppel样锌指转录因子4(Krüppel-like factor 4,KLF4)和Notch1在Barrett食管组织中的表达以及脱氧胆酸(deoxycholic acid,DCA)对正常食管鳞状上皮Het-1A细胞KLF4与Notch1表达水平的影响。方法免疫组化S-P法检测49例人正常食管组织、26例食管炎和22例Barrett食管组织中KLF4、Notch1的表达水平;采用不同浓度(0、100、200μmol/L)的DCA对永生化的正常食管鳞状上皮Het-1A细胞分别处理4、8、12 h,RT-PCR和Western blot检测KLF4、Notch1 mRNA及蛋白表达。结果免疫组化检测发现,与正常人食管鳞状上皮组织相比,食管炎与Barrett食管组织中KLF4呈现高表达,且Barrett食管组织表达最高(P<0.05),而Notch1的表达则无明显差异。RT-PCR及Western blot结果显示,随DCA浓度的增高以及处理时间的增加,Het-1A细胞表达KLF4、Notch1的mRNA和蛋白的水平逐渐升高(P<0.05)。结论 DCA可能通过促进KLF4、Notch1表达而参与正常食管上皮转化为Barrett食管的过程。

Objective To determine the expression of Krüppel-like factor 4 （KLF4） and Notch homolog 1 （Notch1） in Barrett’s esophageal tissues, and the effect of deoxycholic acid （DCA） on the expressions of the 2 molecules in human esophageal squamous epithelial Het-1A cells. Methods Immunohistochemical SP staining was applied to evaluate the levels of KLF4 and Notch1 in 49 samples of normal esophageal tissues, 26 samples of esophagitis and 22 samples of Barrett’s esophageal tissues. After Het-1A cells were treated with different concentrations of DCA for 4, 8 and 12 h, the expressions of KLF4 and Notch1 at mRNA and protein levels were detected by real-time PCR and Western blotting, respectively. Results Immunohistochemical staining indicated that KLF4 was strongly expressed in the Barrett’s esophagus and esophagitis tissues compared with normal tissues, and its level was highest in the Barrett’s esophagus （P〈0.05）, but no obvious change was seen in the expression of Notch1 among the 3 kinds of tissue samples. RT-PCR and Western blotting revealed that the mRNA and protein levels of KLF4 and Notch1 was enhanced in a time- and dose-dependent manner in HET-1A cells induced by DCA （P〈0.05）. Conclusion DCA takes part in the transformation of normal esophageal epithelia to Barrett’s esophagus, probably through promoting the expression of KLF4 and Notch1.