Cdx2蛋白在不同亚型肠上皮化生中的表达及其与H. pylori感染的关系

Expression of Cdx2 in different subtypes of intestinal metaplasia and its relation to H. pylori infection

目的探讨胃黏膜肠上皮化生(intestinal metaplasia,IM)中尾型同源异型盒基因2(caudal type homeobox genes 2,Cdx2)蛋白的表达及其与幽门螺杆菌(helicobacter pylori,H.pylori)感染的关系。方法选取内镜下活检的18例正常胃黏膜和53例IM胃黏膜。采用高铁二铵-爱先蓝-过碘酸雪夫反应(HID-AB-PAS)将胃黏膜IM分为Ⅰ、Ⅱ、Ⅲ型,然后用Cdx2单克隆抗体进行免疫组织化学染色,检测Cdx2在正常胃黏膜及不同亚型IM中的表达。采用一分钟快速尿素酶实验及甲苯胺蓝染色检测H.pylori感染。结果Cdx2蛋白在正常胃黏膜中不表达,IM中Cdx2阳性表达率为83.02%(44/53),其中Ⅰ型IM阳性率为95.45%(21/22),Ⅱ型为83.33%(15/18),Ⅲ型为61.53%(8/13),三者间Cdx2蛋白表达有显著性差异(P=0.036)。IM中H.pylori感染阳性率为47.17%(25/53),其中Ⅰ型IM中H.pylori感染阳性率为27.27%(6/22),Ⅱ型为55.56%(10/18),Ⅲ型为69.23%(9/13),三者间H.pylori感染率亦有显著性差异(P=0.038)。Cdx2蛋白表达主要集中于H.pylori感染阴性者,但H.pylori感染阳性者和阴性者Cdx2表达无统计学差异(P>0.05)。结论Cdx2蛋白异常表达可能参与了胃黏膜IM向胃癌的转变,检测其表达有助于预测胃黏膜IM向胃癌转变的可能性。

Objective To investigate the expression of caudal type homeobox genes 2 （Cdx2） in different subtypes of intestinal metaplasia （ IM ） and its relation to helicobacter pylori （ H. pylori） infection. Methods Eighteen normal gastric mucosae and fifty-three IM were recruited by endoscopic autopsy. IM cases were classified into Ⅰ、Ⅱ、Ⅲ types by High iron diamine/Alcin blue/Periodic acid Schiff method （HID-AB-PAS）. A monoclone antibody was used to test Cdx2 expression. H. pylori infection was confirmed or excluded by one minute urease test and toluidine blue staining. Results Normal gastric mucosa presented no Cdx2 expression. The positive expression rate of Cdx2 was 83.02% （44/ 53） in all IM foci, and 95.45% （21/22） in type Ⅰ, 83.33% （15/18） in type Ⅱ and 61.53% （8/13） in type Ⅲ, showing a significant difference among the three groups （P = 0. 036）. The positive rate of H. pylori infection was 47.17% （25/53） in all IM foci, 27.27% （6/22） in type Ⅰ, 55.56% （10/18） in type Ⅱ and 69.23% （9/13） in type Ⅲ, showing a significant difference among the three types （P = 0. 038）. Most of eases with positive Cdx2 expression didn＇ t show H. pylori infection, but there was no significant difference of Cdx2 expression between cases with H. pylori infection and those without （P 〉 0.05）. Conclusion Abnormal expression of Cdx2 may play an important role in the development of IM. Detection of Cdx2 expression in IM can be useful in the prognosis of malignancy.