[Expression of intestine-specific transcription factor CDX2 in different subtypes of intestinal metaplasia and gastric carcinoma]

Abstract

Background & objective: Intestinal metaplasia (IM) is thought as the precancerous lesion of gastric carcinoma, and CDX2 gene plays important roles in development and differentiation of intestinal epithelium, and maintenance of intestinal phenotype. Recent studies found that CDX2 were expressed aberrantly in IM of chronic atrophic gastritis (CAG) and some gastric carcinomas, which implied that CDX2 may play an important role in IM formation and gastric carcinogenesis. This study was to investigate the roles of CDX2 in the development and progression of IM and gastric carcinogenesis, and determine the correlation of IM to gastric carcinogenesis.

Methods: A tissue microarray containing 46 cases of CAG with IM, 40 cases of gastric carcinoma, and 32 cases of IM foci in paracancerous tissues was constructed. High iron diamine/alcian blue (HID/AB) and HE staining were used to classify IM and gastric carcinoma, and the expression of CDX2 protein and mRNA in different gastric lesions was assessed with immunohistochemistry and in situ hybridization, respectively.

Results: The proportion of type III IM was significantly higher in IM foci in paracancerous tissues than in CAG with IM (56.25% vs. 21.74%, P<0.01). The positive rates of CDX2 protein were 69.56% in IM foci in CAG, 53.13% in IM foci in paracancerous tissues, and 42.50% in gastric carcinomas, and the positive rates of CDX2 mRNA were 63.04%, 46.87%, and 35.00%, respectively. The positive rates were significantly lower in gastric cancer than in IM in CAG (P<0.01), but there was no significant difference between gastric cancer and IM foci in paracancerous tissues (P>0.05). The expression of CDX2 protein and mRNA was significantly higher in intestinal-type gastric cancer than in diffuse-type gastric cancer (54.55% vs. 27.78%, 45.45% vs. 22.22%, P<0.05). The expression of CDX2 protein was significantly lower in type III IM than in type I IM (46.42% vs. 79.31%, P<0.05).

Conclusions: CDX2 may play important roles in the development and progression of IM and gastric carcinogenesis.