Expression of pS2/TFF1 Protein in Normal Colonic Mucosa, Adenoma and Adenocarcinoma

ABSTRACT

BACKGROUND: The trefoil factor 1 protein (pS2/TFF1) is a candidate tumor-suppressor protein, and it is a pleiotropic factor involved in the organization and homeostasis of the gastrointestinal tract and various inflammatory or neoplastic diseases. The purpose of this study was to assess the expression of pS2/TFF1 and its clinicopathologic relationship, including the p53 and Ki-67 labeling index, in colorectal carcinogenesis. METHODS: The expression of pS2/TFF1 protein was evaluated immunohistochemically in 45 samples of normal colonic mucosa, 43 samples of adenoma and 186 samples of colorectal carcinoma. RESULTS: pS2/TFF1 protein was expressed weakly in 37.8% of normal colonic mucosa samples, and it had a weak to strong expression in 48.8% of adenomas and 28% of colorectal adenocarcinomas. pS2/TFF1 expression in carcinoma was slightly increased in the poorly differentiated group compared with the well to moderately differentiated group (p=0.059). Interestingly, mucinous carcinoma (4/4) and signet ring cell carcinoma (2/3) showed significant increase of pS2/TFF1 expression. pS2/TFF1 expression was inversely correlated with the p53 protein expression and the Ki-67 labelling index (p<0.05). There was no significant correlation with the tumor size, metastasis or pathologic staging. CONCLUSIONS: Overexpression of pS2/TFF1 expression in colorectal adenocarcinoma was inversely correlated with the Ki-67 labelling index and the p53 expression in cancer. These results suggest that pS2/TFF1 protein may contribute as tumor suppressor factor in colorectal adenocarcinoma.