Identification of the Prelinitis Condition in Gastric Cancer and Analysis of TGF-β, TGF-β RII and pS2 Expression

Abstract
In the present study, we performed an immunohistochemical examination of the expression of transforming growth factor-β (TGF-β), TGF-β type II receptor (TGF-β RII) and a trefoil peptide, pS2, in the several types of gastric cancer. The TGF-β:TGF-β RII ratios of IIc-like type and Ménétrier type closely resembled that of linitis type. pS2 was intensely expressed in cytoplasm of the superficial and foveolar epithelium, as well as in scirrhous type gastric cancers which retained the gastric or intestinal phenotype. However, pS2 expression was significantly (p < 0.05) reduced in linitis type gastric cancers (1 of 6; 17%) when compared with other scirrhous types of gastric cancers (13 of 22; 59%). A decrease in the TGF-β:TGF-β RII ratios in linitis type, IIc-like type and Ménétrier type gastric cancers may be associated with the fibrosis seen in these types of cancer. Furthermore, reduction of pS2 expression in linitis type gastric cancer may represent a dedifferentiation of the cancer from gastric or intestinal phenotype. Judging by the expression patterns of TGF-β, TGF-β RII and pS2, it is possible that IIc-like type and Ménétrier type gastric cancers are precursor lesions of linitis type gastric cancer.