Abstract:         Background and purpose: This study investigated the relationship between (S100 calcium-binding protein A4, S100A4) in chronic gastritis, intestinal metaplasia, dysplasia adenomatous, normal tissue tissue samples and expression in gastric cancer and clinical characteristics. Methods: HE staining of the use of gastric specimens taken for histopathological diagnosis; using immunohistochemistry to detect the expression of tissue S100A4 protein; qRT-PCR was used to detect mRNA expression of S100A4 gene; Western Blot detection of S100A4 gene encoding protein. Kaplan- Meier survival curves were used to distinguish and compare survival. Results: S100A4 protein and mRNA expression gradually increased in the following order: normal tissue<gastritis<intestinal metaplasia<dysplasia<carcinoma. S100A4 levels with tumor size, depth of invasion, lymphatic invasion, lymph node metastasis and lymph node metastasis (TNM) staging, but with cancer patients independent of age and gender. Intestinal type (IT) cancer showed higher than the diffuse type (DT) of cancer S100A4 expression. S100A4 gene overexpression in a larger diameter, deeper invasion, lymph node metastasis of gastric and IT cancer was found. Kaplan-Meier method using univariate analysis showed weak expression of S100A4 gene is not expressed in patients with moderate or S100A4 gene have lower survival rates compared. Conclusion: Upregulated S100A4 gene may play an important role in the malignant transformation of epithelial cells in the stomach, and gastric cancer growth, invasion, metastasis and prognosis were positively correlated. Thus, S100A4 may be considered as a potential marker to show violations of gastric cancer. S100A4 expression in diffuse unique cancer can be used to distinguish between cancer and diffuse intestinal cancer, and can be used as a molecular characteristic distinguish two types of cancer.

Key words: S100 calcium-binding protein A4, Gastric cancer, Immunohistochemistry, RT-PCR, Western blot