The Expression And Significance Of Glucose Regulated Protein 78 In Human Gastric Cancer Cells And Tissues

Objective:To study the expression of GRP78 in human gastric mucosa and gastric cancer specimens, and its clinical significance in development, invasion and metastasis of gastric cancer.Methods:The expression of GRP78 at mRNA and protein levels was detected by RT-PCR and Western blot assay in gastric mucosa epithelial cell line (GES-1), gastric cancer cell lines (MKN28, SGC7901 and MKN45). Immunohistochemistry was used to examin GRP78 protein expression in gastric cancer tissues, and to its correlation with clinicopathological data.Results:The results from RT-PCR and Western blot revealed that GRP78 mRNA and protein can be detected in GES-1, MKN28, SGC7901 and MKN45, and that the expression of GRP78mRNA and protein in gastric cancer MKN28, SGC7901 and MKN45 was significantly higher than that in gastric mucosa GES-1, which indicated that levels of the GRP78 mRNA and protein expression were closely related with the differentiation of gastric caner.Immunohistochemistry assay showed that the GRP78 protein staining was mainly located in the cytoplasm of cells, its positive expression rate was 95% in gastric cancer and 90% in gastric mucosa away from the cancer tissue respectively, and that GRP78 protein expression of the cancer specimens (average at++-+++) was significantly higher than that of the normal gastric specimens(average at +); The Levels of the GRP78 mRNA and protein expression were closely related with the degree of malignancy, extent and node metastasis of caner(P<0.05), but not related with the patients sex and age(P>0.05).Conclusion:The levels of GRP78 were elevated in the human gastric cancer specimens. GRP78 may play some roles in the development of gastric cancer. and was related with its biological behaviors.