Changes in the Expression of Glucose-regulated Protein 78 in the Occurrence and Progression of Pancreatic Cancer in Mouse Models.

OBJECTIVE: To investigate the changes in the expression of glucose-regulated protein 78 (GRP78) in the occurrence and progression of pancreatic cancer in mouse models. METHODS: The mouse models of chronic pancreatitis,pancreatic intraepithelial neoplasia (PanIN), and pancreatic cancer were successfully established by dimethyl benzene and anthracene (DMBA) embedding in situ. GRP78 expression was detected in various stages by immunohistochemistry. RESULTS: Of these 60 mouse models, 18 mice (30%) died during the observation period. Two months after the embedding,the survived mice were sacrificed,and HE staining and IHC staining were performed. Among these mice, 9 (15%) developed chronic pancreatitis; 18 (30%) had PanIN [PanIN1,5 (8.3%);P anIN2,9 (15%); and PanIN 3,4 (6.7%)];15 (25%) developed pancreatic cancer. Immunohistochemistry showed that the expression of GRP78 in pancreatic cancer tissue was significantly higher than that in adjacent noncancerous duct cells (χ(2)=13.39,P =0.000). Also, GRP78 expression in pancreatic cancer tissue and high grade PanIN was significantly higher than that in low grade PanIN and chronic pancreatitis (χ(2)=17.84,P=0.000). CONCLUSION: The expression of GRP78 remarkably differs in different stages of pancreatic cancer and therefore is associated with the occurrence and progression of this disease.