Expression And Significance Of Insulin,LRP16,ERα,ERβ,GLP-1 And GLP-1R In Insulinomas And Nonfunctioning Pancreatic Endocrine Tumors

ObjectiveTo evaluate the expression and significance of insulin, ERa, ERβ, LRP-16, GLP-1and GLP-1R in insulinomas and nonfunctioning pancreatic endocrine tumors, analyze the correlation between the proteins and the clinicopathological factors, and explore the relationship among insulin, ERa and LRP-16 in insulinomas.Materials and methodsThis study is a retrospective research. We have reviewed the cases who had been operated in the PLA General Hospital during 2005 to 2009.34 cases of insulinomas and 18 cases of nonfunctioning pancreatic endocrine tumors were collected,and we recorded the clinical features of these patients carefully. The immunohistochemical technique was applied to detect the expression of insulin, ERa, ERp, LRP-16, GLP-1and GLP-1R in insulinomas and nonfunctioning pancreatic endocrine tumors. Afte that, the relationship between the expression of the proteins and clinicopathological features was statistically analyzed. ResultsThe positive expression rates of the six proteins in insulinomas were observed as follows:insulin 85.3%, LRP-16 79.4%, ERa 76.5%, ERp 47.1%, GLP-1 76.5%and GLP-1 R 61.8%. In nonfunctioning pancreatic endocrine tumors were observed as follows:insulin 38.9%, LRP-16 55.6%, ERa 33.3%, ERp 22.2%, GLP-1 38.9%and GLP-1 R 33.3%.The six proteins were all correlated with the typing of PETs (P< 0.05),in which the expression of the six proteins was higher in insulinomas than nonfunctioning pancreatic endocrine tumors. The expression of the six proteins showed no significantly statistical correlation with clinical features in insulinomas and nonfunctioning pancreatic endocrine tumors including age,sex,tumor size,glucose and serum insulin level. There was correlation betweeen insulin, LRP-16 and ERa (P< 0.05) in insulinomas.Conclusions1. Insulin, LRP16, ERa, ERβ, GLP-1 and GLP-1R have high expression in insulinomas than in nonfunctioning pancreatic endocrine tumors, suggesting that these proteins are involved in the pathogenesis of insulinomas. The detection of the proteins is useful for the identification of pancreatic endocrine tumor types, and the proteins are useful targets for diagnosis and treatment of insulinomas.2. There is no significantly statistical correlation between the expression of the six proteins and clinical features in insulinomas and nonfunctioning pancreatic endocrine tumors.3. Insulin, LRP-16 and ERa have high positive expression in insulinomas, and there is correlation among insulin, LRP-16 and ERa, which suggests action of induction, regulation and cooperation among them.