Study On The Expression Of AGR2 In Pituitary Adenomas And Its Role On The Diagnosis Of Pituitary Adenomas

Part I The expression of AGR2 in pituitary adenomas and its association with tumor aggressivenessObjective:The aim of this study is to investigate the expression of AGR2 for clinical significance in pituitary adenomas and evaluate the association of AGR2 with tumor aggressivenessMethods:1. Sample collection:One hundred and seventeen pituitary adenomas (PAs) of different histological subtypes were selected randomly from the patients operated between May 2013 and June 2014. All PA tumor tissues were formalin-fixed and paraffinembedded resected and then pathologically diagnosed. Pituitary adenomas were classified as aggressive or non-aggressive tumors according to Hardy and Knosp classification system.2. Immunohistochemical staining:Immunohistochemistry staining was performed to detect the expression and cell distribution of AGR2 in 117 pituitary adenoma tissue samples.3. Western blot:Western blot was performed to confirm the expression profile of AGR2 in different subtypes of PAs.4. Immunofluorescence staining:Immunofluorescence was performed to detect the cell distribution of AGR2 in pituitary adenoma tissue samples.Results:In 117 different histological subtypes of pituitary adenomas (PAs),51.3% of them were AGR2 positive expression. The ratio of positive expression of AGR2 shows no significant differences between PA subtypes. Aggressiveness of PAs is associated with AGR2 expression. AGR2 is distributed in pituitary adenomas cell cytoplasm and membrane.Conclusion:Our results demonstrated that AGR2 expression is associated with the aggressiveness of Pas. AGR2 may be a target for the study of PAs aggressiveness, and a potential index for the diagnosis or prognosis of PAs.Part Ⅱ The role of serum AGR2 as a screening biomarker for the diagnosis and differential diagnosis of pituitary adenomasObjective:The aim of this study is to study the serum level of AGR2 in pituitary adenoma patients and to evaluate whether the serum AGR2 could be a screening biomarker for PAs.Methods:1. Sample collection:One hundred and sixty-three pituitary adenomas (PAs) of different histological subtypes were selected randomly from the patients operated between 2012 and 2014 in the Department of neurosurgery, Jinling Hospital. Ten normal male and 10 normal female were selected as negative control. Forty-three patients with other lesions in saddle area excluding PA were selected randomly to compare with the PA patients. Seven patients with prostate cancer were selected as positive control.2. Enzyme-Linked ImmunoSorbent Assay (ELISA):To measure the serum AGR2 protein levels in blood sample of relevant people.Results:AGR2 level was higher in the serum of PA patients (250.10±79.14ng/ml) than that in normal control (163.67±50.38ng/ml, P<00.001) or Non-PA patients with other lesions in saddle area (220.84±79.62ng/ml, P=0.017<0.05). Moreover, the AGR2 level was higher in the serum of Non-PA patients with other lesions in saddle area (220.84±79.62ng/ml) than that in normal control (163.67±50.38ng/ml, P=0.002<0.01). Receiver operating characteristic (ROC) curve analysis was used. The AUC was 0.835. The calculated sensitivity was 91.4%. The specificity was 65.0%. Despite the variety of PA clinical features, the serum level of AGR2 are definite in PAs, although there may be a difference between male or female patients.Conclusion:Serum level of AGR2 is significant high in pituitary adenomas and could be a screening biomarker for the diagnosis and differential diagnosis of PAs.