Osteoprotegerin is up-regulated in pancreatic cancers and correlates with cancer-associated new-onset diabetes

New-onset diabetes might help to yield biomarkers for the early diagnosis of pancreatic cancer (PaC). In this study, we computationally predicted and experimentally validated osteoprotegerin (OPG) being associated with pancreatic cancer related new-onset diabetes. We first performed a meta-analysis on microarray datasets to search for genes specifically highly expressed in PaC, and then filtered for cytokines involved in islet dysfunction. The expression of OPG in PaC and normal pancreas were validated by immunohistochemistry. Serum OPG levels in healthy controls, non-cancerous diabetes and PaC patients with or without diabetes were detected by enzyme-linked immunosorbent assay (ELISA). In silico assay found that OPG up-regulated in PaC tissues in comparison to normal pancreas. Immunohistochemical data further confirmed that OPG was overexpressed in PaC samples. Furthermore, increased expression of OPG in PaC tissues correlated to the occurrence of new-onset diabetes, and adversely affected the patients' overall survival in both univariate and multivariate analysis. In addition, the serum levels of OPG were significantly higher in pancreatic cancer patients with new-onset diabetes than other groups including pancreatic patients without diabetes, new-onset type 2 diabetes and healthy controls. In conclusion, there is a close association between OPG and pancreatic cancer related new-onset diabetes, and OPG might serve as a potential biomarker for the early diagnosis of pancreatic cancer from populations with new-onset diabetes.