Proteomics-based identification of α-enolase as a potential prognostic marker in cholangiocarcinoma.

OBJECTIVES: To investigate the association of expression status of α-enolase (ENO1) and clinicopathological outcomes of CCA patients. DESIGN AND METHODS: Two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS) were used to compare differential expressed protein profiles of four human CCA cell lines and H69, a non-malignant biliary cell line, as a control. Immunohistochemical analysis was carried out in tissue-microarray of human CCA tissues (n=301). RESULTS: We identified ENO1 in all CCA cell lines but not H69 by proteomics based. About 75% of patients with CCA showed over-expression of ENO1 in hyperplastic bile duct and the tumors compared with that in tumor-adjacent normal tissue counterparts. Moreover, over-expression of ENO1 is significantly associated with poor prognosis and tumor invasion of CCA patients. CONCLUSIONS: ENO1 may serve as a prognostic marker to monitor the disease progression of these patients.