Expression and clinical significance of ezrin in non--small-cell lung cancer

Abstract

Background: Ezrin is known to regulate cellular survival, adhesion, migration, and invasion and has been identified as 1 of the key components of tumor progression and metastasis. The purpose of this study was to evaluate the clinicopathologic and prognostic significance of ezrin expression in non-small-cell lung cancer (NSCLC).

Materials and methods: We investigated the expression pattern of ezrin immunohistochemically in 89 paraffin samples of NSCLC between January 1998 and December 2006 and conducted survival analyses. In addition, 73 frozen specimens (including tumorous and precancerous tissues) of NSCLC and 28 frozen specimens of benign pneumonic diseases collected between January 2009 and December 2009 were analyzed by Western blot and reverse transcriptase-polymerase chain reaction (RT-PCR).

Results: In 89 paraffin samples, ezrin was expressed in 40 cases, either in the cytoplasm or on the membrane. Ezrin-positive expression was significantly associated with increased tumor stage and lymph node (LN) metastasis. The positive rate of cytoplasm expression was significantly associated with LN metastasis. Importantly, ezrin-positive expression independently predicted inferior overall survival (OS) and disease-free survival (DFS). In 73 frozen specimens of NSCLC and 28 frozen specimens of benign pneumonic diseases, the ezrin mRNA, protein, and phospho-ezrin protein expressions in tumorous tissues were higher than they were in precancerous tissues and benign pneumonic tissues.

Conclusion: These results suggested that high-level ezrin expression contributed to NSCLC progression and that phosphorylation and subcellular translocation of ezrin might be the important mechanisms. Ezrin might be a potential prognostic marker of progression in NSCLC.