Expression of flotillin-2 in human non-small cell lung cancer and its correlation with tumor progression and patient survival.

INTRODUCTION Recent studies have revealed that flotillin-2 (FLOT2) played important roles in cancer progression. The aim of this study was to investigate the clinicopathologic and prognostic significance of FLOT2 expression in human non-small cell lung cancer (NSCLC). METHODS Quantitative real-time PCR (qRT-PCR) was performed to detect FLOT2 mRNA expression in lung cancer cell lines, normal bronchial epithelial cells, 24 pairs of NSCLC tissues and matched adjacent non-tumor tissues. Immunohistochemistry (IHC) was performed to examine FLOT2 protein expression in paraffin-embedded tissues from 90 NSCLC patients. Statistical analyses were performed to evaluate the clinicopathological significance of FLOT2 expression. RESULTS FLOT2 mRNA expression was evidently up-regulated in lung cancer cell lines and NSCLC tissues compared with normal bronchial epithelial cells and adjacent non-tumor tissues. In the 90 cases of tested NSCLC samples, FLOT2 protein level was positively correlated with tumor stage, and lymph node metastasis. Patients with high FLOT2 expression had shorter overall survival compared with the low FLOT2 expression group. Univariate and multivariate analyses indicated that high FLOT2 expression was an independent poor prognostic factor for NSCLC patients. CONCLUSIONS Our findings provided that high FLOT2 expression was associated with poor outcomes in NSCLC patients, and FLOT2 could be a potential prognostic biomarker for lung cancer progression.