Overexpression of NR4A1 is associated with tumor recurrence and poor survival in non-small-cell lung carcinoma.

The expression level and clinical significance of NR4A1 are presently unknown in the non-small-cell lung carcinoma (NSCLC). This study aimed to explore the expression, prognostic value, and function of NR4A1 in NSCLC. Methods: Clinicopathological parameters of 167 NSCLC patients who received radical surgery from January 2007 and December 2012 were retrospectively reviewed. The NR4A1 expression in NSCLC tumors and the adjacent matched para-carcinoma specimens were examined, and the association between NR4A1 expression and clinical variables was explored. Cell viability assay, and transwell migration and invasion assays were used to access the function of NR4A1 in NSCLC. Kaplan-Meier analysis and Cox regression were performed to investigate the prognostic significance of NR4A1 for NSCLC. Results: NR4A1 was overexpressed in NSCLC tissues compared with the para-carcinoma specimens. Consistently, Oncomine analysis showed that NR4A1 was overexpressed in NSCLC tissues compared with normal tissues in published datasets (P < 0.001). The elevated NR4A1 expression was associated with carcinoma recurrence (P < 0.05). The 5-year median overall survival (OS) and progression free survival (PFS) were significantly poorer in the NR4A1-overexpression group. Multivariate Cox analysis showed that NR4A1 overexpression was an independent factor for OS (HR, 95%CI: P < 0.05) and PFS (HR, 95%CI: P < 0.05) in NSCLC. Moreover, knockdown of NR4A1 significantly reduced NSCLC cell proliferation, migration, and invasion. Conclusions: NR4A1 exhibits a tumor-promoting effect on NSCLC, and might serve as a promising prognostic biomarker and a therapeutic target for NSCLC.