CircRNA circ_0067934 silencing inhibits the proliferation, migration and invasion of NSCLC cells and correlates with unfavorable prognosis in NSCLC

OBJECTIVE: Circular RNAs are a subgroup of non-coding RNAs and generated by a mammalian genome. The purpose of this study was to investigate the clinical significance, biological function and molecular mechanism of circ_0067934 in human non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: We assayed expression level of circ_0067934 in NSCLC tissues and cell lines by Real-time PCR. The associations of circ_0067934 expression with clinicopathologic features and overall survival of patients with NSCLC were statistically analyzed. Biological functions of circ_0067934 were analyzed using MTT and transwell migration and invasion assays in vitro. The expression of EMT-related mRNAs and proteins was assayed using Real-time PCR and Western blot. RESULTS: We found that circ_0067934 expression was significantly increased in NSCLC tissues and cell lines. High circ_0067934 expression was significantly associated with TNM stage (p= 0.003), lymph node status (p= 0.000), and distant metastasis (p= 0.017). Moreover, Kaplan-Meier curves showed that higher expression of circ_0067934 led to a significantly poorer survival. Multivariate Cox proportional hazards analysis suggested that circ_0067934 was an independent poor prognostic factor for patients with NSCLC. In vitro assay indicated that down-regulation of circ_0067934 could suppress NSCLC cells proliferation, migration, and invasion. Mechanistic analysis showed that aberrant circ_0067934 expression could modulate the expression levels of markers of epithelial- to-mesenchymal transition. CONCLUSIONS: Our data suggested that circ_0067934 functioned as an oncogenic circular RNA in NSCLC, which provided a potential prognostic biomarker and therapeutic target for NSCLC.