Dysregulated circulating miR-4429 serves as a novel non-invasive biomarker and is correlated with EGFR mutation in patients with non-small cell lung cancer

This study aimed to investigate the correlation between microRNA (miR)-4429 and epidermal growth factor receptor (EGFR), the expression, and clinical significance of miR-4429 in patients with non-small cell lung cancer (NSCLC), and the relationship between miR-4429 and EGFR mutation in NSCLC patients. Blood samples were collected from 122 NSCLC patients and 72 healthy volunteers. miR-4429 expression and EGFR mRNA expression were detected by real-time quantitative polymerase chain reaction. Correlation between miR-4429 and EGFR was evaluated by dual-luciferase reporter assay and the Pearson correlation analysis. The ability of serum miR4429 to discriminate between NSCLC patients and healthy controls, and to discriminate between EGFR wild-type (EGFR-W) and EGFR mutant-type (EGFR-M) patients was assessed using receiver operating characteristic analysis. The relationship between miR-4429 and NSCLC patients’ survival was identified by KaplanMeier survival curves and log-rank test. The prognostic value of miR-4429 in NSCLC patients was evaluated by Cox regression analysis. miR-4429 could directly bind to EGFR. Serum miR-4429, decreased in NSCLC patients, was negatively correlated with serum EGFR mRNA expression in NSCLC patients. In addition, miR-4429 had a high diagnostic value for screening NSCLC patients from healthy controls, and was independently correlated with survival prognosis of NSCLC patients. Moreover, miR4429 was decreased in EGFR-M patients, which had a certain screening ability for EGFRM patients. Our findings indicate that miR-4429 is negatively correlated with EGFR in NSCLC, and may function as a diagnostic and prognostic biomarker for NSCLC patients. Additionally, miR-4429 is associated with EGFR mutation in NSCLC patients.