Tumor-Derived Exosomal miR-620 as a Diagnostic Biomarker in Non-Small-Cell Lung Cancer

Background. Evidence has suggested the functional role of exosomal miRNAs in cancer diagnosis. This study aimed to determine whether the serum exosomal biomarkers can improve the diagnosis of patients with non-small-cell lung cancer (NSCLC). Materials and Methods. The exosomes were extracted from the serum of NSCLC patients (n = 235) and healthy donors (n = 231) using ultracentrifugation and then were evaluated by using transmission electron microscopy, qNano, and western blotting. The serum exosomal miRNA expression was validated using qPCR. Results. Exosomal miR-620 was significantly reduced in NSCLC and early-stage NSCLC patients (P<0.0001) when compared to that of healthy controls, with an area under the curve (AUC) of 0.728 and 0.707, respectively. Exosomal miR-620 expression showed an association with drinking (P=0.008) and distant metastasis (P=0.037). Additionally, the downregulated exosomal miR-620 showed association with chemotherapeutic effect (P=0.044). Conclusion. These findings suggest the serum exosomal miR-620 as a promising diagnostic and prognostic noninvasive biomarker in NSCLC patients.