MicroRNA-148b is a potential prognostic biomarker and predictor of response to radiotherapy in non-small-cell lung cancer

miR-148b has been found to be aberrantly expressed in various tumor types. It has recently been reported to be involved in regulating radioresistance in non-small cell lung cancer (NSCLC) cells. However, its expression level and association with radiosensitivity in human patient samples have not been investigated. Real-time PCR was used to evaluate the expression levels of miR-148b. Χ2 test was performed to analyze the association between miR-148b expression levels and clinicopathological factors or radiosensitivity. Kaplan-Meier survival curve was constructed to estimate the overall survival (OS), and the differences in survival were compared using the log-rank test. Cox regression analysis was conducted to determine the prognostic value of miR-148b. The relative level of miR-148b was significantly decreased in NSCLC tissues compared with matched non-cancerous tissues (P < 0.0001), and it was higher in tissues of patients who are good responders compared to those who are poor responders to radiotherapy (P < 0.0001). Lower expression of miR-148b was positively associated with high tumor stage (P = 0.0407) and radioresistance (P = 0.0002), and it predicted poor survival in patients with (P = 0.0129) or without (P = 0.0094) radiotherapy treatment. miR-148b was an independent prognostic factor for NSCLC as demonstrated by Cox proportional hazards risk analysis. miR-148b may serve as a prognostic biomarker of poor survival and a novel predictor of response to radiotherapy treatment in NSCLC.