Overexpression of miR-140-3p Could Reverse Radioresistance of Nasopharyngeal Carcinoma by Targeting XIAP

Abstract BackgroundMalignant behavior and radioresistance, which severely limits the efficacy of radiotherapy (RT) in nasopharyngeal carcinoma (NPC), lead to tumor progression and poor prognosis. The aim of this study was to investigate the underlying molecular mechanism of miR-140-3p on NPC development and radioresistance.MethodsThe expression of genes and proteins was detected by Western blotting, and quantitative reverse transcription PCR (qRT-PCR). Proliferation, apoptosis, and radioresistance of NPC were detected. Luciferase reporter assays were used to detect the interactions of miR-140-3p with its downstream targets.ResultsThe expression of miR-140-3p was associated with the occurrence and radiation resistance of NPC. XIAP as the direct target of miR-140-3p was verified. We found alleviated radioresistance of NPC cells upon miR-140-3p overexpression or XIAP knockdown.ConclusionmiR-140-3p is downregulated in radioresistant NPC. miR-140-3p could hamber radioresistance of NPC via directly target XIAP, suggesting miR-140-3p/XIAP axis is vital in the regulation of irradiation sensitivity.