KIF9-AS1 promotes nasopharyngeal carcinoma progression by suppressing miR-16

Long non-coding RNAs (lncRNAs) have been reported to serve a crucial role in the progression of nasopharyngeal carcinoma (NPC); however, the underlying molecular mechanisms of lncRNA KIF9-AS1 in the tumorigenesis of NPC remains poorly understood. Reverse transcription-quantitative PCR was used to analyze the expression levels of KIF9-AS1 and microRNA (miR)-16, and Cell Counting Kit-8, wound healing and Transwell assays were used to determine the cell viability, invasion and migration, respectively, of NPC cells. In addition, a dual-luciferase reporter assay was used to analyze the direct interaction between KIF9-AS1 and miR-16. NPC stage was classified according to the seventh edition of the AJCC staging system. The results revealed that KIF9-AS1 expression levels were upregulated in NPC tissues and cell lines. In addition, miR-16 was demonstrated to directly interact with KIF9-AS1 and inhibit KIF9-AS1 expression levels, whereas the miR-16 inhibitor rescued the effects of the KIF9-AS1-knockdown in NPC cells. Furthermore, the expression levels of KIF9-AS1 were upregulated, while those of miR-16 were downregulated in NPC tissues. Notably, the expression levels of KIF9-AS1 were observed to be significantly more upregulated in advanced tumors (III–IV vs. I–II) and patients with high KIF9-AS1 expression levels exhibited a worse prognosis. In conclusion, the findings of the present study suggested that KIF9-AS1 may promote the progression of NPC by targeting miR-16, thus KIF9-AS1 may be a novel molecular target for NPC therapy.