miRNA-520c-3p accelerates progression of nasopharyngeal carcinoma via targeting RAB22A

Biological function of microRNA-20c-3p (miRNA-520c-3p) in the progression of nasopharyngeal carcinoma (NPC) and the potential mechanism were investigated. Relative level of miRNA-520c-3p in NPC tissues and adjacent normal tissues was determined by quantitative real-time polymerase chain reaction (qRT-PCR). Particularly, miRNA-520c-3p level in NPC with different tumor stages and tumor sizes was examined. Subsequently, miRNA-520c-3p level in nasopharyngeal epithelial cells and NPC cells was detected. The potential influence of miRNA-520c-3p on the proliferative ability and cell cycle progression of NPC cells were evaluated through cell counting kit-8 (CCK-8) and flow cytometry. The target gene of miRNA-520c-3p was verified by dual-luciferase reporter gene assay. Regulatory role of miRNA-520c-3p/RAB22A in the malignant progression of NPC was identified. miRNA-520c-3p was downregulated in NPC tissues and cell lines. Its level was lower in NPC with worse tumor grade and larger tumor size. Overexpression of miRNA-520c-3p suppressed the proliferative ability and arrested cell cycle in G0/G1 phase. RAB22A was confirmed to be the downstream target of miRNA-520c-3p. In NPC tissues and cell lines, RAB22A remained in higher abundance relative to controls. Overexpression of RAB22A reversed the inhibitory effects of overexpressed miRNA-520c-3p on proliferative ability and cell cycle progression of NPC cells. miRNA-520c-3p is downregulated in NPC, which accelerates the malignant progression of NPC by targeting RAB22A.