Abstract
Accumulating evidence has demonstrated that the abnormal expression of microRNA (miRNA/miR) serves a crucial role in the development of numerous types of human cancer, including neuroblastoma (NB). The present study aimed to investigate the expression levels and biological roles of miR-146b in NB. miR-146b expression levels in NB cell lines and human umbilical vein endothelial cells (HUVECs) were analyzed using reverse transcription-quantitative PCR, and the regulatory effects of miR-146b on NB cell proliferation, invasion and apoptosis in vitro were investigated using CCK-8 assay, transwell invasion assay and flow cytometry. In addition, bioinformatics analysis, western blotting and dual-luciferase reporter assays were used to determine whether NUMB was a target gene of miR-146b. miR-146b expression levels were increased in NB cell lines compared with HUVECs. The knockdown of miR-146b using a miR-146b inhibitor significantly inhibited NB cell proliferation and invasion, but promoted cell apoptosis in vitro. Furthermore, it was revealed that miR-146b promoted NB cell proliferation through targeting NUMB. In conclusion, miR-146b was suggested to serve as an oncogene, at least in part, through directly targeting NUMB, which indicated that miR-146b may be a potential therapeutic target for NB treatment.