LncRNA double homeobox A pseudogene 8 (DUXAP8) facilitates the progression of neuroblastoma and activates Wnt/β-catenin pathway via microRNA-29/nucleolar protein 4 like (NOL4L) axis

The potential mechanism of neuroblastoma (NB) progression remains elusive. We intended to uncover the role and network of long noncoding RNA (lncRNA) double homeobox A pseudogene 8 (DUXAP8) in NB. Quantitative real time polymerase chain reaction (qRT-PCR) was performed to detect the levels of DUXAP8, microRNA-29 (miR-29) and nucleolar protein 4 like (NOL4L). The proliferation, colony formation, cell cycle and metastasis of NB cells were examined by (4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, plate colony formation assay, flow cytometry and transwell assays. Western blot was conducted to detect the expression of metastasis and proliferation-associated proteins and NOL4L. The target relationship was predicted by StarBase software and was confirmed by dual-luciferase reporter assay and RNA binding protein immunoprecipitation (RIP) assay. Nude mice bearing tumors were used to verify the role of DUXAP8 in vivo. We found the expression of DUXAP8 was positively related to the stage of NB tumors, and it was negatively associated with the survival rate of NB patients. DUXAP8 knockdown inhibited the proliferation, colony formation, cycle and motility of NB cells. MiR-29 could interact with DUXAP8, and DUXAP8 exacerbated NB via sponging miR-29. MiR-29 could bind to NOL4L, and the influence of NOL4L intervention on the functions of NB cells could be alleviated by the transfection of miR-29 inhibitor. NOL4L was regulated by DUXAP8/miR-29 axis in NB cells. DUXAP8 knockdown blocked the progression of NB in vivo. Collectively, DUXAP8 deteriorated NB through serving as a sponge for miR-29 to up-regulate the expression of NOL4L in vitro and in vivo.