摘要Background:Neuroblastoma(NB)is a malignant pediatric tumor requiring new therapies.Accumulating evidence has confirmed that microRNAs play critical roles in NB metastasis.Dihydroartemisinin(DHA)is capable of inhibiting the growth of NB cells.The primary ob-jective of the current investigation was to characterize a newly discovered microRNA,miR-32-5p,in terms of the functional role,under-lying mechanism of action,and potential synergistic therapeutic impact in the context of NB metastasis.Materials and methods:Real-time quantitative polymerase chain reaction and Western blotting were employed to assess the expres-sion levels of miR-32-5p and its target,vacuolar protein sorting 4B(VPS4B).Furthermore,Transwell assay was utilized to evaluate in vitro cell migration and invasion,whereas a metastasis xenograft model was established in nude mice via caudal vein injections.Results:Gene Expression Omnibus database and real-time quantitative polymerase chain reaction analysis showed that miR-32-5p was downregulated in human NB samples and NB cell lines,in comparison with the normal tissue and cell lines.Inhibiting miR-32-5p induced the migration and invasion of NB cells,whereas overexpression of miR-32-5p prevented the migration and invasion in NB cell lines.Furthermore,VPS4B was identified as the direct target of miR-32-5p and the miR-32-5p reduction associated with NB metastasis upregulated the expression of VPS4B.Conversely,overexpression of VPS4B reversed the suppressive effects of miR-32-5p on NB cells.Moreover,miR-32-5p increased the sensitivity to DHA both in NB cells and in the metastasis xenograft model of nude mice.Conclusions:The downregulation of miR-32-5p in NB regulates NB metastasis by targeting VPS4B.Moreover,miR-32-5b can im-prove the sensitivity of DHA in the xenograft mouse model.Our findings have important implications for the combined application of miR-32-5p and DHA in the treatment of NB.