Background: Osteosarcoma (OS) is the most prevalent malignant bone tumor and has a particularly unfavorable prognosis. Although miR-490-5p is regarded as an established diagnostic and predictive marker for human cancers, the role of miR-490-5p in OS remains presently unclear. The aim of this study was to clarify the function of miR-490-5p in OS. Methods: Bioinformatics analysis of OS cells was performed to identify differentially expressed microRNAs (miRNAs, miRs). Then, the expression profiles of miR-490-5p in various OS cells were determined by real-time polymerase chain reaction analysis. The roles of miR-490-5p in OS cells were assessed through in vitro cytological experiments. Bioinformatics methods were used to predict target genes. The relationship between miR-490-5p and HDAC2 was demonstrated by a dual-luciferase reporter gene assay. Results: Expression of miR-490-5p was relatively decreased in OS cells. Overexpression of miR-490-5p inhibited proliferation and metastasis of OS cells. Moreover, miR-490-5p was found to negatively regulate HDAC2 as a downstream target gene. Recovery experiments confirmed that HDAC2 overexpression rescued the inhibitory effect on OS progression by overexpression of miR-490-5p. Conclusions: MiR-490-5p directly regulated HDAC2 expression, thereby modulating the growth and metastatic capacity of OS cells. The miR-490-5p/HDAC2 axis could serve as a promising therapeutic target for OS.

Osteosarcoma (OS) is a primary bone malignancy; however, its exact mechanism of development remains largely unknown. Recent studies have shown that miR-381