LncRNA GAS5 Regulates Osteosarcoma Cell Proliferation, Migration, and Invasion by Regulating RHOB via Sponging miR-663a.

Introduction: Emerging evidence has revealed the importance of long non-coding RNAs (lncRNAs) in carcinogenesis. The aim of this work was to investigate the roles of lncRNA growth arrest specific 5 (GAS5) in osteosarcoma (OS) progression.

Methods: Real-time quantitative polymerase chain reaction (RT-qPCR) was performed to explore GAS5, microRNA-663a (miR-663a), and ras homolog family member B (RHOB) expression levels in OS tissues and cells. Moreover, cell counting kit-8 assay, wound-healing assay, and transwell invasion assay were conducted to investigate biological roles of GAS5 in OS progression. In addition, mechanisms underlying the functions of GAS5 in OS were investigated by bioinformatic analysis, luciferase activity reporter assay, and rescue experiments.

Results: The GAS5 expression level was significantly decreased in OS tissues and cells compared with normal tissues and cells, and could negatively regulate miR-663a expression. Moreover, we found RHOB expression can be negatively regulated by miR-663a. Overexpression of GAS5 and RHOB suppresses, while overexpression of miR-663a stimulates, OS cell proliferation, migration, and invasion in vitro. In summary, we revealed lncRNA GAS5 was a downregulated lncRNA in OS and impaired OS malignant behaviors. In addition, this regulation relied on miR-663a and its target gene, RHOB.

Discussion: To sum up, we showed lncRNA GAS5 regulates OS progression via regulating the miR-663a/RHOB axis.