Long Non-Coding RNA FGD5-AS1 Enhances Osteosarcoma Cell Proliferation and Migration by Targeting Mir-506-3p/rab3d Axis

Osteosarcoma (OSA), the malignant bone tumor, predominantly affecting children and adolescents, threatens the life and life quality of the patients. An increasing number of studies have indicated the role of long non-coding RNA (lncRNA) dysregulation in cancer biology. Herein, the study was aimed to explore the role of FGD5 antisense RNA 1 (FGD5-AS1), a lncRNA, in OSA. Expression levels of FGD5-AS1, miR-506-3p and RAB3D mRNA were quantified utilizing qRT-PCR. The expression of RAB3D protein was examined employing Western blot. A series of functional experiments including CCK-8 assay, BrdU assay, wound healing assay, Transwell assay were performed for studying the effects of FGD5-AS1 on the malignancy of OSA cell lines 143B and HOS. The binding site between miR-506-3p and FGD5-AS1 was identified and validated by luciferase reporter assay and RNA immunoprecipitation assay. It was demonstrated that the expression of FGD5-AS1 was up-regulated in OSA tissues and cell lines, and its high expression is associated with higher Enneking stage and poorer histological differentiation. Gain-of-function and loss-of-function studies suggested that FGD5-AS1 facilitated OSA cells proliferation and migration. The promoting effects of FGD5-AS1 overexpression on OSA cell proliferation and migration could be counteracted by miR-506-3p. Moreover, FGD5-AS1 competitively adsorbed miR-506-3p to repress its expression so as to up-regulate the expression of RAB3D. These results indicate that FGD5-AS1 is capable of expediting OSA cell proliferation and migration via sponging miR-506-3p to up-regulate RAB3D.