LncRNA DANCR silence inhibits SOX5-medicated progression and autophagy in osteosarcoma via regulating miR-216a-5p

Osteosarcoma (OS) is the most common type of bone cancer in children and adolescents. LncRNA differentiation antagonizing nonprotein coding RNA (DANCR) has been reported to be aberrant expression in osteosarcoma and contribute to proliferation, migration and invasion of cancer cells. Here, we further explore the exacted molecular mechanism of DANCR in OS. The expression of DANCR, microRNA-216a-5p (miR-216a-5p) and SOX5 was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). Cells proliferation and apoptosis were analyzed by WST-lassay or flow cytometry, respectively. The migratory and invasion abilities were measured by transwell assay. Western blot was used to detect the level of SOX5 and autophagy-related protein of Beclinl, LC3-I and LC3-II. The interaction among DANCR, miR-216a-5p and SOX5 was explored by luciferase reporter assay, RIP assay or Pull-down assay. Murine xenograft model was established using 143B cells transfected with sh-DANCR. We found that a significantly elevated of DNACR was detected in osteosarcoma tissue and cell lines. Functional experiments suggested that down-regulation of DANCR inhibited cells proliferation, migration, invasion and autophagy but induced apoptosis in osteosarcoma in vitro. Additionally, we also determined knockdown of DANCR inhibited the growth and autophagy of osteosarcoma in vivo. DANCR was a sponge of miR-216a-5p activity. DANCR regulated survival of osteosarcoma through targeting miR-216a-5p. Additionally, SOX5 was a direct target of miR-216a-5p, overexpression miR-216a-5p exerted inhibition effects via downregulating SOX5 expression. Furthermore, DANCR regulated SOX5 expression by sponging to miR-216a-5p. In conclusion, LncRNA DANCR silence inhibits SOX5-medicated progression and autophagy in osteosarcoma via regulating miR-216a-5p which indicating DANCR may act as a potential prognostic biomarker and therapeutic target for osteosarcoma.