Long noncoding RNA ATB promotes osteosarcoma cell proliferation, migration and invasion by suppressing miR-200s

Long noncoding RNA activated by transforming growth factor-beta (lncRNA-ATB) is a novel lncRNA, which is recently reported to have critical roles in carcinogenesis and progression of several cancers. However, the expression, clinical values, biological roles, and underlying molecular mechanisms of lncRNA-ATB in osteosarcoma are still known. In this study, we measured lncRNA-ATB expression in serum and osteosarcoma tissues of osteosarcoma patients, analyzed its diagnostic and prognostic values. Serum lncRNA-ATB is increased in osteosarcoma patients and could accurately discriminate osteosarcoma patients from healthy controls. LncRNA-ATB is also upregulated in osteosarcoma tissues and cell lines, and positively associated with Enneking stage, metastasis and recurrence. Increased lncRNA-ATB level indicates poor recurrence-free survival and overall survival. Functional experiments demonstrated that overexpression of lncRNA-ATB enhances osteosarcoma cells proliferation, migration, and invasion, and while depletion of lncRNA-ATB inhibits osteosarcoma cells proliferation, migration, and invasion. Mechanistically, we found that lncRNA-ATB inhibits miR-200s, and upregulates miR-200s target genes ZEB1 and ZEB2. Additionally, the roles of lncRNA-ATB on osteosarcoma cells proliferation, migration, and invasion in vitro, and osteosarcoma tumor growth in vivo are dependent on the regulation of miR-200s. Taken together, this study suggests that lncRNA-ATB may be a potential diagnostic and prognostic biomarker and a therapeutic target for osteosarcoma.