promotes cell apoptosis and cell-cycle arrest in osteosarcoma via the modulation of CDCA8/ATF3 by targeting NUSAP1.

Background: () is associated with a variety of malignancies. However, the role of in osteosarcoma and its underlying mechanism are not yet fully understood. This study aimed to explore the role and the mechanism of in osteosarcoma.

Methods: and nucleolar and spindle-associated protein 1 (NUSAP1) expression in osteosarcoma was detected using real-time quantitative polymerase chain reaction (RT-qPCR). Cell Counting Kit-8 (CCK-8), wound-healing, and transwell assays were used to detect cell proliferation, migration and invasion. Terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) and western blot were used to evaluate the cell apoptosis. Flow cytometry was used to assess the cell cycle. In addition, luciferase reporter assay was used to confirm the binding of and NUSAP1. Western blot and RT-qPCR was used to examine cell division cycle associated 8 (CDCA8) and activating transcription factor 3 (ATF3) expression.

Results: expression was significantly decreased in the osteosarcoma cells. Following the transfection with mimic, it was found that 143B cell proliferation, migration, and invasion were inhibited, while the cell apoptotic levels and cell-cycle arrest were promoted, accompanied with decreased B cell lymphoma protein-2 (Bcl-2) protein expression, and increased protein expressions of Bcl-2-associated X (Bax), cleaved caspase-3, and cleaved caspase-9. In addition, was found to bind to NUSAP1, and negatively regulate NUSAP1 expression. NUSAP1 upregulation reversed the inhibitory effects of overexpression on cell proliferation, migration, and invasion, and the promoting effects on cell apoptosis and cell-cycle arrest in osteosarcoma. Moreover, was identified to mediate CDCA8/ATF3 by targeting NUSAP1.

Conclusions: upregulation inhibited cell proliferation and metastasis but promoted the cell apoptosis and cell-cycle arrest in osteosarcoma via the regulation of CDCA8/ATF3 by targeting NUSAP1. Thus, might be a potential therapeutic target for the treatment of osteosarcoma.