CircBBS9 accelerates the malignant progression of osteosarcoma through sponging miR-485-3p/HMGB1 axis.

Osteosarcoma (OS) is a leading malignant tumor reported with high mortality and morbidity. Dysexpression of CircBBS9 has been reported to exhibit a critical functional role in various diseases. However, the underlying molecular mechanisms of CircBBS9 in osteosarcoma are poorly characterized. The present study aims to investigate the impacts of CircBBS9 on the progression of osteosarcoma. The findings of the study demonstrated the up-regulated expression of CircBBS9 in osteosarcoma. The Actinomycin D and RNase R treatment experiments confirmed that circBBS9 is indeed a circRNA. In addition, the knockdown of circBBS9 negatively impacted the migration, proliferation and invasion of osteosarcoma cells. Further investigations illustrated that circBBS9 controlled miR-485-3p and miR-485-3p might directly interact with HMGB1. miR-485-3p had a negative regulatory role in HMGB1's gene expression. Through rescue assays, it was verified that CircBBS9 promoted osteosarcoma progression through the miR-485-3p/HMGB1 axis. Finally, circBBS9 knockdown attenuated the in-vivo growth of osteosarcoma. Conclusively, our study is the first time to examine the possible functional mechanism and regulation roles of CircBBS9 in osteosarcoma. The findings explained that CircBBS9 promoted the malignant osteosarcoma's progression by sponging miR-485-3p/HMGB1 and proposed CircBBS9 as a prognostic biomarker and therapeutic candidate for osteosarcoma patients. [ABSTRACT FROM AUTHOR]