Circ_0000253 promotes the progression of osteosarcoma via the miR-1236-3p/SP1 axis

Objective: Circular RNAs (circRNAs) play important roles in modulating tumour progression. This study investigated the role of circ_0000253 in Osteosarcoma (OS).

Methods: We downloaded the chip dataset GSE140256 from the Gene Expression Omnibus database and the circRNAs differentially expressed in OS tissue and normal tissue samples were analysed. Quantitative Real-Time PCR (qRT-PCR) was carried out to examine circ_0000253 expression in OS tissues and cells. Cell counting kit-8, BrdU and flow cytometry assays were performed to verify the effects of circ_0000253 on OS cell growth and Apoptosis. Bioinformatics analysis was conducted to predict, and RNA immunoprecipitation assay and dual-luciferase reporter gene assay were performed to verify the targeted relationships of miR-1236-3p with circ_0000253 and Sp1 transcription factor (SP1) mRNA 3'UTR. The effects of miR-1236-3p and circ_0000253 on SP1 expression in OS cells were detected through Western blot.

Key findings: Circ_0000253 was upregulated in OS tissues and cell lines. Circ_0000253 overexpression facilitated OS cell growth and suppressed Apoptosis, whereas knocking down circ_0000253 inhibited OS cell growth and facilitated Apoptosis. Circ_0000253 targeted miR-1236-3p directly and negatively modulated its expression. SP1 was miR-1236-3p's target gene and positively regulated by circ_0000253.

Conclusion: Circ_0000253 promotes OS cell proliferation and suppresses cell Apoptosis via regulating the miR-1236-3p/SP1 molecular axis.