circFLNA promotes glioblastoma proliferation and invasion by negatively regulating miR-199-3p expression

Glioblastoma (GBM) is one of the most common and malignant types of primary cancer in the central nervous system; however, the clinical outcomes of patients with GBM remain poor. Circular RNAs (circRNAs) have been revealed to serve important roles in diverse biological processes, such as regulating cell proliferation, epithelial-mesenchymal transition and tumor development. However, the underlying biological function of circRNA filamin A (circFLNA) and its potential role in GBM remain to be determined. The present study aimed to identify differentially expressed circRNAs in GBM. Reverse transcription-quantitative PCR was used to analyze the expression levels of circFLNA. The results demonstrated that the expression levels of circFLNA were significantly upregulated in clinical GBM samples and GBM cells compared with adjacent healthy brain tissues and normal human astrocytes, respectively. The results of the Cell Counting Kit-8 and Transwell assays revealed that circFLNA knockdown significantly inhibited the proliferative and invasive abilities of GBM cell lines. Moreover, high circFLNA expression levels were associated with a worse prognosis in GBM. MicroRNA (miR)-199-3p was subsequently predicted to be target of circFLNA. The inhibitory effect of miR-199-3p on cell proliferation and invasion was partially reversed following circFLNA knockdown. In conclusion, the findings of the present study identified novel roles for circFLNA in GBM and indicated that the circFLNA/miR-199-3p signaling axis may serve an important role in GBM progression. Therefore, circFLNA may represent a novel target for the diagnosis and treatment of GBM.