Circ-ABCB10 acts as an oncogene in glioma cells via regulation of the miR-620/FABP5 axis

This study aims to investigate the biological function of circular RNA ABCB10 (circ-ABCB10) in regulating the progression of glioma and to study the possible underlying mechanisms.

The expression levels of circ-ABCB10, miR-620 and FABP5 mRNA in glioma tissues, normal surrounding tissues and glioma cell lines were measured by Real-time PCR (RT-PCR). Circ-ABCB10 was silenced by siRNA in glioma cell lines (U87, T98G). The proliferation, migration and invasion of glioma cells were measured by MTT, wound healing and transwell assays, respectively. The relationship between circ-ABCB10, miR-620 and FABP5 was tested by Dual-Luciferase assay. The expression of proteins was measured by Western blot. The cell cycle distribution and apoptosis were measured by flow cytometry.

The expression levels of circ-ABCB10 and FABP5 in glioma tissues and cells were significantly higher than those in their normal counterparts. Moreover, the expression of miR-620 was lower in glioma tissues. Silencing of circ-ABCB10 in glioma cells significantly inhibited the proliferation, migration and invasion of glioma cells. Moreover, downregulation of circ-ABCB10 induced cell cycle arrest and apoptosis in glioma cells. Furthermore, inhibition of miR-620 showed the opposite effects to silencing circ-ABCB10 on glioma cells. Dual-Luciferase reporter assays demonstrated that circ-ABCB10 could bind to miR-620 and that FABP5 was a direct target of miR-620. Western blot results showed that circ-ABCB10 could stabilize the expression of FABP5, while miR-620 decreased the expression of FABP5. Furthermore, overexpression of FABP5 abrogated the silencing effects of circ-ABCB10 in glioma cells.

These data suggest that circ-ABCB10 affects glioma progression by regulating the miR-620/FABP5 axis, and circ-ABCB10 might be used as a potential target for the treatment of glioma.