Circ_0001588 Upregulates ERBB4 to Promote Glioma Malignant Progression Through Sponging miR-1281.

Circular RNA (circRNA) plays a crucial part in glioma progression. However, the function of circ_0001588 in glioma development is still unknown. The study aims to reveal the role of circ_0001588 in glioma malignant progression and the inner molecular mechanism. The RNA expressions of circ_0001588, microRNA-1281 (miR-1281), and erb-b2 receptor tyrosine kinase 4 (ERBB4) were detected by qRT-PCR. Protein expression was checked by western blot analysis or immunohistochemistry assay. Cell proliferation was investigated by cell counting kit-8 and colony formation assays. Flow cytometry, transwell, and tube formation assays were used to detect cell apoptosis, cell migration, and invasion as well as angiogenesis, respectively. The binding relationship between miR-1281 and circ_0001588 or ERBB4 was identified by dual-luciferase reporter and RNA immunoprecipitation assays. Mouse model assay was performed to confirm the effect of circ_0001588 knockdown on tumor formation in vivo. Circ_0001588 and ERBB4 expressions were significantly upregulated, while miR-1281 was downregulated in glioma tissues and cells compared with control groups. Circ_0001588 expression was closely related to tumor size and WHO grade of glioma. Decreased expression of circ_0001588 in glioma cells led to significant decreases of cell proliferation, migration, invasion, and tube formation and an increase of cell apoptosis. Additionally, downregulation of miR-1281, a target miRNA of circ_0001588, rescued circ_0001588 knockdown-mediated effects. MiR-1281 also inhibited glioma malignant progression by targeting ERBB4. Importantly, circ_0001588 regulated ERBB4 expression by interacting with miR-1281. Furthermore, circ_0001588 depletion suppressed tumor formation in vivo. Circ_0001588 acted as an oncogene in glioma malignant progression by miR-1281/ERBB4 pathway, suggesting the potential of circ_0001588 as a therapeutic target for glioma.