Overexpression of circular RNA circ-CDC45 facilitates glioma cell progression by sponging miR-516b and miR-527 and predicts an adverse prognosis

Abstract

Glioma (GM) is a highly lethal human cancer. Circular RNAs (circRNAs) act as an imperative factor in oncogenesis. We aimed to investigate the biological functions and mechanisms of circ-CDC45 in GM. circ-CDC45 expression in GM specimens and cell lines was measured by real-time quantitative reverse transcription polymerase chain reaction. Fisher's exact test and Kaplan-Meier curves further analyzed its clinical implications. A gain/loss-of-function study was conducted to investigate the role of circ-CDC45 in GM. Additionally, luciferase reporter and rescue assays were performed to unravel the mechanisms of circ-CDC45. High circ-CDC45 expression was found in GM specimens and cells, which was tightly related to a larger tumor size, higher world health organization (WHO) stages, and worse survival for patients with GM. Functionally, manipulation of circ-CDC45 expression strongly affected cell growth, apoptosis, migration and invasion, which suggests the oncogenic function of circ-CDC45 in GM oncogenesis. Stepwise mechanism studies indicated that circ-CDC45 sponged and regulated the expression of miR-516b and miR-527 to promote cell growth and invasion. Briefly, the regulatory network of circ-CDC45/miR-516b/miR-527 plays a pivotal role in GM tumorigenesis and may act as a potential target for GM treatment.