Circular RNA circ-PITX1 promotes the progression of glioblastoma by acting as a competing endogenous RNA to regulate miR-379-5p/MAP3K2 axis.

Abstract

As the most fatal disease in human central nerve system, glioblastoma has attracted increasing attention. Unfortunately, the prognosis for patients with glioblastoma still quite unfavorable. Recent years, circular RNAs (circRNAs) have been identified to be associated with carcinogenesis due to their abnormal expression. However, the detailed molecular mechanism of circRNAs in regulating cancer progression is still unclear. This study focused on the potential mechanism of circ-PITX1 in glioblastoma. Herein, circ-PITX1 was found to be upregulated in glioblastoma and could mediate glioblastoma tissues and cell lines. Functionally, downregulation of circ-PITX1 hampered cell proliferation and accelerated cell apoptosis. Through mechanism investigation, we identified the cytoplasmic localization of circ-PITX1 and its molecular sponge role. The interactions between circ-PITX1 and miR-379-5p as well as between miR-379-5p and MAP3K2 were demonstrated. Thus, we confirmed that circ-PITX1 exerted as a competing endogenous RNA (ceRNA) in glioblastoma by sponging miR-379-5p to elevate MAP3K2 expression. Rescue assays demonstrated that MAP3K2 rescued the proliferation and apoptosis mediated by the silencing of circ-PITX1. Collectively, our study elucidated a novel molecular pathway and its functions in glioblastoma.