CircRNA circ_POLA2 Promotes Cervical Squamous Cell Carcinoma Progression via Regulating miR-326/GNB1

Circular RNAs (circRNAs) are a group of non-coding RNAs that have an essential function in the development and progression of various cancers. The expression pattern and function of circRNA in cervical squamous cell carcinoma (CESC) are not fully understood. In the present study, we aimed to investigate the expression profiles and regulation mechanism of circRNA circ_POLA2 in CESC. Circ_POLA2 was highly expressed in CESC tissues and positively correlated with poor prognosis in CESC patients. Knockdown of circ_POLA2 using shRNA inhibited cervical cancer cell proliferation, migration, and invasion bothin vitroandin vivo. Mechanistically, circ_POLA2 could sponge endogenous microRNA-326 (miR-326) and inhibit its expression. Furthermore, miR-326 negatively regulated G protein subunit beta 1 (GNB1) by targeting its 3 '-UTR. Intriguingly, we found thatGNB1was overexpressed and associated with poor prognosis in CESC patients. Overexpression ofGNB1could antagonize the inhibitory effect of miR-326 on cervical cancer cell proliferation, migration, and invasion. In addition, we demonstrated that circ_POLA2/miR-326/GNB1axis regulated ERK signaling. In conclusion, circ_POLA2 promotes cervical squamous cell carcinoma development and progression via regulating the miR-326/GNB1axis, which might serve as a novel therapeutic target for CESC patients.