Circ-0036602 Acts As a Sponge of MiR-34a-5p and MiR-431-5p to Promote Cervical Cancer Proliferation and Invasion

Background: Cervical cancer (CC) is one of the most common female malignancies worldwide. An increasing body of evidence suggests that circular RNAs (circRNAs) participate in the pathogenesis of various cancers, including CC. However, the expression profile and underlying molecular mechanisms remain largely unknown. Methods: In this study, high throughput sequencing was applied to identify circRNA in HPV-16 positive CC tissues. Quantitative real-time PCR (qRT-PCR) was performed to validate the expression in CC tissues and cell lines. RNase R treatment, gel-electrophoresis, and RNA fluorescent in situ hybridization (FISH) were used to characterize the circRNAs. Subsequently, the Cell Counting Kit-8 assay (CCK8), transwell and wound healing assays were performed to assess circRNA function. Meanwhile, dual-luciferase reporter and western blot were used to clarify the associated molecular mechanisms. Results: Circ0036602 was upregulated in HPV-16 positive CC and correlated with a poor prognosis. Moreover, circ0036602 expression significantly correlated with the clinicopathologic characteristics. Knockdown of circ0036602 inhibited CC cell proliferation, migration, and invasion. Further studies showed that circ0036602 could bind to miR-34-5p and miR-431-5p to regulate the expression of the target gene HMGB1. Conclusions: Taken together, our findings suggest that circ0036602 is a tumor-promoting circRNA that promotes CC cells by sponging miR-34-5p and miR-431-5p to regulate HMGB1. Circ0036602 has huge prospects as a potential therapeutic target for CC patients.