CircANKRD52 Promotes the Tumorigenesis of Hepatocellular Carcinoma by Sponging miR-497-5p and Upregulating BIRC5 Expression

CircRNAs participate in the pathogenesis of a variety of cancers. Previous studies showed that baculoviral IAP repeat containing 5 (BIRC5) can promote tumor progression. But, the mechanisms by which circRNAs regulate BIRC5 expression in hepatocellular carcinoma (HCC) remain unknown. The clinical prognosis of BIRC5 or miR-497-5p expression in patients with HCC was assessed by TCGA RNA-seq dataset. hsa_circ_0026939 (circANKRD52) or BIRC5 was identified to bind with miR-497-5p by luciferase gene report, RIP and circRIP assays. MTT, colony formation, Transwell assays and a xenograft tumor model were used to estimate the role of miR-497-5p or circANKRD52 in HCC cells. As a result, we found that elevated expression of BIRC5 or decreased expression of miR-497-5p was linked to poor survival in HCC. Restored expression of miR-497-5p repressed cell proliferation, colony formation and invasiveness by targeting BIRC5, but its inhibitor showed the opposite results. Furthermore, circANKRD52 possessed a tumor-promoting effect by acting as a sponge of miR-497-5p and thereby upregulated BIRC5 in HCC cells. In conclusion, our findings demonstrated that circANKRD52 enhances the tumorigenesis of HCC by sponging miR-497-5p and upregulating BIRC5 expression.

Automated summary

circRNAs are involved in the pathogenesis of various cancers, including hepatocellular carcinoma (HCC). In HCC, BIRC5 and miR-497-5p play critical roles in tumor progression, with miR-497-5p inhibiting cell proliferation and invasiveness by targeting BIRC5, while circANKRD52 acts as a sponge for miR-497-5p, leading to upregulation of BIRC5 expression in HCC cells.