CircTP63 Promotes Cell Proliferation and Invasion by Regulating EZH2 via Sponging miR-217 in Gallbladder Cancer

Abstract Background: Gallbladder cancer (GBC) is the most common biliary tract malignancy and has a poor prognosis in patients with GBC. CircRNA TP63 (circTP63) has been implicated in some tumor proliferation and invasion in some tumors. The study aims to investigate the clinical significance and functional role of circTP63 in GBC.Methods: The expression of circTP63 in GBC was detected by qRT-PCR and the association between circTP63 expression and prognosis of GBC patients was analyzed. CCK8 assay, flow cytometry analysis, transwell assay and in vivo studies were used to evaluated the cell proliferation and invasion after circTP63 knockdown in GBC cells. Luciferase reporter assays and RNA pull-down assay were used to determine the correlation between circTP63 and miR-217. Besides, western blot analysis was also performed.Results: In the present study, we showed that circTP63 expression was upregulated in GBC tissues and cells. Higher circTP63 expression was associated with lymph node metastasis and short overall survival (OS) in patients with GBC. In vitro, knockdown of circTP63 inhibited cell proliferation, cell cycle progression, migration and invasion in GBC. Besides, we demonstrated that knockdown of circTP63 inhibited GBC cell EMT process. In vivo, knockdown of circTP63 inhibited tumor growth in GBC. Mechanistically, we demonstrated that circTP63 competitively bind to miR-217 and promoted EZH2 expression and finally facilitated tumor progression.Conclusions: Our findings demonstrated that circTP63 sponge miR-217 and regulated EZH2 expression and finally facilitates tumor progression. Thus, targeting circTP63 may be a therapeutic strategy for the treatment of GBC.