CircPVT1 promotes progression in clear cell renal cell carcinoma by sponging miR‐145‐5p and regulating TBX15 expression

Emerging evidence revealed that circular RNAs (circRNAs) play significant roles in regulating tumorigenesis and cancer progression. However, few circRNAs were well characterized in clear cell renal cell carcinoma (ccRCC). We found that circPVT1 was significantly upregulated in ccRCC tissues and positively associated with the clinical stage. The Area Under Curve of tissue and serum circPVT1 expression in ccRCC were 0.93 and 0.86, respectively. Importantly, we demonstrated that circPVT1 promoted ccRCC growth and metastasis in vitro and in vivo. We also found that circPVT1 directly binds to miRNA‐145‐5p via the Biotin‐labelled miRNA pulldown assay and dual‐luciferase reporter assay, and miR‐145‐5p inhibitor significantly attenuated the effect of circPVT1 knockdown on ccRCC cells. Moreover, through RNA sequencing and bioinformatics analysis, we demonstrated that TBX15 was regulated by the circPVT1/miR‐145‐5p axis and predicted poor prognosis in ccRCC. These findings suggest that circPVT1 promotes ccRCC growth and metastasis through sponging miR‐145‐5p and regulating downstream target TBX15 expression. The circPVT1/miR‐145‐5p/TBX15 axis might be a potential diagnostic marker and therapeutic target in ccRCC.