CircRPPH1 accelerates the proliferation and migration of bladder cancer via enhancing the STAT3 signaling pathway

Bladder cancer (BCa) is a common malignant disease with high recurrence and variable prognosis. Circular RNAs (circRNAs) are implicated in the development of multiple diseases. However, the biological activities of circRNAs in BCa remain largely elusive. In the present study, it was found that circRPPH1 was upregulated in BCa cell lines compared with normal urothelial cells. CircRPPH1 downregulation could inhibit the proliferation, migration and invasion of BCa cells in vitro and in vivo. Mechanistically, it was demonstrated that circRPPH1 can act as a sponge of miR-296-5P to upregulate STAT3, and interact with FUS to promote phosphorylated (p)-STAT3 nuclear transport. Overall, circRPPH1 could promote BCa progression through sponging miR-296-5p to upregulate the expression of STAT3 and interacting with FUS to promote p-STAT3 nuclear transport. CircRPPH1 was first identified to play a tumorigenic role in BCa, which could be an underlying therapeutic target.