Xiaozheng Decoction Inhibits Bladder Cancer Progression by Regulating the miR-21/SMAD7 Signaling Axis

Background Bladder cancer (BCa) is the most common malignant tumor of the urinary system, and there remains an urgent need for more effective therapeutic strategies. Xiaozheng Decoction has been reported to prevent postoperative recurrence of BCa; however, its specific pharmacological effects and molecular mechanisms remain inadequately defined. Objective This study aimed to investigate the inhibitory effects of Xiaozheng Decoction on BCa progression and elucidate its underlying molecular targets. Methods CCK-8, colony formation, as well as FCM assays showed the effects on bladder cancer cell growth. Transwell assays showed the effects on cell motility. qPCR as well as Immunoblot assays showed the effects on miR-21/ SMAD7 axis. Luciferase activity assay, quantification PCR, and Immunoblot assays showed the effects on the interact between miR-21 and SMAD7. Tumor growth assays were performed in mice. Results The results demonstrated that Xiaozheng Decoction suppressed the growth and induced apoptosis of BCa cells, and also significantly reduced their cell migration. Mechanistically, Xiaozheng Decoction could downregulate the expression of miR-21 and its downstream target SMAD7. Further analysis confirmed that miR-21 directly binds to and suppresses SMAD7 expression. In vivo experiments showed that Xiaozheng Decoction also inhibited tumor growth in a xenograft model of BCa. Conculsion Taken together, these findings indicate that Xiaozheng Decoction exerts anti-tumor effects in BCa by modulating the miR-21/SMAD7 signaling axis, thereby suppressing both proliferation and migration of BCa cells.