Negative Correlation Between Circular RNA SMARC5 and MicroRNA 432, and Their Clinical Implications in Bladder Cancer Patients

Objective: Our study aimed to evaluate the correlation of circular RNA SMARCA5 (circ-SMARCA5) and microRNA 432 (miR-432) with clinical characteristics and survival in bladder cancer patients. Methods: Preoperative clinicopathologic features and survival data of 156 bladder cancer patients were retrospectively reviewed. A total of 156 cases of tumor tissues, whereas 71 cases out of 156 available adjacent tissues were obtained from the Pathology Department for circ-SMARCA5 and miR-432 detections using real-time quantitative polymerase chain reaction. Results: Circ-SMARCA5 was upregulated but miR-432 was downregulated in tumor tissues compared with adjacent tissues; meanwhile, circ-SMARCA5 expression was negatively correlated with miR-432 in bladder cancer tissues. Circ-SMARCA5 high expression was correlated with larger tumor size, higher tumor stage, and lymph node (LYN) metastasis. However, miR-432 high expression was correlated with single multiplicity, smaller tumor size, lower tumor stage, less LYN metastasis in bladder cancer patients. Regarding survival, circ-SMARCA5 high expression was correlated with shorter disease-free survival (DFS) and overall survival (OS); whereas, miR-432 high expression was correlated with longer DFS and OS in bladder cancer patients. Further multivariate Cox's regression analysis displayed that circ-SMARCA5 high expression was an independent predictive factor for both worse DFS and OS in bladder cancer patients. Conclusion: Circ-SMARCA5 high expression but miR-432 low expression is correlated with advanced tumor features and poor survival of bladder cancer patients, which present as potential prognostic markers in bladder cancer.