Exploring the Role of MicroRNAs in Bladder Cancer Prognosis and Treatment Response

Abstract

Background: Bladder cancer is a common urological malignancy associated with recurrence, progression, and repeated invasive surveillance. MicroRNAs have emerged as potential molecular biomarkers because they regulate tumor growth, invasion, and treatment-related pathways. Objective: To compare selected microRNA expression between bladder cancer patients and controls and to examine their association with clinicopathological aggressiveness, treatment response, and diagnostic discrimination. Methods: This hospital-based analytical molecular genetics study included 120 participants, comprising 90 histologically confirmed bladder cancer patients and 30 controls. Selected microRNAs, including miR-21, miR-155, miR-145, miR-99a, and miR-125b, were analyzed using quantitative real-time polymerase chain reaction, and relative expression was calculated using the 2^−ΔΔCT method. Expression patterns were compared between groups and examined according to tumor grade, disease stage, and treatment-response records. Results: miR-21 and miR-155 were increased in bladder cancer patients, while miR-145, miR-99a, and miR-125b were reduced. miR-21 showed the strongest increase in cancer patients compared with controls, while miR-145 showed the most marked reduction. Higher miR-21 and miR-155 and lower miR-145 were associated with high-grade tumors, muscle-invasive disease, and poor response or recurrence. miR-21 showed the highest individual diagnostic performance, while the combined miR-21 and miR-145 panel showed the best discrimination. Conclusion: Selected microRNAs showed clinically relevant expression differences in bladder cancer and may support exploratory diagnosis and risk stratification. Larger prospective validation studies are required before clinical application