MicroRNAs in bladder cancer: biogenesis, function, and therapeutic strategies.

MicroRNAs (miRNAs), a class of small noncoding RNA molecules, play a pivotal regulatory role in bladder cancer initiation, progression, and metastasis through precise modulation of gene expression. This review systematically elucidates miRNA biogenesis pathways (canonical and non-canonical), dynamic regulatory mechanisms, and their multidimensional functional networks in bladder cancer. In bladder carcinogenesis, specific miRNAs significantly inhibit tumor cell proliferation and metastasis by targeting key genes such as p21, TAGLN2, and PROM2. Furthermore, miRNAs mediate immune evasion mechanisms by remodeling the tumor immune microenvironment through regulation of T-cell differentiation and myeloid-derived suppressor cell functions. Emerging miRNA-based therapeutic strategies, including replacement therapy and antisense oligonucleotide technology, demonstrate clinical potential in enhancing chemosensitivity and suppressing tumor progression. However, critical challenges persist in understanding the molecular interaction networks underlying miRNA dynamics, spatiotemporal heterogeneity of non-canonical pathways, and clinical translation mechanisms. Future investigations should integrate multi-omics data with systems biology approaches to decipher core molecular targets within miRNA regulatory networks, thereby advancing the optimization of precision diagnosis and treatment systems for bladder cancer.