RBPMS inhibits bladder cancer migration and invasion by downregulating the MYC pathway through alternative splicing of ANKRD10

RNA-binding proteins (RBPs) are pivotal mediators of the alternative splicing (AS) machinery of pre-mRNA, allowing the generation of diverse protein structures and functions from a single gene. Research has demonstrated that the AS process in bladder cancer (BLCA) is significantly dysregulated and plays a crucial role in the development, progression, aggressiveness, and therapeutic resistance of this disease. We conducted comprehensive screening and analysis of the TCGA-BLCA cohort, specifically focusing on genes with significant differences in expression levels between carcinoma and adjacent non-cancerous tissues. Among the 500 differentially expressed genes, 5 RNA-binding proteins were identified. Only the RNA-binding protein mRNA processing factor (RBPMS) demonstrated a consistent downregulation in BLCA and was correlated with an unfavorable prognosis for affected patients. Subsequent in vitro and in vivo experiments revealed that RBPMS exerted inhibitory effects on the epithelial-mesenchymal transition (EMT) pathway and the migratory potential of BLCA cells. RNA-Seq analysis identified ANKRD10 as a key target mRNA regulated by RBPMS in BLCA. RBPMS depletion in BLCA cells resulted in AS of ANKRD10 and increased ANKRD10-2 expression. ANKRD10-2 functioned as a transcriptional co-activator of MYC proteins, thereby augmenting their transcriptional activity. Furthermore, ANKRD10-2 knockdown significantly rescued the migration enhancement induced by RBPMS depletion in BLCA cells. Taken together, this study revealed a mechanism whereby RBPMS suppresses the migration and invasion of BLCA cells by attenuating MYC pathway activity via the AS of ANKRD10.