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. Overall design: To investigate the downstream mechanisms by which RBPMS and ANKRD10 transcripts regulate bladder cancer, we performed three RNA sequencing. The first time, we performed RNA sequencing on three sets of duplicates of RBPMS-WT and RBPMS-KO in 5637 cells. The second time, we performed RNA sequencing on three sets of duplicated Vector, ANKRD10-1 overexpressing and ANKRD-2 overexpressing 5637 cells. For the second time, we performed RNA sequencing on three sets of replicates of siNC, siANKRD10-1 and siANKRD-2 in 5637 cells.