Centrosome-related gene SPHK1 drives bladder cancer progression and therapeutic vulnerability.

BACKGROUND: Centrosome-related genes (CRGs) regulate cell division and genomic stability and may influence tumor progression, but their prognostic and functional roles in bladder cancer (BLCA) are not fully defined. METHODS: We curated 698 CRGs and identified 12 prognostic genes to construct a centrosome-related signature score (CRSS). The prognostic value of CRSS was evaluated in TCGA and GSE13507 cohorts. Functional enrichment, immune landscape, and drug sensitivity were analyzed through pathway analysis, ESTIMATE, and IC50 prediction. Machine learning and Mendelian randomization were used to identify the most promising CRGs. Furthermore, we performed single-cell RNA sequencing analysis to uncover the expression patterns of candidate CRGs. Expression and functional validation were performed using RT-qPCR, CCK-8, wound-healing assays, and immunohistochemistry. RESULTS: CRSS stratified patients into high- and low-risk groups with significant differences in overall survival. High-risk patients exhibited upregulated Aerobic glycolysis (AC), oxidative phosphorylation (OxPhos) and partial epithelial-mesenchymal transition (pEMT) pathways, higher immune/stromal scores, and distinct immune infiltration, including increased M0/M2 macrophages and decreased CD8⁺ T and follicular helper T cells. High-risk tumors showed altered sensitivity to multiple drugs, including AZD8186 and Staurosporine. Integrative analyses identified SPHK1 as a key candidate CRG. SPHK1 expression was associated with tumor grade, stage, poor survival, and the wound-healing molecular subtype. Functional assays showed that SPHK1 knockdown inhibited bladder cancer cell proliferation and migration. Immunohistochemistry further confirmed higher SPHK1 expression in tumors with more aggressive clinicopathological features. CONCLUSIONS: We established a CRG-based model for BLCA and identified SPHK1 as a key gene associated with tumor progression and clinical outcomes.