Tumor Stemness Score to Estimate Epithelial-to-Mesenchymal Transition (EMT) and Cancer Stem Cells (CSCs) Characterization and to Predict the Prognosis and Immunotherapy Response in Bladder Urothelial Carcinoma

Background: The relationships between cancer stem cells (CSCs), epithelial-to-mesenchymal transition (EMT), and the tumor microenvironment (TME) in bladder urothelial carcinoma (BLCA) remain unclear. Methods: We first constructed tumor stemness (TS) score using principal component analysis to quantify tumor stemness in BLCA. Then, we evaluated the clinical value of the TS score for predicting the response to tumor immunotherapy using immunotherapy cohorts. Finally, we built an EMT cell model by treating T24 cells with TGF-β and validated the relationship between the TS score and the EMT process in tumors by real-time quantitative PCR, cell invasion assays, and RNA-seq. Results: A TS scoring system was established with 61 TS-related genes to quantify the TS. The prognostic value of the TS score was then confirmed in multiple independent cohorts. A high TS score was associated with high EMT activity, CSC characteristics, high stromal cell content, high TP53 mutation rate, poor prognosis, and high tumor immunotherapy tolerance. Conclusion: The TS score provides an index for EMT and CSC research and helps clinicians develop treatment plans and predict outcomes for patients. Comparative gene expression profiling analysis of RNA-seq data for T24 cells with or without TGF-β treatment for 48h