Proteomic Profiling of Non-Muscle Invasive Bladder Cancer Reveals Potential Biomarkers for Recurrence and Progression Risk

Nonmuscle invasive bladder cancer (NMIBC) represents a significant clinical challenge due to its high recurrence and progression rates. We aimed to characterize proteomic differences between matched pairs of tumor and control bladder tissues in NMIBC to identify potential biomarkers and underlying molecular mechanisms. <b>Methods</b>: Data-independent analysis proteomics experiments were conducted in paired samples from 45 patients with NMIBC, comprising 45 tumor and 45 control tissues. Tumor and nontumor results were compared using a paired Student's <i>t</i> test. Proteins detected in at least 50% of the samples were used. <b>Results</b>: A total of 188 differentially abundant detected proteins were identified, along with 11 proteins exclusively detected in tumor tissues, including SPINT1, TXNDC12, GTF2F1, COPZ1, RS25, PTK2, LSR, SNRNP40, NCOA5, SEC63, and CD2AP. The protein interaction network analysis among this set of proteins revealed AGR2, FLNA, TPM1, and CALD1. Additionally, CNDP2 and CTSD expression were inversely correlated with tumor recurrence and progression risk respectively, while EPS8L2 and KRT7 levels were associated with tumor staging. <b>Conclusions</b>: Our study identified specific proteins as potential NMIBC biomarkers and drug targets. The identified proteins, particularly those linked to tumor recurrence and staging, warrant further validation to assess their clinical utility in NMIBC diagnosis, prognosis, and treatment strategies.