Discovery of potential TMPRSS2 inhibitors using integrated computational and experimental screening

In prostate cancer (PCa), the TMPRSS2-ERG fusion gene drives aberrant activation of androgen receptor (AR) signaling, while TMPRSS2 protease activity contributes to remodeling the tumor microenvironment. Targeting TMPRSS2 can suppress cancer metastasis and represents a potential therapeutic strategy for castration-resistant prostate cancer (CRPC). This study aimed to screen and identify promising TMPRSS2-binding lead candidates via integrated virtual screening and experimental validation. Screening of the ChemDiv, ChemBridge, and TargetMol compound libraries yielded 53 hit compounds. Surface plasmon resonance (SPR) assays were subsequently performed to evaluate binding affinities. Six candidate compounds (15, 26, 29, 31, 41, and 42) exhibited higher affinity for TMPRSS2 compared to the reference inhibitor Nafamostat (K_D = 6.09 × 10^-5 M). Among them, compound 26 showed the highest affinity (K_D = 3.88 × 10^-6 M). Subsequent in vitro inhibition assays using LNCaP clone FGC cells demonstrated that compound 26 possessed the strongest anti-proliferative activity (IC₅₀ = 10.95 μM), indicating its therapeutic potential against PCa. Confocal microscopy showed apparent reduced TMPRSS2 staining after 24 h compound 26 treatment, implying potential TMPRSS2 modulation. Further mechanistic insights were gained through molecular dynamics (MD) simulations, alanine scanning mutagenesis, quantum mechanics/molecular mechanics (QM/MM) calculations, and dynamical cross-correlation matrix (DCCM) analysis, which revealed specific ligand-protein interactions in the compound 26-TMPRSS2 complex and reinforced the reliability of our findings. Collectively, these results identify compound 26 as a promising TMPRSS2-binding lead candidate, providing a solid foundation for further biochemical verification and structural optimization.