Pan-inhibition of the GPC3/Wnt/Fzd7, LRP6, and ROR2 Signaling Axis via KOH-Mediated Selective Ionic Denaturation in Lung Squamous Cell Carcinoma (LUSC)

Objective: This study aims to investigate, at an in silico level, the potential for "upstream" sabotage of the GPC/Wnt/Frizzled signaling axis—a pathway of critical importance in lung squamous cell carcinoma (LUSC)—via potassium hydroxide (KOH)-mediated ionic denaturation. Material and Methods: In this study, the interactions between the extracellular domains (ECDs) of seven critical protein targets within the LUSC signaling axis (GPC3, GPC5, Wnt3a, Wnt5a, Fzd7, LRP6, and ROR2) and KOH along with its ionic components (K ⁺ , OH ^- ) were analyzed using systematic molecular docking simulations and Ligand Efficiency (LE) metrics. Despite their structural similarities, the pro-tumoral GPC3 and anti-tumoral GPC5 proteins—which possess opposing biological roles—were specifically examined in terms of the ionic agent's target selectivity and conformational interaction geometry. The affinity of ions for strategic disulfide bridges was subjected to a comprehensive evaluation based on thermodynamic stability parameters. Results: Molecular docking analyses revealed that KOH and its ionic components (K ⁺ , OH ^- ) establish thermodynamically spontaneous (exergonic) interactions with all target ligand and receptor complexes within the GPC/Wnt/Fzd axis. Exergonic binding profiles were observed across all seven disulfide bonds in both the GPC3 and GPC5 proteins. Notably, in the pro-tumoral GPC3 protein, the K ⁺ ion approached the Cys262 residue at a precise, topologically perpendicular angle (91.12°). This geometric orientation was identified as a critical mechanism triggering the selective denaturation of the strategic disulfide bridge, interacting with a Ligand Efficiency (LE) of -0.739 an exceptionally high value for a single ionic component. In contrast, the anti-tumoral GPC5 model exhibited significantly increased angular deviations, indicating structural resistance to the ionic disruption. The negative binding energies and high LE values detected across all complexes confirm that KOH exhibits substantial structural sabotage capacity on target disulfide bridges, despite its low molecular weight. Conclusion: These findings indicate that KOH possesses the potential to act as a molecular agent with high target specificity, capable of structurally modulating the signal transduction pathway. This study provides a theoretical biochemical framework for the development of low-cost, high-efficiency "Ionic Therapy" protocols in the treatment of LUSC.