Work

Identification of internalizing ScFvs for EGFR inhibition and apoptosis induction in cholangiocarcinoma cells

Year: 2025

Type: article

Abstract: Cholangiocarcinoma (CCA) is an aggressive malignancy with limited treatment options. EGFR overexpression is associated with tumor recurrence and poor prognosis, yet current EGFR-targeted therapies show limited efficacy. To identify alternative therapeutic candidates, we performed subtractive bio-panning of a naïve human single-chain variable fragment (scFv) phage display library against CCA cell lysates. Three novel scFv antibodies-E1, G8, and H2-were selected based on preferential binding to CCA cells with minimal cross-reactivity to unrelated cancers and normal fibroblasts. Surface plasmon resonance and kinase inhibition assays demonstrated that G8 and H2 bound the EGFR tyrosine kinase (EGFR-TK) domain with nanomolar affinities and suppressed kinase activity, whereas E1 showed weak binding and no kinase inhibition. All three scFvs exhibited efficient internalization into EGFR-overexpressing HuCCA-1 cells. Functional analyses revealed distinct effects on cell growth: G8 and H2 reduced EGFR phosphorylation, decreased cell viability, and induced apoptosis accompanied by S/G₂-M phase accumulation, whereas E1 primarily inhibited proliferation through G₁-phase arrest without significantly affecting EGFR phosphorylation. Molecular docking predicted that G8 interacts near the ATP-binding pocket and H2 at the dimerization interface of EGFR-TK. These interactions may contribute to EGFR inhibition in HuCCA-1 cells. These findings suggest that G8 and H2 function as intracellular inhibitors of EGFR-TK activity and are promising candidates for antibody-based therapy in EGFR-driven CCA.

Source: Scientific Reports

DOI: 10.1038/s41598-025-24324-w