Elbasvir triggers ferroptosis in esophageal squamous cell carcinoma through NCOA4-mediated ferritinophagy

Area of Science:

• Oncology
• Molecular Biology
• Drug Repurposing

Background:

• Esophageal squamous cell carcinoma (ESCC) presents significant treatment resistance.
• Ferroptosis, a regulated cell death pathway, is implicated in cancer therapy.
• NS5A inhibitors are primarily known for antiviral activity.

Purpose of the Study:

• To investigate Elbasvir, an NS5A inhibitor, as a potential ferroptosis inducer for ESCC treatment.
• To elucidate the molecular mechanism of Elbasvir-induced ferroptosis.
• To evaluate the in vivo efficacy and safety of Elbasvir in ESCC models.

Main Methods:

• Cell viability assays (CCK-8), flow cytometry for apoptosis and cell cycle analysis.
• Western blotting for key protein markers, mass spectrometry for proteomics.
• In vivo xenograft studies in BALB/c nude mice, transmission electron microscopy (TEM).
• Ferroptosis assays (JC-1, FerroOrange, DCFH-DA, MDA), SPR, and DARTS for target binding.

Main Results:

• Elbasvir (40 µM, 48h) reduced ESCC cell viability and inhibited xenograft growth with no observed toxicity.
• Elbasvir induced apoptosis and G0/G1 cell cycle arrest.
• Proteomics identified ferroptosis as the primary affected pathway; Elbasvir triggered NCOA4-mediated ferritinophagy, FTH1 degradation, iron accumulation, and lipid peroxidation.
• Surface plasmon resonance (SPR) and drug affinity responsive target stability (DARTS) assays confirmed Elbasvir binds to NCOA4.

Conclusions:

• Elbasvir effectively induces ferroptosis in ESCC by targeting the NCOA4-FTH1 complex, leading to ferritinophagy and cell death.
• Elbasvir represents a promising repurposed therapeutic strategy for treatment-resistant ESCC.
• The favorable safety profile suggests potential for clinical translation in iron metabolism-dependent cancers.