GLUT1 maintains esophageal cancer stem cell-like characteristics by inhibiting autophagy-dependent ferroptosis via EGFR

Abstract

Esophageal cancer, a highly malignant tumor with poor prognosis, is characterized by the presence of cancer stem cells (CSCs) that drive tumor initiation, metastasis, and recurrence. This study investigates the molecular mechanism by which glucose transporter 1 (GLUT1) maintains esophageal CSC-like properties through regulation of autophagy-dependent ferroptosis via epidermal growth factor receptor (EGFR). Using shRNA to knock down GLUT1 or EGFR and constructing a GLUT1 overexpression vector in KYSE520 cells, we employed western blotting, qRT-PCR, flow cytometry, sphere formation, Transwell assays, and xenograft models to assess stemness markers (NANOG, OCT4, SOX2), autophagic flux (LC3B, P62, Beclin1), and ferroptosis-related parameters (ROS, Fe²⁺, GSH, GPX4, COX2). Mechanistic analyses included co-immunoprecipitation to validate the GLUT1-EGFR interaction, chloroquine to inhibit autophagy, and cycloheximide/MG132 to evaluate EGFR protein stability. Results showed that GLUT1 depletion reduced CSC marker expression, increased ROS and Fe²⁺ levels, depleted GSH, and induced lipid peroxidation, sensitizing cells to ferroptosis while activating autophagy (elevated LC3 II/I, Beclin1; reduced P62); autophagy inhibition exacerbated cell death, indicating a protective role for autophagy in this context. GLUT1 directly bound to EGFR, stabilizing the receptor by blocking ubiquitin-proteasome-mediated degradation, whereas EGFR knockdown enhanced autophagic flux and reversed GLUT1-overexpression-induced ferroptosis resistance and stemness maintenance. In vivo, GLUT1 knockdown suppressed tumor growth and lung metastasis, and clinical samples revealed a positive correlation between GLUT1 and EGFR expression, linked to advanced TNM stages and poor survival. Collectively, these findings demonstrate that GLUT1 preserves esophageal CSC-like characteristics by stabilizing EGFR to inhibit autophagy-dependent ferroptosis, highlighting targeting GLUT1 as a potential therapeutic strategy to eliminate CSCs and combat esophageal cancer progression.