Radiotherapy (RT) is the most common nonsurgical treatment for head and neck squamous cell carcinoma (HNSCC), while HNSCC was insensitive to RT, which is the primary cause of treatment failure. Thus, exploring the novel molecular mechanisms of HNSCC progression may help to increase tumor radiosensitivity. Previous studies have revealed the induction of apoptosis in anti-tumor treatment with oleuropein; while the effect of oleuropein on pyroptosis is unclear. This study explored the effect of oleuropein on HNSCC and the underlying mechanisms in HNSCC cells and HNSCC mice. HNSCC cells were exposed to central irradiation at 5 Gy with 6MV-X-ray to mimic cell RT, and HNSCC mice received a dose of 12 Gy on days 7 and 14 to mimic the in vivo RT. Cell proliferation and apoptosis were assessed via cell counting Kit-8 assay and flow cytometry; RNA expression and protein levels were detected via quantitative real time-polymerase chain reaction (PCR) and western blotting; gasdermin E (GSDME) promoter methylation level was assessed by Methylation-specific PCR and MassARRAY assay; tumor growth and death were assessed via Ki67 immunohistochemical staining and terminal deoxynucleotidyl Transferase Mediated Nick End Labeling staining; pathological changes in tumor tissues was assessed via hematoxylin-eosin staining. The results showed that oleuropein inhibited cell proliferation and enhanced radiosensitivity by inducing caspase3/GSDME-N-dependent pyroptosis in HNSCC cells. Additionally, oleuropein up-regulated miR-194-5p expression and miR-194-5p inhibitor reversed the suppression of cell proliferation induced by oleuropein. Mechanistically, miR-194-5p targeted DNMT3A to affect GSDME promoter methylation, thereby regulating GSDME expression to affect pyroptosis. In vivo experiments further demonstrated that oleuropein blocked tumor growth and enhanced radiosensitivity in HNSCC. In conclusion, these results provide an experimental basis for the application of oleuropein in HNSCC treatment.
Keywords: GSDME-N; Head and neck squamous cell carcinoma; MiR-194-5p; Oleuropein; Pyroptosis.
© 2026. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.