Esculetin Induces Apoptosis Through EGFR/PI3K/Akt Signaling Pathway and Nucleophosmin Relocalization

Area of Science:

• Biochemistry
• Molecular Biology
• Oncology

Background:

• Oral squamous cell carcinoma (OSCC) is a prevalent cancer with limited treatment options.
• Esculetin, a natural coumarin compound, exhibits anti-proliferative properties against various cancer types.
• The anti-cancer effects of esculetin on OSCC remain largely unexplored.

Purpose of the Study:

• To investigate the anti-proliferative effects of esculetin on OSCC cell lines.
• To elucidate the molecular mechanisms underlying esculetin's action in OSCC.
• To assess the potential of esculetin as a therapeutic agent for OSCC.

Main Methods:

• Cell viability assays were performed on HN22 and HSC2 OSCC cell lines.
• Apoptosis was assessed through morphological changes, nuclear fragmentation, and caspase/MMP activity.
• Proteomic analysis identified key proteins affected by esculetin treatment.
• Western blotting and immunofluorescence were used to analyze signaling pathways and protein expression/localization.

Main Results:

• Esculetin significantly inhibited OSCC cell viability by inducing apoptosis.
• Proteomic analysis revealed that esculetin treatment inhibited the EGFR/PI3K/Akt signaling pathway.
• Esculetin treatment led to decreased nucleophosmin (NPM) expression and its relocalization from the nucleus to the cytoplasm.
• NPM expression was found to be significantly higher in OSCC tissues compared to normal tissues.

Conclusions:

• Esculetin demonstrates potent anti-proliferative effects on OSCC cells, primarily through the induction of apoptosis.
• The anti-cancer activity of esculetin is mediated by the inhibition of the EGFR signaling pathway and the down-regulation/mislocalization of NPM.
• Targeting NPM and the EGFR pathway represents a promising therapeutic strategy for OSCC, with esculetin as a potential agent.