Dynamic O-GlcNAcylation coordinates etoposide-triggered tumor cell pyroptosis by regulating p53 stability

Area of Science:

• Biochemistry
• Cell Biology
• Immunology

Background:

• O-GlcNAcylation is a critical post-translational modification in cellular processes.
• Pyroptosis is programmed cell death linked to innate immunity.
• The relationship between O-GlcNAcylation and pyroptosis in cancer therapy is not well understood.

Purpose of the Study:

• To investigate the role of O-GlcNAcylation in chemotherapy-induced pyroptosis.
• To elucidate the mechanisms linking O-GlcNAcylation to pyroptosis.
• To explore therapeutic potential in pyroptosis-related diseases.

Main Methods:

• Studied etoposide-induced pyroptosis in SH-SY5Y and A549 cells.
• Utilized pharmacological inhibition and genetic manipulation of O-GlcNAcylation (OGT inhibition, OGA overexpression).
• Analyzed p53 O-GlcNAcylation, p53-MDM2 interaction, p53 ubiquitination, and protein stability.
• Assessed transcriptional upregulation of p53 target genes (Fas, DR-5, Puma, PIDD).
• Examined the caspase-3-GSDME axis activation.

Main Results:

• O-GlcNAcylation levels were significantly reduced during etoposide-induced pyroptosis.
• Inhibition of O-GlcNAcylation sensitized cells to etoposide-induced pyroptosis in vitro and in vivo.
• Mutations at p53 S96 and S149 residues impaired O-GlcNAcylation, weakened p53-MDM2 interaction, reduced p53 ubiquitination, and increased p53 stability.
• p53 target genes were upregulated, activating the caspase-3-GSDME pathway and promoting pyroptosis.

Conclusions:

• O-GlcNAcylation is downregulated during chemotherapy-induced pyroptosis.
• Reduced O-GlcNAcylation enhances etoposide-induced pyroptosis by modulating p53.
• This study uncovers a novel link between O-GlcNAcylation and pyroptosis, suggesting therapeutic strategies for cancer treatment.