Epstein-Barr Virus Silences GSDME and Pyroptosis in Gastric Cancer

Area of Science:

• Oncology
• Molecular Biology
• Epigenetics

Background:

• Epstein-Barr virus (EBV)-associated gastric carcinoma (EBVaGC) is a distinct subtype with unique molecular features.
• Gasdermin E (GSDME) is a key mediator of pyroptosis, a programmed cell death pathway.

Purpose of the Study:

• To investigate the regulation and function of GSDME in EBVaGC.
• To understand the role of EBV-induced epigenetic modifications in GSDME expression and cell death signaling.

Main Methods:

• Analysis of The Cancer Genome Atlas (TCGA) data for GSDME expression.
• Cell line experiments involving EBV infection, DNA methylation analysis, and treatment with 5-azacytidine and paclitaxel (PTX).
• Assessment of caspase-3 activation, GSDME cleavage, lactate dehydrogenase (LDH) release, and pyroptotic morphology.

Main Results:

• EBV infection selectively suppressed GSDME expression in gastric cancer through promoter hypermethylation.
• EBV-positive cells showed enhanced caspase-3 activation and GSDME cleavage upon PTX treatment, leading to pyroptosis.
• GSDME overexpression amplified PTX-induced pyroptosis, while knockdown or caspase-3 inhibition suppressed it.

Conclusions:

• EBV epigenetically silences GSDME in gastric cancer, modulating chemotherapy-induced cell death.
• GSDME acts as a critical effector converting apoptosis to pyroptosis via caspase-3 activation.
• Restoring GSDME expression is a potential therapeutic strategy for EBVaGC.