• • PKM2 knockout reduced GATA3 levels, leading to decreased PD-L1 and increased PD-L2 expression in human cancer cells, revealing a dual regulatory mechanism that could be exploited to modulate immune checkpoint balance and improve immunotherapy response rates.
• • In a xenograft model using immune-competent C57/BL6N mice, PKM2 knockdown resulted in significant downregulation of both PD-L1 and PD-L2 expression, indicating species-specific differences in PKM2-mediated checkpoint regulation that must be considered in preclinical drug development.
• • ChIP-qPCR demonstrated that GATA3 directly binds to the promoters of PD-L1 and PD-L2, establishing a direct transcriptional mechanism; this provides a concrete target for small-molecule inhibitors aimed at disrupting the PKM2-GATA3 interaction.
• • In silico analysis of 81 esophageal squamous cell carcinoma (ESCC) cases from TCGA showed that PKM2 mRNA is unrelated to PD-L1 and PD-L2 expression but is negatively correlated with CD8+ T-cell infiltration (p < 0.01), suggesting that PKM2-mediated immune evasion in humans may operate through alternative pathways, necessitating combination strategies.