Multiomics identifies a cholesterol–TFEB–PLD3–TLR9 axis driving immunosuppressive tumor-associated macrophage polarization in esophageal squamous cell carcinoma
Menée à l'aide de modèles murins de carcinome épidermoïde de l'oesophage, d'échantillons tumoraux ou d'échantillons tissulaires normaux prélevés sur des patients atteints d'un carcinome épidermoïde de l'oesophage et de données multiomiques du programme "The Cancer Genome Atlas", cette étude identifie une population de macrophages protumoraux exprimant fortement la phospholipase D3 (PLD3) et met en évidence un mécanisme par lequel le cholestérol, sécrété par les cellules cancéreuses et absorbé par les macrophages TAM, maintient un microenvironnement tumoral immunosuppresseur en déclenchant la translocation nucléaire de TFEB, un facteur impliqué dans la transcription de PLD3
This study reveals how ESCC cells manipulate TAMs to promote tumor progression. We found that tumor-secreted cholesterol triggers a molecular network in macrophages (TFEB-PLD3-TLR9 axis), suppressing their ability to activate antitumor T cells. Using multiomics and preclinical models, we showed that targeting this pathway with a dual-action therapy (TLR9 agonist + PLD3-targeted siRNA) restores immune function and shrinks tumors. These findings identify PLD3-high macrophages as both a biomarker for poor prognosis and a therapeutic target, offering a promising strategy to enhance immunotherapy for ESCC. The work bridges cancer metabolism and immunology, providing translational insights for overcoming immunosuppression in solid tumors. Tumor-associated macrophages (TAMs) reshape the tumor immune microenvironment and promote tumor progression, yet the underlying mechanisms remain largely unclear. Through integration of single-cell RNA (scRNA) sequencing datasets from esophageal squamous cell carcinoma (ESCC), we identified a distinct protumoral macrophage population with elevated expression of phospholipase D3 (PLD3). Multiomics investigations revealed that high infiltration of these PLD3-high macrophages was associated with poor clinical outcomes in ESCC patients. Mechanistically, tumor cells secreted cholesterol to modulate the microenvironment. Upon the uptake by TAMs, cholesterol triggered the nuclear translocation of transcription factor EB (TFEB), which directly bound to the PLD3 promoter region and activated its transcription. The overexpressed PLD3 localized to lysosomes, enzymatically degrading single-stranded nucleic acids, thereby suppressing the activation of the toll-like receptor 9 (TLR9) pathway. This cascade ultimately impaired effector T cell function and sustained an immunosuppressive tumor microenvironment (TME). Notably, therapeutic intervention using ODN2216-siPLD3 in murine models enhanced CD8 T cell infiltration and significantly inhibited tumor growth. Our findings highlight PLD3-high macrophages as a promising diagnostic biomarker and a therapeutic target for ESCC, paving the way for potential clinical translation.
Proceedings of the National Academy of Sciences , résumé, 2026