Linoleic acid drives pulmonary lymphoepithelioma-like carcinoma progression via PPAR-α/TF axis.

BACKGROUND: Primary pulmonary lymphoepithelioma-like carcinoma (pLELC) is a rare subtype of non-small cell lung cancer(NSCLC) with unclear etiological mechanisms. This study aimed to investigate the underlying molecular mechanisms and therapeutic targets for pLELC. METHODS: Retrospectively collected samples from advanced pLELC patients underwent proteomic and metabolomic analyses, and patient-derived xenograft (PDX) models were established for validation. Data-independent acquisition (DIA) quantitative proteomics revealed upregulated tissue factor (TF) protein expression in pLELC, while untargeted metabolomics identified key metabolites such as linoleic acid (LA). RESULTS: Results demonstrated that LA promotes tumor progression by facilitating M2-type tumor-associated macrophage infiltration and suppressing natural killer (NK) cell activity, effects reversible by the TF inhibitor Tisotumab. Mechanistic studies indicated that LA enhances TF expression via peroxisome proliferator-activated receptor α (PPAR-α), and TF inhibitors effectively counteract LA-induced malignant phenotypes. CONCLUSION: This study reveals that LA remodels the pLELC tumor microenvironment through the PPAR-α/TF axis, suggesting TF as a potential therapeutic target for pLELC.