Gut. 2026 Sep 7:gutjnl-2025-337414. doi: 10.1136/gutjnl-2025-337414. Online ahead of print.

ABSTRACT

BACKGROUND: Neutrophils are increasingly recognised as immunosuppressive drivers of hepatocellular carcinoma (HCC), yet their persistence in the oxidative, lipid-rich tumour microenvironment remains poorly understood.

OBJECTIVE: To elucidate the metabolic and molecular programmes that enable tumour-associated neutrophils (TANs) to resist ferroptosis and sustain immunosuppression in HCC.

DESIGN: We employed human HCC samples, multiple murine HCC models, transcriptomic and lipidomic profiling, genetic loss-of-function systems and therapeutic interventions. Ferroptosis sensitivity, lipid metabolic rewiring and immunological consequences of TANs were systematically evaluated across models and validated in patient datasets and biospecimens.

RESULTS: TANs in human HCC and mouse models exhibit pronounced lipid accumulation and oxidative stress compared with peripheral neutrophils. Multi-omic profiling revealed that TANs are enriched for lipid-binding gene programmes and undergo rewiring towards sphingolipid and unsaturated fatty acid metabolism. We identified triggering receptor expressed on myeloid cells 2 (TREM2) as a key lipid-sensing receptor selectively expressed in TANs. Functional deletion of TREM2 reprogrammed the tumour immune microenvironment, restoring CD8⁺ T cell activity and suppressing HCC progression. Mechanistically, tumour-derived sphingosine-1-phosphate (S1P) activates TREM2, triggering nuclear factor erythroid 2-related factor 2 (NRF2)-mediated transcription of glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11), thereby promoting ferroptosis resistance. TREM2 expression is transcriptionally induced by granulocyte-macrophage colony-stimulating factor-signal transducer and activator of transcription 3 (GM-CSF-STAT3) signalling. Genetic deletion of TREM2, clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9)-mediated knockout of sphingosine kinase 1/2 (SPHK1/2) in tumour cells, or pharmacological inhibition of S1P synthesis disrupts this protective lipid-immune circuit, sensitises TANs to ferroptosis and restricts tumour growth. Therapeutically, a peptide-based TREM2 inhibitor reprogrammes TANs, restores CD8⁺ T cell function and enhances anti-programmed cell death protein 1 (PD-1) immunotherapy efficacy. Clinically, TREM2⁺ polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) are enriched in HCC tumours, correlate with SPHK1/2 expression and T cell dysfunction and associate with poor patient prognosis.

CONCLUSION: Our study uncovers the S1P-TREM2-NRF2 axis as a critical metabolic-immune circuit that preserves neutrophil survival and immunosuppressive function in HCC. Targeting this lipid-dependent ferroptosis resistance pathway offers a promising therapeutic strategy to overcome immunotherapy resistance in liver cancer.

PMID:42705697 | DOI:10.1136/gutjnl-2025-337414

Phytomedicine. 2026 Aug 26;161:158760. doi: 10.1016/j.phymed.2026.158760. Online ahead of print.

ABSTRACT

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) harbors TP53 mutations at high frequency, yet therapeutic strategies that specifically target mutant p53 remain limited.

PURPOSE: This study aimed to identify S100A6, a calcium-binding protein frequently upregulated in TP53-mutant PDAC, as a critical regulator of mutant p53 stability and tumor progression, and to explore potential S100A6-targeting agents for therapeutic intervention.

METHODS: We integrated computer-assisted drug screening with transcriptomics, acetylation omics, and molecular biology techniques to identify Agrimol B (AgrB), a bioactive compound derived from the traditional Chinese herb Agrimonia pilosa Ledeb., as a potential S100A6-targeting agent.

RESULTS: High S100A6 expression was closely associated with poor prognosis in patients with TP53-mutant PDAC, whereas S100A6 depletion markedly suppressed PDAC cell growth and metastatic potential. Mechanistically, AgrB enhanced the interaction between S100A6 and the deacetylase HDAC2, leading to reduced acetylation of mutant p53 at lysine 382. This disruption activated autophagy-dependent cell death and thereby inhibited PDAC progression.

CONCLUSION: Our findings reveal an S100A6-HDAC2-mutant p53 acetylation axis that regulates TP53-mutant pancreatic tumorigenesis, providing mechanistic evidence supporting S100A6 as a therapeutic vulnerability and highlighting AgrB as a promising natural-product-derived candidate for further development against this aggressive malignancy.

PMID:42700714 | DOI:10.1016/j.phymed.2026.158760