Pancreatic ductal adenocarcinoma (PDAC) is an incurable cancer resistant to traditional treatments, although a limited number of early-stage patients can undergo radical resection. Immunotherapies for the treatment of haematological malignancies as well as solid tumours have been substantially improved over the past decades, and impressive results have been obtained in recent preclinical and clinical trials. However, PDAC is likely the exception because of its unique tumour microenvironment (TME). In this review, we summarize the characteristics of the PDAC TME and focus on the network of various tumour-infiltrating immune cells, outlining the current advances in PDAC immunotherapy and addressing the effect of the PDAC TME on immunotherapy. This review further explores the combinations of different therapies used to enhance antitumour efficacy or reverse immunodeficiencies and describes optimizable immunotherapeutic strategies for PDAC. The concordant combination of various treatments, such as targeting cancer cells and the stroma, reversing suppressive immune reactions and enhancing antitumour reactivity, may be the most promising approach for the treatment of PDAC. Traditional treatments, especially chemotherapy, may also be optimized for individual patients to remodel the immunosuppressive microenvironment for enhanced therapy.

Background: Acinar-to-ductal metaplasia (ADM) is a pivotal step in pancreatic tumorigenesis, reversible in normal contexts but progressing to PanIN and pancreatic cancer (PC) in the presence of Kras mutation and inflammation. Thus, delineating exocrine cell heterogeneity and identifying regulators of ADM are essential for understanding pancreatic tumorigenesis. Methods: We collected single-cell RNA sequencing (scRNA-seq) data of 146 human pancreatic samples, followed by comprehensive exploration of dynamic change and heterogeneity of ADM via machine learning algorithms. Multi-omics analysis integrating ATAC-seq and RNA-seq highlights the association of Klf4-Tymp axis with ADM. A dual-luciferase reporter assay was performed to evaluate the transcriptional activation of the Tymp promoter by Klf4. AAV-mediated gene silencing was performed in vivo to elucidate the roles and underlying mechanisms of the Klf4/Tymp axis during the ADM process in Pdx1-Cre; Kras ^G12D/+ (KC) mice. In-vitro mouse pancreatic organoid model combined with amino acid mutation was established to investigate the role of Tymp in regulating ADM and its underlying mechanisms. Results: scRNA-seq revealed one S100A4 ⁺ acinar subpopulation and six ductal subpopulations (GPX1 ⁺ , CD24 ⁺ , TFF3 ⁺ , MT-ATP8 ⁺ , S100A9 ⁺ , and HMGB2 ⁺ ) associated with poor prognosis in PC. Integrated pseudotime analysis of pancreatic acinar and ductal cells highlighted the potential involvement of TYMP in regulating the pathological process of ADM. Klf4 was identified as an upstream transcription factor regulating the Tymp gene. ATAC-seq revealed increased chromatin accessibility at the Klf4 and Tymp locus under inflammatory injury or oncogenic Kras conditions. Dual-luciferase reporter assays demonstrated that the transcription factor Klf4 binds to the promoter region of Tymp, thereby promoting its transcriptional expression. Pancreatic overexpression of Klf4 in mice upregulated Tymp expression and facilitated inflammation-induced initiation and progression of ADM. Exogenous supplementation with Tipiracil Hydrochloride suppressed the effects induced by Klf4. Knockdown of the Tymp gene suppressed inflammation-driven initiation and progression of ADM in KC mice through Pi3k/Akt and Mek/Erk pathways. Conclusions: The Klf4-Tymp axis promotes inflammation-associated early pancreatic tumorigenesis by enhancing KRAS mutation-induced ADM through activation of the Pi3k/Akt and Mek/Erk signaling pathways. These findings provide new insights into the molecular mechanisms linking inflammatory injury to ADM and early pancreatic tumorigenesis.

The discrepancy between serum triglyceride levels and the clinical severity of hyperlipidemic acute pancreatitis (HLAP) complicates risk stratification. Traditional lipidomics, which primarily rely on linear abundance, often fail to distinguish the HLAP-specific lipidome from the metabolic background of hypertriglyceridemia (HTG). To overcome this limitation, DeepLipiDecipher was developed as a knowledge-guided graph neural network framework that integrates lipid chemical structures with metabolic topology to identify latent lipotoxic features. In a retrospective cohort of 433 subjects, DeepLipiDecipher demonstrated robust classification performance (AUC = 0.810), effectively distinguishing the HLAP phenotype and outperforming conventional machine learning models. Interpretability analysis revealed that HLAP susceptibility correlated with a distinct structural lipid profile, marked by the synergistic enrichment of polyunsaturated and ether-linked phospholipids, rather than total lipid mass. Moreover, computational causal inference implicated a pathogenic mechanism wherein SMPD3-mediated ceramide accumulation induced basal cytotoxicity, and PTGS2 hyperactivation promoted the peroxidation of these vulnerable lipids, triggering systemic inflammation. These results highlight the value of incorporating network topology into lipidomic analysis and suggest the network-inferred SMPD3-Ceramide-PTGS2 immunometabolic axis as a potential therapeutic target for preventing the progression from metabolic dysfunction to acute organ injury.

Broussoflavonol B (Bf-B), a flavonoid compound identified in the roots of Daphne giraldii Nitsche, has been extensively investigated for its potential anti-inflammatory, antioxidant, and anticancer properties. However, the precise mechanism underlying the regulation of AURKA/PLK1 pathway-mediated cell cycle arrest by Bf-B in pancreatic cancer remains poorly understood. The objective of this study was to investigate the inhibitory effect of Bf-B on pancreatic ductal adenocarcinoma (PDAC) and its underlying mechanism. A CCK8 assay was conducted to identify the flavonoids with the highest inhibitory activity against PANC-1, the pancreatic cancer cell line among the 25 flavonoids. Through bioinformatics analysis and molecular docking, the pathogenic targets of pancreatic cancer and flavonoid-related targets were explored, and the key targets and signaling pathways of drug intervention in pancreatic cancer were analyzed. The viability and migration ability of pancreatic cancer cells were assessed following treatment with Bf-B via the CCK8, colony formation, and wound healing assays. The cell cycle distribution and cell apoptosis were analyzed through flow cytometry and Hoechst staining. Western blotting and qPCR were employed to investigate the expression of relevant proteins and genes. For in vivo experiments, we employed a xenograft mouse model to evaluate the anticancer efficacy of Bf-B. Immunohistochemistry and immunofluorescence assays were employed to investigate the expression of relevant proteins. In this study, the structure‒activity relationships of 25 flavonoids were evaluated. The results demonstrated that Bf-B with diisopentenyl has potent cytotoxic effects on PANC-1 cancer cells. AURKA, PLK1, and MET might serve as key targets for Bf-B inhibition of disease progression in PDAC patients. The results demonstrated that Bf-B inhibits the proliferation and migration of PANC-1 and BXPC-3 cells and induces cell cycle S-phase arrest, apoptosis, and DNA damage. Moreover, the results of western blot and qPCR experiments indicated that Bf-B exerts anticancer effects by downregulating the expression of the genes encoding AURKA/PLK1, the cell cycle checkpoint kinase ATR/CHK1/CDC25C, and Cyclin B1/CDK1 signaling pathway-related proteins and upregulating the expression of PP53, P21, and histone H2A. XS139ph expression. In xenograft-bearing mice, AURKA/PLK1 expression was reduced in a dose-dependent manner, accompanied by an increase in histone H2A. XS139ph expression. Bf-B might be a potent therapeutic agent for pancreatic cancer because of its ability to suppress the expression of AURKA/PLK1.

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy with significant cellular heterogeneity, which poses a significant challenge for treatment. We integrated three single-cell RNA sequencing (scRNA-seq) datasets to construct an expression matrix, identify cell types, and assess copy number variation (CNV) scores, with a particular focus on ductal cells. Our study found that ductal cells are the primary source of malignant cells in PDAC and identified a high-malignancy subtype—ductal cell-3—where RACK1 was the most significantly differentially expressed gene. Through the analysis of public and clinical data, along with RT-qPCR and immunohistochemistry validation, we confirmed the high expression of RACK1 in PDAC tumors, which correlated with lymph node metastasis, clinical staging, histological differentiation, and prognosis. Further investigation revealed that RACK1 promotes PDAC cell proliferation, migration, and invasion. Sequencing analysis indicated that RACK1 inhibits the FOXO signaling pathway, promotes epithelial-mesenchymal transition (EMT), and facilitates the progression and metastasis of PDAC. This study provides new insights into the role of RACK1 in PDAC and its underlying mechanisms.