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Objectives: To determine the role of keratin 17 (K17) as a predictive biomarker for response to chemotherapy by defining thresholds of K17 expression based on immunohistochemical tests that could be used to optimize therapeutic intervention for patients with pancreatic ductal adenocarcinoma (PDAC)., Methods: We profiled K17 expression, a hallmark of the basal molecular subtype of PDAC, by immunohistochemistry in 2 cohorts of formalin-fixed, paraffin-embedded PDACs (n = 305). We determined a K17 threshold of expression to optimize prognostic stratification according to the lowest Akaike information criterion and explored the potential relationship between K17 and chemoresistance by multivariate predictive analyses., Results: Patients with advanced-stage, low K17 PDACs treated using 5-fluorouracil (5-FU)-based chemotherapeutic regimens had 3-fold longer survival than corresponding cases treated with gemcitabine-based chemotherapy. By contrast, PDACs with high K17 did not respond to either regimen. The predictive value of K17 was independent of tumor mutation status and other clinicopathologic variables., Conclusions: The detection of K17 in 10% or greater of PDAC cells identified patients with shortest survival. Among patients with low K17 PDACs, 5-FU-based treatment was more likely than gemcitabine-based therapies to extend survival., (© American Society for Clinical Pathology, 2024.)

The dolichyl-diphosphooligosaccharide-protein glycosyltransferase non-catalytic subunit (DDOST) is a key component of the oligosaccharyltransferase complex catalyzing N-linked glycosylation in the endoplasmic reticulum lumen. DDOST is associated with several cancers and congenital disorders of glycosylation. However, its role in pancreatic cancer remains elusive, despite its enriched pancreatic expression. Using quantitative mass spectrometry, we identify 30 differentially expressed proteins and phosphopeptides (DEPs) after DDOST knockdown in the pancreatic ductal adenocarcinoma (PDAC) cell line PA-TU-8988T. We evaluated DDOST / DEP protein-protein interaction networks using STRING database, correlation of mRNA levels in pancreatic cancer TCGA data, and biological processes annotated to DEPs in Gene Ontology database. The inferred DDOST regulated phenotypes were experimentally verified in two PDAC cell lines, PA-TU-8988T and BXPC-3. We found decreased proliferation and cell viability after DDOST knockdown, whereas ER-stress, ROS-formation and apoptosis were increased. In conclusion, our results support an oncogenic role of DDOST in PDAC by intercepting cell stress events and thereby reducing apoptosis. As such, DDOST might be a potential biomarker and therapeutic target for PDAC., (© 2024. The Author(s).)

Pancreatic ductal adenocarcinoma (PDAC) is characterized by poor response to all therapeutic modalities and dismal prognosis. The presence of tertiary lymphoid structures (TLSs) in various solid cancers is of crucial prognostic significance, highlighting the intricate interplay between the tumor microenvironment and immune cells aggregation. However, the extent to which TLSs and immune status affect PDAC prognosis remains incompletely understood. Here, we sought to unveil the unique properties of TLSs in PDAC by leveraging both single-cell and bulk transcriptomics, culminating in a risk model that predicts clinical outcomes. We used TLS scores based on a 12-gene (CCL2, CCL3, CCL4, CCL5, CCL8, CCL18, CCL19, CCL21, CXCL9, CXCL10, CXCL11, and CXCL13) and 9-gene (PTGDS, RBP5, EIF1AY, CETP, SKAP1, LAT, CCR6, CD1D, and CD79B) signature, respectively, and examined their distribution in cell clusters of single-cell data from PDAC samples. The markers involved in these clusters were selected to develop a prognostic model using The Cancer Genome Atlas Program database as the training cohort and Gene Expression Omnibus database as the validation cohort. Further, we compared the immune infiltration, drug sensitivity, and enriched and differentially expressed genes between the high- and low-risk groups in our model. Therefore, we established a risk model that has significant implications for the prognostic assessment of PADC patients with remarkable differences in immune infiltration and chemosensitivity between the low- and high-risk groups. This paradigm established by TLS-related cell marker genes provides a prognostic prediction and a panel of novel therapeutic targets for exploring potential immunotherapy., Competing Interests: Conflict of interest statement. None declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of Society for Leukocyte Biology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

In this study, a novel pancreatic cancer cell line, termed pancreatic ductal adenocarcinoma (PDAC)-X3 cell line, was successfully derived from the primary tumor. Comprehensive analyses of its malignant phenotype, molecular properties, specific biomarkers, and histological features confirmed that PDAC-X3 cells serve as a valuable model for investigating the underlying mechanisms driving pancreatic carcinogenesis and advancing potential therapeutic strategies. The newly established cell line was continuously cultured for over 12 months and was stably passaged through more than 50 generations. Morphologically, PDAC-X3 cells displayed characteristics typical of epithelial tumors. The population doubling time for PDAC-X3 cells was determined to be 50 h. Karyotype analysis revealed that 75% of PDAC-X3 cells presented as hypotriploid, while 25% were sub-tetraploid, with representative karyotypes being 53 and XY der (1) inv (9) der (22). In suspension culture, PDAC-X3 cells efficiently formed organoids. Upon inoculation into BALB/C nude mice, these cells initiated the development of xenograft tumors, achieving a tumor formation rate of 33%. Morphologically, these xenografted tumors closely resembled the primary tumor. Drug sensitivity assays indicated that PDAC-X3 cells exhibited resistance to oxaliplatin but demonstrated sensitivity to 5-Fluorouracil (5-FU), gemcitabine, and paclitaxel. Immunohistochemical analysis revealed that CK7, CK19, E-cadherin, Vimentin, CA19-9 were positively expressed in PDAC-X3 cells. Meanwhile, the expression rate for Ki-67 was 30%, and that for CEA was not detected. Our findings underscore that PDAC-X3 represents a novel pancreatic cancer cell line, positioning it as a valuable model for basic research and the advancement of therapeutic strategies against pancreatic cancer., (© 2024. The Author(s) under exclusive licence to Japan Human Cell Society.)

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease, notably resistant to existing therapies. Current research indicates that PDAC patients deficient in homologous recombination (HR) benefit from platinum-based treatments and poly-ADP-ribose polymerase inhibitors (PARPi). However, the effectiveness of PARPi in HR-deficient (HRD) PDAC is suboptimal, and significant challenges remain in fully understanding the distinct characteristics and implications of HRD-associated PDAC. We analyzed 16 PDAC patient-derived tissues, categorized by their homologous recombination deficiency (HRD) scores, and performed high-plex immunofluorescence analysis to define 20 cell phenotypes, thereby generating an in-situ PDAC tumor-immune landscape. Spatial phenotypic-transcriptomic profiling guided by regions-of-interest (ROIs) identified a crucial regulatory mechanism through localized tumor-adjacent macrophages, potentially in an HRD-dependent manner. Cellular neighborhood (CN) analysis further demonstrated the existence of macrophage-associated high-ordered cellular functional units in spatial contexts. Using our multi-omics spatial profiling strategy, we uncovered a dynamic macrophage-mediated regulatory axis linking HRD status with SIGLEC10 and CD52. These findings demonstrate the potential of targeting CD52 in combination with PARPi as a therapeutic intervention for PDAC., Competing Interests: Declaration of interests N.W is a full-time employee of Cosmos Wisdom Biotech and worked for Fynn Biotechnologies. ZT.S is a full-time employee of Fynn Biotechnologies. G.B.M. is one of the SAB (Scientific Advisory Board) members or consults with AstraZeneca, Chrysallis Biotechnology, GSK, ImmunoMET, Ionis, Lilly, PDX Pharmaceuticals, Signalchem Lifesciences, Symphogen, Tarveda, Turbine, Zentalis Pharmaceuticals. G.B.M has stock options with Catena Pharmaceuticals, ImmunoMet, SignalChem, Tarveda. Other authors declare no competing interests., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer type that urgently requires effective therapeutic strategies. Andrographolide, a labdane diterpenoid compound abundant in Andrographis paniculata, has anticancer effects against various cancer types, but its anticancer activity and mechanism against PDAC remain largely uncharacterized., Purpose: This study explores novel drug target(s) and underlying molecular mechanism of andrographolide against PDAC., Study Design and Methods: The malignant phenotypes of PDAC cells, PANC-1 and MIA PaCa-2 cells, were measured using MTT, clonogenic assays, and Transwell migration assays. A PDAC xenograft animal model was used to evaluate tumor growth in vivo. Western blot, immunofluorescence and immunohistochemistry were used for measuring protein expression. The TCGA database was analyzed to evaluate promoter methylation status, gene expression, and their relationship with patient survival rates. RT-qPCR was used for detecting mRNA expression. Reporter assays were used for detecting signal transduction pathways. Promoter DNA methylation was determined by sodium bisulfite treatment and methylation-specific PCR (MSP). The biological function and role of specific genes involved in drug effects were measured through gene overexpression., Results: Andrographolide treatment suppressed the proliferation and migration of PDAC cells and impaired tumor growth in vivo. Furthermore, andrographolide induced the mRNA and protein expression of zinc finger protein 382 (ZNF382) in PDAC cells. Overexpression of ZNF382 inhibited malignant phenotypes and cancer-associated signaling pathways (AP-1, NF-κB and β-catenin) and oncogenes (ZEB-1, STAT-3, STAT-5, and HIF-1α). Overexpression of ZNF382 delayed growth of PANC-1 cells in vivo. ZNF382 mRNA and protein expression was lower in tumor tissues than in adjacent normal tissues of pancreatic cancer patients. Analysis of the TCGA database found the ZNF382 promoter is hypermethylated in primary pancreatic tumors which correlates with its low expression. Furthermore, andrographolide inhibited the expression of DNA methyltransferase 3 beta (DNMT3B) and increased the demethylation of the ZNF382 promoter in PDAC cells. Overexpression of DNMT3B attenuated the andrographolide-suppressed proliferation and migration of PDAC cells., Conclusion: Our finding revealed that ZNF382 acts as a tumor suppressor gene in pancreatic cancer and andrographolide restores ZNF382 expression to suppress pancreatic cancer, providing a novel molecular target and a promising therapeutic approach for treating pancreatic cancer., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Shu-ling Fu reports financial support was provided by the National Science and Technology Council in Taiwan. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier GmbH. All rights reserved.)

The presence of abundant tumor stroma is a prominent characteristic of pancreatic ductal adenocarcinomas (PDAC) that potentially influences disease progression and therapy response. This study aims to investigate immune cell infiltration and epigenetic profiles in tumor cell enriched ("Tumor") and stroma cell enriched ("Stroma") regions within human PDAC tissue samples. By comparing those regions, we identified 25,410 differentially methylated positions (DMPs) distributed across 6,963 unique genes. Pathway enrichment analysis using the top 2,000 DMPs that were either hyper- or hypomethylated indicated that immune response pathways and the estrogen receptor pathway are epigenetically dysregulated in Tumor and Stroma regions, respectively. In terms of immune cell infiltration, we observed overall low levels of T cells in both regions. In Tumor regions however, occurrence of tumor-associated macrophages (TAMs) was higher than in Stroma regions (p = 0.02) concomitant with a dualistic distribution that stratifies PDAC patients into those with high and low TAM infiltration. By categorizing TAM levels into quartiles, our analysis revealed that PDAC patients with more than 1,515 TAMs per mm² exhibited significantly shorter overall survival (p = 0.036). Our data suggest that variations in inflammatory characteristics between the Tumor and Stroma defined compartments of PDAC may primarily stem from the presence of macrophages rather than lymphocytes. The abundance of TAMs within regions enriched with tumor cells correlates with patient survival, underscoring the potential significance of exploring therapeutic interventions targeting TAMs. Furthermore, directing attention towards the estrogen receptor pathway may represent a promising strategy to address the stroma cell component within the PDAC tumor microenvironment., Competing Interests: Conflict of Interest statement Anna Sophie Berghoff has research support from Daiichi Sankyo, Roche and honoraria for lectures, consultation, and advisory board participation from Roche Bristol-Meyers Squibb, Merck, Daiichi Sankyo, AstraZeneca, CeCaVa, and travel support from Roche, Amgen, and AbbVie. Matthias Preusser has received honoraria for lectures, consultation, and advisory board participation from the following for-profit companies: Bayer, Bristol-Myers Squibb, Novartis, Gerson Lehrman Group (GLG), CMC Contrast, GlaxoSmithKline, Mundipharma, Roche, BMJ Journals, MedMedia, Astra Zeneca, AbbVie, Lilly, Medahead, Daiichi Sankyo, Sanofi, Merck Sharp & Dome, Tocagen, Adastra, Gan & Lee Pharmaceuticals, and Servier. All other authors declare no conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background & Aims: Acinar-to-ductal metaplasia (ADM) is crucial in the development of pancreatic ductal adenocarcinoma. However, our understanding of the induction and resolution of ADM remains limited. We conducted comparative transcriptome analyses to identify conserved mechanisms of ADM in mouse and human., Methods: We identified Sox4 among the top up-regulated genes. We validated the analysis by RNA in situ hybridization. We performed experiments in mice with acinar-specific deletion of Sox4 (Ptf1a: CreER; Rosa26 -LSL-YFPLSL-YFP ; Sox4 fl/fl ) with and without an activating mutation in Kras (Kras LSL-G12D/+ ). Mice were given caerulein to induce pancreatitis. We performed phenotypic analysis by immunohistochemistry, tissue decellularization, and single-cell RNA sequencing., Results: We demonstrated that Sox4 is reactivated in ADM and pancreatic intraepithelial neoplasias. Contrary to findings in other tissues, Sox4 actually counteracts cellular dedifferentiation and helps maintain tissue homeostasis. Moreover, our investigations unveiled the indispensable role of Sox4 in the specification of mucin-producing cells and tuft-like cells from acinar cells. We identified Sox4-dependent non-cell-autonomous mechanisms regulating the stromal reaction during disease progression. Notably, Sox4-inferred targets are activated upon KRAS inactivation and tumor regression., Conclusions: Our results indicate that our transcriptome analysis can be used to investigate conserved mechanisms of tissue injury. We demonstrate that Sox4 restrains acinar dedifferentiation and is necessary for the specification of acinar-derived metaplastic cells in pancreatic injury and cancer initiation and is activated upon Kras ablation and tumor regression in mice. By uncovering novel potential strategies to promote tissue homeostasis, our findings offer new avenues for preventing the development of pancreatic ductal adenocarcinoma., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: After surgical resection of pancreatic ductal adenocarcinoma (PDAC), patients are predominantly treated with adjuvant chemotherapy, commonly consisting of gemcitabine (GEM)-based regimens or the modified FOLFIRINOX (mFFX) regimen. While mFFX regimen has been shown to be more effective than GEM-based regimens, it is also associated with higher toxicity. Current treatment decisions are based on patient performance status rather than on the molecular characteristics of the tumor. To address this gap, the goal of this study was to develop drug-specific transcriptomic signatures for personalized chemotherapy treatment., Patients and Methods: We used PDAC datasets from preclinical models, encompassing chemotherapy response profiles for the mFFX regimen components. From them we identified specific gene transcripts associated with chemotherapy response. Three transcriptomic artificial intelligence signatures were obtained by combining independent component analysis and the least absolute shrinkage and selection operator-random forest approach. We integrated a previously developed GEM signature with three newly developed ones. The machine learning strategy employed to enhance these signatures incorporates transcriptomic features from the tumor microenvironment, leading to the development of the 'Pancreas-View' tool ultimately clinically validated in a cohort of 343 patients from the PRODIGE-24/CCTG PA6 trial., Results: Patients who were predicted to be sensitive to the administered drugs (n = 164; 47.8%) had longer disease-free survival (DFS) than the other patients. The median DFS in the mFFX-sensitive group treated with mFFX was 50.0 months [stratified hazard ratio (HR) 0.31, 95% confidence interval (CI) 0.21-0.44, P < 0.001] and 33.7 months (stratified HR 0.40, 95% CI 0.17-0.59, P < 0.001) in the GEM-sensitive group when treated with GEM. Comparatively patients with signature predictions unmatched with the treatments (n = 86; 25.1%) or those resistant to all drugs (n = 93; 27.1%) had shorter DFS (10.6 and 10.8 months, respectively)., Conclusions: This study presents a transcriptome-based tool that was developed using preclinical models and machine learning to accurately predict sensitivity to mFFX and GEM., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Context.—: Macroscopic precursor lesions of the pancreas represent a complex clinical management problem. Molecular characterization of pancreatic cysts has helped to confirm and refine clinical and pathologic classifications of these lesions, inform our understanding of tumorigenesis in the pancreas, and provide opportunities for preoperative diagnosis., Objective.—: To review the pathologic classification of macroscopic cystic lesions of the pancreas: intraductal papillary mucinous neoplasms (IPMNs), mucinous cystic neoplasms (MCNs), intraductal oncocytic papillary neoplasms (IOPNs), and intraductal tubulopapillary neoplasms (ITPNs), and to describe our current state of understanding of their molecular underpinnings, relationship to invasive carcinomas, and implications for diagnosis and prognostication., Data Sources.—: We assessed the current primary literature and current World Health Organization Classification of Digestive System Tumours., Conclusions.—: Macroscopic cystic lesions of the pancreas are morphologically and molecularly diverse. IPMNs and MCNs share mucinous cytoplasm with papillae. MCNs are defined by ovarian-type stroma. IOPNs have granular eosinophilic cytoplasm, prominent nucleoli, and complex, arborizing papillae. ITPNs demonstrate complex, back-to-back tubules and anastomosing papillae and lack prominent intracellular mucin. IPMNs and MCNs are characterized by driver mutations in KRAS/GNAS (IPMNs) and KRAS (MCNs), with later driver events in RNF43, CDKN2A, SMAD4, and TP53. In contrast, IOPNs and ITPNs have recurrent rearrangements in PRKACA/PRKACB and MAPK-associated genes, respectively. The recurrent alterations described in cysts provide an opportunity for diagnosis using aspirated cyst fluid. Molecular characterization of IPMNs shows a striking spatial and mutational heterogeneity, challenging traditional models of neoplastic development and creating challenges to interpretation of cyst fluid sequencing results., Competing Interests: The author has no relevant financial interest in the products or companies described in this article., (© 2024 College of American Pathologists.)

Understanding progression mechanisms and developing new targeted therapies is imperative in pancreatic ductal adenocarcinoma (PDAC). In this study, 80 metastatic PDAC patients were prospectively recruited and divided into discovery (n=37) and validation (n=43) cohorts. Tumor and plasma samples taken at diagnosis were pair analyzed using whole exome sequencing (WES) in patients belonging to the discovery cohort alone. The variant allele frequency (VAF) of KRAS mutations was measured by ddPCR in plasma at baseline and response assessment in all patients. Plasma WES identified at least one pathogenic variant across the cohort, uncovering oncogenic mechanisms, DNA repair, microsatellite instability, and alterations in the TGFb pathway. Interestingly, actionable mutations were mostly found in plasma rather than tissue. Patients with shorter survival showed enrichment in cellular organization regulatory pathways. Through WES we could identify a specific molecular profile of patients with liver metastasis, which exhibited exclusive mutations in genes related to the adaptive immune response pathway, highlighting the importance of the immune system in liver metastasis development. Moreover, KRAS mutations in plasma (both at diagnosis and persistent at follow-up) correlated with shorter progression free survival (PFS). Patients presenting a reduction of over 84.75 % in KRAS VAF at response assessment had similar PFS to KRAS-negative patients. Overall, plasma WES reveals molecular profiles indicative of rapid progression, potentially actionable targets, and associations between adaptive immune response pathway alterations and liver tropism., Competing Interests: Declaration of competing interest AC declares institutional research funding from Genentech, Merck Serono, BMS, MSD, Roche, Beigene, Bayer, Servier, Lilly, Natera, Novartis, Takeda, Astellas and Fibrogen and advisory board or speaker fees from Merck Serono, Roche, Servier, Takeda and Astellas. NT declares advisory board or speaker fees from Merck Serono, Servier, Pfizer, Natera and Guardant Health. MH declares advisory board and speaker fees from Servier. TF declares institutional research funding from Genentech, Adapt immune, Roche, Beigene, Astelas, BMS, Daichii Sanyo, Amgen and speaker fees from Astrazeneca, Amgen, Bayer, BMS, Lilly, MSD and Servier. VG declares advisory board fees from Boehringer Ingelheim and institutional research funding from Bayer, Boehringer, Roche, Genentech, Merck Serono, Beigene, Servier, Lilly, Novartis, Takeda, Astelas, Fibrogen, Amcure, Natera, Sierra Oncology, AstraZeneca, Medimmune, BMS, MSD. SR declares personal fees as an invited speaker from Amgen, MSD and Servier. Advisory board fees from Amgen, Servier and Sirtex and institutional funding from Ability Pharmaceuticals, Astellas, G1 Therapeutics, Hutchinson, Menarini, Mirati, Novartis, Pfizer, Pierre Fabre, Roche and Seagen. LS declares advisory board or speaker fees from Johnson and Johnson, Medtronic, Baxter, Cella Medical Solutions. The remaining authors declare no competing interests. All authors have read the journal's policy on disclosure of potential conflicts of interest., (Copyright © 2024. Published by Elsevier Inc.)

Objectives: The pathogenesis of pancreas cancer (PDAC) remains poorly understood, hindering efforts to develop a more effective therapy for PDAC. Recent discoveries show the aryl hydrocarbon receptor (AHR) plays a crucial role in the development of several cancers and can be targeted for therapeutic effect. However, its involvement in the pathogenesis of PDAC remains unclear. To address this gap, we evaluated the role of AHR in the development of PDAC precancerous lesions in vivo ., Materials and Methods: We created a global AHR-null, mutant Kras -driven PDAC mouse model (A -/- KC) and evaluated the changes in PDAC precursor lesion formation (PanIN-1, 2, and 3) and associated fibro-inflammation between KC and A -/- KC at 5 months of age. We then examined the changes in the immune microenvironment followed by single-cell RNA-sequencing analysis to evaluate concomitant transcriptomic changes., Results: We identified a significant increase in PanIN-1 lesion formation and PanIN-1 associated fibro-inflammatory infiltrate in A -/- KC versus KC mice. This was associated with significant changes in the adaptive immune system, particularly a decrease in the CD4+/CD8+ T-cell ratio, as well as a decrease in the T-regulatory/Th17 T-cell ratio suggesting unregulated inflammation., Conclusions: These findings show the loss of AHR results in heightened Kras -induced PanIN formation, through modulation of immune cells within the pancreatic tumor microenvironment., Competing Interests: The authors declare no conflict of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: Cholesterol metabolism reprograming has been acknowledged as a novel feature of cancers. Pancreatic ductal adenocarcinoma (PDAC) is a cancer with a high demand of cholesterol for rapid growth. The underlying mechanism of how cholesterol metabolism homestasis are disturbed in PDAC is explored., Experimental Design: The relevance between PDAC and cholesterol was confirmed in TCGA database. The expression and clinical association were discovered in TCGA and GEO datasets. Knockdown and overexpression of AGFG1 was adopted to perform function studies. RNA sequencing, cholesterol detection, transmission electron microscope, co-immunoprecipitation, and immunofluorescence et al. were utilized to reveal the underlying mechanism., Results: AGFG1 was identified as one gene positively correlated with cholesterol metabolism in PDAC as revealed by bioinformatics analysis. AGFG1 expression was then found associated with poor prognosis in PDAC. AGFG1 knockdown led to decreased proliferation of tumor cells both in vitro and in vivo. By RNA sequencing, we found AGFG1 upregulated expression leads to enhanced intracellular cholesterol biosynthesis. AGFG1 knockdown suppressed cholesterol biosynthesis and an accumulation of cholesterol in the ER. Mechanistically, we confirmed that AGFG1 interacted with CAV1 to relocate cholesterol for the proceeding of cholesterol biosynthesis, therefore causing disorders in intracellular cholesterol metabolism., Conclusions: Our study demonstrates the tumor-promoting role of AGFG1 by disturbing cholesterol metabolism homestasis in PDAC. Our study has present a new perspective on cancer therapeutic approach based on cholerstrol metabolism in PDAC., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Cancer cells rewire metabolism to sculpt the immune tumor microenvironment (TME) and propel tumor advancement, which intricately tied to post-translational modifications. Histone lactylation has emerged as a novel player in modulating protein functions, whereas little is known about its pathological role in pancreatic ductal adenocarcinoma (PDAC) progression. Employing a multi-omics approach encompassing bulk and single-cell RNA sequencing, metabolomics, ATAC-seq, and CUT&Tag methodologies, we unveiled the potential of histone lactylation in prognostic prediction, patient stratification and TME characterization. Notably, "LDHA-H4K12la-immuno-genes" axis has introduced a novel node into the regulatory framework of "metabolism-epigenetics-immunity," shedding new light on the landscape of PDAC progression. Furthermore, the heightened interplay between cancer cells and immune counterparts via Nectin-2 in liver metastasis with elevated HLS unraveled a positive feedback loop in driving immune evasion. Simultaneously, immune cells exhibited altered HLS and autonomous functionality across the metastatic cascade. Consequently, the exploration of innovative combination strategies targeting the metabolism-epigenetics-immunity axis holds promise in curbing distant metastasis and improving survival prospects for individuals grappling with challenges of PDAC., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Gemcitabine is the first-line treatment option for patients with locally advanced or metastatic pancreatic ductal adenocarcinoma (PDAC). However, the frequent adoption of resistance to gemcitabine by cancer cells poses a significant challenge in treating this aggressive disease. In this study, we focused on analyzing the role of trefoil factor 1 (TFF1) in gemcitabine resistance in PDAC. Analysis of PDAC TCGA and cell line datasets indicated an enrichment of TFF1 in the gemcitabine-resistant classical subtype and suggested an inverse correlation between TFF1 expression and sensitivity to gemcitabine treatment. The genetic ablation of TFF1 in PDAC cells enhanced their sensitivity to gemcitabine treatment in both in vitro and in vivo tumor xenografts. The biochemical studies revealed that TFF1 contributes to gemcitabine resistance through enhanced stemness, increasing migration ability of cancer cells, and induction of anti-apoptotic genes. We further pursued studies to predict possible receptors exerting TFF1-mediated gemcitabine resistance. Protein-protein docking investigations with BioLuminate software revealed that TFF1 binds to the chemokine receptor CXCR4, which was supported by real-time binding analysis of TFF1 and CXCR4 using SPR studies. The exogenous addition of TFF1 increased the proliferation and migration of PDAC cells through the pAkt/pERK axis, which was abrogated by treatment with a CXCR4-specific antagonist AMD3100. Overall, the present study demonstrates the contribution of the TFF1-CXCR4 axis in imparting gemcitabine resistance properties to PDAC cells., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: SKB is one of the co-founders of Sanguine Diagnostics and Therapeutics, Inc. The other authors declare no potential conflicts of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Pancreatic ductal adenocarcinoma (PDAC) features substantial matrix stiffening and reprogrammed glucose metabolism, particularly the Warburg effect. However, the complex interplay between these traits and their impact on tumor advancement remains inadequately explored. Here, we integrated clinical, cellular, and bioinformatics approaches to explore the connection between matrix stiffness and the Warburg effect in PDAC, identifying CLIC1 as a key mediator. Elevated CLIC1 expression, induced by matrix stiffness through Wnt/β-catenin/TCF4 signaling, signifies poorer prognostic outcomes in PDAC. Functionally, CLIC1 serves as a catalyst for glycolytic metabolism, propelling tumor proliferation. Mechanistically, CLIC1 fortifies HIF1α stability by curbing hydroxylation via reactive oxygen species (ROS). Collectively, PDAC cells elevate CLIC1 levels in a matrix-stiffness-responsive manner, bolstering the Warburg effect to drive tumor growth via ROS/HIF1α signaling. Our insights highlight opportunities for targeted therapies that concurrently address matrix properties and metabolic rewiring, with CLIC1 emerging as a promising intervention point., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Pancreatic cancer is anatomically divided into pancreatic head and body/tail cancers, and some studies have reported differences in prognosis. However, whether this discrepancy is induced from the difference of tumor biology is hotly debated. Therefore, we aimed to evaluate the differences in clinical outcomes and tumor biology depending on the tumor location., Methods: In this retrospective cohort study, we identified 800 patients with pancreatic ductal adenocarcinoma who had undergone upfront curative-intent surgery. Cox regression analysis was performed to explore the prognostic impact of the tumor location. Among them, 153 patients with sufficient tumor tissue and blood samples who provided informed consent for next-generation sequencing were selected as the cohort for genomic analysis., Results: Out of the 800 patients, 500 (62.5%) had pancreatic head cancer, and 300 (37.5%) had body/tail cancer. Tumor location in the body/tail of the pancreas was not identified as a significant predictor of survival outcomes compared to that in the head in multivariate analysis (hazard ratio, 0.94; 95% confidence interval, 0.77-1.14; P = 0.511). Additionally, in the genomic analyses of 153 patients, there were no significant differences in mutational landscapes, distribution of subtypes based on transcriptomic profiling, and estimated infiltration levels of various immune cells between pancreatic head and body/tail cancers., Conclusions: We could not find differences in prognosis and tumor biology depending on tumor location in pancreatic ductal adenocarcinoma. Discrepancies in prognosis may represent a combination of lead time, selection bias, and clinical differences, including the surgical burden between tumor sites., (© 2024. The Author(s).)

This study introduces a new imaging, spatial transcriptomics (ST), and single-cell RNA-sequencing integration pipeline to characterize neoplastic cell state transitions during tumorigenesis. We applied a semi-supervised analysis pipeline to examine premalignant pancreatic intraepithelial neoplasias (PanINs) that can develop into pancreatic ductal adenocarcinoma (PDAC). Their strict diagnosis on formalin-fixed and paraffin-embedded (FFPE) samples limited the single-cell characterization of human PanINs within their microenvironment. We leverage whole transcriptome FFPE ST to enable the study of a rare cohort of matched low-grade (LG) and high-grade (HG) PanIN lesions to track progression and map cellular phenotypes relative to single-cell PDAC datasets. We demonstrate that cancer-associated fibroblasts (CAFs), including antigen-presenting CAFs, are located close to PanINs. We further observed a transition from CAF-related inflammatory signaling to cellular proliferation during PanIN progression. We validate these findings with single-cell high-dimensional imaging proteomics and transcriptomics technologies. Altogether, our semi-supervised learning framework for spatial multi-omics has broad applicability across cancer types to decipher the spatiotemporal dynamics of carcinogenesis., Competing Interests: Declaration of interests E.M.J. reports other support from Abmeta; personal fees from Genocea; personal fees from Achilles; personal fees from DragonFly; personal fees from Candel Therapeutics; other support from the Parker Institute; grants and other support from Lustgarten; personal fees from Carta; grants and other support from Genentech; grants and other support from AstraZeneca; personal fees from NextCure; and grants and other support from Break Through Cancer outside of the submitted work. E.J.F. is on the Scientific Advisory Board of Viosera Therapeutics/Resistance Bio and is a consultant to Mestag Therapeutics. W.J.H. reports patent royalties from Rodeo/Amgen and speaking/travel honoraria from Exelixis and Standard BioTools., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Ferroptosis, a novel form of iron-dependent non-apoptotic cell death, plays an active role in the pathogenesis of diverse diseases, including cancer. However, the mechanism through which ferroptosis is regulated in pancreatic ductal adenocarcinoma (PDAC) remains unclear. Here, our study, via combining bioinformatic analysis with experimental validation, showed that ferroptosis is inhibited in PDAC. Genome-wide sequencing further revealed that the ferroptosis activator imidazole ketone erastin (IKE) induced upregulation of the E3 ubiquitin ligase RBCK1 in PDAC cells at the transcriptional or translational level. RBCK1 depletion or knockdown rendered PDAC cells more vulnerable to IKE-induced ferroptotic death in vitro. In a mouse xenograft model, genetic depletion of RBCK1 increased the killing effects of ferroptosis inducer on PDAC cells. Mechanistically, RBCK1 interacts with and polyubiquitylates mitofusin 2 (MFN2), a key regulator of mitochondrial dynamics, to facilitate its proteasomal degradation under ferroptotic stress, leading to decreased mitochondrial reactive oxygen species (ROS) production and lipid peroxidation. These findings not only provide new insights into the defense mechanisms of PDAC cells against ferroptotic death but also indicate that targeting the RBCK1-MFN2 axis may be a promising option for treating patients with PDAC., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Taiping Zhang reports financial support was provided by National Natural Science Foundation of China. Taiping Zhang reports financial support was provided by Beijing Natural Science Foundation. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

There is a significant difference in prognosis and response to chemotherapy between basal and classical subtypes of pancreatic ductal adenocarcinoma (PDAC). Further biomarkers are required to identify subtypes of PDAC. We selected candidate biomarkers via review articles. Correlations between these candidate markers and the PDAC molecular subtype gene sets were analyzed using bioinformatics, confirming the biomarkers for identifying classical and basal subtypes. Subsequently, 298 PDAC patients were included, and their tumor tissues were immunohistochemically stratified using these biomarkers. Survival data underwent analysis, including Cox proportional hazards modeling. Our results indicate that the pairwise and triple combinations of KRT5/KRT17/S100A2 exhibit a higher correlation coefficient with the basal-like subtype gene set, whereas the corresponding combinations of GATA6/HNF4A/TFF1 show a higher correlation with the classical subtype gene set. Whether analyzing unmatched or propensity-matched data, the overall survival time was significantly shorter for the basal subtype compared with the classical subtype (p < .001), with basal subtype patients also facing a higher risk of mortality (HR = 4.017, 95% CI 2.675-6.032, p < .001). In conclusion, the combined expression of KRT5, KRT17, and S100A2, in both pairwise and triple combinations, independently predicts shorter overall survival in PDAC patients and likely identifies the basal subtype. Similarly, the combined expression of GATA6, HNF4A, and TFF1, in the same manner, may indicate the classical subtype. In our study, the combined application of established biomarkers offers valuable insights for the prognostic evaluation of PDAC patients., (© 2024 The Author(s). The FASEB Journal published by Wiley Periodicals LLC on behalf of Federation of American Societies for Experimental Biology.)

Pancreatic ductal adenocarcinoma (PDAC) is one of the leading causes of cancer-related death worldwide, primarily due to its rapid progression. The current treatment options for PDAC are limited, and a better understanding of the underlying mechanisms responsible for PDAC progression is required to identify improved therapeutic strategies. In this study, we identified FBXO32 as an oncogenic driver in PDAC. FBXO32 was aberrantly upregulated in PDAC, and high FBXO32 expression was significantly associated with an unfavorable prognosis in patients with PDAC. FRG1 deficiency promoted FBXO32 upregulation in PDAC. FBXO32 promoted cell migration and invasion in vitro and tumor growth and metastasis in vivo. Mechanistically, FBXO32 directly interacted with eEF1A1 and promoted its polyubiquitination at the K273 site, leading to enhanced activity of eEF1A1 and increased protein synthesis in PDAC cells. Moreover, FBXO32-catalyzed eEF1A1 ubiquitination boosted the translation of ITGB5 mRNA and activated focal adhesion kinase (FAK) signaling, thereby facilitating focal adhesion assembly and driving PDAC progression. Importantly, interfering with the FBXO32-eEF1A1 axis or pharmaceutical inhibition of FAK by defactinib, an FDA-approved FAK inhibitor, substantially inhibited PDAC growth and metastasis driven by aberrantly activated FBXO32-eEF1A1 signaling. Overall, this study uncovers a mechanism by which PDAC cells rely on FBXO32-mediated eEF1A1 activation to drive progression and metastasis. FBXO32 may serve as a promising biomarker for selecting eligible patients with PDAC for treatment with defactinib. Significance: FBXO32 upregulation in pancreatic cancer induced by FRG1 deficiency increases eEF1A1 activity to promote ITGB5 translation and stimulate FAK signaling, driving cancer progression and sensitizing tumors to the FAK inhibitor defactinib., (©2024 American Association for Cancer Research.)

Pancreatic ductal adenocarcinoma (PDAC) poses a significant threat due to its tendency to evade early detection, frequent metastasis, and the subsequent challenges in devising effective treatments. Processes that govern epithelial-mesenchymal transition (EMT) in PDAC hold promise for advancing novel therapeutic strategies. SAMD1 (SAM domain-containing protein 1) is a CpG island-binding protein that plays a pivotal role in the repression of its target genes. Here, we revealed that SAMD1 acts as a repressor of genes associated with EMT. Upon deletion of SAMD1 in PDAC cells, we observed significantly increased migration rates. SAMD1 exerts its effects by binding to specific genomic targets, including CDH2, encoding N-cadherin, which emerged as a driver of enhanced migration upon SAMD1 knockout. Furthermore, we discovered the FBXO11-containing E3 ubiquitin ligase complex as an interactor and negative regulator of SAMD1, which inhibits SAMD1 chromatin-binding genome-wide. High FBXO11 expression in PDAC is associated with poor prognosis and increased expression of EMT-related genes, underlining an antagonistic relationship between SAMD1 and FBXO11. In summary, our findings provide insights into the regulation of EMT-related genes in PDAC, shedding light on the intricate role of SAMD1 and its interplay with FBXO11 in this cancer type., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Simon et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Inflammation and aberrant cellular metabolism are widely recognized as hallmarks of cancer. In pancreatic ductal adenocarcinoma (PDAC), inflammatory signaling and metabolic reprogramming are tightly interwoven, playing pivotal roles in the pathogenesis and progression of the disease. However, the regulatory functions of inflammatory mediators in metabolic reprogramming in pancreatic cancer have not been fully explored. Earlier, we demonstrated that pro-inflammatory mediator macrophage migration inhibitory factor (MIF) enhances disease progression by inhibiting its downstream transcriptional factor nuclear receptor subfamily 3 group C member 2 (NR3C2). Here, we provide evidence that MIF and NR3C2 interactively regulate metabolic reprogramming, resulting in MIF-induced cancer growth and progression in PDAC. MIF positively correlates with the HK1 (hexokinase 1), HK2 (hexokinase 2) and LDHA (lactate dehydrogenase) expression and increased pyruvate and lactate production in PDAC patients. Additionally, MIF augments glucose uptake and lactate efflux by upregulating HK1, HK2 and LDHA expression in pancreatic cancer cells in vitro and in mouse models of PDAC. Conversely, a reduction in HK1, HK2 and LDHA expression is observed in tumors with high NR3C2 expression in PDAC patients. NR3C2 suppresses HK1, HK2 and LDHA expression, thereby inhibiting glucose uptake and lactate efflux in pancreatic cancer. Mechanistically, MIF-mediated regulation of glycolytic metabolism involves the activation of the mitogen-activated protein kinase-ERK signaling pathway, whereas NR3C2 interacts with the activator protein 1 to regulate glycolysis. Our findings reveal an interactive role of the MIF/NR3C2 axis in regulating glucose metabolism supporting tumor growth and progression and may be a potential target for designing novel approaches for improving disease outcome., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Pancreatic cancer (PC) poses a substantial global health challenge, ranking as the fourth leading cause of cancer-related deaths due to its high mortality rate. Late-stage diagnoses are common due to the absence of specific symptoms. Pancreatic ductal adenocarcinoma (PDAC) accounts for the majority of PC cases. Recent research has suggested a potential link between elevated serum levels of bile acids (BAs) and tumorigenesis of PDAC. This study aims to understand how taurochenodeoxycholic acid (TCDCA), a secondary BA, influences PDAC using RNA sequencing techniques on the Capan-1 cell line. We identified 2,950 differentially expressed genes (DEGs) following TCDCA treatment, with 1,597 upregulated and 1,353 downregulated genes. These DEGs were associated with critical PDAC pathways, including coagulation, angiogenesis, cell migration, and signaling regulation. Furthermore, we reviewed relevant literature highlighting genes like DKK-1, KRT80, UPLA, and SerpinB2, known for their roles in PDAC tumorigenesis and metastasis. Our study sheds light on the complex relationship between BAs and PDAC, offering insights into potential diagnostic markers and therapeutic targets. Further research is needed to unravel these findings' precise mechanisms and clinical implications, potentially improving PDAC diagnosis and treatment., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Zoltan Vereb reports financial support was provided by Hungarian Academy of Sciences. Viktoria Venglovecz reports financial support was provided by National, Research, Development and Innovation Office. Lajos Kemeny reports financial support was provided by Hungarian Centre of Excellence for Molecular Medicine. Zoltan Vereb reports financial support was provided by National, Research, Development and Innovation Office. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Introduction: Pancreatic Ductal Adenocarcinoma (PDA) is one of the most aggressive malignancies with a 5-year survival rate of 13%. Less than 20% of patients have a resectable tumor at diagnosis due to the lack of distinctive symptoms and reliable biomarkers. PDA is resistant to chemotherapy (CT) and understanding how to gain an anti-tumor effector response following stimulation is, therefore, critical for setting up an effective immunotherapy., Methods: Proliferation, and cytokine release and TCRB repertoire of from PDA patient peripheral T lymphocytes, before and after CT, were analyzed in vitro in response to four tumor-associated antigens (TAA), namely ENO1, FUBP1, GAPDH and K2C8. Transcriptional state of PDA patient PBMC was investigated using RNA-Seq before and after CT., Results: CT increased the number of TAA recognized by T lymphocytes, which positively correlated with patient survival, and high IFN-γ production TAA-induced responses were significantly increased after CT. We found that some ENO1-stimulated T cell clonotypes from CT-treated patients were expanded or de-novo induced, and that some clonotypes were reduced or even disappeared after CT. Patients that showed a higher number of effector responses to TAA (high IFN-γ/IL-10 ratio) after CT expressed increased fatty acid-related transcriptional signature. Conversely, patients that showed a higher number of regulatory responses to TAA (low IFN-γ/IL-10 ratio) after CT significantly expressed an increased IRAK1/IL1R axis-related transcriptional signature., Conclusion: These data suggest that the expression of fatty acid or IRAK1/IL1Rrelated genes predicts T lymphocyte effector or regulatory responses to TAA in patients that undergo CT. These findings are a springboard to set up precision immunotherapies in PDA based on the TAA vaccination in combination with CT., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Brugiapaglia, Bulfamante, Curcio, Arigoni, Calogero, Bonello, Genuardi, Spadi, Satolli, Campra, Giordano, Cappello, Cordero and Novelli.)

Objective: Pancreatic ductal adenocarcinoma (PDAC) has limited therapeutic options, particularly with immune checkpoint inhibitors. Highly chemoresistant 'stem-like' cells, known as cancer stem cells (CSCs), are implicated in PDAC aggressiveness. Thus, comprehending how this subset of cells evades the immune system is crucial for advancing novel therapies., Design: We used the KPC mouse model ( LSL-Kras G12D/+ ; LSL-Trp53 R172H/+ ; Pdx-1-Cre ) and primary tumour cell lines to investigate putative CSC populations. Transcriptomic analyses were conducted to pinpoint new genes involved in immune evasion. Overexpressing and knockout cell lines were established with lentiviral vectors. Subsequent in vitro coculture assays, in vivo mouse and zebrafish tumorigenesis studies, and in silico database approaches were performed., Results: Using the KPC mouse model, we functionally confirmed a population of cells marked by EpCAM, Sca-1 and CD133 as authentic CSCs and investigated their transcriptional profile. Immune evasion signatures/genes, notably the gene peptidoglycan recognition protein 1 (PGLYRP1), were significantly overexpressed in these CSCs. Modulating PGLYRP1 impacted CSC immune evasion, affecting their resistance to macrophage-mediated and T-cell-mediated killing and their tumourigenesis in immunocompetent mice. Mechanistically, tumour necrosis factor alpha (TNFα)-regulated PGLYRP1 expression interferes with the immune tumour microenvironment (TME) landscape, promoting myeloid cell-derived immunosuppression and activated T-cell death. Importantly, these findings were not only replicated in human models, but clinically, secreted PGLYRP1 levels were significantly elevated in patients with PDAC., Conclusions: This study establishes PGLYRP1 as a novel CSC-associated marker crucial for immune evasion, particularly against macrophage phagocytosis and T-cell killing, presenting it as a promising target for PDAC immunotherapy., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY. Published by BMJ.)

Objective: The hallmark oncogene MYC drives the progression of most tumours, but direct inhibition of MYC by a small-molecule drug has not reached clinical testing. MYC is a transcription factor that depends on several binding partners to function. We therefore explored the possibility of targeting MYC via its interactome in pancreatic ductal adenocarcinoma (PDAC)., Design: To identify the most suitable targets among all MYC binding partners, we constructed a targeted shRNA library and performed screens in cultured PDAC cells and tumours in mice., Results: Unexpectedly, many MYC binding partners were found to be important for cultured PDAC cells but dispensable in vivo. However, some were also essential for tumours in their natural environment and, among these, the ATPases RUVBL1 and RUVBL2 ranked first. Degradation of RUVBL1 by the auxin-degron system led to the arrest of cultured PDAC cells but not untransformed cells and to complete tumour regression in mice, which was preceded by immune cell infiltration. Mechanistically, RUVBL1 was required for MYC to establish oncogenic and immunoevasive gene expression identifying the RUVBL1/2 complex as a druggable vulnerability in MYC-driven cancer., Conclusion: One implication of our study is that PDAC cell dependencies are strongly influenced by the environment, so genetic screens should be performed in vitro and in vivo. Moreover, the auxin-degron system can be applied in a PDAC model, allowing target validation in living mice. Finally, by revealing the nuclear functions of the RUVBL1/2 complex, our study presents a pharmaceutical strategy to render pancreatic cancers potentially susceptible to immunotherapy., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY. Published by BMJ.)

Immunotherapy for pancreatic ductal carcinoma (PDAC) remains disappointing due to the repressive tumor microenvironment and T cell exhaustion, in which the roles of interferon-stimulated genes were largely unknown. Here, we focused on a typical interferon-stimulated gene, GBP4, and investigated its potential diagnostic and therapeutic value in pancreatic cancer. Expression analysis on both local samples and public databases indicated that GBP4 was one of the most dominant GBP family members present in the PDAC microenvironment, and the expression level of GBP4 was negatively associated with patient survival. We then identified DNA hypo-methylation in regulatory regions of GBP4 in PDAC, and validated its regulatory role on GBP4 expression via performing targeted methylation using dCas9-SunTag-DNMAT3A-sgRNA-targeted methylation system on selected DNA locus. After that, we investigated the downstream functions of GBP4, and chemotaxis assays indicated that GBP4 overexpression significantly improved the infiltration of CD8 + T cells, but also induced upregulation of immune checkpoint genes and T cell exhaustion. Lastly, in vitro T cell killing assays using primary organoids suggested that the PDAC samples with high level of GBP4 expression displayed significantly higher sensitivity to anti-PD-1 treatment. Taken together, our studies revealed the expression patterns and epigenetic regulatory mechanisms of GBP4 in pancreatic cancer and clarified the effects of GBP4 on T cell exhaustion and antitumor immunology., (© 2024. The Author(s).)

Pancreatic cancer is a malignancy arising from the endocrine or exocrine compartment of this organ. Tumors from exocrine origin comprise over 90% of all pancreatic cancers diagnosed. Of these, pancreatic ductal adenocarcinoma (PDAC) is the most common histological subtype. The five-year survival rate for PDAC ranged between 5 and 9% for over four decades, and only recently saw a modest increase to ∼12-13%, making this a severe and lethal disease. Like other cancers, PDAC initiation stems from genetic changes. However, therapeutic targeting of PDAC genetic drivers has remained relatively unsuccessful, thus the focus in recent years has expanded to the non-genetic factors underlying the disease pathogenesis. Specifically, it has been proposed that dynamic changes in the epigenetic landscape promote tumor growth and metastasis. Emphasis has been given to the re-organization of enhancers, essential regulatory elements controlling oncogenic gene expression, commonly marked my histone 3 lysine 4 monomethylation (H3K4me1). H3K4me1 is typically deposited by histone lysine methyltransferases (KMTs). While well characterized as oncogenes in other cancer types, recent work has expanded the role of KMTs as tumor suppressor in pancreatic cancer. Here, we review the role and translational significance for PDAC development and therapeutics of KMTs., (© 2024 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.)

Super-enhancers are a class of DNA cis-regulatory elements that can regulate cell identity, cell fate, stem cell pluripotency, and even tumorigenesis. Increasing evidence shows that epigenetic modifications play an important role in the pathogenesis of various types of cancer. However, the current research is far from enough to reveal the complex mechanism behind it. This study found a super-enhancer enriched with abnormally active histone modifications in pancreatic ductal adenocarcinoma (PDAC), called DKK1-super-enhancer (DKK1-SE). The major active component of DKK1-SE is component enhancer e1. Mechanistically, AP1 induces chromatin remodeling in component enhancer e1 and activates the transcriptional activity of DKK1. Moreover, DKK1 was closely related to the malignant clinical features of PDAC. Deletion or knockdown of DKK1-SE significantly inhibited the proliferation, colony formation, motility, migration, and invasion of PDAC cells in vitro, and these phenomena were partly mitigated upon rescuing DKK1 expression. In vivo, DKK1-SE deficiency not only inhibited tumor proliferation but also reduced the complexity of the tumor microenvironment. This study identifies that DKK1-SE drives DKK1 expression by recruiting AP1 transcription factors, exerting oncogenic effects in PDAC, and enhancing the complexity of the tumor microenvironment., (© 2024. The Author(s).)

Desmosomes are intercellular adhesion complexes providing mechanical coupling and tissue integrity. Previously, a correlation of desmosomal molecule expression with invasion and metastasis formation in several tumor entities was described together with a relevance for circulating tumor cell cluster formation. Here, we investigated the contribution of the desmosomal core adhesion molecule desmoglein-2 (DSG2) to the initial steps of liver metastasis formation by pancreatic cancer cells using a novel ex vivo liver perfusion mouse model. We applied the pancreatic ductal adenocarcinoma cell line AsPC-1 with and without a knockout (KO) of DSG2 and generated mouse lines with a hepatocyte-specific KO of the known interacting partners of DSG2 (DSG2 and desmocollin-2). Liver perfusion with DSG2 KO AsPC-1 cells led to smaller circulating cell clusters and a reduced number of cells adhering to murine livers compared to control cells. While this was independent of the expression levels of desmosomal adhesion molecules in hepatocytes, we show that increased cluster size of cancer cells, which correlates with stronger cell-cell adhesion and expression of desmosomal molecules, is a major factor contributing to the early phase of metastatic spreading. In conclusion, impaired desmosomal adhesion results in reduced circulating cell cluster size, which is relevant for seeding and attachment of metastatic cells to the liver., (© 2024. The Author(s).)

53BP1 nucleates the anti-end resection machinery at DNA double-strand breaks, thereby countering BRCA1 activity. Loss of 53BP1 leads to DNA end processing and homologous recombination in BRCA1-deficient cells. Consequently, BRCA1-mutant tumors, typically sensitive to PARP inhibitors (PARPi), become resistant in the absence of 53BP1. Here, we demonstrate that the 'leaky' DNA end resection in the absence of 53BP1 results in increased micronuclei and cytoplasmic double-stranded DNA, leading to activation of the cGAS-STING pathway and pro-inflammatory signaling. This enhances CD8 + T cell infiltration, activates macrophages and natural killer cells, and impedes tumor growth. Loss of 53BP1 correlates with a response to immune checkpoint blockade (ICB) and improved overall survival. Immunohistochemical assessment of 53BP1 in two malignancies, high grade serous ovarian cancer and pancreatic ductal adenocarcinoma, which are refractory to ICBs, reveals that lower 53BP1 levels correlate with an increased adaptive and innate immune response. Finally, BRCA1-deficient tumors that develop resistance to PARPi due to the loss of 53BP1 are susceptible to ICB. Therefore, we conclude that 53BP1 is critical for tumor immunogenicity and underpins the response to ICB. Our results support including 53BP1 expression as an exploratory biomarker in ICB trials for malignancies typically refractory to immunotherapy., (© 2024. The Author(s).)

Pancreatic ductal adenocarcinoma (PDAC) is an extremely lethal tumor with increasing incidence, presenting numerous clinical challenges. The histopathological examination of novel, unexplored biomarkers offers a promising avenue for research, with significant translational potential for improving patient outcomes. In this study, we evaluated the prognostic significance of ferroptosis markers (TFRC, ALOX-5, ACSL-4, and GPX-4), circadian clock regulators (CLOCK, BMAL1, PER1, PER2), and KLOTHO in a retrospective cohort of 41 patients deceased by PDAC. Immunohistochemical techniques (IHC) and multiple statistical analyses (Kaplan-Meier curves, correlograms, and multinomial linear regression models) were performed. Our findings reveal that ferroptosis markers are directly associated with PDAC mortality, while circadian regulators and KLOTHO are inversely associated. Notably, TFRC emerged as the strongest risk marker associated with mortality (HR = 35.905), whereas CLOCK was identified as the most significant protective marker (HR = 0.01832). Correlation analyses indicate that ferroptosis markers are positively correlated with each other, as are circadian regulators, which also positively correlate with KLOTHO expression. In contrast, KLOTHO and circadian regulators exhibit inverse correlations with ferroptosis markers. Among the clinical variables examined, only the presence of chronic pathologies showed an association with the expression patterns of several proteins studied. These findings underscore the complexity of PDAC pathogenesis and highlight the need for further research into the specific molecular mechanisms driving disease progression.

Background: With poor prognosis and high mortality, pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies. Standard of care therapies for PDAC have included gemcitabine for the past three decades, although resistance often develops within weeks of chemotherapy initiation through an array of possible mechanisms., Methods: We reanalyzed publicly available RNA-seq gene expression profiles of 28 PDAC patient-derived xenograft (PDX) models before and after a 21-day gemcitabine treatment using our validated analysis pipeline to identify molecular markers of intrinsic and acquired resistance., Results: Using normalized RNA-seq quantification measurements, we first identified oxidative phosphorylation and interferon alpha pathways as the two most enriched cancer hallmark gene sets in the baseline gene expression profile associated with intrinsic gemcitabine resistance and sensitivity, respectively. Furthermore, we discovered strong correlations between drug-induced expression changes in glycolysis and oxidative phosphorylation genes and response to gemcitabine, which suggests that these pathways may be associated with acquired gemcitabine resistance mechanisms. Thus, we developed prediction models using baseline gene expression profiles in those pathways and validated them in another dataset of 12 PDAC models from Novartis. We also developed prediction models based on drug-induced expression changes in genes from the Molecular Signatures Database (MSigDB)'s curated 50 cancer hallmark gene sets. Finally, pathogenic TP53 mutations correlated with treatment resistance., Conclusion: Our results demonstrate that concurrent upregulation of both glycolysis and oxidative phosphorylation pathways occurs in vivo in PDAC PDXs following gemcitabine treatment and that pathogenic TP53 status had association with gemcitabine resistance in these models. Our findings may elucidate the molecular basis for gemcitabine resistance and provide insights for effective drug combination in PDAC chemotherapy., (© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Pancreatic ductal adenocarcinoma (PDAC)/pancreatic cancer, is a highly aggressive malignancy with poor prognosis. Gemcitabine-based chemotherapy remains the cornerstone of PDAC treatment. Nonetheless, the development of resistance to gemcitabine among patients is a major factor contributing to unfavorable prognostic outcomes. The resistance exhibited by tumors is modulated by a constellation of factors such as genetic mutations, tumor microenvironment transforms, environmental contaminants exposure. Currently, comprehension of the relationship between environmental pollutants and tumor drug resistance remains inadequate. Our study found that PFOS/6:2 Cl-PFESA exposure increases resistance to gemcitabine in PDAC. Subsequent in vivo trials confirmed that exposure to PFOS/6:2 Cl-PFESA reduces gemcitabine's efficacy in suppressing PDAC, with the inhibition rate decreasing from 79.5 % to 56.7 %/38.7 %, respectively. Integrative multi-omics sequencing and molecular biology analyses have identified the upregulation of ribonucleotide reductase catalytic subunit M1 (RRM1) as a critical factor in gemcitabine resistance. Subsequent research has demonstrated that exposure to PFOS and 6:2 Cl-PFESA results in the upregulation of the RRM1 pathway, consequently enhancing chemotherapy resistance. Remarkably, the influence exerted by 6:2 Cl-PFESA exceeds that of PFOS. Despite 6:2 Cl-PFESA being regarded as a safer substitute for PFOS, its pronounced effect on chemotherapeutic resistance in PDAC necessitates a thorough evaluation of its potential risks related to gastrointestinal toxicity., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Pancreatic stellate cells (PSC) are one source of cancer-associated fibroblasts (CAF) and play, therefore, an essential role in pancreatic ductal adenocarcinoma (PDA). Paracrine signalling between PDA cells and CAF has been widely studied, yet external influences on paracrine crosstalk are poorly understood. This study aimed to gain a deeper insight into the communication of PSC and cancer cells under different co-culture conditions via analysis of PSC gene expression profiles. Two contactless co-culture models with tumor cells from the p48-Cre; lox-stop-lox-Kras G12D/+ ; lox-stop-lox-Trp53 R172H/+ mouse model (KPC) and murine PSC separated through a microporous membrane and grown in different compartments (standard co-culture) or on different sides of the same membrane (inverse co-culture), were established. RNA-Sequencing analysis of PSC mRNA was performed 24 h and 72 h after co-culture with KPC cells. For selected genes, results were confirmed by quantitative RT-PCR and immunocytochemistry. Standard co-culture displayed 19 differentially expressed genes (DEG) at 24 h and 52 DEG at 72 h. In inverse co-culture, 800 DEG at 24 h and 2213 DEG at 72 h were enriched. PSC showed great heterogeneity in their gene expression profiles; however, mutually regulated genes of both co-cultures, such as VCAN and CHST11, could be identified. VCAN-protein-protein interaction-network analysis revealed several shared genes between co-culture models, such as SDC4 and FN1. In conclusion, PSC show a varying susceptibility to cancer cell signals depending on the co-culture method, with intensified transcriptome changes with closer proximity., (© 2024. The Author(s).)

Background: Despite advances in the treatment of cancer, pancreatic ductal adenocarcinoma (PDAC) remains highly lethal due to the lack of effective therapies. Our previous study showed that Luteolin (Lut), a flavonoid, suppressed pancreatocarcinogenesis and reduced the expression of dihydropyrimidine dehydrogenase (DPYD), an enzyme that degrades pyrimidines such as 5-fluorouracil (5-FU), in PDACs. In this study, we investigated the role of DPYD and evaluated the therapeutic potential of combining 5-FU with Lut in PDACs., Methods and Results: PDAC cells overexpressing DPYD showed increased proliferation, and invasiveness, adding to the resistance to 5-FU. The xenograft tumors of DPYD-overexpressing PDAC cells also exhibit enhanced growth and invasion compared to the control xenograft tumors. RNA-seq analysis of the DPYD-overexpressing PDAC xenograft tumors revealed an upregulation of genes associated with metallopeptidase activity-MMP9 and MEP1A. Furthermore, the overexpression of MEP1A in PDAC was associated with invasion. Next, we investigated the combined effects of Lut, a DPYD suppressor, and 5-FU on DPYD-overexpressing xenograft tumors and PDAC of Pdx1-Cre; LSL-KrasG12D/+; Trp53flox/flox(KPPC) mice. Neither single administration of 5-FU nor Lut showed significant inhibitory effects; however, the combined administration of 5-FU and Lut exhibited a significant tumor-suppressive effect in both the xenograft tumors and KPPC models., Conclusion: We have elucidated that DPYD expression contributes to proliferation, invasiveness, and 5-FU resistance, in PDACs. The combination therapy of Lut and 5-FU holds the potential for enhanced efficacy against PDACs., (© 2024 The Author(s). Cancer Medicine published by John Wiley & Sons Ltd.)

Background: pancreatic ductal adenocarcinoma (PDAC) is a malignant tumor with a very poor prognosis and a complex tumor microenvironment, which plays a key role in tumor progression and treatment resistance. Glycosylation plays an important role in processes such as cell signaling, immune response and protein stability., Materials and Methods: single-cell RNA sequencing data and spatial transcriptome data were obtained from GSE197177 and GSE224411, respectively, and RNA-seq data and survival information were obtained from UCSC Xena and TCGA. Multiple transcriptomic data were comprehensively analyzed to explore the role of glycosylation processes in tumor progression, and functional experiments were performed to assess the effects of MGAT1 overexpression on PDAC cell proliferation and migration., Results: In PDAC tumor samples, the glycosylation level of macrophages was significantly higher than that of normal samples. MGAT1 was identified as a key glycosylation-related gene, and its high expression was associated with better patient prognosis. Overexpression of MGAT1 significantly inhibited the proliferation and migration of PDAC cells and affected intercellular interactions in the tumor microenvironment., Conclusion: MGAT1 plays an important role in PDAC by regulating glycosylation levels in macrophages, influencing tumor progression and improving prognosis.MGAT1 is a potential therapeutic target for PDAC and further studies are needed to develop targeted therapeutic strategies against MGAT1 to improve clinical outcomes., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Jiang, Liu, Zhang, Jiang, Huang, Chen, Zhou, Fu, Yang, Wang, Yang, Chi and Li.)

Purpose: Approximately 5%-10% of patients with pancreatic ductal adenocarcinoma (PDAC) have an inherited basis, yet uptake of genetic testing remains low and subject to disparities. This study compared two genetic testing pathways available to patients referred to a provincial cancer center, BC Cancer: a traditional hereditary cancer clinic-initiated testing (HCT) pathway and a new oncology clinic-initiated testing (OCT) pathway., Methods: Study subjects were patients with confirmed PDAC referred for genetic testing through the HCT or OCT pathway between June 1, 2020, and February 1, 2022. Charts were retrospectively reviewed for patient characteristics and testing outcomes., Results: The study population was 397 patients (HCT, n = 279 and OCT, n = 118). OCT patients were more likely to have non-European ethnicity compared with HCT patients (41.9% v 25.6%, P = .004), to have earlier-stage disease ( P = .012), and to have better Eastern Cooperative Oncology Group performance status than the HCT group ( P = .001). A total of 306 patients completed testing (77%). OCT patients had higher test completion rates than HCT patients (odds ratio, 3.74 [95% CI, 1.66 to 9.62]). Median time for results was shorter in OCT than in HCT (53 days [IQR, 44-76] v 107 days [IQR, 63.8-158.3]). Pancreatic cancer susceptibility pathogenic gene variants were identified in 8.5% (26/306)., Conclusion: The real-world observations in our study show that oncology clinic-initiated hereditary testing is more effective and faster than testing through hereditary cancer clinic referrals and reaches a more ethnically diverse population. This has important implications for publicly funded environments with limited resources for genetic counseling.

Perineural invasion (PNI) is an adverse prognostic feature of pancreatic ductal adenocarcinoma (PDAC). However, the understanding of the interactions between tumors and neural signaling within the tumor microenvironment is limited. In the present study, we found that MUC21 servers as an independent risk factor for poor prognosis in PDAC. Furthermore, we demonstrated that MUC21 promoted the metastasis and PNI of PDAC cells by activating JNK and inducing epithelial-mesenchymal transition (EMT). Mechanistically, glial cell-derived neurotrophic factor, secreted by Schwann cells, phosphorylates the intracellular domain S543 of MUC21 via CDK1 in PDAC cells, facilitating the interaction between MUC21 and RAC2. This interaction leads to membrane anchoring and activation of RAC2, which in turn activates the JNK/ZEB1/EMT axis, ultimately enhancing the metastasis and PNI of PDAC cells. Our results present a novel mechanism of PNI, suggesting that MUC21 is a potential prognostic marker and therapeutic target for PDAC., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Pancreatic ductal adenocarcinoma (PDAC) is characterized by its fibrotic and stiff extracellular matrix. However, how the altered cell/extracellular-matrix signalling contributes to the PDAC tumour phenotype has been difficult to dissect. Here we design and engineer matrices that recapitulate the key hallmarks of the PDAC tumour extracellular matrix to address this knowledge gap. We show that patient-derived PDAC organoids from three patients develop resistance to several clinically relevant chemotherapies when cultured within high-stiffness matrices mechanically matched to in vivo tumours. Using genetic barcoding, we find that while matrix-specific clonal selection occurs, cellular heterogeneity is not the main driver of chemoresistance. Instead, matrix-induced chemoresistance occurs within a stiff environment due to the increased expression of drug efflux transporters mediated by CD44 receptor interactions with hyaluronan. Moreover, PDAC chemoresistance is reversible following transfer from high- to low-stiffness matrices, suggesting that targeting the fibrotic extracellular matrix may sensitize chemoresistant tumours. Overall, our findings support the potential of engineered matrices and patient-derived organoids for elucidating extracellular matrix contributions to human disease pathophysiology., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Recent studies reveal a critical role of tumor cell-released extracellular vesicles (EVs) in pancreatic cancer (PC) progression. However, driver genes that direct EV function, the EV-recipient cells, and their cellular response to EV uptake remain to be identified. Therefore, we studied the role of Bcl-2-associated-anthanogene 6 (BAG6), a regulator of EV biogenesis for cancer progression. We used a Cre recombinase/LoxP-based reporter system in combination with single-cell RNA sequencing to monitor in vivo EV uptake and tumor microenvironment (TME) changes in mouse models for pancreatic ductal adenocarcinoma (PDAC) in a Bag6 pro- or deficient background. In vivo data were validated using mouse and human organoids and patient samples. Our data demonstrated that Bag6-deficient subcutaneous and orthotopic PDAC tumors accelerated tumor growth dependent on EV release. Mechanistically, this was attributed to mast cell (MC) activation via EV-associated IL33. Activated MCs promoted tumor cell proliferation and altered the composition of the TME affecting fibroblast polarization and immune cell infiltration. Tumor cell proliferation and fibroblast polarization were mediated via the MC secretome containing high levels of PDGF and CD73. Patients with high BAG6 gene expression and high protein plasma level have a longer overall survival indicating clinical relevance. The current study revealed a so far unknown tumor-suppressing activity of BAG6 in PDAC. Bag6-deficiency allowed the release of EV-associated IL33 which modulate the TME via MC activation promoting aggressive tumor growth. MC depletion using imatinib diminished tumor growth providing a scientific rationale to consider imatinib for patients stratified with low BAG6 expression and high MC infiltration. EVs derived from BAG6-deficient pancreatic cancer cells induce MC activation via IL33/Il1rl1. The secretome of activated MCs induces tumor proliferation and changes in the TME, particularly shifting fibroblasts into an inflammatory cancer-associated fibroblast (iCAF) phenotype. Blocking EVs or depleting MCs restricts tumor growth., (© 2024. The Author(s).)

The E3 ubiquitin ligase thyroid hormone receptor interacting protein 12 (TRIP12) has been implicated in pancreatic adenocarcinoma (PDAC) through its role in mediating the degradation of pancreas transcription factor 1a (PTF1a). PTF1a is a transcription factor essential for the acinar differentiation state that is notably diminished during the early steps of pancreatic carcinogenesis. Despite these findings, the direct involvement of TRIP12 in the onset of pancreatic cancer has yet to be established. In this study, we demonstrated that TRIP12 protein was significantly upregulated in human pancreatic preneoplastic lesions. Furthermore, we observed that TRIP12 overexpression varied within PDAC samples and PDAC-derived cell lines. We further demonstrated that TRIP12 was required for PDAC-derived cell growth and for the expression of E2F-targeted genes. Acinar-to-ductal cell metaplasia (ADM) is a reversible process that reflects the high plasticity of acinar cells. ADM becomes irreversible in the presence of oncogenic Kras mutations and leads to the formation of preneoplastic lesions. Using two genetically modified mouse models, we showed that a loss of TRIP12 prevented acini from developing ADM in response to pancreatic injury. With two additional mouse models, we further discovered that a depletion of TRIP12 prevented the formation of Kras G12D -induced preneoplastic lesions and impaired metastasis formation in the presence of mutated Kras G12D and Trp53 R172H genes. In summary our study identified an overexpression of TRIP12 from the early stages of pancreatic carcinogenesis and proposed this E3 ubiquitin ligase as a novel regulator of acinar plasticity with an important dual role in initiation and metastatic steps of PDAC. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland., (© 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.)

Synthetic lethality is a novel model for cancer therapy. To understand the function and mechanism of BEN domain-containing protein 4 (BEND4) in pancreatic cancer, eight cell lines and a total of 492 cases of pancreatic neoplasia samples were included in this study. Methylation-specific polymerase chain reaction, CRISPR/Cas9, immunoprecipitation assay, comet assay, and xenograft mouse model were used. BEND4 is a new member of the BEN domain family. The expression of BEND4 is regulated by promoter region methylation. It is methylated in 58.1% (176/303) of pancreatic ductal adenocarcinoma (PDAC), 33.3% (14/42) of intraductal papillary mucinous neoplasm, 31.0% (13/42) of pancreatic neuroendocrine tumor, 14.3% (3/21) of mucinous cystic neoplasm, 4.3% (2/47) of solid pseudopapillary neoplasm, and 2.7% (1/37) of serous cystic neoplasm. BEND4 methylation is significantly associated with late-onset PDAC (> 50 years, P < 0.01) and tumor differentiation (P < 0.0001), and methylation of BEND4 is an independent poor prognostic marker (P < 0.01) in PDAC. Furthermore, BEND4 plays tumor-suppressive roles in vitro and in vivo. Mechanistically, BEND4 involves non-homologous end joining signaling by interacting with Ku80 and promotes DNA damage repair. Loss of BEND4 increased the sensitivity of PDAC cells to ATM inhibitor. Collectively, the present study revealed an uncharacterized tumor suppressor BEND4 and indicated that methylation of BEND4 may serve as a potential synthetic lethal marker for ATM inhibitor in PDAC treatment., (© 2024. Higher Education Press.)

Purpose: Guidelines recommend germline genetic testing (GT) for patients with pancreatic ductal adenocarcinoma (PDAC). This study aims to evaluate the utilization and outcomes of multigene panel GT in patients with PDAC., Methods: This retrospective, multisite study included patients with PDAC diagnosed between May 2018 and August 2020 at Mayo Clinic Arizona, Florida, and Minnesota. Discussion, uptake, and outcomes of GT were compared before (May 1, 2018-May 1, 2019) and after (August 1, 2019-August 1, 2020) the guideline update, accounting for a transition period., Results: The study identified 533 patients with PDAC, with 321 (60.2%) preguideline and 212 (39.8%) postguideline. Patient characteristics did not differ between the preguideline and postguideline periods. GT was discussed in 34.3% (110 of 321) of preguideline and 39.6% (84 of 212) of postguideline patients (odds ratio [OR], 1.26 [95% CI, 0.88 to 1.80]) and subsequently performed in 80.9% (89 of 110) of preguideline and 75.0% (63 of 84) of postguideline patients (OR, 1.10 [95% CI, 0.75 to 1.61]). Of 152 tested patients, 26 (17.1%) had a pathogenic variant (PV), of whom 17 (11.2%; 17 of 152) were PDAC-associated. Over the entire study period, GT was more likely in younger patients (65 v 70 years; P < .001), those seen by a medical oncologist (82.9% v 69.0%; P < .001), and those surviving more than 12 months from diagnosis (70.4% v 43.4%; P < .001). Demographics and personal/family cancer history were comparable between patients with and without a PDAC PV., Conclusion: GT remains underutilized despite National Comprehensive Cancer Network guideline recommendations. Given the poor prognosis of PDAC and potential implications of GT, efforts to increase utilization are needed to provide surveillance and support to both patients with PDAC and at-risk family members.

Among individuals with pancreatic ductal adenocarcinoma (PDAC) 5-10% have a pathogenic germline variant (PGV) in a PDAC susceptibility gene. Guidelines recommend genetic testing among all individuals with PDAC. Additionally, at-risk relatives of PDAC patients benefit from their own genetic education, risk assessment, and testing. Multigene panel testing (MGPT) can identify individuals with inherited cancer risk who can benefit from early cancer surveillance and risk reduction strategies. This manuscript discusses various healthcare delivery models for MGPT including traditional in-person genetic counseling, novel integrated in-person infrastructures, telemedicine genetics care via telephone- or video-visits and direct-to-consumer testing. Barriers and facilitators to care on the individual, provider, and system level are also outlined including specific considerations for historically marginalized communities., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Competing Interests: Conflicts of interest None declared.

Intraductal tubulopapillary neoplasms (ITPNs) are rare pancreatic tumors with distinct histological and molecular features. Distinction of ITPN from other pancreatic neoplasms is crucial given the known favorable prognosis and the high frequency and diversity of potentially targetable fusions in ITPN. While the histological features of ITPN are well documented, there are few reports on the cytological features, and molecular characterization of ITPN. The authors reported three cases diagnosed in their laboratory between 2016 and 2021. Clinical data, cytomorphological and histological features, with immunophenotypic and molecular characterizations of these cases are described and compared with those reported in the literature. All 3 cases were diagnosed as ITPN based on the microscopic presence of intraductal nodules composed of tightly packed small tubular glands lined by cuboidal cells lacking apparent mucin. On molecular profiling KRAS and TP53 variants were found in Case 1, FGFR2-INA fusion in Case 2, and STARD3NL-BRAF fusion was detected in Case 3. Immunohistochemistry (IHC) revealed that the neoplastic cells in Case 1 were MUC2 positive and MUC6 negative, but in Cases 2 and 3, were negative for MUC2 and positive for MUC6. These results demonstrate the immunophenotypic and molecular variabilities of histologically similar pancreatic neoplasms. The absence of alterations characteristic of more common pancreatic neoplasms should prompt the consideration of fusion studies in morphologically relevant cases. The combination of morphological, IHC, and molecular analyses is important for reliable identification of ITPN given its potential clinical management implications., Competing Interests: Declaration of competing interest The authors have nothing to disclose., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Intraductal oncocytic papillary neoplasms (IOPNs) of the pancreatobiliary tract are considered a separate entity from intraductal papillary mucinous neoplasms (IPMNs), especially because of the distinct molecular alterations represented by PRKACA or PRKACB fusion. However, IOPNs display a spectrum of cytoarchitectural features. Typically, an IOPN is composed of arborizing papillae lined by layers of cells with oncocytic cytoplasm, prominent nucleoli, and intraepithelial lumina, while a significant subset shows atypical morphology: lack of the characteristic cytoarchitectural features such as arborizing papillae and prominent nucleoli, or mixture with nononcocytic IPMN-like components within a single lesion. To elucidate the tumorigenesis and morphologic spectrum of IOPNs, we analyzed 22 IOPNs, including those with atypical morphology for PRKACA/PRKACB fusions in each different component separately using fluorescence in situ hybridization. In total, 18 of 22 (82%) cases harbored PRKACA/PRKACB fusions, including 3 of 3 (100%) purely typical IOPNs and 15 of 19 (79%) IOPNs with atypical morphology. In the latter, PRKACA/PRKACB fusions were noted in atypical components as well as typical IOPN components. Notably, gastric-type IPMN-like components in the fusion-positive cases were usually low grade and had scattered neoplastic cells with eosinophilic cytoplasm, a morphologic feature suggestive of an early lesion of IOPN. In summary, most IOPNs with atypical morphology either lack characteristic cytoarchitectural features or exhibit a mixture with nononcocytic IPMN-like components, harbored PRKACA/PRKACB fusion as did typical IOPN components. Our observations expanded the morphologic spectrum of IOPNs. They are expected to be useful for correct diagnosis of this neoplasm., Competing Interests: Conflicts of Interest and Source of Funding: The authors have disclosed that they have no significant relationships with or financial interest in any commercial companies pertaining to this article., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)