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The article discusses a study on ductal pancreatic cancer in humans and mice. Pancreatic ductal adenocarcinoma (PDA) misses early detection and resists current treatments, earning its distinction as the most lethal malignancy by organ site in the western world. The lessons learned from modeling PDA discussed in the article may be applicableto other tumor types and illuminate general principles of carcinogenesis.

Objective: The dysregulation of the axon guidance pathway is common in pancreatic ductal adenocarcinoma (PDAC), yet our understanding of its biological relevance is limited. Here, we investigated the functional role of the axon guidance cue SEMA3A in supporting PDAC progression., Design: We integrated bulk and single-cell transcriptomic datasets of human PDAC with in situ hybridisation analyses of patients' tissues to evaluate SEMA3A expression in molecular subtypes of PDAC. Gain and loss of function experiments in PDAC cell lines and organoids were performed to dissect how SEMA3A contributes to define a biologically aggressive phenotype., Results: In PDAC tissues, SEMA3A is expressed by stromal elements and selectively enriched in basal-like/squamous epithelial cells. Accordingly, expression of SEMA3A in PDAC cells is induced by both cell-intrinsic and cell-extrinsic determinants of the basal-like phenotype. In vitro , SEMA3A promotes cell migration as well as anoikis resistance. At the molecular level, these phenotypes are associated with increased focal adhesion kinase signalling through canonical SEMA3A-NRP1 axis. SEMA3A provides mouse PDAC cells with greater metastatic competence and favours intratumoural infiltration of tumour-associated macrophages and reduced density of T cells. Mechanistically, SEMA3A functions as chemoattractant for macrophages and skews their polarisation towards an M2-like phenotype. In SEMA3A high tumours, depletion of macrophages results in greater intratumour infiltration by CD8+T cells and better control of the disease from antitumour treatment., Conclusions: Here, we show that SEMA3A is a stress-sensitive locus that promotes the malignant phenotype of basal-like PDAC through both cell-intrinsic and cell-extrinsic mechanisms., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY. Published by BMJ.)

Intratumoral B cell responses are associated with more favorable clinical outcomes in human pancreatic ductal adenocarcinoma (PDAC). However, the antigens driving these B cell responses are largely unknown. We sought to discover these antigens by using single-cell RNA sequencing (scRNA-Seq) and immunoglobulin (Ig) sequencing of tumor-infiltrating immune cells from 7 primary PDAC samples. We identified activated T and B cell responses and evidence of germinal center reactions. Ig sequencing identified plasma cell (PC) clones expressing isotype-switched and hypermutated Igs, suggesting the occurrence of T cell-dependent B cell responses. We assessed the reactivity of 41 recombinant antibodies that represented the products of 235 PCs and 12 B cells toward multiple cell lines and PDAC tissues and observed frequent staining of intracellular self-antigens. Three of these antigens were identified: the filamentous actin (F-actin), the nucleic protein RuvB like AAA ATPase 2 (RUVBL2), and the mitochondrial protein heat shock protein family D (Hsp60) member 1 (HSPD1). Antibody titers against F-actin and HSPD1 were substantially elevated in the plasma of patients with PDAC compared with healthy donors. Thus, PCs in PDAC produce autoantibodies reacting with intracellular self-antigens, which may result from promotion of preexisting, autoreactive B cell responses. These observations indicate the chronic inflammatory microenvironment of PDAC can support the adaptive immune response.

Background & Aims: SIRT5 plays pleiotropic roles via post-translational modifications, serving as a tumor suppressor, or an oncogene, in different tumors. However, the role SIRT5 plays in the initiation and progression of pancreatic ductal adenocarcinoma (PDAC) remains unknown., Methods: Published datasets and tissue arrays with SIRT5 staining were used to investigate the clinical relevance of SIRT5 in PDAC. Furthermore, to define the role of SIRT5 in the carcinogenesis of PDAC, we generated autochthonous mouse models with conditional Sirt5 knockout. Moreover, to examine the mechanistic role of SIRT5 in PDAC carcinogenesis, SIRT5 was knocked down in PDAC cell lines and organoids, followed by metabolomics and proteomics studies. A novel SIRT5 activator was used for therapeutic studies in organoids and patient-derived xenografts., Results: SIRT5 expression negatively regulated tumor cell proliferation and correlated with a favorable prognosis in patients with PDAC. Genetic ablation of Sirt5 in PDAC mouse models promoted acinar-to-ductal metaplasia, precursor lesions, and pancreatic tumorigenesis, resulting in poor survival. Mechanistically, SIRT5 loss enhanced glutamine and glutathione metabolism via acetylation-mediated activation of GOT1. A selective SIRT5 activator, MC3138, phenocopied the effects of SIRT5 overexpression and exhibited antitumor effects on human PDAC cells. MC3138 also diminished nucleotide pools, sensitizing human PDAC cell lines, organoids, and patient-derived xenografts to gemcitabine., Conclusions: Collectively, we identify SIRT5 as a key tumor suppressor in PDAC, whose loss promotes tumorigenesis through increased noncanonic use of glutamine via GOT1, and that SIRT5 activation is a novel therapeutic strategy to target PDAC., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

The COVID-19 pandemic is profoundly changing cancer researchers and cancer research. Leaders from different fields and at different career stages share their perspectives., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The advance of science is dependent upon collaboration, which does not have a visa attached to it. Indeed, over 40% of all American-based Nobel Prize winners are immigrants, and data from the National Science Foundation show that 49% of postdocs and 29% of science and engineering faculty in the US are foreign-born. However, restrictive new immigration policies in the US have left many scientists deeply concerned about their future and many American-based laboratories worried about attracting the best talent. At JEM, we're celebrating immigration by sharing the experiences of immigrant and nonimmigrant scientists on our editorial board. Alexander Rudensky and Jean-Laurent Casanova give their firsthand perspective on immigrating to the US, while Jedd Wolchok, Carl Nathan, David Holtzman, Susan Kaech, Lewis Lanier, and David Tuveson reflect on how immigration has affected their laboratories., (© 2020 Casanova et al.)

Significant advances have been made towards understanding the role of immune cell-tumor interplay in either suppressing or promoting tumor growth, progression, and recurrence, however, the roles of additional stromal elements, cell types and/or cell states remain ill-defined. The overarching goal of this NCI-sponsored workshop was to highlight and integrate the critical functions of non-immune stromal components in regulating tumor heterogeneity and its impact on tumor initiation, progression, and resistance to therapy. The workshop explored the opposing roles of tumor supportive versus suppressive stroma and how cellular composition and function may be altered during disease progression. It also highlighted microenvironment-centered mechanisms dictating indolence or aggressiveness of early lesions and how spatial geography impacts stromal attributes and function. The prognostic and therapeutic implications as well as potential vulnerabilities within the heterogeneous tumor microenvironment were also discussed. These broad topics were included in this workshop as an effort to identify current challenges and knowledge gaps in the field., Competing Interests: CONFLICTS OF INTEREST Authors have no conflicts of interest to declare., (Copyright: © 2020 Vickman et al.)

Objective: Treatment options for non-hospitalised patients with coronavirus disease 2019 (COVID-19) to reduce morbidity, mortality and spread of the disease are an urgent global need. The over-the-counter histamine-2 receptor antagonist famotidine is a putative therapy for COVID-19. We quantitively assessed longitudinal changes in patient reported outcome measures in non-hospitalised patients with COVID-19 who self-administered high-dose famotidine orally., Design: Patients were enrolled consecutively after signing written informed consent. Data on demographics, COVID-19 diagnosis, famotidine use, drug-related side effects, temperature measurements, oxygen saturations and symptom scores were obtained using questionnaires and telephone interviews. Based on a National Institute of Health (NIH)-endorsed Protocol to research Patient Experience of COVID-19, we collected longitudinal severity scores of five symptoms (cough, shortness of breath, fatigue, headaches and anosmia) and general unwellness on a four-point ordinal scale modelled on performance status scoring. All data are reported at the patient level. Longitudinal combined normalised symptom scores were statistically compared., Results: Ten consecutive patients with COVID-19 who self-administered high-dose oral famotidine were identified. The most frequently used famotidine regimen was 80 mg three times daily (n=6) for a median of 11 days (range: 5-21 days). Famotidine was well tolerated. All patients reported marked improvements of disease related symptoms after starting famotidine. The combined symptom score improved significantly within 24 hours of starting famotidine and peripheral oxygen saturation (n=2) and device recorded activity (n=1) increased., Conclusions: The results of this case series suggest that high-dose oral famotidine is well tolerated and associated with improved patient-reported outcomes in non-hospitalised patients with COVID-19., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Prior studies demonstrated that the irreversible ERBB1/2/4 inhibitor neratinib caused plasma membrane-associated mutant K-RAS to localize in intracellular vesicles, concomitant with its degradation. Herein, we discovered that neratinib interacted with the chemically distinct irreversible ERBB1/2/4 inhibitor afatinib to reduce expression of ERBB1, ERBB2, K-RAS and N-RAS; this was associated with greater-than-additive cell killing of pancreatic tumor cells. Knock down of Beclin1, ATG16L1, Rubicon or cathepsin B significantly lowered the ability of neratinib to reduce ERBB1 and K-RAS expression, and to cause tumor cell death. Knock down of ATM-AMPK suppressed vesicle formation and knock down of cathepsin B-AIF significantly reduced neratinib lethality. PKG phosphorylates K-RAS and HMG CoA reductase inhibitors reduce K-RAS farnesylation both of which remove K-RAS from the plasma membrane, abolishing its activity. Neratinib interacted with the PKG activator sildenafil and the HMG CoA reductase inhibitor atorvastatin to further reduce K-RAS expression, and to further enhance cell killing. Neratinib is also a Ste20 kinase family inhibitor and in carcinoma cells, and hematopoietic cancer cells lacking ERBB1/2/4, it reduced K-RAS expression and the phosphorylation of MST1/3/4/Ezrin by ~ 30%. Neratinib increased LATS1 phosphorylation as well as that of YAP and TAZ also by ~ 30%, caused the majority of YAP to translocate into the cytosol and reduced YAP/TAZ protein levels. Neratinib lethality was enhanced by knock down of YAP. Neratinib, in a Rubicon-dependent fashion, reduced PAK1 phosphorylation and that of its substrate Merlin. Our data demonstrate that neratinib coordinately suppresses both mutant K-RAS and YAP function to kill pancreatic tumor cells.

Introduction : Pancreatic cancer (PC) remains a disease with a dismal prognosis. Despite accounting for only 3% of cancer diagnosis, 7% of all cancer deaths in the United States are from PC. This is explained by many being diagnosed with late-stage disease and the cancer's resistance to chemotherapy. Since 1996 there have only been two upfront regimens found to be superior to gemcitabine, FOLFIRINOX (5-fluorouracil/leucovorin and oxaliplatin) and gemcitabine plus nab-paclitaxel. Areas covered : Clinical pharmacology of newer agents that are either approved or being investigated in the management of PC. Knowledge of their pharmacokinetics, pharmacodynamics, and pharmacogenetics can be used to predict outcomes for specific patient populations. Drugs discussed include nanoliposomal irinotecan, pegvorhyaluronidase alfa, poly (ADP-ribose) polymerase enzyme inhibitors, larotrectinib, and napabucasin. Expert opinion : PC is a heterogeneous disease and outcomes are likely to improve as better predictive models of an individual's response to different therapies are developed. This may be best accomplished through phase 0 studies and the use of tumor organoid models grown from initial biopsies or resected tissue. The genetic and physical makeup of the tumor as well as the functional characterization in patient-derived organoids (PDOs), can help guide which agents may be most efficacious or toxic.

Organoids are microscopic self-organizing, three-dimensional structures that are grown from stem cells in vitro. They recapitulate many structural and functional aspects of their in vivo counterpart organs. This versatile technology has led to the development of many novel human cancer models. It is now possible to create indefinitely expanding organoids starting from tumor tissue of individuals suffering from a range of carcinomas. Alternatively, CRISPR-based gene modification allows the engineering of organoid models of cancer through the introduction of any combination of cancer gene alterations to normal organoids. When combined with immune cells and fibroblasts, tumor organoids become models for the cancer microenvironment enabling immune-oncology applications. Emerging evidence indicates that organoids can be used to accurately predict drug responses in a personalized treatment setting. Here, we review the current state and future prospects of the rapidly evolving tumor organoid field., (Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

Oncogenic Kras are genetic dependencies for the majority of pancreatic and colorectal adenocarcinomas; however, much remains to be understood regarding its tropism to these carcinomas. Recently developed organoid technology presents a more representative model culture system for pancreatic and colon epithelial tissues as well as better fostering the culture of nonimmortalized cells than two-dimensional culture. These advantages enable cancer researchers to directly compare tumor and normal tissue models to better study tumor initiation as well as therapeutic efficacy. Although in vivo models better model the complexity of multiple cell types, the organoid system allows for easier genetic manipulations and isolation of specific cell types. Furthermore, syngeneic orthotopically transplanted organoids recapitulate tumor histologically and gene expression of the tumors from which they were derived. Thus, organoids may extend the use of genetically engineered mouse models. These advantages of organoid cultures allow for many questions, including but not limited to studying the interaction between different cell types within a tumor and elucidating dependencies of Kras-driven tumors., (Copyright © 2018 Cold Spring Harbor Laboratory Press; all rights reserved.)

Traditional high-throughput drug screening in oncology routinely relies on two-dimensional (2D) cell models, which inadequately recapitulate the physiologic context of cancer. Three-dimensional (3D) cell models are thought to better mimic the complexity of in vivo tumors. Numerous methods to culture 3D organoids have been described, but most are nonhomogeneous and expensive, and hence impractical for high-throughput screening (HTS) purposes. Here we describe an HTS-compatible method that enables the consistent production of organoids in standard flat-bottom 384- and 1536-well plates by combining the use of a cell-repellent surface with a bioprinting technology incorporating magnetic force. We validated this homogeneous process by evaluating the effects of well-characterized anticancer agents against four patient-derived pancreatic cancer KRAS mutant-associated primary cells, including cancer-associated fibroblasts. This technology was tested for its compatibility with HTS automation by completing a cytotoxicity pilot screen of ~3300 approved drugs. To highlight the benefits of the 3D format, we performed this pilot screen in parallel in both the 2D and 3D assays. These data indicate that this technique can be readily applied to support large-scale drug screening relying on clinically relevant, ex vivo 3D tumor models directly harvested from patients, an important milestone toward personalized medicine.

Background: The Notch pathway is frequently activated in cancer. Pathway inhibition by γ-secretase inhibitors has been shown to be effective in pre-clinical models of pancreatic cancer, in combination with gemcitabine., Methods: A multi-centre, non-randomised Bayesian adaptive design study of MK-0752, administered per os weekly, in combination with gemcitabine administered intravenously on days 1, 8 and 15 (28 day cycle) at 800 or 1000 mg m -2 , was performed to determine the safety of combination treatment and the recommended phase 2 dose (RP2D). Secondary and tertiary objectives included tumour response, plasma and tumour MK-0752 concentration, and inhibition of the Notch pathway in hair follicles and tumour., Results: Overall, 44 eligible patients (performance status 0 or 1 with adequate organ function) received gemcitabine and MK-0752 as first or second line treatment for pancreatic cancer. RP2Ds of MK-0752 and gemcitabine as single agents could be combined safely. The Bayesian algorithm allowed further dose escalation, but pharmacokinetic analysis showed no increase in MK-0752 AUC (area under the curve) beyond 1800 mg once weekly. Tumour response evaluation was available in 19 patients; 13 achieved stable disease and 1 patient achieved a confirmed partial response., Conclusions: Gemcitabine and a γ-secretase inhibitor (MK-0752) can be combined at their full, single-agent RP2Ds.

This manuscript follows a single patient with pancreatic adenocarcinoma for a five year period, detailing the clinical record, pathology, the dynamic evolution of molecular and cellular alterations as well as the responses to treatments with chemotherapies, targeted therapies and immunotherapies. DNA and RNA samples from biopsies and blood identified a dynamic set of changes in allelic imbalances and copy number variations in response to therapies. Organoid cultures established from biopsies over time were employed for extensive drug testing to determine if this approach was feasible for treatments. When an unusual drug response was detected, an extensive RNA sequencing analysis was employed to establish novel mechanisms of action of this drug. Organoid cell cultures were employed to identify possible antigens associated with the tumor and the patient's T-cells were expanded against one of these antigens. Similar and identical T-cell receptor sequences were observed in the initial biopsy and the expanded T-cell population. Immunotherapy treatment failed to shrink the tumor, which had undergone an epithelial to mesenchymal transition prior to therapy. A warm autopsy of the metastatic lung tumor permitted an extensive analysis of tumor heterogeneity over five years of treatment and surgery. This detailed analysis of the clinical descriptions, imaging, pathology, molecular and cellular evolution of the tumors, treatments, and responses to chemotherapy, targeted therapies, and immunotherapies, as well as attempts at the development of personalized medical treatments for a single patient should provide a valuable guide to future directions in cancer treatment., Competing Interests: CONFLICTS OF INTEREST There are no conflicts of interest.

Nerves are a notable feature of the tumor microenvironment in some epithelial tumors, but their role in the malignant progression of pancreatic ductal adenocarcinoma (PDAC) is uncertain. Here, we identify dense innervation in the microenvironment of precancerous pancreatic lesions, known as pancreatic intraepithelial neoplasms (PanIN), and describe a unique subpopulation of neuroendocrine PanIN cells that express the neuropeptide substance P (SP) receptor neurokinin 1-R (NK1-R). Using organoid culture, we demonstrated that sensory neurons promoted the proliferation of PanIN organoids via SP-NK1-R signaling and STAT3 activation. Nerve-responsive neuroendocrine cells exerted trophic influences and potentiated global PanIN organoid growth. Sensory denervation of a genetically engineered mouse model of PDAC led to loss of STAT3 activation, a decrease in the neoplastic neuroendocrine cell population, and impaired PanIN progression to tumor. Overall, our data provide evidence that nerves of the PanIN microenvironment promote oncogenesis, likely via direct signaling to neoplastic neuroendocrine cells capable of trophic influences. These findings identify neuroepithelial cross-talk as a potential novel target in PDAC treatment. Cancer Res; 77(8); 1868-79. ©2017 AACR ., (©2017 American Association for Cancer Research.)

Modulation of Toll-like receptor (TLR) signaling can have protective or protumorigenic effects on oncogenesis depending on the cancer subtype and on specific inflammatory elements within the tumor milieu. We found that TLR9 is widely expressed early during the course of pancreatic transformation and that TLR9 ligands are ubiquitous within the tumor microenvironment. TLR9 ligation markedly accelerates oncogenesis, whereas TLR9 deletion is protective. We show that TLR9 activation has distinct effects on the epithelial, inflammatory, and fibrogenic cellular subsets in pancreatic carcinoma and plays a central role in cross talk between these compartments. Specifically, TLR9 activation can induce proinflammatory signaling in transformed epithelial cells, but does not elicit oncogene expression or cancer cell proliferation. Conversely, TLR9 ligation induces pancreatic stellate cells (PSCs) to become fibrogenic and secrete chemokines that promote epithelial cell proliferation. TLR9-activated PSCs mediate their protumorigenic effects on the epithelial compartment via CCL11. Additionally, TLR9 has immune-suppressive effects in the tumor microenvironment (TME) via induction of regulatory T cell recruitment and myeloid-derived suppressor cell proliferation. Collectively, our work shows that TLR9 has protumorigenic effects in pancreatic carcinoma which are distinct from its influence in extrapancreatic malignancies and from the mechanistic effects of other TLRs on pancreatic oncogenesis., (© 2015 Zambirinis et al.)