bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract B011: Identifying druggable lipid synthesis targets as novel therapeutics for pancreatic cancer
Authors: Kubota Casie S. , Ishida Chiaki T. , Myers Stephanie , Espenshade Peter J.
Published: November 2022

Lipid metabolic reprogramming is a hallmark of cancer that contributes to tumorigenesis by supporting energy metabolism and the synthesis of signaling molecules, cellular membranes, and protein modifications. Cells modulate lipid metabolic genes through the regulation of sterol regulatory element-binding proteins (SREBPs), which serve as transcriptional activators of genes responsible for fatty acid and cholesterol synthesis and uptake. Despite efforts demonstrating that the SREBP pathway is an attractive chemotherapeutic target, a potent bioavailable inhibitor of the pathway has not yet been discovered. Here, we identify druggable SREBP target genes as potential targets in pancreatic ductal adenocarcinoma (PDAC). Results: To discover candidate genes, we constructed a CRISPR knockout library containing 148 known SREBP target genes. We used a patient-derived PDAC cell line to conduct the knockout screens in vivo (n = 7 tumors) by injecting library-infected cells into the pancreas of nude mice. After 4 weeks of growth, mouse PDAC tumors showed a statistically significant depletion of guide RNAs targeting 8 genes within the mevalonate pathway, which is responsible for synthesizing cholesterol and isoprenoids such as farnesyl-diphosphate and geranyl-diphosphate. One of the most significant hits was HMG-CoA reductase (HMGCR), which catalyzes the formation of mevalonate. We chose to investigate statins, which are a well-characterized class of FDA-approved drugs that inhibit HMGCR. Using flow cytometry, we stained for annexin-V as a marker for apoptosis and found minimal cell death induced by Fluvastatin alone. Given that inhibiting HMGCR would disrupt lipid homeostasis and in turn activate the SREBP pathway, we hypothesized that a combination therapy with an SREBP inhibitor, TMDP, would potentiate statin-induced cell death. We observed minimal cell death with TMDP alone, but striking synergy between Fluvastatin and TMDP, showing a five-fold increase in annexin-V staining after 48 hours. Mevalonate and geranylgeranyl-diphosphate both fully rescued this cell death to basal levels. Conclusions: In vivo CRISPR screening is a powerful tool for the identification of novel therapeutic targets for cancer. We found that the mevalonate pathway plays a significant role in pancreatic tumor growth in vivo and that existing FDA-approved drugs can be used in combination with an SREBP inhibitor to dramatically enhance cell killing in vitro.

Citation Format: Casie S. Kubota, Chiaki T. Ishida, Stephanie Myers, Peter J. Espenshade. Identifying druggable lipid synthesis targets as novel therapeutics for pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr B011.
Abstract B015: Systemic reprogramming of fibroblasts and immune cells precedes metastatic spread in pancreatic cancer
Authors: Opsahl Emily L. Lasse , Velez-Delgado Ashley , Donahue Katelyn L. , Kadiyala Padma , Espinoza Carlos , Zhang Yaqing , di Magliano Marina Pasca
Published: November 2022

Oncogenic KRAS (Kras*) is a near-universal driver of pancreatic ductal adenocarcinoma (PDA), and its activity is required for the formation of the PDA precursor lesions, pancreatic intraepithelial neoplasia (PanIN). PanIN formation is accompanied by fibrosis and immune cell infiltration, creating a precursor tumor microenvironment (PME) that is maintained and evolves through the disease progression. In mice bearing overt pancreatic cancer, pancreatic cells secrete specific factors to prime the liver and lung, forming the premetastatic niche. Presently, it remains to be elucidated at what stage of PDA tumorigenesis the premetastatic niche is initiated, as well as the mechanisms underlying this formation. As PDA patients are commonly diagnosed with metastatic disease, it is imperative to understand the mechanism underlying formation of the premetastatic niche, as well as determinants of metastasis outgrowth. To determine whether Kras*-dependent signals are required for the formation of the premetastatic niche, we used an inducible and reversible murine model of pancreas-specific Kras* expression developed by our group known as the iKras* mouse. We expressed Kras* in the pancreatic epithelium of adult mice for 16 weeks and validated the presence of advanced PanIN lesions without overt malignancy. We then performed single cell RNA sequencing (scRNA-seq) on the pancreas, liver, and lung of these mice, with liver and lung being common sites of metastasis for pancreatic cancer. We have previously shown that pancreatic fibroblasts are reprogrammed early during carcinogenesis, a finding that holds true at this later timepoint. Interestingly, we observed parallel changes in gene expression in fibroblasts, macrophages, and T cells in the lungs of PanIN bearing mice. Ongoing studies aim to validate the changes seen in the scRNA-seq and functionally evaluate systemic activation of fibroblasts and immune cells within the premetastatic niche.

Citation Format: Emily L. Lasse Opsahl, Ashley Velez-Delgado, Katelyn L. Donahue, Padma Kadiyala, Carlos Espinoza, Yaqing Zhang, Marina Pasca di Magliano. Systemic reprogramming of fibroblasts and immune cells precedes metastatic spread in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr B015.
Abstract B042: Inhibition of CPSF3 attenuates pancreatic cancer cell proliferation through disruption of histone processing
Authors: Alahmari Abdulrahman A. , Chaubey Aditi , Tisdale Arwen , Schwarz Carla , Cornwell Abigail , Maraszek Kathryn , Paterson Emily , Kim Minsuh , Venkat Swati , Gomez Eduardo Cortes , Wang Jianmin , Gurova Katerina , Feigin Michael E.
Published: November 2022

Treatment regimens of pancreatic ductal adenocarcinoma (PDAC) are limited and minimally effective which potentiates the importance of discovering novel potential drug targets. We discovered widespread dysregulation of alternative polyadenylation (APA) in PDAC patients. APA is a pre-mRNA processing mechanism that generates mRNAs isoforms with distinct 3’ untranslated regions (3’UTRs). These isoforms contribute to the expression and function of mRNAs and proteins. Our recent study revealed that APA alterations in PDAC drive dysregulation of PDAC-promoting genes and present a reliable prognostic marker. APA is controlled by a suite of genes, including cleavage and polyadenylation specificity factor 3 (CPSF3). Because CPSF3 is the endonuclease that catalyzes mRNA cleavage, we here sought to target CPSF3 in PDAC. We show that CPSF3 expression is significantly upregulated and associated with unfavorable prognosis in PDAC patients. Loss of CPSF3 decreases PDAC cell proliferation, clonogenicity and tumor growth. We show that CPSF3 loss causes APA changes of tumor-associated genes and validate the tumor suppressing activity of one APA-altered gene, FHL1. Using JTE-607, a chemical inhibitor of CPSF3, we find that PDAC cells are preferentially sensitive while non-transformed cell lines are resistant to CPSF3 inhibition. Notably, we show that JTE-607 decreases proliferation-dependent histone expression and disrupts nucleosome assembly. Finally, we find that JTE-607 arrests cells in early to mid S-phase of the cell cycle, resembling histone defect-induced cell cycle arrest. Overall, we reveal alternative polyadenylation and histone processing as two distinct mechanisms underlying CPSF3-induced attenuation of cell proliferation and identify CPSF3 as a potential therapeutic target in PDAC.

Citation Format: Abdulrahman A. Alahmari, Aditi Chaubey, Arwen Tisdale, Carla Schwarz, Abigail Cornwell, Kathryn Maraszek, Emily Paterson, Minsuh Kim, Swati Venkat, Eduardo Cortes Gomez, Jianmin Wang, Katerina Gurova, Michael E. Feigin. Inhibition of CPSF3 attenuates pancreatic cancer cell proliferation through disruption of histone processing [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr B042.
Abstract B052: Uncovering the lineage of chemosensory cells in the progression of pancreatic cancer
Authors: Salas-Escabillas Daniel , Crawford Howard , Hoffman Megan
Published: November 2022

Pancreatic ductal adenocarcinoma (PDA) is predicted to become the second leading cause of cancer-related death in 2025 and has a 5-year survival rate of only 11%. Progression of the pancreatic disease is in part driven by the transdifferentiation of acinar cells into metaplastic ducts in the pancreas. Metaplastic tuft cells (MTCs) are a specialized subset of the metaplastic epithelium that has the potential to drive tumor progression through communication with the microenvironment and modulate PDA progression. Also known as solitary chemosensory cells, tuft cells were first discovered in rodent luminal surfaces, including the nose, stomach, intestine, and bladder, more than 60 years ago. They are characterized by the “tuft” of microvilli reaching into the lumen and, only recently, have studies started to determine the role of normal tuft cells in different organs. These studies determined that tuft cells have different roles depending on the organ in which they reside. Tuft cells are found in several different organs during normal development; however, studies have shown that tuft cells are not present in a normal pancreas. MTCs are only present in the pancreas in PanINs during PDA progression in both humans and mice. Furthermore, the population of MTCs in the pancreas disappears as PDA progresses into invasive carcinoma when using canonical markers of tuft cells. We know little about the role of MTCs in the pancreas, but prior studies have suggested their role as a progenitor cell during PDA. However, these studies do not exclusively mark MTCs during their genesis in a progressive model of PDA due to a lack of a mouse model as well as the complexity of culturing them ex vivo. We have generated a unique mouse model to drive lineage tracing of MTCs during PDA, and I have preliminary data to suggest that MTCs are not disappearing as PDA progresses but can transdifferentiate into another cell type that is correlated with lower survival in patients.

Citation Format: Daniel Salas-Escabillas, Howard Crawford, Megan Hoffman. Uncovering the lineage of chemosensory cells in the progression of pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr B052.
Abstract B058: The lincRNA Neat1 controls SWI/SNF occupancy to retain ductal cell identity in the pancreas
Authors: Berry Emily , Soares Zamira Guerra , Twardowski Jennifer , Wang Wenjia , Hezel Aram , Mello Stephano S.
Published: November 2022

Pancreatic ductal adenocarcinoma (PDAC) is the 4th leading cause of cancer deaths in the US and among the most fatal. Cancer originating from the ductal compartment often leads to the emergence of the highly aggressive basal subtype of PDAC. Defining the cellular and molecular origins of basal subtype PDAC would greatly improve our ability to devise strategies to treat patients with this aggressive form of PDAC. Towards this end, we have discovered that loss of the long intergenic non-coding RNA (lincRNA) Neat1 promotes ductal cell plasticity, dramatically inducing the formation of duct-derived preneoplastic lesions known as intraductal papillary mucinous neoplasms (IPMNs), and increasing the likelihood of basal subtype PDAC. Neat1 deficiency has a profound impact on chromatin organization and on the distribution of the SWI/SNF chromatin remodeling complex at the chromatin, suggesting that Neat1 maintains ductal cell identity via impacting SWI/SNF function. Probing for Brg1, a core component of the SWI/SNF complex, we demonstrated that Neat1 loss leads to decreased SWI/SNF binding at enhancer regions. This idea is further supported by the phenotypic similarities between mice deficient for Neat1 and Arid1a. We thus hypothesize that Neat1 and SWI/SNF are critical for the maintenance of ductal cell identity in the pancreas via controlling SWI/SNF-dependent enhancer activity and that loss of Neat1 increases ductal cell transformation and thus facilitates IPMN formation and progression to basal subtype PDAC. These studies will reveal both the biological role and mechanistic underpinnings of the lincRNA Neat1 in relationship with the SWI/SNF chromatin remodeling complexes. Our data suggest that Neat1 or SWI/SNF loss-of-function predisposes pancreatic ductal cells towards the most aggressive subtype of PDAC, laying critical groundwork for development of new diagnostic tools and therapeutic targets.

Citation Format: Emily Berry, Zamira Guerra Soares, Jennifer Twardowski, Wenjia Wang, Aram Hezel, Stephano S. Mello. The lincRNA Neat1 controls SWI/SNF occupancy to retain ductal cell identity in the pancreas [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr B058.
Abstract B059: RNA exosome component EXOSC4 amplified in multiple cancer types is required for the pancreatic cancer cell survival via the regulation of BIK and SESN2 mRNA
Authors: Taniue Kenzui , Mizukami Yusuke , Akimitsu Nobuyoshi
Published: November 2022

RNA decay plays a crucial role in the post-transcriptional regulation of gene expression. The RNA exosome is a multi-subunit ribonuclease complex that is evolutionally conserved and the major cellular machinery for the surveillance, processing, degradation, and turnover of diverse RNAs essential for cell viability. The RNA exosome is composed of a catalytically inactive barrel structure of nine core subunits (known as EXO9) that achieves its catalytic activity via the interaction with the exoribonuclease exosome component 10 (EXOSC10), the exo/endo-ribonuclease DIS3, and the two DIS3-like proteins (the exoribonucleases DIS3L and DIS3L2). Moreover, exosome activity is regulated by associated co-factors and RNA-binding adaptor proteins that recruit the exosome to its many targets. Here we performed integrated genomic and clinicopathological analyses of 27 RNA exosome components across 32 tumor types using The Cancer Genome Atlas PanCancer Atlas Studies’ datasets. We discovered that the EXOSC4 gene, which encodes a barrel component of the RNA exosome, was amplified across multiple cancer types. We further found that EXOSC4 alteration is associated with a poor prognosis in pancreatic cancer patients. Moreover, we demonstrated that EXOSC4 is required for the survival of pancreatic cancer cells. EXOSC4 also repressed BIK expression and destabilized SESN2 mRNA by promoting its degradation. Furthermore, knockdown of BIK and SESN2 could partially rescue pancreatic cells from the reduction in cell viability caused by EXOSC4 knockdown. Our study provides evidence for EXOSC4-mediated regulation of BIK and SESN2 mRNA in the survival of pancreatic tumor cells.

Citation Format: Kenzui Taniue, Yusuke Mizukami, Nobuyoshi Akimitsu. RNA exosome component EXOSC4 amplified in multiple cancer types is required for the pancreatic cancer cell survival via the regulation of BIK and SESN2 mRNA [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr B059.
Abstract B073: C-terminal Binding Protein (CtBP): a critical regulator of ErbB2/3 signaling in PDAC
Authors: Chougoni Kranthi Kumar , Park Haemin , Damle Priyadarshan K. , Dcona Martin Michael , Szomju Barbara , Dozmorov Mikhail G. , Idowu Michael , Grossman Steven R.
Published: November 2022

Pancreatic ductal adenocarcinoma (PDAC) remains among the most lethal of human cancers with a 5-year survival of ~10%, underscoring the need to identify new therapeutic vulnerabilities. Previously, we reported high expression of transcriptional co-regulators C-terminal binding proteins (CtBP) 1 and 2 in human PDAC, however their precise role in PDAC formation or progression remains unclear. Here we have studied PDAC tumor dependency on CtBPs for growth and metastasis, using an orthotopic syngeneic pancreatic tumor mouse model employing a mouse PDAC cell line (CKP) derived from a pancreatic tumor that formed in a mouse expressing mutated K-Ras in the setting of p53 deletion. CRISPR-based homozygous deletion of Ctbp2 in the parental mouse PDAC cell line (CKP CtBP2 KO) dramatically decreased orthotopic PDAC tumor growth, drastically reduced metastatic potential, and significantly prolonged survival. Interrogating differential gene expression of the orthotopic PDAC tumors from Ctbp2 WT vs Ctbp2 KO cohorts, we identified significant downregulation of the EGFR-superfamily receptor ErbB3 in Ctbp2 KO tumors, and further determined that CtBP2 regulates expression of both the ErbB2 and 3 EGFR superfamily genes in PDAC cells. We therefore hypothesized that CtBP regulation of physiologic ErbB2/3 signaling contributes, in part, to PDAC growth and metastasis. Indeed, we observed that Ctbp2 KO cells exhibited near complete loss of ErbB2/3 expression and exhibited severely attenuated activation of phospho-Akt after neuregulin stimulation of ErbB2/3, and furthermore, human PDAC cells also demonstrated CtBP dependence of ErbB3 expression. Our results suggest that a subset of PDAC tumors are dependent on physiologic ErbB2/3 signaling and could be targeted by pharmacologic inhibitors of ErbB2 and/or ErbB3. Providing proof of concept, the ErbB2-targeted multikinase inhibitor lapatinib effectively killed the ErbB3 expressing CKP PDAC cells, while CKP CtBP2 KO cells, where ErbB3 expression was extinguished, were resistant to lapatinib. Taken together, our data suggests that ErB2/3 targeted therapeutics can effectively target a critical PDAC dependency on physiologic ErbB2/3 signaling which is the result of CtBP’s oncogenic transcriptional program that drives PDAC tumor progression.

Citation Format: Kranthi Kumar Chougoni, Haemin Park, Priyadarshan K. Damle, Martin Michael Dcona, Barbara Szomju, Mikhail G. Dozmorov, Michael Idowu, Steven R. Grossman. C-terminal Binding Protein (CtBP): a critical regulator of ErbB2/3 signaling in PDAC [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr B073.
Abstract B082: Autoimmune conditions and pancreatic cancer risk in older American adults
Authors: Yuan Fancheng , Pfeiffer Ruth M. , Julian-Serrano Sachelly , Arjani Simran , Barrett Michael J. , Koshiol Jill , Stolzenberg-Solomon Rachael Z.
Published: November 2022

Pancreatic cancer (PC) is highly fatal, and its incidence is increasing in the United States. Population-based registry studies suggest associations between a few autoimmune conditions and PC risk, albeit based on a relatively small number of cases. We hypothesize that autoimmune conditions are associated with risk of PC. We conducted a population-based, nested case-control study to examine the association between autoimmune conditions and PC risk within the Surveillance, Epidemiology, and End Results Program (SEER)-Medicare population. Incident primary malignant PC cases (n=80,074) were adults > 66 years and diagnosed between 1992 and 2015. Controls (n=320,296) were alive at the time cases were diagnosed and frequency-matched to cases (4:1 ratio) by age, sex, and year of diagnosis. We used multivariable-adjusted, unconditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for 45 autoimmune conditions identified from Medicare claims. Eight autoimmune conditions including ankylosing spondylitis (OR = 1.45; 95% CI: 1.14-1.84), Graves’ disease (OR = 1.18; 95% CI: 1.03-1.34), localized scleroderma (OR = 1.27; 95% CI: 1.06-1.52), pernicious anemia (OR = 1.08; 95% CI: 1.02-1.14), primary sclerosing cholangitis (OR = 1.37; 95% CI: 1.18-1.59), pure red cell aplasia (OR = 1.31; 95% CI: 1.16-1.47), type 1 diabetes (OR = 1.11; 95% CI: 1.07-1.15), and ulcerative colitis (OR = 1.18; 95% CI: 1.07-1.31) were associated with increased PC risk (false discovery rate-adjusted P values < 0.10). In subtype analyses, these conditions were associated with pancreatic ductal adenocarcinoma, whereas only ulcerative colitis was associated with pancreatic neuroendocrine tumors. Our results support the hypothesis that autoimmune conditions may play a role in PC development.

Citation Format: Fancheng Yuan, Ruth M. Pfeiffer, Sachelly Julian-Serrano, Simran Arjani, Michael J. Barrett, Jill Koshiol, Rachael Z. Stolzenberg-Solomon. Autoimmune conditions and pancreatic cancer risk in older American adults [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr B082.
Abstract C019: FAK suppresses antigen processing and presentation to promote immune evasion in pancreatic cancer
Authors: Canel Marta , Slawinska Aleksandra , Lonergan David W. , Kallor Ashwin A. , Upstill-Goddard Rosie , Davidson Catherine , von Kriegsheim Alex , Biankin Andrew V. , Bryron Adam , Alfaro Javier , Serrels Alan
Published: November 2022

Immunotherapy for the treatment of Pancreatic Ductal Adenocarcinoma (PDAC) has shown limited efficacy. Poor CD8 T-cell infiltration, low neoantigen load and a highly immunosuppressive tumor microenvironment are key factors that contribute to this lack of response. Here, we identify a novel role for Focal Adhesion Kinase (FAK) in regulating type-II interferon signalling in human and murine PDAC cells and tumors, leading to suppression of antigen processing and presentation pathways critical for T-cell tumor recognition. We find that FAK loss promotes expression of the immunoproteasome and MHC-I, resulting in a significant increase in the diversity of antigens presented by FAK-/- PDAC cells. We show that regulation of the immunoproteasome subunit Psmb8 (β5i) is a critical determinant of this response, optimising the physicochemical properties of the peptide repertoire for high-affinity binding to MHC-I. Expression of the immunoproteasome and MHC-I can be further amplified in a STAT1-dependent manner via co-depletion of FAK and STAT3, leading to extensive CD8 T-cell infiltration into PDAC tumors and further restraint of tumor growth. Regulation of antigen processing and presentation by FAK preferentially occurs in human and murine PDAC cells and tumors of the classical/progenitor molecular subtype, further suggesting that precision medicine approaches based on molecular subtyping should be integrated into current and future clinical testing of FAK targeted therapies for the treatment of pancreatic cancer.

Citation Format: Marta Canel, Aleksandra Slawinska, David W. Lonergan, Ashwin A. Kallor, Rosie Upstill-Goddard, Catherine Davidson, Alex von Kriegsheim, Andrew V. Biankin, Adam Bryron, Javier Alfaro, Alan Serrels. FAK suppresses antigen processing and presentation to promote immune evasion in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr C019.
Abstract C049: WT1+ cancer-associated fibroblasts promote pancreatic cancer growth
Authors: Bischoff Allison , Zhang Yaqing , Yan Wei , Brown Kristee , Du Wenting , di Magliano Marina Pasca
Published: November 2022

Pancreatic ductal adenocarcinoma (PDA) is characterized by dense, fibro-inflammatory stroma that is established in early pathogenesis. Cancer-associated fibroblasts (CAFs) make up a significant proportion of the tumor microenvironment and represent a heterogeneous cell population that play both tumor-promoting and tumor-restricting roles. Despite their dramatic expansion in PDA pathogenesis, it is still unclear what cells in the normal pancreas give rise to these CAFs. Lineage-tracing experiments have previously identified pancreatic stellate cells, mesothelial, and tissue-resident fibroblasts as progenitors to subsets of CAFs. In this research, we firstly pulse-labeled cells expressing the mesothelial and fibroblast marker Wilms tumor 1 (WT1) in the normal pancreas of WT1CreERT;R26tdTomato mice and used an orthotopic model of PDA to trace their contribution to the PDA tumor microenvironment. We found WT1+ cells in the normal pancreas expanded to comprise a significant proportion of PDA CAFs according to immunofluorescence. Based upon single-cell RNA-sequencing (scRNA-seq), these WT1+ precursors represent an endogenous pancreatic fibroblast population similar to previously characterized universal adventitial fibroblasts (Pi16+, Dpp4+). To determine the role of WT1 in established PDA, we labeled WT1+ cells following orthotopic tumor implantation into WT1CreERT;R26tdTomato mice, and scRNA-seq analysis revealed that both inflammatory CAFs (iCAFs) and myofibroblastic CAFs (MyCAFs) express WT1. Notably, iCAFs had higher relative expression of WT1+. Additionally, we depleted WT1+ cells with diphtheria toxin from orthotopic tumors established in WT1CreERT;R26tdTomato/iDTR mice. We found depletion of WT1+ cells reduced orthotopic tumor growth, and depleted fibroblasts from the PDA tumor microenvironment. These findings implicate WT1 as a promising lineage tracing marker for a subset of pancreatic fibroblasts and demonstrates a pro-tumorigenic role of WT1+ fibroblasts in PDA.

Citation Format: Allison Bischoff, Yaqing Zhang, Wei Yan, Kristee Brown, Wenting Du, Marina Pasca di Magliano. WT1+ cancer-associated fibroblasts promote pancreatic cancer growth [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr C049.
Abstract C067: Understanding the tumor extrinsic role of oncogenic Kras in pancreatic cancer
Authors: Bonilla Monica E.
Published: November 2022

Pancreatic ductal adenocarcinoma (PDA) is a lethal disease with a 5-year survival rate of 10.8%. Most patients present with locally advanced or metastatic disease which is refractory to therapy. Even when surgical resection is possible, relapse is frequent. Thus, there is a need to understand relapse and treatment resistance in pancreatic cancer to develop more effective treatments. Oncogenic KRAS is a driving mutation in PDA. Work in mouse models demonstrated that oncogenic KRAS drives the initiation of pancreatic cancer. Further, our group and others showed that oncogenic KRAS is required for the maintenance of precursor lesions as well as advanced and metastatic disease. We have recently investigated the extrinsic effects of oncogenic KRAS in precursor lesions of pancreatic cancer; we found that oncogenic KRAS drives reprogramming of precursor associated fibroblasts (PAFs or pre-cancer associated fibroblasts; pre-CAFs) to express immunosuppressive cytokines. The extrinsic effects of oncogenic KRAS in advanced disease have so far not been fully elucidated. In brief, we orthotopically transplanted iKRAS cells —derived from a mouse model of inducible and reversible oncogenic KRAS expression— in the pancreas of syngeneic mice. We then administered Doxycycline (DOX) to induce tumor growth. Once tumors had reached the desired size, we split the mice in two cohorts, one that was kept of DOX and one that was taken off DOX. All the animals were sacrificed 3 days later, tumors were dissected and processed for single cell RNA sequencing. We performed bioinformatics analysis on the tumors using the SEURAT pipeline, and mapped cellular composition, changes in gene expression and predicted interactions regulated by oncogenic KRAS. Interestingly, we discovered that several immunosuppressive pathways are alleviated upon KRAS inactivation, and CD8+ T cell infiltration increases. We and others have described resistance to oncogenic KRAS and eventual relapse in the iKRAS mouse model. Further, clinical data from the first KRAS inhibitors tested in clinical trials (G12C mutant-specific inhibitors in lung adenocarcinoma) similarly revealed initial response followed, in most cases, by relapse. We are thus interested in studying the mechanisms of KRAS inhibition resistance and specifically determine whether immunotherapy can be combined with KRAS inactivation to prevent relapse.

Citation Format: Monica E. Bonilla. Understanding the tumor extrinsic role of oncogenic Kras in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr C067.
Abstract C073: CRO-67 is a novel therapeutic for pancreatic cancer: Implications for tumor and stromal reprogramming
Authors: Kokkinos John , Sharbeen George , Haghighi Koroush S. , Youkhana Janet , Raina Aparna , Pitiyarachchi Omali , Truong Quach , Wenholz Daniel , Laczka Olivier , Kumar Naresh , Goldstein David , Phillips Phoebe A.
Published: November 2022

Background: Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies and new therapeutic strategies are urgently required. A key drug delivery barrier and promoter of tumor progression is the fibrotic and heterogeneous microenvironment of PDAC which is mainly orchestrated by stromal cancer-associated fibroblasts (CAFs). Thus, any novel therapeutic strategy should not only target PDAC cells but should also aim to inhibit the pro-tumor properties of the PDAC stroma. However, to accurately evaluate the clinical potential of novel PDAC therapeutics, preclinical models are required that closely mimic the heterogeneity and multicellular architecture of human disease. Aim: We aimed to investigate the therapeutic potential of novel functionalized benzopyrans (CRO-05 & CRO-67) in a patient-derived PDAC tumor explant model. Methods: We collected PDAC tumor samples from patients undergoing resection of their primary tumor. We cultured whole tumor explants (1-2mm diameter) on gelatin sponges. This model accurately maintains the multicellular tumor and stromal architecture of human PDAC [Kokkinos et al, Scientific Reports, 11,1941 (2021)]. Tumor explants were treated every 3 days with the racemic compound CRO-05 or its active enantiomer CRO-67 and explants were fixed in paraformaldehyde at day-12. Therapeutic response was assessed by immunohistochemistry for markers of tumor cells (cytokeratin), CAFs (α-Smooth Muscle Actin), cell-proliferation (Bromodeoxyuridine), and cell-death (TUNEL). Results: Treatment of human PDAC explants with CRO-05 resulted in reduced tumor cell frequency in 3/4 patients and in 4/4 patients, reduced CAF frequency, decreased cell-proliferation, and increased cell-death relative to controls. CRO-67 treatment in explants from 4/5 patients led to reduced tumor cell frequency, and in 5/5 patients, reduced CAF frequency, decreased cell-proliferation, and increased cell-death relative to controls. Conclusions: This work identifies the functionalized benzopyrans CRO-05 and CRO-67 as novel dual-cell therapeutics that potently inhibit both PDAC tumor cells and their surrounding CAFs and provides support for their clinical development as novel PDAC therapeutics.

Citation Format: John Kokkinos, George Sharbeen, Koroush S. Haghighi, Janet Youkhana, Aparna Raina, Omali Pitiyarachchi, Quach Truong, Daniel Wenholz, Olivier Laczka, Naresh Kumar, David Goldstein, Phoebe A. Phillips. CRO-67 is a novel therapeutic for pancreatic cancer: Implications for tumor and stromal reprogramming [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr C073.
Abstract C074: Mining the secreted microproteome for novel regulators of PDAC progression
Authors: Martinez Marion , Hergueta Marta , de Embún Pilar Ximénez , Dueso Ana , Torrents David , Macarulla Teresa , Muñoz Javier , Peinado Héctor , Abad María
Published: November 2022

Recent work has unveiled a hidden microproteome composed by thousands of small proteins named microproteins: they are functional short proteins coded by genomic regions previously considered non-coding, and which had been completely ignored, mainly due to their small size (<100 aminoacids). To date, only a small part of the thousands of microproteins present in our cells have been characterized, and they are key players in fundamental processes such as DNA repair, mRNA splicing or cell metabolism. In cancer, they have been shown to regulate most tumor hallmarks, and present a huge potential for the clinic as diagnostic and prognostic biomarkers as well as therapeutic targets. Interestingly, their small size makes them ideal candidates to be shed in tumor-derived exosomes. PDAC-shed exosomes have been shown to prepare the pre-metastatic niche in the liver, and their presence in the bloodstream can be used as a surrogate marker of metastasis. Herein, we have mined the PDAC exosome-secreted microproteome for novel regulators of tumor progression and metastasis. Using proteogenomics in PDAC patient-derived explants, we have identified 439 microproteins secreted in exosomes by pancreatic tumors. We have selected a set of top microprotein candidates for further characterization by in silico analyses (e.g. phylogenetic conservation, predicted protein stability and localisation, mRNA expression in PDAC, etc). We have confirmed their exosome secretion in PDAC cell lines, and preliminary characterisation of these top candidates has shown that they extrinsically promote PDAC cell growth and invasion in vitro. Together, this work advances our knowledge on the underexplored field of secreted microproteins and provides pioneering evidence of their role in tumor cell communication in PDAC. It may further be a source of novel therapeutic targets and PDAC biomarkers for liquid biopsy in the clinic.

Citation Format: Marion Martinez, Marta Hergueta, Pilar Ximénez de Embún, Ana Dueso, David Torrents, Teresa Macarulla, Javier Muñoz, Héctor Peinado, María Abad. Mining the secreted microproteome for novel regulators of PDAC progression [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr C074.
Abstract C077: Evidence for a tumoral temperature driven chemoresistance pathway in pancreatic cancer
Authors: de Laat Vincent , Topal Halit , Dehairs Jonas , Spotbeen Xander , Talebi Ali , Vanderhoydonc Frank , Ostyn Tessa , Roskams Tania , Topal Baki , Swinnen Johan
Published: November 2022

Tumor growth is inevitably accompanied by changes in the tumor-microenvironment to which cancer cells have to adapt in order to thrive. Alterations in metabolism and blood perfusion of solid tumors have been suggested to drive a spontaneous increase in tumoral temperature. However, it is currently unknown if this phenomenon affects cancer biology. We found increased temperature in human pancreatic ductal adenocarcinoma (PDAC) tumors. By mimicking this observation in PDAC cell lines, we found that cancer cells adapt to tumoral temperature by altering the cellular lipidome and accordingly evade ferroptosis, a lipid-dependent form of cell death. We found evidence that tumoral temperature-induced ferroptosis evasion depends on p38-MAPK deactivation and ultimately drives resistance to the chemotherapeutic drug gemcitabine. Collectively, our findings suggest a direct role for p38-dependend ferroptosis evasion in gemcitabine resistance, and we identify tumoral temperature as a pathophysiological driver of this process. Our discovery unveils temperature as an unexplored hallmark of the tumor-microenvironment.

Citation Format: Vincent de Laat, Halit Topal, Jonas Dehairs, Xander Spotbeen, Ali Talebi, Frank Vanderhoydonc, Tessa Ostyn, Tania Roskams, Baki Topal, Johan Swinnen. Evidence for a tumoral temperature driven chemoresistance pathway in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr C077.
Abstract C082: Signaling pathways inducing tumoricidal phagocytosis in pancreatic cancer
Authors: Qiang Li , Liu Samantha , Ro Gabrielle , Ali Lestat , Lenehan Patrick , Hambizer Felix , Dougan Michael , Dougan Stephanie
Published: November 2022

Macrophages can be repolarized to promote tumor destruction, particularly by triggering tumoricidal phagocytosis of cancer cells. Despite the increasing interest in monoclonal antibody therapies targeting tumor antigens to drive cancer cell elimination via phagocidal macrophages, we still face tremendous challenges in developing adequate therapeutics due to lack of knowledge of the signaling pathways that induce phagocidal macrophages. Our previous work showed that cIAP1/2 antagonism and T cell derived cytokines promote anti-tumor immunity by reprogramming tumoricidal macrophages to phagocytose both live and dead tumor cells. Here we performed transcriptional analysis on both macrophages and tumor cells treated with cIAP1/2 antagonism or vehicle and identified candidate positive and negative regulators of phagocytosis. We are demonstrating how these receptors-ligand pairs on macrophages and tumor cells are induced and the mechanisms by which they effect tumor cell destruction. We also performed an in vitro CRISPR screen on tumor cells cocultured with macrophages, treated with cIAP1/2 antagonism or vehicle, recovered the DNA of phagocytosed tumor cells from within macrophages and compared to non-phagocytosed tumor cells to discover mediators of resistance or sensitivity to both baseline phagocytosis (efferocytosis) and cIAP1/2 antagonism induced phagocytosis.Our screen revealed a striking lack of dependence on MHC class I for tumors treated in vivo. Genes involved in phagocytosis resistance instead converged on regulation of the cytoskeleton and the tumor suppressor gene Stk11. This study will provide critical insights on tumoricidal macrophages, uncover the key pathways reprogramming these myeloid cells, and decipher the essential tumor-intrinsic pathways resulting in sensitivity and resistance to anti-tumor phagocytosis.

Citation Format: Li Qiang, Samantha Liu, Gabrielle Ro, Lestat Ali, Patrick Lenehan, Felix Hambizer, Michael Dougan, Stephanie Dougan. Signaling pathways inducing tumoricidal phagocytosis in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr C082.
Abstract IA011: Precision oncology approaches in pancreatic cancer
Authors: Yeh Jen Jen
Published: November 2022

Advances in next generation sequencing and therapies have led to an explosion of possibilities for precision oncology in pancreatic cancer. The talk will focus on current and up and coming precision approaches for patients with pancreatic cancer.

Citation Format: Jen Jen Yeh. Precision oncology approaches in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr IA011.
Abstract IA018: ATP production in pancreas cancer and tumor infiltrating lymphocytes
Authors: Rabinowitz Joshua D.
Published: November 2022

Diet can influence both the microbiome and (at least in mice) the outcomes of pancreas cancer therapy. For example, ketogenic diet can synergize with either current standard of care therapy ( gemcitabine + nab-paclitaxel) or PI3K inhibition in mouse models of pancreas cancer. I will discuss our recent work exploring how diet interacts with the microbiome, and how such interactions may influence pancreas cancer chemotherapy response. A simple hypothesis for how diet influences microbiome composition is that certain microbes prefer certain nutrients, and diets high in those nutrients lead to outgrowth of those microbes. To enable testing of this hypothesis, we developed isotope-tracer strategies that directly measure the nutrient preferences of different members of the gut microbiome. I will describe this new technology and its application to support the above hypothesis. I will further describe experiments manipulating diet and/or microbiome to influence the response of pancreas cancer to PI3K inhibition. The longterm goal is to understand, at a biochemical level, the links between diet, microbiome, and the effectiveness of cancer therapy, and to develop translatable strategies for manipulating metabolism via diet to improve therapeutic outcomes.

Citation Format: Joshua D. Rabinowitz. ATP production in pancreas cancer and tumor infiltrating lymphocytes [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr IA018.
Abstract PR011: Proteomic profiling reveals subtype specific kinase expression in pancreatic cancer
Authors: Xu Yi , Morrison Ashley B. , Herrera Silvia G. , East Michael P. , Johnson Gary L. , Yeh Jen Jen
Published: November 2022

We have previously identified two tumor specific molecular subtypes in pancreatic ductal adenocarcinoma (PDAC), basal-like and classical. Although basal-like tumors are found in less than 20% of patients, patients with basal-like tumors have a worse prognosis and are largely resistant to FOLFIRINOX chemotherapy. To identify targetable basal-like subtype specific vulnerabilities in PDAC, we utilized Multiplexed kinase Inhibitor Beads and Mass Spectrometry (MIB-MS) to profile the kinome in patient derived xenograft (PDX) models that recapitulate the tumor subtypes found in patients. MIB-MS results show that kinase expression is significantly associated with molecular subtype. Notably, basal-like tumors show increased expression of receptor tyrosine kinases (RTKs) including EGFR, MET, and IGF1R and MAP kinase members MEK2 and BRAF indicating activation of the MAP kinase signaling cascade. These RTKs including EGFR are also differentially expressed in primary patient tumors suggesting the true efficacy of EGFR and other kinase inhibitors in basal-like tumors may have been masked by the larger proportion of patients (>80%) with unresponsive classical tumors. Furthermore, inhibition of MAP kinase signaling with the MEK inhibitor trametinib results in kinome reprogramming exclusive to classical tumors. MIB-MS profiling reveals upregulation of TAOK3 and MEK3/6 indicating activation of p38 MAP kinase signaling as a classical subtype specific compensatory mechanism against MEK inhibition. Overall, these results present actionable basal-like subtype specific kinase targets by defining a novel subtype specific kinome in PDAC. Precision approaches in clinical trials are needed to determine if new and previously thought to be disappointing kinase inhibitors may be efficacious in patients with basal-like tumors.

Citation Format: Yi Xu, Ashley B. Morrison, Silvia G. Herrera, Michael P. East, Gary L. Johnson, Jen Jen Yeh. Proteomic profiling reveals subtype specific kinase expression in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr PR011.
MMN and P3a Elicited by a Novelty Oddball Paradigm Are Not Reduced in Early-Phase Psychosis
Authors: Riel Hayley , Rudolph Erica , MacPhee Catrina , Tibbo Philip G. , Fisher Derek J.
Published: November 2022

Introduction: The present study compared the mismatch negativity (MMN) and P3a waveforms among early-phase psychosis (EPP; n = 13) individuals and healthy controls (n = 30) to contribute to the research on these waveforms as potential biomarkers for schizophrenia. Methods: MMN and P3a were elicited with a novelty paradigm using complex stimuli with electrophysiological technology. Results: No significant group differences of amplitude were observed with either waveform. Increased asociality and blunted affect were associated with a reduction in both MMN and P3a waveforms indicating a relationship between these negative symptoms and cognitive deficits. Good social and occupational functioning correlated with improved MMN and P3a waveforms in the EPP group. Conclusions: This study suggests that MMN and P3a may be more appropriately used as an indicator of illness progression and symptomology rather than a biomarker in the early phase of the illness.
Diagnóstico broncoscópico por imagen microscópica en tiempo real in vivo en la EPI: una serie de casos
Authors: Wijmans Lizzy , Kalverda Kirsten , de Bruin Daniel , Brinkman Paul , van den Berk Inge , Roelofs Joris J.T.H. , Jonkers René , Bonta Peter I. , Annema Jouke
Published: November 2022

Antecedentes: Con frecuencia, los pacientes con enfermedades pulmonares intersticiales (EPI) presentan resultados no-diagnósticos en la tomografía computarizada de alta resolución (TCAR) y el lavado broncoalveolar (LBA), lo que hace necesario realizar una biopsia quirúrgica o criopulmonar invasiva, que se asocia con morbilidad significativa. La endomicroscopía láser confocal (CLE) y la tomografía de coherencia óptica (OCT) son técnicas de alta resolu­ción basadas en el láser y la luz, que proporcionan imágenes en tiempo real del compartimento alveolar durante la broncoscopía, con distinta profundidad y campo de visión. Objetivos: El objetivo del estudio fue correlacionar las imágenes por OCT y CLE con imágenes por TCAR en la EPI. Métodos: Presentamos una serie retrospectiva con casos de 20 pacientes con EPI, en quienes se tomaron imágenes por CLE y OCT alveolares durante una broncoscopía estándar con LBA, seguida de una biopsia pulmonar cuando ésta estaba indicada. Las imágenes por CLE y OCT se compararon con cuatro patrones principales de TCAR y con la histología. El diagnóstico final se basó en una discusión multidisciplinaria. Resultados: La obtención de imágenes por CLE y OCT broncoscópicas fue factible y segura, y proporcionó información anatómica adicional de gran detalle en comparación con la TCAR. La CLE broncoscópica en tiempo real fue capaz de identificar «células alveolares» (opacidades con aspecto de vidrio esmerilado) y fibrosis pulmonar (aumento de las fibras de elastina alveolares). La OCT broncoscópica en tiempo real permitió visualizar la «enfermedad fibrótica en parches», el «panal de abejas» (microquistes) y granulomas en la mucosa respiratoria. Conclusiones: La CLE y la OCT broncoscópicas del compartimento alveolar son factibles y seguras, y permiten detectar de forma mínimamente invasiva y con alta resolución las características específicas de la EPI, con potencial para mejorar el diagnóstico y el seguimiento de la enfermedad, y reducir la necesidad de realizar biopsias quirúrgicas o criopulmonares.