bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract A30: Chronic inflammation induces severe stromal damage and early pancreatic tumors in mice with activated Akt1 and KRas
Authors: Gitto Sarah B. , Cline Kathryn A. , Khaled Amr S. , Altomare Deborah A.
Published: December 2016

Inflammation and the immune environment is implicated as a risk for pancreatic ductal adenocarcinoma (PDAC), especially in chronic conditions. However, a mechanistic link is unknown. Recently, radiotherapy followed by immune checkpoint inhibitors are being tested and show promising results, thereby introducing immune modulation as a new investigational area for the treatment of pancreatic cancer. A potential barrier is that pancreatic fibrosis and desmoplastic reactivity are common characteristics of PDAC and makes therapeutic delivery difficult. To define how inflammation and desmoplasia effects the immune-pancreatic stromal environment and progression of PDAC, we have chronically injected caerulein into genetically engineered mice that we previously showed spontaneously develop PDAC through the cooperation of mutant active Akt1 and KRas. We show that injected Akt1Myr/KRasG12D mice have increased tissue remodeling, stellate cell activation, collagen production, and mucin production when compared to KRasG12D mice. They also have increased ductal proliferation, accelerated tumor formation, and increased immune cell infiltration in the pancreas ducts and stroma compared to control PBS- and caerulein-injected KRasG12D mice. Pro-inflammatory cytokines and macrophages likely activate stellate cells, which in turn facilitate additional cytokines to enhance a pro-tumor immune environment. Other than macrophages, the role that innate immune cells contribute to pancreatic cancer has not been well studied. Ongoing studies will delineate the immune cell infiltration, cytokine levels, and the effect on tumor formation in double mutant Akt1Myr/KRasG12D mice. Understanding the mechanisms by which inflammation affects tumor formation can lead to strategies to inhibit pro-tumor changes, impede PDAC development and improve overall patient survival.

Citation Format: Sarah B. Gitto, Kathryn A. Cline, Amr S. Khaled, Deborah A. Altomare.{Authors}. Chronic inflammation induces severe stromal damage and early pancreatic tumors in mice with activated Akt1 and KRas. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr A30.
Abstract A40: Gene expression profiling of pancreatic cancer precursors directly from formalin fixed paraffin embedded (FFPE) tissue without nucleic acid extraction
Authors: Smiley Sheila , Marginean Celia , Lo Bryan
Published: December 2016

Gene expression analysis of pancreatic intraepithelial neoplasia (PanINs), the pancreatic ductal adenocarcinoma precursor, has been challenging because extracting and purifying RNA from pancreatic tissue is difficult. Since the pancreas is rich in ribonucleases and PanINs are typically very small lesions, attempts to purify RNA of sufficient quality and quantity for microarray or RNAseq are usually unsuccessful. This is especially true if the starting material is formalin fixed paraffin embedded tissue, where the fixation process introduces further degradation of the RNA. We sought to solve this problem of PanIN gene expression profiling by using the HTG Edgeseq instrument platform. This instrument is designed to work with small FFPE specimens and perform RNA profiling even when RNA is partially degraded by employing a novel extraction free hybridization approach. In our pilot study, we show that the HTG Edgeseq can be used to profile ~2500 genes from a cohort of microdissected low and high grade PanIN from FFPE of human pancreatic adenocarcinoma resections. We speculate that most of these PanIN lesions would not have been amenable to other gene expression methodologies and that the PanIN data from the HTG Edgeseq will contribute to our understanding of the molecular pathways that underlie pancreatic cancer.

Citation Format: Sheila Smiley, Celia Marginean, Bryan Lo.{Authors}. Gene expression profiling of pancreatic cancer precursors directly from formalin fixed paraffin embedded (FFPE) tissue without nucleic acid extraction. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr A40.
Abstract A44: Coordination of stress signals by the lysine methyltransferase SMYD2 promotes pancreatic cancer
Authors: Mazur Pawel K. , Reynoird Nicolas , Stellfeld Timo , Flores Natasha M. , Lofgren Shane M. , Carlson Scott M. , Brambilla Elisabeth , Hainaut Pierre , Kaznowska Ewa B. , Arrowsmith Cheryl H. , Khatri Purvesh , Stresemann Carlo , Gozani Or , Sage Julien
Published: December 2016

Pancreatic ductal adenocarcinoma (PDAC) is a lethal form of cancer with few therapeutic options. We find that levels of the lysine methyltransferase SMYD2 are elevated in precancerous lesions and PDAC and that SMYD2 normally promotes Ras-driven development of PDAC. Notably, loss of SMYD2 correlates with diminished inflammation in PDAC and we identify the stress-response kinase MAPKAPK3 as a new and physiologically relevant SMYD2 substrate. Inhibition of MAPKAPK3 impedes PDAC growth, identifying a potential new kinase target in PDAC. Finally, we show that inhibition of SMYD2 cooperates with standard chemotherapy to treat PDAC cells and tumors. Together, our findings suggest new roles for SMYD2 in inflammation and stress responses, and identify SMYD2 and MAPKAPK3 as potential therapeutic targets to treat pancreatic cancer.

Citation Format: Pawel K. Mazur, Nicolas Reynoird, Timo Stellfeld, Natasha M. Flores, Shane M. Lofgren, Scott M. Carlson, Elisabeth Brambilla, Pierre Hainaut, Ewa B. Kaznowska, Cheryl H. Arrowsmith, Purvesh Khatri, Carlo Stresemann, Or Gozani, Julien Sage.{Authors}. Coordination of stress signals by the lysine methyltransferase SMYD2 promotes pancreatic cancer. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr A44.
Abstract A49: Pharmacological inhibition of PIM kinases in combination with chemotherapeutic drugs decreases cell viability of pancreatic cancer cells
Authors: Nixon Brittany K. , He Qingping , Singh Vandana , Compton Sarah A. , Warner Steve , Bearss David , Sexton Jonathan Z. , Baines Antonio T.
Published: December 2016

Current drug treatments have proven ineffective in pancreatic ductal adenocarcinoma (PDAC) as chemoresistance is a common occurrence in this disease. In order to improve survival rates, a combination treatment regimen of anti-cancer drugs will most likely be needed. The oncogenic serine/threonine PIM kinase family has been shown to regulate drug resistance in various cancers, including pancreatic cancer. Several PIM kinase inhibitors have been developed over the years and tested against a number of cancers, including solid tumors. Previous studies in our laboratory have shown a potential synergistic effect on cell viability of PDAC cells when treated with the PIM kinase inhibitor SGI-1776 and gemcitabine. Unfortunately, due to medical problems occurring during Phase I clinical trials , clinical studies using SGI-1776 were terminated. This led to the development by Tolero Pharmaceuticals of a more selective second generation PIM kinase inhibitor, TP-3654. However, to our knowledge no research has been conducted on the interaction of TP-3654 with gemcitabine or other FDA-approved chemotherapeutics. To address this concern, a 384-well high-content cell viability assay was designed to assess synergism between TP-3654 and the National Cancer Institute (NCI) catalog of 88 FDA-approved chemotherapeutics. Using high-content automated microscopy and image analysis, we acquired total cell counts and other important cellular data, such as nuclear and cell morphology. While some drug combinations with TP-3654 proved ineffective, decreased cell viability was observed in several drug classes, including hormonal agents, mTOR inhibitors, and alkylating agents. Compounds causing significant cytotoxicity in combination with TP-3654 were further evaluated to not only confirm synergism, but to potentially understand the cellular mechanisms and signaling pathways involved. Additional studies will include testing TP-3654 with non-chemotherapeutic compounds and purified natural products. The results of these studies could be used to help develop better drug combination strategies to treat pancreatic cancer and increase the survival rate of patients.

Citation Format: Brittany K. Nixon, Qingping He, Vandana Singh, Sarah A. Compton, Steve Warner, David Bearss, Jonathan Z. Sexton, Antonio T. Baines.{Authors}. Pharmacological inhibition of PIM kinases in combination with chemotherapeutic drugs decreases cell viability of pancreatic cancer cells. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr A49.
Abstract A50: Genotype tunes PDAC tension to induce matricellular-fibrosis and tumor aggression
Authors: Laklai Hanane , Miroshnikova Yekaterina , Pickup Michael , Collisson Eric , Grace Kim , Barrett Alex , Hill Ryan , Lakins Johnathon , Schlaepfer David , Mouw Janna , LeBleu Valerie , Novitskiy Sergey , Johansen Julie , Poli Valeria , Kalluri Rahgu , Wood Laura , Hebrok Matthias , Hansen Kirk , Moses Harold , Weaver Valerie
Published: December 2016

Fibrosis compromises pancreatic ductal carcinoma (PDAC) treatment and contributes to patient mortality. Nevertheless, anti-stromal therapies for pancreatic cancer patients have had mixed results, suggesting there are multifaceted, anti and pro-tumorigenic roles of fibrosis in tumor pathogenesis. We found that human PDACs lacking epithelial TGFβ activity have elevated epithelial Stat3 activity and develop a stiffer, matricellular-enriched fibrosis that associates with high epithelial tension and shorter patient survival. Using several Kras-driven mouse models, we found that both the loss of TGFβ signaling and elevated β1 integrin mechanosignaling engage a positive feedback loop whereby Stat3 signaling modulates pancreatic cancer malignancy by increasing matricellular fibrosis and tissue tension. By contrast, epithelial Stat3 ablation attenuated pancreatic malignancy by reducing the stromal stiffening and epithelial contractility induced by loss of TGFβ signaling. In PDAC patient biopsies, higher matricellular protein and activated Stat3 associated with SMAD4 mutation and shorter survival. The findings implicate epithelial actomyosin tension and matricellular fibrosis in the aggressiveness of SMAD4 mutant pancreatic tumors, and highlight Stat3 as a key driver of the phenotype. These data illustrate how tumor genotype can directly tune tissue mechanics and support the development of genotype-driven, anti-stromal therapies targeting PDAC.

Citation Format: Hanane Laklai, Yekaterina Miroshnikova, Michael Pickup, Eric Collisson, Kim Grace, Alex Barrett, Ryan Hill, Johnathon Lakins, David Schlaepfer, Janna Mouw, Valerie LeBleu, Sergey Novitskiy, Julie Johansen, Valeria Poli, Rahgu Kalluri, Laura Wood, Matthias Hebrok, Kirk Hansen, Harold Moses, Valerie Weaver.{Authors}. Genotype tunes PDAC tension to induce matricellular-fibrosis and tumor aggression. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr A50.
Abstract A61: CAF-derived ANXA6+-exosomes support pancreatic cancer aggressiveness and serve as a circulating biomarker
Authors: Leca Julie , Martinez Sebastien , Lac Sophie , Nigri Jeremy , Secq Veronique , Rubis Marion , Dusetti Nelson , Loncle Celine , Roques Julie , Pietrasz Daniel , Garcia Stéphane , Granjeaud Samuel , Ouaissi Mehdi , Bachet Jean-Baptiste , Brun Christine , Iovanna Juan L. , Zimmermann Pascale , Vasseur Sophie , Tomasini Richard
Published: December 2016

Pancreatic ductal adenocarcinoma (PDA) is one of deadliest human malignancies with a median survival barely reaching 6 months post-diagnosis. Such epidemiologic data highlight the urgent need to refine current therapies by integrating recent available knowledge on PDA biology. The malignant progression of PDA is characterized by the presence of an exuberant intra-tumoral microenvironment mainly composed of cancer associated fibroblasts (CAFs) and immune cells. This compartment interacts with pancreatic tumor cells surrounded by dense matrix and hypoxic areas, and affects their behavior through a poorly understood network. Indeed, cellular crosstalk between stromal and tumor cells is of major importance in pancreatic ductal adenocarcinoma (PDA). Here, by analyzing the proteomic stromal signature of human PDA, we highlight a possible contribution of the ANXA6/LRP1/TSP1 complex in such crosstalk. Following in vivo validations and stromal localization of each three candidates, we demonstrated that the formation of this complex is restricted to cancer associated fibroblasts (CAFs) cultured under physiopathological conditions (co-culture with macrophages, under hypoxia and lipid deprivation). Increased PDA aggressiveness is dependent on the uptake by tumor cells of CAFs-derived ANXA6+-exosomes. Targeting of ANXA6, and the relevant complex, in CAFs impairs PDA and metastasis occurrence while injection of ANXA6+-exosomes enhances tumorigenesis. Detection of ANXA6+-exosomes in serum is restricted to PDA patients and can distinguish PDA grade. Our data reveal a new CAF-tumor cell crosstalk supported by ANXA6+-exosomes and highlight a therapeutic target and an interesting biomarker for PDA.

Citation Format: Julie Leca, Sebastien Martinez, Sophie Lac, Jeremy Nigri, Veronique Secq, Marion Rubis, Nelson Dusetti, Celine Loncle, Julie Roques, Daniel Pietrasz, Stéphane Garcia, Samuel Granjeaud, Mehdi Ouaissi, Jean-Baptiste Bachet, Christine Brun, Juan L. Iovanna, Pascale Zimmermann, Sophie Vasseur, Richard Tomasini.{Authors}. CAF-derived ANXA6+-exosomes support pancreatic cancer aggressiveness and serve as a circulating biomarker. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr A61.
Abstract A63: Human pancreatic cells have distinct aspects in induction of acinar to ductal metaplasia
Authors: Liu Jun , Akanuma Naoki , Sun Luzhe , Wang Pei
Published: December 2016

Multiple animal studies suggest that pancreatitis-induced acinar-to-ductal metaplasia (ADM) is a key event for the initiation of pancreatic ductal adenocarcinoma (PDAC) tumorigenesis. However, until now, there has not been an adequate system to explore the mechanisms of ADM induction in humans. To address this problem, we have developed a flow cytometry-based, high resolution lineage tracing method to analyse ADM in primary human cells. Using a set of cell surface markers, we have successfully defined and purified human acinar, ductal and acinar-to-ductal transdifferentiated (AD) cells. A Matrigel-based 3D culture system which suppresses spontaneous ADM was developed to identify ADM inducers of primary human acinar cells. In contrast to the effect in mouse acinar cells, TGF-β1 efficiently converted human acinar cells to AD cells in a SMAD-dependent manner. Consistently, phospho-SMAD3 (p-SMAD3) expression was significantly increased in acinar cells from human pancreatitis samples, supporting an important role of the TGF-β/SMAD axis for human ADM in vivo. Furthermore, all known inducers of ADM in mice did not promote ADM in human cells, highlighting fundamental differences between the species. Capitalizing on our ability to separate different cell populations for functional analysis, we found that AD cells gained transient proliferative capacity. More interestingly, while oncogenic KRAS did not induce acinar cell proliferation, it did sustain proliferation of AD cells, suggesting that oncogenic KRAS requires ADM-associated-changes to promote PDAC initiation. This ADM model provides a novel platform to explore the mechanisms involved in the development of human pancreatic diseases.

Grant Support: Support received from the Cancer Prevention and Research Institute of Texas (P. Wang). Jun Liu received support by way of the training grant (RP140105) from the Cancer Prevention and Research Institute of Texas.

Citation Format: Jun Liu, Naoki Akanuma, Luzhe Sun, Pei Wang.{Authors}. Human pancreatic cells have distinct aspects in induction of acinar to ductal metaplasia. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr A63.
Abstract A65: Initiation of pancreatic metaplasia requires ADAM17-mediated autocrine signaling, not paracrine signaling derived from macrophages
Authors: Wen Hui-Ju , Crawford Howard C.
Published: December 2016

Acinar-to-ductal metaplasia (ADM) has been frequently seen in the damaged pancreatic tissues. It is also associated with PanIN lesions in PDAC samples derived from human and mouse and has been shown to act as a preneoplastic lesion in mice. Therefore, understanding the mechanisms of lesion formation at the earliest phase would provide needed information for studying pancreatic tumorigenesis. Previously, we have shown that EGFR activity is required for metaplastic duct formation and KRas-induced pancreatic tumorigenesis. In addition, a prominent macrophage infiltration has been shown to be important in the early phase of lesion formation. To investigate the origin of EGFR ligands for EGFR activation during ADM formation in vivo, we examined the metaplasia formation by administration of cerulein in the mice with the conditional knockout of a key EGFR ligand sheddase ADAM17 in the pancreas (ADAM17fl/fl;Ptf1aCre/+) or in the myeloid cells (ADAM17fl/fl;LysM-Cre). With 2 weeks cerulein treatment, wild type and ADAM17fl/fl;LysM-Cre mice showed a similar degree of metaplastic and fibrotic response. However, the mice with ADAM17-null pancreas displayed significant protection from chronic pancreatitis induced by cerulein, including a lack of significant macrophage infiltration, making the analysis of any additional contribution from macrophage derived EGFR ligands. To remedy this, we conditionally knocked out HB-EGF (Heparin-binding EGF-like growth factor) one of the most robustly expressed EGFR ligands in macrophages using LysM-Cre. We examined cerulein-induced metaplasia in HB-EGFfl/fl;LysM-Cre mice. Compared to wild type mice, HB-EGFfl/fl;LysM-Cre mice showed a similar degree of metaplastic and fibrotic response and a decrease in cell proliferation; moreover, myeloid cell-specific ablation of HB-EGF dramatically delayed the healing and the restoration of normal pancreatic epithelium after cessation of cerulein treatment. These results indicate that an ADAM17/EGFR ligand/EGFR autocrine loop derived from pancreatic parenchymal cells is required for metaplastic duct formation, and macrophage-derived HBEGF acting in a paracrine fashion contributes to cell survival and tissue remodeling.

Citation Format: Hui-Ju Wen, Howard C. Crawford.{Authors}. Initiation of pancreatic metaplasia requires ADAM17-mediated autocrine signaling, not paracrine signaling derived from macrophages. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr A65.
Abstract A68: Oncogenic Kras prevents myeloid cell-mediated pancreatic tissue repair
Authors: Zhang Yaqing , Yan Wei , Mathew Esha , Kane Kevin T. , Magliano Marina Pasca di
Published: December 2016

The iKras* mouse model of pancreatic cancer allows inducible and reversible expression of oncogenic Kras, and is thus perfectly suited to determine the role of Kras at different stages of carcinogenesis. KRAS has emerged as a targeted interest for study by the NCI; elucidating Kras-dependent signaling pathways and understanding the role of epithelial cells harboring oncogenic Kras in modulating essential components of the tumor microenvironment will provide new opportunities to attack KRAS driven cancers.

Using this model, we have demonstrated that, in addition to epithelial changes, the accumulation of a fibro-inflammatory stroma is continuously dependent on oncogenic Kras. Pancreatic Intraepithelial Neoplasia (PanIN), the precursor lesion to pancreatic cancer, is characterized by the accumulation of a fibro-inflammatory stroma rich in myeloid cell infiltrates. Here, we generated p48Cre; TetO-KrasG12D; Rosa26rtTa-IRES-EGFP; CD11b-diphtheria toxin (DT) receptor (iKras*;CD11b-DTR) mice that allow us to deplete myeloid cells during the onset and progression of PanINs. We show that myelois infiltration and polarization is dependent on oncogenic Kras both during the initiation and the progression of PanINs. Furthermore, signals derived from oncogenic Kras–expressing cells regulate the polarization of myeloid cells, maintaining them in a pro-tumor status. We show that myeloid cells are required for the initiation and progression of pancreatic cancer precursor lesions by regulating the inflammatory microenvironment and the extracellular matrix (ECM) deposition in pancreatic neoplasia. Inactivation of oncogenic Kras leads to a change in polarization of myeloid cells, which take on a pro-repair phenotype. Finally, by ablating myeloid cells upon inactivation of oncogenic Kras we show that pro-repair myeloid cells are required for pancreas remodeling and repair by regulating ECM degradation and epithelial cell survival involving activation of multiple signaling pathways in both stromal and epithelial compartments. Thus, the interplay between epithelial cells expressing oncogenic Kras and myeloid cells determines the balance between carcinogenesis and tissue remodeling, a finding that could be exploited to favor repair at the expense of tumor progression.

Citation Format: Yaqing Zhang, Wei Yan, Esha Mathew, Kevin T. Kane, Marina Pasca di Magliano.{Authors}. Oncogenic Kras prevents myeloid cell-mediated pancreatic tissue repair. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr A68.
Abstract A85: Metabolic wiring dictates GOT1 dependency in pancreatic cancer
Authors: Lyssiotis Costas A.
Published: December 2016

Pancreatic Ductal Adenocarcinoma (PDA) is an extremely aggressive disease. The 5-year survival rate is a shockingly low 8%, a number that has hardly increased in the last 30 years. This owes in large part to the fact that effective treatment options for PDA do not exist. A hallmark of pancreatic cancers, and one that contributes to this resistance, is the metabolic environments that they create locally and systemically. Pancreatic tumors exist in a highly inflammatory environment, are under severe physical and oxidative stress, and do not have functional vasculature to deliver oxygen and nutrients. Despite these unfavorable circumstances for growth, these tumors thrive. Clearly metabolism is rewired in unique ways to facilitate survival and growth in this unusual and hostile environment. Based on this framework, we have been mapping the metabolic pathways in PDA to identify aspects of metabolism that are unique or highly over-utilized.

Previously, we defined a novel pathway used by PDA cells to maintain redox balance via NADPH generation. Inhibition of a central enzyme in this pathway, cytosolic aspartate aminotransferase (GOT1), dramatically impairs growth in vitro and in vivo. Importantly, these effects can be completely reversed by supplying PDA cells with antioxidants. We also found that this pathway is regulated by mutant KRAS in PDA and, accordingly, non-transformed pancreatic epithelial cells are unresponsive to GOT1 inhibition. Subsequently, we interrogated GOT1 dependence in another KRAS transformed cancer, colon cancer, and found that they, like non-transformed cells, do not respond to GOT1 inhibition. Through a detailed series of metabolomics and functional assays, we ultimately found that colon cancers bypass GOT1 dependence favoring flux through ATP citrate lyase (ACL), a mechanism dictated not at the transcriptional level but by the metabolic wiring in these cells. Furthermore, ACL knockdown dramatically sensitizes colon cancer cells to GOT1 inhibition mediated redox and growth defects. In addition to revealing novel aspects of tissue specific metabolic pathway regulation, this analysis also illustrated novel metabolic dependencies that can be exploited for therapeutic gain.

Citation Format: Costas A. Lyssiotis.{Authors}. Metabolic wiring dictates GOT1 dependency in pancreatic cancer. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr A85.
Abstract A88: The synthetic triterpenoid CDDO-Imidazolide reduces immune cell infiltration and cytokine secretion in the KC mouse model of pancreatic cancer
Authors: Leal Ana Sofia , Sporn Michael B. , Pioli Patricia A. , Liby Karen T.
Published: December 2016

Survival rates for pancreatic cancer remain at 7-8%, and as the incidence and deaths are expected to increase, new drugs are needed for the prevention and treatment of this devastating disease. LSL-KrasG12D/+;Pdx-1-Cre (KC) mice replicate the genetics, symptoms and histopathology found in human pancreatic cancer. Immune cells infiltrate into the pancreas of these mice and produce inflammatory cytokines that promote tumor growth. This process can be accelerated with the administration of lipopolysaccharide (LPS) or caerulein so KC mice at 9 weeks of age were injected once a week for 4 weeks with LPS (4mg/kg). One or four weeks after the LPS injections, plasma, pancreas and spleens were collected. KC mice were particularly sensitive to the effects of LPS, as only 48% of the KC mice survived an LPS challenge while 100% of wildtype (WT) mice survived. Survival was increased when KC mice were pre-treated with the triterpenoid CDDO-Imidazolide (CDDO-Im) (71% survival). LPS increased the percentage of CD45+ immune cells in the pancreas and immunosuppressive Gr1+ myeloid derived suppressor cells (MDSC) in the spleen of KC mice. In contrast, CDDO-Im decreased the infiltration of CD45+ cells into the pancreas and the percentage of Gr1+ MDSC in the spleen of KC mice challenged with LPS. Levels of inflammatory cytokine levels also were markedly higher in KC mice vs. WT mice challenged with LPS. Pre-treatment with CDDO-Im decreased the production of IL-6, CCL-2, VEGF, and G-CSF in the KC mice. These cytokines are prognostic markers in pancreatic cancer or play important roles in the progression of this disease. Disrupting inflammation during tumorigenesis with drugs such as CDDO-Im might be useful for preventing pancreatic cancer, especially in high risk populations.

Citation Format: Ana Sofia Leal, Michael B. Sporn, Patricia A. Pioli, Karen T. Liby.{Authors}. The synthetic triterpenoid CDDO-Imidazolide reduces immune cell infiltration and cytokine secretion in the KC mouse model of pancreatic cancer. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr A88.
Abstract B04: NRF2 regulates serine biosynthesis in pancreatic ductal adenocarcinoma
Authors: DeNicola Gina M. , Chen Pei-Hsuan , Mullarky Edouard , Chio Christine , Asara John M. , Minna John D. , Tuveson David A. , DeBerardinis Ralph J. , Cantley Lewis C.
Published: December 2016

Tumors have high energetic and anabolic needs for rapid growth and proliferation, and the serine biosynthetic pathway has recently been identified as an important source of metabolic intermediates for these processes. We recently demonstrated that a substantial fraction of NSCLC cell lines displayed significant serine/glycine biosynthetic activity due to KEAP1 and NRF2 mutations (DeNicola et al. Nature Genetics 2015). We demonstrated that NRF2 regulates glucose flux to serine by controlling transcription of serine biosynthetic genes through the transcription factor ATF4. Importantly, elevated expression of these genes conferred poor prognosis in human NSCLC. Thus, a substantial fraction of human NSCLC activates an NRF2-dependent transcriptional network that regulates serine and glycine metabolism and is linked to clinical aggressiveness.

Pancreatic ductal adenocarcinoma (PDAC) also demonstrates high NRF2 activity due to mutations in KRAS and high MAPK signaling (DeNicola et al. Nature 2011). We demonstrate that serine biosynthesis enzyme expression is elevated in a mouse model of PDAC and that NRF2 regulates PHGDH expression in human PDAC cell lines. Furthermore, PDAC cell lines are resistant to serine starvation. PHGDH knockdown impairs the growth of tumor organoid orthotopic transplants, and the role of PHGDH in tumor maintenance is currently being investigated. These results suggest that the serine biosynthesis pathway is regulated by NRF2 in multiple cancers and may be an important therapeutic target.

Citation Format: Gina M. DeNicola, Pei-Hsuan Chen, Edouard Mullarky, Christine Chio, John M. Asara, John D. Minna, David A. Tuveson, Ralph J. DeBerardinis, Lewis C. Cantley.{Authors}. NRF2 regulates serine biosynthesis in pancreatic ductal adenocarcinoma. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr B04.
Abstract B11: Development of orthotopically grafted organoid models to study pancreatic cancer progression
Authors: Hwang Chang-Il , Lee EunJung , Oni Tobiloba , Park Youngkyu , Tuveson David A.
Published: December 2016

Pancreatic ductal adenocarcinoma (PDA) is one of the most difficult human malignancies to treat. The 5-year survival rate of PDA patients is 7% and PDA is predicted to become the second leading cancer-related cause of death in the USA. A subset of potential tumor suppressor (Ts) genes was identified by genome-wide analysis of human PDA and insertional mutagenesis in genetically engineered mouse models (GEMMs). Since the functional validation of these genes in GEMMs is time-consuming and labor-intensive, we have developed a rapid and efficient “orthotopically grafted organoid’ (OGO) models in conjunction with RNAi and CRISPR/Cas9 technology to study PDA progression. Previously, we showed that OGO model represents the full spectrum of PDA progression in vivo upon orthotopic engraftment. Here, as a proof-of-concept experiment, we demonstrate that ablation of Trp53 by shRNA or gRNA in PanIN-derived organoids accelerates PDA progression upon transplantation. Therefore, OGO models should provide an excellent platform to study the functional role of genes in PDA progression in vivo.

Note: This abstract was not presented at the conference.

Citation Format: Chang-Il Hwang, EunJung Lee, Tobiloba Oni, Youngkyu Park, David A. Tuveson.{Authors}. Development of orthotopically grafted organoid models to study pancreatic cancer progression. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr B11.
Abstract B17: BET inhibitors block pancreatic stellate cell collagen production and attenuate fibrosis in vivo
Authors: Kumar Krishan , DeCant Brian , Hattaway Hattaway Z. , Grippo Paul J. , Bentrem David J. , Ebine Kazumi , Munshi Hidayatullah G.
Published: December 2016

The fibrotic reaction, which can account for over 70% of the tumor mass, is a characteristic feature of the majority of human pancreatic ductal adenocarcinoma (PDAC) tumors. It is associated with proliferation of pancreatic stellate cells (PSCs), which are key regulators of collagen production and fibrosis in vivo. In this report we show that bromodomain-containing protein 4 (BRD4), a member of bromodomain and extraterminal (BET) family of proteins, is expressed in activated PSCs in human PDAC tumors. We also show that BET inhibitors and specific targeting of BRD4, in contrast to targeting of BRD2 and BRD3, decrease collagen production by primary PSCs isolated from human PDAC tumors. While BET inhibitors do not induce apoptosis of primary PSCs or affect α-SMA expression, BET inhibitors disrupt α-SMA filament organization in stellate cells. Additionally, BET inhibitors attenuate stellate cell activation, fibrosis and collagen production in vivo in a Kras mouse model of pancreatic tumorigenesis. Our results demonstrate that BET inhibitors regulate fibrosis partly by modulating PSC activation and function.

Citation Format: Krishan Kumar, Brian DeCant, Hattaway Z. Hattaway, Paul J. Grippo, David J. Bentrem, Kazumi Ebine, Hidayatullah G. Munshi.{Authors}. BET inhibitors block pancreatic stellate cell collagen production and attenuate fibrosis in vivo. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr B17.
Abstract B31: The MUC4 oncomucin mediates resistance of human pancreatic cancer cells to FOLFIRINOX drugs
Authors: Skrypek Nicolas , Boukrout Nihad , Lahdaoui Fatima , Schulz Céline , Vasseur Romain , Duchêne Belinda , Seuningen Isabelle Van , Jonckheere Nicolas
Published: December 2016

Introduction: Pancreatic adenocarcinoma (PDAC) is one of the most deadly cancers in western countries with an extremely poor prognosis because of a lack of efficient therapeutic tools. Gemcitabine, a fluorinated analog of deoxycytidine, is the main chemotherapy in PDAC, but survival remains poor. FOLFIRINOX, a more aggressive protocol combining 5-fluorouracil (5-FU), irinotecan/SN-38, oxaliplatin and leucovorin, emerged as a new option in patients with metastatic pancreatic cancer. MUC4 is a membrane-bound oncomucin involved in pancreatic cancer (PC) pathogenesis and chemoresistance to gemcitabine. MUC4 is not expressed in healthy pancreas whereas its expression increases constantly during carcinogenetic progression. In this work, we aimed to decipher the involvement of MUC4 and associated cellular mechanisms in chemoresistance to FOLFIRINOX drugs.

Material and Methods: MUC4 expression was knocked down (KD) by stable ShRNA in CAPAN-1/-2 PC cells. IC50 and cell viability to FOLFIRINOX drugs were determined by tetrazolium salt (MTT) assays. Expression of genes involved in drug metabolism was assessed by quantitative RT-PCR (qRT-PCR) and Western blot. MiRnomes of Mock and MUC4-KD cells were determined using miRNA array (8x15K Agilent).

Results: MUC4 depletion in PC cells leads to an increase of sensitivity to 5-FU and to an increased resistance to oxaliplatin. Combined treatments of 5-FU and oxaliplatin (FOX) lead to an intermediate survival rate suggesting additional effects. This altered chemosensitivity is associated with an altered expression of drug transporters/channels and drug metabolism actors. Notably, an increase of CTR1 and ATP7B transporters and DPYD enzyme was observed in MUC4-KD cells. Furthermore, we have observed downregulation of miR-96-5p, miR-132-3p and miR-210 suggesting a possible link between MUC4 expression, drug resistance and regulation by miRNAs. The involvement of these molecules is currently validated by transient RNA interference and miRNA transfections.

Conclusion: this work led to the identification of proteins and miRNAs specifically involved in priming PC chemoresistance. These factors may represent critical therapeutic targets and also robust prognostic/predictive markers, and thus provide better healthcare and management of PC patients.

Citation Format: Nicolas Skrypek, Nihad Boukrout, Fatima Lahdaoui, Céline Schulz, Romain Vasseur, Belinda Duchêne, Isabelle Van Seuningen, Nicolas Jonckheere.{Authors}. The MUC4 oncomucin mediates resistance of human pancreatic cancer cells to FOLFIRINOX drugs. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr B31.
Abstract B37: Mesothelin-targeted immunotoxin RG7787 (LMB-100) preferentially depletes secreted proteins and short-lived intracellular proteins to augment tumor cell killing by taxanes
Authors: Alewine Christine , Landsman Rebekah , Rudloff Michael , Kolyvas Emily , Chen Jinqiu , Pastan Ira
Published: December 2016

Mesothelin (MSLN) is a cell surface antigen expressed by a number of solid tumors including most pancreatic adenocarcinomas. RG7787 is a MSLN-targeted immunotoxin that is entering clinical testing for patients with advanced pancreatic cancer. RG7787 binds to MSLN on the cancer cell surface through a high affinity Fab and delivers a modified Pseudomonas exotoxin A (PE) payload into the cell cytosol. PE induces apoptosis by catalyzing the irreversible modification and inactivation of elongation factor-2 (EF-2), halting protein synthesis. This is a novel mechanism of action which produces synergistic tumor killing in combination with nab-paclitaxel in preclinical mouse models and in cell culture. Our goal is to understand the mechanism of this interaction. We have previously demonstrated that taxane does not increase delivery of RG7787 to tumors grown in mice and that taxane does not augment protein synthesis inhibition caused by RG7787. We hypothesized that RG7787 should deplete levels of secreted proteins and short-lived intracellular proteins and that insufficiencies of these factors may enhance taxane-mediated killing. To examine the effect of RG7787 on the pancreatic cancer secretome, we treated pancreatic cancer cells grown in culture or mice bearing tumor xenografts with RG7787 and used ELISA to examine levels of secreted proteins in conditioned medium and interstitial tumor fluid. We found that RG7787 treatment causes dose-dependent decreases in secreted proteins even at non-lethal doses. To demonstrate proof of principle that short-lived proteins are preferentially depleted, we created a reporter cell line co-expressing both GFP and a destabilized fluorescent Cherry protein (Cherry-PEST). We found that treatment with RG7787 reduced the levels of Cherry-PEST but not GFP in a dose-dependent fashion confirming our hypothesis. Consistent with this, we found that levels of the short-lived Bcl-2 family survival factor Mcl-1 are reduced in cells treated with the combination of RG7787 and taxane compared to taxane treatment alone. We conclude that RG7787 depletion of Mcl-1 primes cells for killing by taxane. We are now testing the combination of RG7787 (LMB-100) with nab-paclitaxel in a Phase IB/II trial for patients with pancreatic cancer.

Citation Format: Christine Alewine, Rebekah Landsman, Michael Rudloff, Emily Kolyvas, Jinqiu Chen, Ira Pastan.{Authors}. Mesothelin-targeted immunotoxin RG7787 (LMB-100) preferentially depletes secreted proteins and short-lived intracellular proteins to augment tumor cell killing by taxanes. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr B37.
Abstract B41: The angiotensin receptor blocker telmisartan inhibits the growth of pancreatic ductal adenocarcinoma and improves survival
Authors: Grahovac Jelena , Han Shiwei , Liu Hao , Jain Rakesh , Boucher Yves
Published: December 2016

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal forms of cancer with a 5-year survival rate of less than 5%. PDAC is highly resistant to chemotherapy, which impels search for novel approaches for treatment. Our group has previously shown in PDAC models that the angiotensin II type 1 receptor (AT1R) blocker losartan decreases desmoplasia and solid stress, which enhances blood flow, and improves the delivery and effectiveness of cytotoxic agents (Chauhan et al, Nature Comm 2013). In contrast to losartan, which had no effects on the growth of primary PDAC, we recently found that the AT1R blocker telmisartan significantly reduces the growth of PDAC. In addition to inhibiting AT1R activity telmisartan is also a partial agonist of Peroxisome Proliferator Activated Receptor γ (PPARγ). We determined in a panel of PDAC cell lines the effects of telmisartan on cellular viability. Our findings suggest that the sensitivity to telmisartan treatment correlates with low steady-state expression of PPARγ and a mesenchymal morphology. Furthermore, telmisartan induced a transcriptional profile distinct from the response to the direct PPARγ agonist pioglitazone. In support of our correlative results, the genetic knockdown of PPARγ increased the sensitivity to telmisartan and stimulated epithelial to mesenchymal transition (e.g. decreased expression of E-cadherin, increased expression of the mesenchymal markers Snail and N-cadherin). We also tested the effects of telmisartan in orthotopically implanted and genetically engineered mouse models of PDAC. Telmisartan inhibited the growth of primary tumors, decreased the incidence of metastasis and improved mice survival. In summary, our findings show that telmisartan reduces the viability of PDAC cells with a mesenchymal morphology and low expression of PPARγ, inhibits PDAC growth and improves the survival of mice.

Citation Format: Jelena Grahovac, Shiwei Han, Hao Liu, Rakesh Jain, Yves Boucher.{Authors}. The angiotensin receptor blocker telmisartan inhibits the growth of pancreatic ductal adenocarcinoma and improves survival. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr B41.
Abstract B65: The combination of beta-cyclodextrin & 2-deoxyglucose worked synergistically with TRAIL to induce apoptosis in 90% of Panc-1 cells at 10ng/ml of TRAIL
Authors: Yamaguchi Ryuji
Published: December 2016

Since over 95% of pancreatic cancer cells express P-glycoprotein which could exclude chemotherapeutics from entering the cell, making it difficult to treat pancreatic cancer. To address this problem we used 2-deoxyglucose (2DG), beta-cyclodextrin (bCD) and TNFa-Related Apoptosis Inducing Ligand (TRAIL) combination to induce apoptosis in pancreatic cancer cells. 2DG can enter highly glycolytic cells through glucose transporters, while bCD could deplete cholesterol from the plasma membranes without entering the cell, inhibiting the signal transduction between PI3K and AKT, and TRAIL could activate TRAIL-receptors, activating caspases from outside. These three agents worked synergistically to induce apoptosis in Panc-1 pancreatic cancer cells; Panc-1 cells were incubated in medium containing 10 mM 2DG and 25 mM glucose for 90 minutes. Then 10 mM methyl-beta-cyclodextrin (MBCD) was added, and 30 minutes later, 10 ng/ml of TRAIL was added. 2 hours later, cells were washed and incubation continued. When cells were harvested 16 hours later, over 90% of cells were propidium iodide (PI) positive, while 0% of cells treated with TRAIL alone, and less than 30% of cells treated with 2DG-MBCD were PI positive.

Citation Format: Ryuji Yamaguchi.{Authors}. The combination of beta-cyclodextrin & 2-deoxyglucose worked synergistically with TRAIL to induce apoptosis in 90% of Panc-1 cells at 10ng/ml of TRAIL. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr B65.
Abstract B84: Physiologic pancreatic cancer imaging using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI)
Authors: Fischer Laura E. , Schabel Matthias , Foster Bryan , Thomas Charles R. , Rooney William , Sheppard Brett C. , Gilbert Erin W.
Published: December 2016

Background: Accurately identifying and monitoring pancreatic ductal adenocarcinoma (PDA) remains a significant challenge. Whereas conventional imaging (CT and MRI) report only anatomic information, dynamic contrast-enhanced MRI (DCE-MRI) has the ability to show physiologic differences in tissue perfusion based on the kinetics of IV-contrast. We coupled DCE-MRI with data-modeling methods to obtain reproducible, high-resolution physiologic images in a series of patients with and without PDA in order to more accurately identify PDA.

Methods: Patients with borderline-resectable PDA (BR-PDA) or at high-risk for PDA (HR), but without cancer were imaged with DCE-MRI. T1-weighted images were collected during IV contrast injections [Figure 1]. Both tumor and the pancreatic body or non-tumor pancreas were identified and using dual-compartment pharmacokinetic modelling, DCE-MRI parameters were quantified and compared between groups.

Results: Between 6/2014 and 2/2015, 12 DCE-MRIs were completed: 9 HR and 3 BR-PDA. Significant differences in the DCE-MRI parameters blood flow (F), first-pass extraction (E), mean capillary transit-time (tc), transfer constant (Ktrans), volume of extravascular-extracellular space (Ve) and blood volume (Vb) were found in normal HR pancreases vs. the tumors in BR-PDA patients [Table 1A]. When comparing non-tumoral pancreases in both cohorts, only F, Ktrans, and Vb differed [Table 1B].

Conclusions: DCE-MRI of the pancreas is feasible and provides imaging biomarkers of vascular structure and function in both tumoral and non-tumoral pancreases which may allow for earlier and more accurate identification of PDA in these high risk populations.

Citation Format: Laura E. Fischer, Matthias Schabel, Bryan Foster, Charles R. Thomas, Jr., William Rooney, Brett C. Sheppard, Erin W. Gilbert.{Authors}. Physiologic pancreatic cancer imaging using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr B84.