bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract B25: Engrailed-1 promotes pancreatic cancer progression via antagonizing COMPASS activity
Authors: Hwang Chang-il , Roe Jae-Seok , Lee Eun Jung , Tonelli Claudia , Somervile Tim D.D. , Yao Melissa , Milazzo Joseph P. , Tiriac Hervé , Park Youngkyu , Vakoc Christopher , Tuveson David
Published: March 2020

Pancreatic ductal adenocarcinoma (PDA) is the most deadly disease in human malignancies. Using pancreatic organoid models, we have shown that enhancer reprogramming allows pancreatic cancer cells to acquire aggressive characteristics during disease progression. Recently we found that organoid cultures (mM) derived from metastatic lesions of KPC mice (Kras+/LSL-G12D; Trp53+/LSL-R172H; Pdx1-Cre) can survive in the reduced condition, unlike the paired primary tumor-derived organoid cultures (mT). We implicate Engrailed-1 (EN1), a neurodevelopmental transcription factor (TF), in this process as a prosurvival factor. We show that EN1 is indispensable for organoid survival in the reduced condition, highly expressed in mM compared to mT organoid cultures, and associated with poor prognosis. Gain- and loss-of-function experiments further show that EN1 is responsible for the aggressiveness of pancreatic cancer cells in vitro (anchorage-independent growth, migration, and invasion) and in vivo. On the other hand, subcutaneous tumors derived from EN1 expressing mT organoids exhibit squamous-like differentiation compared to control. In line with this, squamous-type PDA patients tend to express EN1 compared to other subtypes of PDA. Furthermore, EN1 perturbation renders the changes of squamous-PDA identity and KDM6A deficiency signatures. Mechanistically, EN1 can physically interact with KDM6A and repress H3K4me3 occupancy in a subset of genes without affecting H3K27me3 and H3K27ac occupancies, suggesting that the regulation of COMPASS (Complex Proteins Associated with Set1) activity by EN1 might be critical in this process. Finally, by combining EN1 with FOXA1, previously shown to be responsible for enhancer activation in PDA organoids, we were able to fully reprogram pancreatic cancer cells into highly aggressive pancreatic cancer cells. In sum, we report that EN1 confers the aggressiveness of pancreatic cancer cells via regulation of COMPASS activity and contributes to squamous-type identity and PDA progression.

Citation Format: Chang-il Hwang, Jae-Seok Roe, Eun Jung Lee, Claudia Tonelli, Tim D.D. Somervile, Melissa Yao, Joseph P. Milazzo, Hervé Tiriac, Youngkyu Park, Christopher Vakoc, David Tuveson. Engrailed-1 promotes pancreatic cancer progression via antagonizing COMPASS activity [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr B25.
Abstract B29: Outcomes of DNA repair-deficient pancreatic cancers: KU Cancer Center experience
Authors: Kasi Anup , Bajwa Suhaib , Al-Jumayli Mohammed , Saeed Anwaar , Godwin Andrew
Published: March 2020

Background: DNA repair-defective pancreatic cancers are a subset that could be exploited therapeutically. BRCA 1 and 2 deficient pancreatic cancers have shown improved survival outcomes with platinum-based chemotherapy and/or PARP inhibitors. However, survival outcomes of pancreatic cancers harboring other DNA repair defects are not well understood.

Methods: We retrospectively evaluated survival outcomes of 60 metastatic pancreatic cancer patients who had their tumors profiled by standard-of-care next-generation sequencing. Patients with deficient DNA repair genes such as BRCA1 (n=2), BRCA2 (n=12), ATM (n=7), PALB2 (n=1), NBN (n=1), and BRIP1 (n=1) were grouped into DNA repair-deficient group. The remaining patients were grouped into DNA repair-proficient group. Comparative survival analysis between the two groups was performed using Kaplan-Meir methods.

Results: Demographic/baseline data for the DNA repair-deficient group (n=22) vs. the proficient group (n=38) are compared as follows: 12 vs. 20 males, 10 vs. 18 females, 20 vs. 33 with ECOG scores 0-1, 1 vs. 4 with a ECOG score 2+, 12 vs. 19 with tumors in the head, 7 vs. 6 with tumors in the body, 4 vs. 12 with tumors in the tail, 4 vs. 10 with a CA 19-9 of <34, 12 vs. 24 with a CA 19-9 of >34, 7 vs. 19 received initial gemcitabine-based therapy, and 15 vs. 19 received initial FOLFIRINOX chemotherapy. Survival analysis in DNA repair-deficient vs. proficient group revealed comparable median PFS of 7 months (95%CI 5-32 months) vs. 7 months (95% CI 4-30 months) [HR 0.97, p=0.9] but a longer median OS of 18 months vs. 12 months [HR 0.51, p=0.07]. Among DNA repair-deficient group, median OS was 12 months for patients who received first-line platinum-based chemo (n=15) vs. 5 months for first-line non-platinum chemo (n=7) [HR 0.57, p=0.39].

Conclusion: In addition to BRCA1/2 deficiency, pancreatic cancers that harbor other DNA repair defects also show trend towards improved OS when compared to DNA repair-proficient cancers. Treatment with first-line platinum-based chemo favored better OS in DNA repair-deficient cancers. Though median PFS appears comparable, the upper limit of 95% CI for PFS is higher for the DNA repair-deficient cancers. These findings did not meet statistical significance given our small sample size and need to be validated in a larger cohort. We currently have an ongoing clinical trial to investigate DNA repair defects in addition to BRCA1/2 in pancreatic cancers (NCT03553004).

Citation Format: Anup Kasi, Suhaib Bajwa, Mohammed Al-Jumayli, Anwaar Saeed, Andrew Godwin. Outcomes of DNA repair-deficient pancreatic cancers: KU Cancer Center experience [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr B29.
Abstract B37: The complex immune-microenvironment heterogeneity in pancreatic cancer
Authors: Grevers Frederieke , Latifi Diba , Koning Willem de , Eijck Casper H.J. van , Mustafa Dana A.
Published: March 2020

Introduction: Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy, resulting in more than 3,000 deaths per year in The Netherlands. The tumor microenvironment (TME) contributes largely to the treatment failure of the disease. TME consists of the stromal compartment, extracellular matrix, and tumor-infiltrative lymphocytes (TILs). Types and numbers of TILs are associated with clinical outcome, i.e., highCD8+: FOXP3 ratio is linked to a favorable prognosis. However, the intratumor immune variation in pancreatic cancer has not been studied so far. This study aims at investigating the differences of the immune infiltration within various areas of the same pancreatic cancer samples (intratumor variation) and comparing to healthy controls (extratumor variation). Such differences may be used for microenvironment remodeling, which may open new therapeutic approaches for PDAC patients.

Materials and Methods: Formalin-fixed, paraffin-embedded (FFPE) samples of 26 PDAC patients and 8 healthy controls were selected. RNA was isolated separately from the tumor core and from the adjacent normal-like pancreatic tissue of the same sample. Immune profiling was carried out using the PanCancer Immune Profiling Panel of Nanostring technology. Subsequently, the gene expression data were analyzed using nSolver basic software and the advanced module.

Results: The immune infiltration in the core of PDAC samples was different from that in the adjacent normal-like areas of the same patients. Tumor samples exhibited the lowest CD8+, Th1, neutrophil, and Natural Killer cell infiltration as compared to normal-like areas. In addition, the normal-like areas of PDAC samples showed a different immune profile as compared to the healthy controls. B lymphocytes were significantly higher in healthy controls compared to normal-like PDAC samples.

Discussion and Conclusion: Our results present the variation in the immune microenvironment between the normal-like pancreatic tissue and the healthy pancreas, indicating that changes at the immune levels precede morphologic changes, tumorigenesis, and tumor cell infiltration. Additionally, specific changes in TILs occur in a gradient fashion from adjacent normal-like tissue to the tumor core. Understanding the differences of the immune microenvironment in the same tissue samples will enable developing an accurate microenvironment remodeling therapeutic approaches to treat PCDA patients.

Citation Format: Frederieke Grevers, Diba Latifi, Willem de Koning, Casper H.J. van Eijck, Dana A. Mustafa. The complex immune-microenvironment heterogeneity in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr B37.
Abstract B38: Calcium signaling induces a partial EMT in pancreatic ductal adenocarcinoma
Authors: Norgard Robert J. , Maddipati Ravikanth , Aiello Nicole M. , Balli David , Pitarresi Jason R. , Rosario-Berrios Derick N. , Li Jinyang , Yuan Salina , Yamazoe Taiji , Sela Yogev , Merrell Allyson J. , Wengyn Maximilian D. , Sun Kathryn , Rustgi Anil K. , Stanger Ben Z.
Published: March 2020

Metastasis and chemoresistance—the two main reasons for the high mortality of cancer—are associated with a form of cellular plasticity known as epithelial-to-mesenchymal transition (EMT). Cancer cells undergoing EMT become invasive, facilitating metastasis, and undergo a shift in their vulnerability to antineoplastic drugs. In recent work, it has been shown that EMT does not involve a single mechanism but rather a diversity of programs, yielding a continuum of cell phenotypes along the epithelial-mesenchymal spectrum. We previously developed a lineage-traced model of pancreatic ductal adenocarcinoma (PDA) to study EMT in the context of stochastically-arising tumors. As expected, epithelial-mesenchymal plasticity in some tumors involves transcriptional repression of the epithelial state, resulting in a “classical EMT” (C-EMT) phenotype. Surprisingly, however, epithelial-mesenchymal plasticity in the majority of tumors involves post-transcriptional repression of the epithelial state, resulting in a “partial EMT” (P-EMT) phenotype. These two plasticity programs are associated with other aspects of tumor biology as well, including distinct modes of cellular invasion. Here, we identify calcium signaling in pancreatic cancer cells as a regulator of the P-EMT phenotype. Prolonged calcium flux induces PDA cells to remove E-cadherin (ECAD) and other epithelial proteins from the surface and relocalize it intracellularly. This loss of the epithelial phenotype occurs without changes in the abundance of mRNAs for these proteins, reminiscent of the P-EMT phenotype observed in tumors in vivo. In addition, inhibition of the calcium-signaling protein calmodulin blunts this EMT-inducing effect. These results implicate calcium signaling as a mediator of partial EMT phenotypes.

Citation Format: Robert J. Norgard, Ravikanth Maddipati, Nicole M. Aiello, David Balli, Jason R. Pitarresi, Derick N. Rosario-Berrios, Jinyang Li, Salina Yuan, Taiji Yamazoe, Yogev Sela, Allyson J. Merrell, Maximilian D. Wengyn, Kathryn Sun, Anil K. Rustgi, Ben Z. Stanger. Calcium signaling induces a partial EMT in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr B38.
Abstract B42: Patient stratification and precision medicine in pancreatic cancer: GemciTest, an innovative in vitro diagnostic for the decision-making process of pancreatic cancer treatment
Authors: Ritter Didier , Piquemal David , Noguier Florian , Pierrat Fabien , Bruno Roman
Published: March 2020

Pancreatic cancer is currently the 4th leading cause of death by cancer in Europe. If no action is taken, it is set to be 2nd by 2021. For nearly 80% of patients, diagnosis occurs at an advanced stage, too late (metastatic pancreatic adenocarcinoma; mPDAC), making them nonelective for surgery. The high mortality rate (less than 5% of patients alive at 5 years), is partly due to the difficulty to diagnose and to the lack of patients’ stratification for effective treatments. Despite advances in treatment and outcomes, the capability of biomarkers to improve treatment is potentially greater than in any other area of current medical research. Based on a multicenter, randomized, retrospective clinical phase III evaluation (ClinicalTrials.gov: NCT00789633), Acobiom identified an 11-gene blood signature and developed the GemciTest, an IVD associated with gemcitabine treatment in mPDAC. This blood signature evaluates both progression-free survival (PFS) and overall survival (OS) rates, and identifies the patients who are likely to benefit from 1st-line gemcitabine treatment. Briefly, the IVD allows to identify 37% of patients having a median overall survival of 15 months with 1-year survival rate superior to 65%. The GemciTest, a quantitative real-time PCR assay, is currently a prototype in an operational environment through a Clinician Peer Network in EU and US. In this context, Acobiom is always looking for new partnerships (public or private), the right way to open opportunities to develop the GemciTest solution for mPDAC patients (bench-to-bedside), and to assist physicians in routine patient care.

Citation Format: Didier Ritter, David Piquemal, Florian Noguier, Fabien Pierrat, Roman Bruno. Patient stratification and precision medicine in pancreatic cancer: GemciTest, an innovative in vitro diagnostic for the decision-making process of pancreatic cancer treatment [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr B42.
Abstract B45: IL35/STAT3 axis as regulator of tolerance and T-cell exclusion in pancreatic cancer
Authors: Mirlekar Bhalchandra , Michaud Daniel , Pylayeva-Gupta Yuliya
Published: March 2020

Pancreatic ductal adenocarcinoma (PDA) is an aggressive malignancy refractory to immunotherapeutic interventions. The mechanisms that drive robust immunosuppression and CD8+ T-cell dysfunction in PDA are not well known. Using the Kras- and p53-driven mouse model of pancreatic cancer, we show that activation of IL35/STAT3 pathways directs reprogramming of suppressive regulatory B-cell lineage and inhibits CD8+ T cells via suppression of gene program that regulates infiltration and effector function. Activation of STAT3 in CD8+ T cells is driven by B cell, but not Treg-specific production of cytokine IL35. Targeting IL35 via cell lineage-specific deletion or therapeutic anti-IL35 blockade converts PDA from CD8+ T cell low to high tumor and confers sensitivity to anti-PD1 immunotherapy. Therapeutic inhibition of STAT signaling in tumor-educated CD8+ T cells improves PDA growth control upon adoptive transfer to tumor-bearing animals. Finally, we identify IL35+ B cell subset in patients with PDA and demonstrate that the presence of IL35+ cells in tumor samples predicts increased occurrence of dysfunctional CD8+ T cells. Together, these data identify IL35/STAT3 signaling as an important mediator of immune tolerance and a direct link to CD8+ T-cell exclusion and immunotherapy resistance in PDA.

Citation Format: Bhalchandra Mirlekar, Daniel Michaud, Yuliya Pylayeva-Gupta. IL35/STAT3 axis as regulator of tolerance and T-cell exclusion in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr B45.
Abstract B51: Examining the differential cellular response of pancreatic cancer cell lines to 12C vs. photon irradiation
Authors: Saha Janapriya , Story Michael D. , Davis Anthony , Sishc Brock J.
Published: March 2020

Pancreatic ductal adenocarcinoma (PDAC) is expected by 2020 to become the second most common cause of cancer-related deaths globally. The 5-year overall survival rate for patients with locally advanced nonresectable (LANR) PDAC is ~12%, likely because of the inherent resistance to conventional radio- and chemotherapy and the fact that the majority of pancreatic cancer patients present with advanced disease. While median overall survival (mOS) for chemoradiotherapy is 15.2 months, mOS determined from a retrospective analysis of patients with LANR PDAC treated with carbon ion therapy (CIRT) and concurrent gemcitabine was 21.5 months. Recently, UTSW initiated a randomized multi-institutional phase III trial (CIPHER) comparing CIRT to intensity-modulated radiation therapy for LANR PDAC. In conjunction with CIPHER, we initiated preclinical studies to exploit genetic vulnerabilities amenable to CIRT vs. IMRT. Eight PDAC cell lines with known genetic backgrounds were exposed to g-rays and 12C ions to determine the range of relative biologic effectiveness of 12C ion exposure. A specific area of interest is the DNA damage response given the vulnerability of tumor cells with slight deficiencies in genes associated with homologous recombination or replication fork maintenance to 12C ion exposure that is not seen with g-rays. Other endpoints being examined include differences in cell signaling that may affect inflammatory and immune responses, alterations to the microenvironment, or other signaling pathways that may identify druggable targets for combination with CIRT.

Citation Format: Janapriya Saha, Michael D. Story, Anthony Davis, Brock J. Sishc. Examining the differential cellular response of pancreatic cancer cell lines to 12C vs. photon irradiation [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr B51.
Abstract B56: Endogenous retrovirus transcript levels are associated with immunogenic signatures in multiple metastatic cancer types
Authors: Topham James T. , Titmuss Emma , Pleasance Erin , Williamson Laura M. , Karasinska Joanna M. , Culibrk Luka , Lee Michael K.C. , Kalloger Steve E. , Mendis Shehara , Moore Richard A. , Mungall Andrew J. , Laskin Janessa , Loree Jonathan M. , Mager Dixie L. , Marra Marco A. , Jones Steven J.M. , Schaeffer David F. , Renouf Daniel J.
Published: March 2020

Variability in the immunogenic landscape of metastatic cancer lesions has revealed insight into detection of potential immunotherapy-responsive patients, though underlying mechanisms driving such variation are not fully understood. Endogenous retrovirus (ERV)-containing transcripts have recently emerged as a potential source of tumor-associated antigen that are orthogonal to somatic mutation-derived neoantigens. To characterize the intersection between ERV levels and predicted immunogenicity in metastatic cancer, we comprehensively profiled the transcript abundance of 702,533 ERV loci in 199 metastatic tumors from breast, colorectal, and pancreatic cancer patients. In all three cancer types, overall ERV transcript load was associated with upregulation of genes involved in innate antiviral response pathways as well as genes involved in both adaptive and innate immune signaling. In colorectal and pancreatic tumors, samples with concomitant increases in ERV load and antiviral response gene expression, termed viral mimicry tumors, showed high expression of the DNA demethylation gene TET2, a gene previously described to promote transcription of ERV-containing transcripts. Collectively, these data are compatible with the notion that an increased level of ERV-containing transcripts may account for increased immunogenicity in a subset of metastatic tumors and support the relationship between DNA demethylation and ERV load in colorectal and pancreatic tumors.

Citation Format: James T. Topham, Emma Titmuss, Erin Pleasance, Laura M. Williamson, Joanna M. Karasinska, Luka Culibrk, Michael K.C. Lee, Steve E. Kalloger, Shehara Mendis, Richard A. Moore, Andrew J. Mungall, Janessa Laskin, Jonathan M. Loree, Dixie L. Mager, Marco A. Marra, Steven J.M. Jones, David F. Schaeffer, Daniel J. Renouf. Endogenous retrovirus transcript levels are associated with immunogenic signatures in multiple metastatic cancer types [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr B56.
Abstract C12: Lipids signaling contributes to glucose-independent metabolic adaptation in pancreatic ductal adenocarcinoma
Authors: Chen Ziheng , Liu Jintan , Ho I-Lin , Rose Johnathan , Yan Liang , Yao Wantong , Viale Andrea , Carugo Alessandro , Ying Haoqiang , Draetta Giulio
Published: March 2020

Increasing researches verify that mitochondrial oxidase phosphorylation (OXPHOS) plays remarkable roles in cancer initiation, development, and drug resistance. Our previous study identified that preclinic OXPHOS inhibitor IACS-010759 significantly suppressed cancer cell growth in brain cancer and acute myeloid leukemia (AML) in vivo and in vitro with very low compound concentration. In pancreatic ductal adenocarcinoma (PDAC), there were actually different responses to OXPHOS inhibition in glucose-independent conditions. Using patient-derived xenograft (PDX) model, we identified sensitive and resistant groups to IACS-010759, and there were dramatic metabolic changes to feed-back compound resistance. By metabolomics analysis, we found a novel lipids-signaling activation mechanism that is responsible for the adaptive metabolic resistance. Furthermore, combination of OXPHOS inhibitor and specific lipids pathway inhibitor showed significant cancer cell growth suppression in resistant PDAC types. Our findings uncovered a novel adaptive metabolism in drug resistance and provide new thoughts on therapy strategy in PDAC.

Citation Format: Ziheng Chen, Jintan Liu, I-Lin Ho, Johnathan Rose, Liang Yan, Wantong Yao, Andrea Viale, Alessandro Carugo, Haoqiang Ying, Giulio Draetta. Lipids signaling contributes to glucose-independent metabolic adaptation in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr C12.
Abstract C19: Impaired adaptation to negative energy balance in pancreatic cancer-associated wasting
Authors: Mendez Heike , Zhu Xinxia , Olsen Brennan , Marks Daniel L. , Grossberg Aaron J.
Published: March 2020

Purpose/Objectives: The disease-associated wasting condition cachexia is a common complication of pancreatic ductal adenocarcinoma (PDAC) that impacts quality of life and portends poor survival. Undernutrition is a major driver of wasting in PDAC, yet cachexia remains refractory to nutritional supplementation. By modifying nutritional challenges at different stages of cachexia development, we sought to understand the relative contributions of undernutrition and metabolic reprogramming on adipose and skeletal muscle wasting.

Materials/Methods: Adult mice received orthotopic PDAC tumor injections (KrasG12D; p53R172H/+; Pdx1-cre) or sham injections. Mice were fasted or food restricted at different times during tumor growth in a series of 2x2 factorial studies. Anthropometrics, voluntary wheel running activity, and body composition were measured throughout study. Blood glucose and ketones were measured by glucometer and ketometer. Ketogenic potential was assessed using octanoate challenge after fasting. Liver mRNA levels were measured using qPCR. Hepatic IL-6 signaling was assessed using qPCR and ELISA for plasma IL-6.

Results: PDAC mice maintained food intake and wheel running for 8 days after tumor injection, before progressive decline. Loss of adipose mass in PDAC mice occurred only in the context of decreased nutrition, whereas loss of lean mass preceded decreases in food intake. Overnight fasting mitigated differences in fat mass between groups, whereas the effect of fasting on skeletal muscle loss was similar in PDAC and control mice. Fasting blood glucose and ketogenic potential were lower in PDAC mice, suggesting impaired hepatic response to metabolic stress. In the liver, glycolytic genes were increased, whereas gluconeogenic and ketogenic genes were decreased in PDAC mice. Wasting and hepatic reprogramming occurred independently of hepatic IL-6 signaling.

Conclusions: Undernutrition drives PDAC-associated adipose wasting, yet muscle wasting occurs prior to changes in food intake and in the absence of systemic inflammation. Hepatic macronutrient partitioning and metabolic gene expression are altered in PDAC, implicating impaired adaptive responses to negative energy balance in PDAC-associated cachexia.

Citation Format: Heike Mendez, Xinxia Zhu, Brennan Olsen, Daniel L. Marks, Aaron J. Grossberg. Impaired adaptation to negative energy balance in pancreatic cancer-associated wasting [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr C19.
Abstract C21: KRAS confers resistance to mechanical compression in pancreatic cancer cells
Authors: Brittingham Gregory P. , Holt Liam J.
Published: March 2020

Physical pressure is fundamentally important for cancer biology, but its effects remain poorly understood. When solid tumors grow confined within surrounding tissue, they build up compressive stress. Given that cells evolved to function in a stable mechanical environment, even slight changes in pressure perturb physiology. Normal cells and early-stage cancer cells stop growing when pressure builds up. In contrast, in advanced cancer, compression can change cellular behavior to drive migration or confer resistance to chemotherapy. This difference implies that cancer cells somehow adapt to physical pressure. Pancreatic ductal adenocarcinoma (PDAC) builds the most compressive stress of any tumor because it grows in the context of a stiff fibrotic microenvironment. We have discovered that KRAS activation, present in >90% PDAC, enables survival under pressure. We propose that the prevalence of KRAS mutation in PDAC is partly due to its role in adaption to the compressive microenvironment in pancreatic tumors.

Citation Format: Gregory P. Brittingham, Liam J. Holt. KRAS confers resistance to mechanical compression in pancreatic cancer cells [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr C21.
Abstract C26: Oncogenic mechanism of soluble keratin 17 offers potential therapeutic vulnerability in pancreatic cancer
Authors: Kawalerski Ryan R. , Roa-Pena Lucia , Torre-Healy Luke A. , Boyle Taryn , Leiton Cindy V. , Snider Natasha T. , Shroyer Kenneth R. , Escobar-Hoyos Luisa F.
Published: March 2020

Clinical Need and Objectives: Our previous reports suggest that keratin 17 (K17), an intermediate filament (IF), is an oncoprotein and biomarker of the most aggressive and treatment-resistant form of pancreatic ductal adenocarcinoma (PDAC). Importantly, K17 transitions from its “insoluble” IF form to a “soluble” form that can regulate cell cycle progression and gene expression, though the mechanisms that mediate K17 solubilization are yet unknown. Determining these mechanisms may uncover new keratin 17-specific PDAC therapeutic vulnerabilities.

Methods and Results: We found that in human and murine PDAC models, the soluble fraction of K17 exists in the full-length form (flK17) and as a caspase-cleaved peptide (ccK17), each with potential roles as biomarkers and/or functional drivers of PDAC aggression. In a PDAC tumor mouse model and human samples, we show, independent of total K17 protein amount, that the percent of soluble and ccK17 in tumor cells is negatively prognostic. We sequenced both the soluble and cytoskeletal insoluble forms of K17 from primary PDACs using liquid chromatography mass spectrometry (LC-MS) and identified that K17 is phosphorylated on several N-terminal serine residues, some of which identify a semiconserved IF motif that may regulate caspase cleavage and solubilization. Serine phosphatase inhibition in vitro demonstrated that phosphorylation is necessary to trigger K17 solubilization followed by nuclear translocation. Mutagenesis of N-terminal serine sites demonstrated that phosphorylation of three serine residues is sufficient to solubilize K17 from its filamentous state, and that phosphorylation of K17 by a PKC-RSK signaling pathway is likely to induce solubilization. In vitro and in vivo experiments are ongoing to address the functional role of this mechanism in regulating PDAC pathogenesis.

Conclusion: Phosphorylation is an important regulator of K17 dynamics in PDAC, promoting solubilization and, in some cases, caspase cleavage. Our results suggest that soluble K17 may have a functional role in promoting tumor aggression. Inhibiting RSK or PKC kinases that phosphorylate K17 could impact tumor growth by blocking K17 solubilization/cleavage, and this line of research could accelerate the development of more effective treatments, coupled to soluble K17 testing as a predictive biomarker for PDAC.

Citation Format: Ryan R. Kawalerski, Lucia Roa-Pena, Luke A. Torre-Healy, Taryn Boyle, Cindy V. Leiton, Natasha T. Snider, Kenneth R. Shroyer, Luisa F. Escobar-Hoyos. Oncogenic mechanism of soluble keratin 17 offers potential therapeutic vulnerability in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr C26.
Abstract C38: HNF4a regulates progression and molecular subtype of pancreatic ductal adenocarcinoma
Authors: Camolotto Soledad A. , Torre-Healy Luke , Belova Veronika , Vahrenkamp Jeffrey , Berrett Kris , Stubben Chris , Gertz Jay , Moffit Richard , Snyder Eric L.
Published: March 2020

Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive malignancy in which the vast majority of patients succumb to disease. Transcriptomic analysis has identified two major molecular subtypes of PDAC, classical and basal-like. The classical subtype is associated with an increased response rate to standard-of-care therapies and improved overall survival. Furthermore, classical tumors have higher levels of lineage specifiers that regulate endodermal differentiation, including the nuclear receptor HNF4a. We now show that HNF4a expression is functionally tied to induction and maintenance of the classical subtype of PDAC. We used multiple preclinical models to investigate HNF4a in PDAC. We first used the KPC (KrasLSL-G12D/+; Trp53F/+; Pdx1-Cre) mouse model in which we deleted Hnf4a at the time of tumor initiation (KPC-Hnf4aF/F). We then derived cell lines from these HNF4a-negative mouse tumors, rescued HNF4a, and analyzed their proliferation and viability in vitro. Additionally, we used a sequential recombination strategy to derive murine PDAC organoid cultures in which Hnf4a could be deleted in vitro. Finally, in a retrospective analysis, we investigated clinical and molecular associations with HNF4a expression in PDAC patients from TCGA. Our data in genetically engineered mouse models show that loss of HNF4a causes increased tumorigenicity and decreased overall survival. In cell lines, rescue of HNF4a expression impairs proliferation and alters differentiation state. In organoid cultures, Hnf4a deletion changes the in vivo three-dimensional growth pattern, resulting in a more malignant phenotype. In all of these model systems, RNA sequencing shows that loss of HNF4a expression results in a significant loss of classical subtype gene expression. In PDAC patients, HNF4a expression was strongly correlated with classical subtype gene expression (R = .71) and was mildly associated with better survival (p = .088). Taken together, our data suggest that HNF4a is a key lineage specifier within a larger transcriptional network that regulates the growth and molecular subtype of PDAC. Thus, we anticipate that these data will advance the development of novel therapeutics that take advantage of HNF4a’s important role in the classical subtype of this disease.

Citation Format: Soledad A. Camolotto, Luke Torre-Healy, Veronika Belova, Jeffrey Vahrenkamp, Kris Berrett, Chris Stubben, Jay Gertz, Richard Moffit, Eric L. Snyder. HNF4a regulates progression and molecular subtype of pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr C38.
Abstract C45: NT219, a novel bispecific inhibitor of STAT3 and IRS1/2, combined with chemotherapy or MEK inhibitor in gemcitabine-resistant pancreatic tumors, induced tumor regression
Authors: Reuveni Hadas , Kupershmidt Lana , Moskovits Neta , Solomonov Evgeny , Stemmer Salomon M , Haviv Izhak
Published: March 2020

Background: Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer-related death worldwide, with poor outcome of current treatments. Major contributors to therapeutic resistance in PDAC include Kras mutations, a dense desmoplastic stroma, and activation of feedback signaling pathways. STAT3 and Insulin Receptor Substrate 1/2 (IRS1/2) regulate tumor survival and metastasis, the crosstalk of the tumor and its microenvironment, and play major role in drug resistance. NT219 is a novel bispecific inhibitor of IRS1/2 and STAT3, leading to IRS1/2 elimination and STAT3 dephosphorylation. The purpose of this study was to assess NT219 activity in PDAC PDX models and define schedule and regimens and combinations to overcome resistance to optimize future clinical protocols.

Methods: Patient-derived tumor xenograft (PDX) models of mutated KRAS pancreatic cancer were used to test the efficacy of NT219 in combination with gemcitabine, trametinib, and folfirinox. RNAseq was used to analyze the pharmacodynamic effect of NT219. Pharmacokinetic profile of NT219 was tested.

Results: Chemoresistent tumors of 4 PDAC PDX models were exposed to NT219 with gemcitabine demonstrated reversal of pre-existing resistance. One of these models demonstrated complete response in 5 out of 10 mice upon addition of NT219 to gemcitabine. Similar results were observed when NT219 was combined with trametinib (a MEK inhibitor) and with folfirinox (chemotherapy). There was a correlative dose-escalation response of both plasma and tumor levels and the therapeutic effect. NT219 delivered prior to gemcitabine showed a much better response than the inverse schedule/drug administration. RNAseq analysis of the tumors revealed that the combined treatment with NT219 and gemcitabine lowered the levels of IRS1 to 20% of the control group. Similar reductions were observed for STAT3-regulated genes, as well as for Ki67 (a proliferation marker), cyclin D (prognostic marker), and TGFβ (driver of epithelial to mesenchymal transition).

Conclusion: NT219 overcomes gemcitabine acquired resistance in PDAC. The combination of NT219 with modern chemotherapy in pancreatic cancer may enhance efficacy and delay acquired resistance in this fatal disease.

Citation Format: Hadas Reuveni, Lana Kupershmidt, Neta Moskovits, Evgeny Solomonov, Salomon M Stemmer, Izhak Haviv. NT219, a novel bispecific inhibitor of STAT3 and IRS1/2, combined with chemotherapy or MEK inhibitor in gemcitabine-resistant pancreatic tumors, induced tumor regression [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr C45.
Abstract C46: Establishing a living biobank of patient-derived organoids of intraductal papillary mucinous neoplasms
Authors: Reverón Dayana , Beato Francisca , DeNicola Gina , Ortiz Antonio , Centeno Barbara , Jiang Kun , Jeong Daniel , Malafa Mokenge , Hodul Pamela , Deszi Kaleena , Permuth Jennifer , Fleming Jason
Published: March 2020

Pancreatic cancer is the third leading cause of cancer-related deaths in the United States. There is an unmet need to develop strategies to detect pancreatic cancer at an early, operable stage and prevent its progression. Intraductal papillary mucinous neoplasms (IPMNs) are cystic pancreatic cancer precursors that comprise nearly 50% of pancreatic cysts detected incidentally via computed tomography (CT) scans. Since IPMNs can progress from low- and moderate-grade dysplasia and invasion, the study of these lesions offers a prime opportunity to develop early detection and prevention strategies. Organoids are an ideal preclinical platform to study IPMNs, and the objective of the current investigation was to establish the first living biobank of IPMN tumor organoids. IPMN tumors and adjacent normal pancreatic tissues were harvested from 15 patients undergoing pancreatic surgical resection at Moffitt Cancer Center & Research Institute (Tampa, FL) between 2017 and 2019. Following immunohistopathologic analysis of primary tissues, organoid cultures were generated, expanded, and cryopreserved. Furthermore, organoid cultures were generated from cryopreserved tissues as well. Count and size of the organoids over time was determined via the Image-Pro Premier 3D Version digital platform. Genomic characterization of the organoids was performed through DNA fingerprinting, and a subset of cases were sequenced. The success rates of organoid generation from IPMN tumor and adjacent normal pancreatic tissues were 81% and 87%, respectively. IPMN organoids derived from different IPMN subtypes tissues showed different morphologies in vitro, with the low- and moderate-grade pancreatobiliary subtypes showing the highest proliferation rates. This model has potential to provide new opportunities to unveil mechanisms of IPMN progression to invasion and to shed insight into novel biomarkers for detection and targets for chemoprevention.

Citation Format: Dayana Reverón, Francisca Beato, Gina DeNicola, Antonio Ortiz, Barbara Centeno, Kun Jiang, Daniel Jeong, Mokenge Malafa, Pamela Hodul, Kaleena Deszi, Jennifer Permuth, Jason Fleming. Establishing a living biobank of patient-derived organoids of intraductal papillary mucinous neoplasms [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr C46.
Abstract C61: Dysregulation of HNF1B/Clusterin axis enhances disease progression in a highly aggressive subset of pancreatic cancer
Authors: Yang Shouhui , Tang Wei , He Peijun , Wang Limin , Gaedcke Jochen , Ghadim B. Michael , Ströbel Philipp , Azizian Azadeh , Gaida Matthias M. , Bergmann Frank , Alexander H. Richard , Hanna Nader , Hussain S. Perwez
Published: March 2020

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy and is largely refractory to available treatments with heterogenous chemotherapeutic response in subsets of patients. Identifying key pathways associated with disease aggressiveness and therapeutic resistance may characterize candidate targets to improve patient outcome. We used a strategy of examining the molecular subset of PDAC patients with worst survival to understand the underlying mechanisms of disease progression and to identify candidate molecular targets with potential therapeutic significance. Non-negative matrix factorization (NMF) clustering using gene expression profile revealed three patient subsets. A 142-gene signature specific to the subset with the worst patient survival predicted prognosis and stratified patients in two clusters in a test (N=126) and validation (N=176) cohorts with significantly different survival. Gene-network and pathway analysis of the 142-gene signature revealed dysregulation of hepatocyte nuclear factor 1-B (HNF1B)/Clusterin (CLU) axis in the highly aggressive patient subset. HNF1B positively regulated CLU and a lower expression of HNF1B and CLU was associated with poor patient survival. Mechanistic and functional analyses revealed that CLU inhibits proliferation, migration, invasion, and 3D spheroid growth and epithelial-to-mesenchymal transition in pancreatic cancer cells. Furthermore, CLU enhanced sensitivity of pancreatic cancer cells, representing the aggressive patient subset, to the chemotherapeutic drug gemcitabine. Taken together, targeting HNF1B/CLU axis may attenuate disease progression with potential therapeutic implication in a subset of pancreatic cancer.

Citation Format: Shouhui Yang, Wei Tang, Peijun He, Limin Wang, Jochen Gaedcke, B. Michael Ghadim, Philipp Ströbel, Azadeh Azizian, Matthias M. Gaida, Frank Bergmann, H. Richard Alexander, Nader Hanna, S. Perwez Hussain. Dysregulation of HNF1B/Clusterin axis enhances disease progression in a highly aggressive subset of pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr C61.
Abstract I07: Multimodal evolutionary dynamics of pancreatic cancer
Authors: Iacobuzio-Donahue Christine
Published: March 2020

The pancreatic cancer genome has been well annotated through multiple large-scale efforts. However, the extent to which specific genes correspond to specific subtypes of PDA or to specific patterns of failure remains a work in progress. Transcriptional subtypes of PDA have also emerged as an important variable for this disease, with classical-type and basal-like profiles now recognized as potential extremes of a range of phenotypes. We integrated evolutionary analysis and expression profiling in multiregion sampled metastatic pancreatic cancers, finding that squamous features are the histologic correlate of an RNA-seq defined basal-like subtype. In patients with coexisting basal/squamous and classical/glandular morphology, phylogenetic studies revealed that squamous morphology represented a subclonal population in an otherwise classical/glandular tumor. Cancers with squamous features were notable for MYC amplification. We also identify entosis, a unique form of cell competition in which one cancer cell engulfs another, as a predominant feature of squamous morphology in PDAC. Entosis is associated with profound intercellular heterogeneity for MYC copy number, suggesting a mechanistic link between MYC amplification, cell competition and the microenvironment in squamous features. These data provide a unifying paradigm for integrating basal-type expression profiles, squamous histology, and genomic alterations in the context of clonal evolution of pancreatic cancer.

Citation Format: Christine Iacobuzio-Donahue. Multimodal evolutionary dynamics of pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr I07.
Abstract I12: CD40 immunotherapy for pancreatic cancer
Authors: Vonderheide Robert H.
Published: March 2020

CD40 is a cell-surface member of the TNF receptor superfamily that upon activation can license dendritic cells (DC) to promote antitumor T-cell activation and re-educate macrophages to destroy tumor stroma. Mechanistically, the combination of chemotherapy followed by CD40 mAb functions as an “in situ” vaccine; in addition, destruction of stroma by CD40-activated macrophages may enhance chemotherapy delivery. In a recent study sponsored by the Parker Institute of Cancer Immunotherapy of gemcitabine and nab-paclitaxel chemotherapy plus CD40 mAb APX005M, with or without PD-1 nivolumab mAb, we found the objective response rate among 30 patients with untreated, metastatic pancreatic cancer was more than 50% in the DLT-evaluable population. 13 patients experienced an AE leading to discontinuation, and 10 patients experienced a treatment-related serious AE. Two DLTs were observed, grade 3 and 4 febrile neutropenia, respectively. A three-arm randomized study of gemcitabine, nab-paclitaxel with APX005M, or with nivolumab, or with both APX005M and nivolumab has completed enrollment. Evidence to date suggests that CD40 activation is a critical and nonredundant mechanism to convert “cold” tumors to “hot” (with prominent tumor infiltration of T cells), sensitizing them to checkpoint inhibition.

Citation Format: Robert H. Vonderheide. CD40 immunotherapy for pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr I12.
Abstract I14: Polymerase theta synthetic lethal interaction in homologous recombination-deficient pancreatic ductal adenocarcinoma
Authors: Wang Annie , Zamperone Andrea , Sohail Mohammad , Wang Lidong , Balogun Fiyinfolu , Li Jiufeng , Zhao Ende , Diolaiti Daniel , Sfeir Agnel , Simeone Diane M.
Published: March 2020

Recent genomic characterization of PDA reveals that between 20-25 % of PDA harbor recurrent mutations in genes, including BRCA1/2, PALB2, and ATM, which are critical for homologous recombination (HR), an important form of DNA repair. In many patients, these may be germline mutations. This subgroup of PDAs, termed HR-deficient PDA, has emerged as a defined biological entity associated with increased chemoresistance and a more aggressive disease course. The defects in HR observed in these tumors impart cells with a specific vulnerability to PARP inhibitors and platinum-containing therapy. Still, as observed in the case of many other targeted therapies, only a fraction of HR-defective patient tumors respond to PARP inhibition. More so, many patients that initially respond eventually often develop resistance and progress. Therefore, novel therapies which can be effective against HR-defective PDA, alone or in combination with PARP inhibitors or other combinatorial regimens, are urgently needed. We have recently determined that inactivation of the HR pathway is associated with overexpression of polymerase theta (PolO–, also known as POLQ) in PDA. POLQ is a key enzyme that regulates an alternative pathway of DNA repair, known as the alternative non-homologous end-joining (Alt-NHEJ) pathway. In the setting of defective HR, Alt-NHEJ becomes a critical pathway responsible for the repair of DNA breaks and POLQ inhibition in HR-defective tumor cells demonstrates a synthetic lethality phenotype, not observed in cells with intact HR. Furthermore, POLQ knockdown significantly upregulated the cGAS-STING pathway in HR-deficient PDAs linking the DNA damage response to the immune response. Overall, targeting POLQ may represent a novel and in a valuable therapeutic strategy in HR-defective pancreatic cancer, as POLQ inhibitors are currently in development for clinical use.

Citation Format: Annie Wang, Andrea Zamperone, Mohammad Sohail, Lidong Wang, Fiyinfolu Balogun, Jiufeng Li, Ende Zhao, Daniel Diolaiti, Agnel Sfeir, Diane M. Simeone. Polymerase theta synthetic lethal interaction in homologous recombination-deficient pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr I14.