bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract A87: Pancreatic tumor stem cells resistant to inhibition of oncogenic signaling are dependent on mitochondrial function
Authors: Viale Andrea , Pettazzoni Piergiorgio , Lyssiotis Costas , Ying Haoqiang , Sánchez Nora , Marchesini Matteo , Carugo Alessandro , Green Tessa , Seth Sahil , Giuliani Virginia , Heffernan Timothy , Kimmelman Alec , Wang Huamin , Fleming Jason , Cantley Lewis , DePinho Ronald , Draetta Giulio
Published: October 2015

This abstract is also being presented as a short talk in Session 7: New Therapies. A full abstract is printed in the Proffered Abstracts section (PR13) of the Conference Proceedings.

Citation Format: Andrea Viale, Piergiorgio Pettazzoni, Costas Lyssiotis, Haoqiang Ying, Nora Sánchez, Matteo Marchesini, Alessandro Carugo, Tessa Green, Sahil Seth, Virginia Giuliani, Timothy Heffernan, Alec Kimmelman, Huamin Wang, Jason Fleming, Lewis Cantley, Ronald DePinho, Giulio Draetta. Pancreatic tumor stem cells resistant to inhibition of oncogenic signaling are dependent on mitochondrial function. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr A87.
Abstract A90: Non-canonical effects of PTEN restoration therapy contribute to improved survival in a GEM model of pancreatic ductal adenocarcinoma
Authors: Hopkins Benjamin , Palermo Carmine , Ahmed Roshan A. , Sastra Stephen A. , Parsons Ramon , Olive Kenneth P.
Published: October 2015

Expression of the PTEN tumor suppressor protein is frequently altered in human pancreatic tumors, and deletion of PTEN in genetically engineered mouse (GEM) models accelerates pancreatic tumorigenesis. However, efforts to target components of the PTEN pathway, through inhibitors of PI3-Kinases, AKT, or mTOR, have failed to provide significant survival benefit to date. We utilized a naturally occurring, membrane-permeable variant of the PTEN protein, called PTEN-Long, to restore PTEN-function in trans to established pancreatic tumors in the KPC GEM model of pancreatic ductal adenocarcinoma (PDA). Combination PTEN-Long + gemcitabine therapy prolonged overall survival by 2-fold in this model and led to frank regressions of varying duration in a subset of tumors.

In order to study the mechanisms of response to PTEN-Long therapy, we utilized variants of the PTEN-Long protein that are functionally mutated in different ways. A phosphatase-dead variant of PTEN-Long failed to have any effect on tumor growth in KPC mice. Interestingly, a variant of PTEN-Long that is no longer membrane permeable actually reduced overall survival in combination with gemcitabine, perhaps indicating a role for the protein in the extracellular matrix. Finally, we compared the effect of PTEN-Long in KPC mice to that of the pan-PI3K inhibitor GDC-0449. In contrast to PTEN-Long + gemcitabine, GDC-0449 + gemcitabine failed to extend survival or produce tumor regressions. Investigating the distinctions between pan-PI3K inhibition and PTEN restoration, we noted disparate, indeed opposite, effects of these two therapies on blood glucose maintenance and insulin levels, strongly that PTEN can function though additional, non-canonical intermediates beyond phospho-inositides. With the development of a clinical grade PTEN-Long material under way, we believe that these studies highlight the potential therapeutic utility of PTEN restoration therapy in PDA. These experiments provide the opportunity to dissect non-canonical aspects of PTEN signalling through in vivo structure/function analysis in GEM models of pancreatic cancer.

Citation Format: Benjamin Hopkins, Carmine Palermo, Roshan A. Ahmed, Stephen A. Sastra, Ramon Parsons, Kenneth P. Olive. Non-canonical effects of PTEN restoration therapy contribute to improved survival in a GEM model of pancreatic ductal adenocarcinoma. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr A90.
Abstract B05: Assessing and removing biophysical barriers to treatment
Authors: DelGiorno Kathleen E. , Carlson Markus , Provenzano Paolo P. , Brockenbough Scott , Hingorani Sunil R.
Published: October 2015

Pancreatic ductal adenocarcinoma (PDA) is a confounding cancer with a penchant for metastasis and resistance to therapy. Cell autonomous events, such as mutations in the Kras proto-oncogene, are essential for the initiation and maintenance of PDA; however non-malignant cells as well as non-cellular components have been shown to contribute to tumor growth, immunosuppression, and chemotherapeutic resistance. The stromal compartment can comprise more than 80% of tumor content and is characterized by a dynamic and deregulated extracellular matrix (ECM). In addition to a role in tissue structure, the ECM provides biophysical and biochemical cues that determine cell responses. PDA presents its own characteristic ECM signature including large deposits of the negatively charged glycosaminoglycan (GAG) hyaluronan (HA), as well as fibrillary collagens which increases matrix stiffness. We have previously demonstrated that high levels of HA in PDA contribute to extraordinary interstitial fluid pressures (IFP) and vascular collapse. We show here that IFP is comprised of both freely mobile and immobile fluid phases. Due to its highly charged nature, HA binds large amounts of water to create an immobile-fluid phase with a significant swelling pressure. This pressure is not detected by conventional methods that can measure only free fluid pressure. The swelling pressure stresses abundant collagen fibrils which contract through cellular efforts to maintain homeostasis, further contributing to IFP. Targeting HA through systemic administration of pegylated hyaluronidase (PEGPH20) liberates the immobile fluid phase and dramatically reduces IFP, increasing vessel patency and bioavailability of systemically delivered agents. We present results on the effects of targeting additional ECM components and signaling pathways to help remove biophysical barriers to chemotherapeutic access. We also compare the abilities of different methodologies to measure interstitial pressures associated with the distinct fluid phases in a variety of experimental contexts.

Citation Format: Kathleen E. DelGiorno, Markus Carlson, Paolo P. Provenzano, Scott Brockenbough, Sunil R. Hingorani. Assessing and removing biophysical barriers to treatment. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr B05.
Abstract B10: Function and therapeutic implications of p53 in the stroma of pancreatic cancer
Authors: Ridinger Maya , Kraus Annabelle , Cox Miranda , Wade Mark , Liddle Christopher , Downes Michael , Evans Ron , Wahl Geoffrey
Published: October 2015

Pancreatic ductal adenocarninoma (PDA) is one of the most aggressive human cancers and is characterized by a predominant stromal compartment mainly composed of fibroblastic and immune cells. Pancreatic stellate cells (PSCs) are the main fibroblastic cells in the pancreatic tumor microenvironment. During tumor progression, they evolve into activated and proliferative myofibroblast-like cells that synthesize copious amounts of extracellular matrix (ECM) proteins and have diminished lipid storage capacity. They produce a dense fibrous stroma that obstructs intratumoral vasculature to create physical and biological therapeutic barriers. These observations suggest that strategies that normalize the stroma may enhance anti-tumor treatment strategies.

Activated PSCs in pancreatic cancers encode wild type p53, raising the possibilities that p53 activation could prevent their proliferation, and induce other paracrine anti-tumor effects. Nutlin-3a is a small-molecule p53 agonist that blocks the binding of its major negative regulator, Mdm2. As Nutlin derivatives are currently in clinical trials, we tested the consequences of activating p53 by Nutlin-3a in PSCs.

The data to be presented show that Nutlin-3a induces transcriptional regulation of genes that induce multiple changes consistent with quiescence. Using PSCs from patient samples, we show that p53 activation induces lipid droplet formation, decreases expression of αSMA (ACTA2), and produces growth arrest. We also observed that p53 activation inhibits TGFβ-induced transcription of genes involved in PSC activation.

To assess the genome-wide effects of p53, we performed transcriptome analysis of PSCs grown in the presence or absence of Nutlin-3a. This analysis revealed that p53 inhibits the expression of genes associated with the activation of PSCs such as ECM components and induces the expression of genes implicated in lipid metabolism characteristic of the quiescent state. P53 activation also decreased expression of genes with tumor-supporting potential including cytokines, growth factors and signaling molecules.

Ongoing investigations are designed to determine the consequences of stromal p53 activation on cancer cells using in vitro co-culture systems and mouse models of pancreatic cancer.

Citation Format: Maya Ridinger, Annabelle Kraus, Miranda Cox, Mark Wade, Christopher Liddle, Michael Downes, Ron Evans, Geoffrey Wahl. Function and therapeutic implications of p53 in the stroma of pancreatic cancer. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr B10.
Abstract B105: Significance of BRCA mutation for the patients with pancreatic cancer
Authors: Kashintsev Alexey , Imyanitov Evgeny , Kokhanenko Nikolai , Ievleva Aglaya
Published: October 2015

Background: Several independent reports have indicated the efficacy of DNA damaging therapy for the oncological patients with loss of homolog recombination in consequence of BRCA 1,2 or PALB2 germiline mutation. There are similar works about pancreatic cancer but the frequency and localization of defects in these genes and the results of chemotherapy are variable.

Methods: From 2009 to 2012 years 257 patients with PAC were included in the study. The analysis of the Russian founder mutation BRCA1 5382insC is performed in 150 PAC: 116 pacients included accidentally and 34 – by the presence of kindred’s with oncology. We had compared our results with the control group of 1007 healthy people. Prevalence of BRCA2 6174delT were analyzed in 22 cases. For these two genes we used allele specific real-time PCR. Full exon sequencing of coding region of BRCA2, PALB2 was conducted on DNA samples extracted from 8 patients by the HRM-analysis. For the administration of chemotherapy (ChT) we estimated a performance status by ECOG scale and efficacy by the RECIST criteria.

Results: Two patients had carriers of BRCA1 mutation and one – BRCA2 5197_5198delTC. In the control group only 1/1007 had BRCA1 allele. All patients with founder mutations had 2 or more kindred’s with oncology and 1 had carriers of BRCA1 5382insC. Defects in the PALB 2 were not identified. ChT was administered only for 1 patients with BRCA2 allele because only he had a 1 score for ECOG scale. He had a 4 line of ChT (FOLFIRINOX, cisplatin, chlorambucil, mitomicin) and only in last one there was stabilization of the process by RECIST criteria and decrease the level of CA 19-9 from 3810 to 547 U/ml. FTP was a 4,1 months and overall survival – 8,1.

Conclusion: The frequency of BRCA1/2mutation carriers was rare for PAC but higher than in the general population and probability of detection was depended on familial history. It means that samples from patients with PAC whom had 2 or more relatives or kindred carrier of BRCA mutation should be selected for DNA analysis. The DNA crosslink agents are preferable for patients with BRCA mutation.

Note: This abstract was not presented at the conference.

Citation Format: Alexey Kashintsev, Evgeny Imyanitov, Nikolai Kokhanenko, Aglaya Ievleva. Significance of BRCA mutation for the patients with pancreatic cancer. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr B105.
Abstract B107: BET proteins are key mediators of pancreatic cancer cell growth and its tumor microenvironment
Authors: Liss Andrew S. , Nahar Sabikun , Mertz Jennifer A. , Bryant Barbara , Sims Robert J. , Castillo Carlos Fernandez-del , Lillemoe Keith D. , Warshaw Andrew L. , Thayer Sarah P.
Published: October 2015

Pancreatic ductal adenocarcinoma (PDAC) is extraordinarily chemoresistant and the abundant stromal content of these tumors contributes to the ineffective treatment of this disease. While the genetic alterations of PDAC have been well characterized, the epigenetic pathways regulating PDAC remain, for the most part, elusive. Employing an in vivo shRNA screen targeting 150 epigenetic regulators we identified BRD2 and BRD3, members of the BET family of chromatin adaptors, as key regulators of PDAC cell growth and maintenance of the tumor stroma. PDAC cells are broadly dependent on the activity of BET proteins, as the growth of 17/20 cell lines was sensitive to the BET inhibitor CPI203. BET family members contribute to PDAC cell growth by modulating the expression of MYC and the activity of GLI, two key transcriptional programs. Xenograft tumors in mice treated with BET inhibitor exhibited little to no growth, while tumors in control mice grew to 5 times their starting size. In addition to diminishing the proliferation of cells in these tumors, BET inhibition also effects the tumor stroma. A four-fold reduction in fibroblast content of tumors was observed which correlated with a 60-90% down-regulation of a key mediator of the tumor microenvironment, SHH, within the cancer cells. Taken together, these results suggest that therapeutic inhibition of BET proteins offers a novel mechanism to target both the neoplastic and stromal components of PDAC.

Citation Format: Andrew S. Liss, Sabikun Nahar, Jennifer A. Mertz, Barbara Bryant, Robert J. Sims, III, Carlos Fernandez-del Castillo, Keith D. Lillemoe, Andrew L. Warshaw, Sarah P. Thayer. BET proteins are key mediators of pancreatic cancer cell growth and its tumor microenvironment. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr B107.
Abstract B111: Functional analysis of the chr13q22.1 pancreatic cancer risk locus suggests allele-specific effects on DIS3 expression with prognostic implications
Authors: Hoskins Jason W. , Ibrahim Abdisamad , Emmanuel Mickey , Parikh Hemang , Jia Jinping , Collins Irene , Ylaya Kris , Altekruse Sean F. , Hewitt Stephen M. , Petersen Gloria M. , Amundadottir Laufey T.
Published: October 2015

A genome-wide association study (GWAS) of pancreatic cancer conducted within the NCI Cohort Consortium (PanScan I and II) identified pancreatic cancer susceptibility loci on chromosomes 1q32.1/NR5A2, 5p15.33/CLPTM1L/TERT, 9q34.2/ABO, and 13q22.1. The most significant single-nucleotide polymorphism (SNP) identified on 13q22.1, rs9543325, lies in a 600 kb gene desert; the nearest genes are KLF5, KLF12, PIBF1, DIS3, and BORA (265–586 kb). Imputation using the 1000 Genomes and DCEG reference datasets did not improve the GWAS signal, but produced a set of highly correlated SNPs for functional follow-up. We performed eQTL analysis to test for association between the genotypes of these functional candidate variants and expression of nearby genes. Among 100 normal derived pancreatic tissue samples, DIS3 expression showed the strongest association with a novel 30 bp indel variant in the risk locus (P = 4.0 × 104), indicating risk alleles associate with reduced DIS3 expression. Mutations in DIS3 have previously been identified in acute myeloid leukemia and multiple myeloma, and its expression has been correlated with metastatic potential in colorectal cancer, suggesting DIS3 is relevant to cancer biology. Chromosome conformation capture identified a physical interaction between the indel-containing locus and a region near the DIS3 promoter. Luciferase assay for regulatory function of this indel-containing locus revealed allele-specific silencer activity for the insertion allele. Supershift electromobility shift assay (EMSA) demonstrated binding of LEF1 specifically to the insertion allele of the indel, which contains two in silico predicted LEF1 binding elements. Finally, through immunohistochemical analysis, high DIS3 protein levels associated with better survival for pancreatic cancer patients (hazard ratio = 2.87, 95% CI = 1.49–5.53, P = 0.001). Our results suggest that at least one target gene for the pancreatic cancer risk variants on chr13q22.1 may be DIS3, and that the underlying biology may be mediated by the novel indel through a long-range repressive effect on DIS3 expression.

Citation Format: Jason W. Hoskins, Abdisamad Ibrahim, Mickey Emmanuel, Hemang Parikh, Jinping Jia, Irene Collins, Kris Ylaya, Sean F. Altekruse, Stephen M. Hewitt, Gloria M. Petersen, Laufey T. Amundadottir. Functional analysis of the chr13q22.1 pancreatic cancer risk locus suggests allele-specific effects on DIS3 expression with prognostic implications. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr B111.
Abstract B115: PD0332991 induces epithelial to mesenchymal transition in pancreatic cancer
Authors: Imasuen I. E. , Gore A. Jesse , Korc M.
Published: October 2015

Pancreatic ductal adenocarcinoma (PDAC) remains the fourth leading cause of cancer-related death among both men and women in the United States, with an overall survival rate of 6%. Moreover, the median survival in PDAC is only five to six months, underscoring the need for improved therapies. Cancer cell proliferation and cell cycle dysregulation is a major target in cancer treatment. Cyclin-dependent kinase (CDK) and cyclin inhibitors act as anti-proliferative agents that target upregulated cell-cycle progression proteins in various tumors. The efficacy of PD0332991, a CDK4/6 inhibitor, is currently being investigated in clinical trials in patients with retinoblastoma protein (Rb)-positive breast, ovarian, and non-small-cell lung cancers, but has not yet been examined for treatment in PDAC. We have recently shown that PD0332991 inhibits cell proliferation in PDAC cell lines but initiates epithelial to mesenchymal transition (EMT) and induces cancer cell invasion in some of these cells. Using human PDAC tissues and tissues from genetically engineered mouse models (GEMMs) of PDAC, we also recently showed that loss of RB function is common in PDAC. To further assess the therapeutic potential of PD0332991 in PDAC, we now compared its effects in PANC-1 human PDAC cells (wild-type RB1 gene) and in murine PDAC cells devoid of RB that were derived from a GEMM expressing mutant KRASG12D (KRC mice). In PANC-1 cells, PD0332991 (1 μM) inhibited proliferation and induced EMT. By contrast, in KRC 1022-4 murine PDAC cells, the same concentration of PD0332991 induced EMT without altering proliferation. Moreover, removal of PD0332991 from the incubation medium reversed its growth inhibitory actions in PANC-1 cells, but did not reverse its effects on EMT in either PANC-1 or KRC 1022-4 cells. Taken together, these findings suggest that PD0332991 may exert long-term deleterious effects in patients with PDAC limiting its potential therapeutic use in this deadly cancer, except in conjunction with agents that target EMT.

This study was supported, in part, by NCI grant R37-075059 to MK.

Citation Format: I. E. Imasuen, A. Jesse Gore, M. Korc. PD0332991 induces epithelial to mesenchymal transition in pancreatic cancer. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr B115.
Abstract B122: Hypoxia-inducible factor (HIF)-1α directly activates the leptin receptor (Ob-R) in pancreatic cancer cells
Authors: Ren He , Jia Lingling , Hao Jihui
Published: October 2015

The aim of this study is to investigate the regulatory mechanism of Ob-R in pancreatic cancer cells. we found that HIF-1α expression was correlated with Ob-R in both pancreatic cancer cell lines and tissues. Overexpression of HIF-1α and hypoxia upregulated the expression of Ob-R in pancreatic cancer cells. When hypoxia-inducible factor (HIF)-1α gene was silenced in vitro, the expression of Ob-R was significantly decreased. Furthermore, HIF-1α directly bound to the hypoxia-responsive element (HRE) located in Ob-R gene promoter (-828/-832) and activated the transcription. Finally, we demonstrated that silence of HIF-1α gene reversed the inhibitory effect of leptin/ObR in pancreatic cancer cells. Taken together, our results indicated that HIF-1α directly regulated Ob-R expression in pancreatic cancer, which might be a valuable therapeutic target to pancreatic cancer.

Note: This abstract was not presented at the conference.

Citation Format: He Ren, Lingling Jia, Jihui Hao. Hypoxia-inducible factor (HIF)-1α directly activates the leptin receptor (Ob-R) in pancreatic cancer cells. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr B122.
Abstract B18: MicroRNA-21 is involved in pancreatic cancer fibroblast tumor supportiveness
Authors: Nguyen Andrew Hieu , Li Luyi , Toste Paul , Wu Nanping , Donahue Timothy R.
Published: October 2015

Background: Pancreatic ductal adenocarcinoma (PDAC) is characterized by poor survival despite current medical and surgical therapies and has a propensity towards subclinical metastasis even with resectable disease. The tumor microenvironment consists of a network of supporting cells, including tumor-associated fibroblasts (TAFs), which promote tumor invasion and metastasis, and contribute to PDAC’s extremely poor prognosis. MicroRNAs (miRs) have recently emerged as critical players in post-transcriptional regulation of pathways in cancer biology. In this study, we identified miRs in fibroblasts induced by PDAC tumor cells (TCs). Further, we study the stable suppression of one of these miRs in TAFs and the effects upon fibroblast migration and invasion, as well as tumor cell proliferation.

Methods: Primary pancreatic fibroblasts were cultured with MIA PaCa-2 TC conditioned media and RNA was analyzed by the NanoString MicroRNA Expression Assay. Stable miR knockdown (KD) was achieved with a stably expressed shRNA anti-microRNA by lentiviral vector. Migration was determined by an 18 hour scratch assay and 24 hour invasion by modified Boyden chamber. TC proliferation was measured by MTT assay. In vivo tumor growth was evaluated by subcutaneous TC and TAF co-implantation in NSG mice.

Results: In primary pancreatic fibroblasts, MIA PaCa-2 tumor cells induced 62 miRs >50% increase or 30% decrease in expression. The most prevalent induced miR with 2-fold increase in expression was miR-21. miR-21 KD in TAFs was achieved by introducing stable expression of anti-miR-21, which resulted in a 75% decrease in expression (P<0.001). miR-21 KD TAFs had a >50% decreased ability to migrate (p<0.001) and were 67% less invasive (p<0.001). miR-21 KD TAF conditioned media induced less rapid TC proliferation (p<0.05). Further, in an in vivo model of tumor proliferation, TCs co-implanted with miR-21 KD TAFs showed 45% decreased tumor size (P<0.05), compared to controls.

Conclusions: Pancreatic cancer TCs can induce tumor supportive miRs in TAFs. miR-21 KD in PDAC TAFs results in decreased TAF migration and invasion, as well as reduced ability to support in vitro and in vivo tumor growth.

Citation Format: Andrew Hieu Nguyen, Luyi Li, Paul Toste, Nanping Wu, Timothy R. Donahue. MicroRNA-21 is involved in pancreatic cancer fibroblast tumor supportiveness. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr B18.
Abstract B24: Targeting pancreatic ductal adenocarcinoma acidic microenvironment
Authors: Cruz-Monserrate Zobeida , Roland Christina L. , Deng Defeng , Arumugam Thiruvengadam , Moshnikova Anna , Andreev Oleg A. , Reshetnyak Yana , Logsdon Craig D.
Published: October 2015

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer death in the USA, accounting for ~40,000 deaths annually. The dismal prognosis for PDAC is largely due to its late diagnosis. Currently, the most sensitive diagnosis of PDAC requires invasive procedures, such as endoscopic ultrasonography, which has inherent risks and accuracy that is highly operator dependent. Here we took advantage of a general characteristic of solid tumors, the acidic microenvironment that is generated as a by-product of metabolism, to develop a novel approach of using pH (Low) Insertion Peptides (pHLIPs) for imaging of PDAC. We show that fluorescently labeled pHLIPs can localize and specifically detect PDAC in human xenografts as well as PDAC and PanIN lesions in genetically engineered mouse models. This novel approach may improve detection, differential diagnosis and staging of PDAC

Citation Format: Zobeida Cruz-Monserrate, Christina L. Roland, Defeng Deng, Thiruvengadam Arumugam, Anna Moshnikova, Oleg A. Andreev, Yana Reshetnyak, Craig D. Logsdon. Targeting pancreatic ductal adenocarcinoma acidic microenvironment. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr B24.
Abstract B34: Diagnostics of pancreatic duct hypertension by the serotonin-stimulated magnetic resonance cholangiopancreatography
Authors: Kashintsev Alexey , Pavelets Konstantin , Kokhanenko Nikolai , Imyanitov Evgeny
Published: October 2015

Background: Serotonin is a neurotransmitter and humoral enhancer which stimulates the pancreatic secretion. Unlike secretin serotonin doesn’t change the proteinogramm of pancreatic juice1. Pancreatic and periampullary tumors can cause the dilatation of the main pancreatic duct. Its partial stenosis can remain undiagnosed on conventional MRCP. Increasing secretion of pancreatic juice after serotonin stimulation can improve the diagnosis, particularly the location and length of a lesion.

Method: Eighteen patients with pancreatic cancer (n=14) and tumor of papilla Vateri (n=4) were included into the study. Median age was 64.9 years with range 45-84 years. Serotonin (0,01mg/kg) was administered perorally (n=2), intramuscularly (n=2), or intravenously with dilution (n=5) and without it (n=9). MRCP was performed before the drug application and 7 minutes after that.

Results: In cases where serotonin was administered perorally, intramuscularly or intravenously with dilution we have not received any significant results (Tab. 1). The positive results were obtained in 5 (55.6%) of 9 cases when MRCP was performed 7 minutes after intravenous administration of concentrated solution. The mean increase in width of the main pancreatic duct was 1.1 mm (range 0.9-1.9 mm).

Conclusion: The method of serotonin-stimulated MRCP can improve the diagnosis of pancreatic ductal hypertension. In these 5 cases the presented technique allowed us to detect the size and localization of a lesion more precisely: tumor of a papilla (n=2), cancer of a pancreatic head (n=3) including one case with involvement of the pancreatic body. In cases of primary ductal dilatation more than 5 mm (n=3) we have not received any positive results, so these patients were excluded from the study.

Note: This abstract was not presented at the conference.

Citation Format: Alexey Kashintsev, Konstantin Pavelets, Nikolai Kokhanenko, Evgeny Imyanitov. Diagnostics of pancreatic duct hypertension by the serotonin-stimulated magnetic resonance cholangiopancreatography. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr B34.
Abstract B42: Metabolic changes, associated with loss of the tumor suppressor LKB1, promote tumorigenesis
Authors: Kottakis Filippos , Nicolay Brandon N. , Julia Nagle M. , Liesa Marc , Sirihai Orian S. , Dyson Nicholas J. , Bardeesy Nabeel
Published: October 2015

The LKB1 tumor suppressor encodes a serine/threonine kinase that serves as a master regulator of energy metabolism. Germline mutations in LKB1 cause the Peutz-Jeghers polyposis and cancer syndrome and are associated with a high risk of pancreatic cancer development. Despite being the subject of extensive investigation for more than 15 years, the primary mechanisms of LKB1-mediated tumor suppression remain poorly defined. The best-characterized function of LKB1 in cell physiology is to coordinate adaptation to a drop in ATP stores, shutting down multiple biosynthetic processes and favoring catabolic pathways, thereby restoring cellular energy charge. Since LKB1 has pleiotropic effects on cell polarity, migration, and inflammation in addition to cell metabolism, it remains uncertain to what extent LKB1-mediated tumor suppression involves its roles in metabolic reprogramming. In this regard, LKB1 inactivation renders cells vulnerable to a number of metabolic stress stimuli such as glucose deprivation or reactive oxygen species (ROS), indicating that alterations in metabolic control may decrease, rather than increase, the fitness of LKB1 deficient cells. To resolve these questions, we have conducted comprehensive metabolic profiling and functional studies that revealed that LKB1 inactivation results in greatly improved efficiency of nutrient acquisition and utilization, which fuels accelerated cell growth and tumorigenesis. By using a series of primary epithelial culture systems and genetically engineered mouse models coupled with integrative metabolic profiling and flux analyses, we find that LKB1 loss potentiates glucose uptake and glycolysis, and diverts a significant amount of glycolytic intermediates toward biosynthetic processes. Most notably fatty acid and nucleotide pools are greatly expanded upon LKB1 inactivation. This extensive metabolic reprogramming results in a shift in the nutrient requirements of LKB1 mutant cells including a reduced dependence on select exogenous amino acids and greatly increased need for glutamine and glucose. Collectively, our studies uncover adaptive metabolic changes conferred by LKB1 inactivation and suggest potential targetable vulnerabilities of LKB1 mutant cancers.

Citation Format: Filippos Kottakis, Brandon N. Nicolay, Nagle M. Julia, Marc Liesa, Orian S. Sirihai, Nicholas J. Dyson, Nabeel Bardeesy. Metabolic changes, associated with loss of the tumor suppressor LKB1, promote tumorigenesis. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr B42.
Abstract B45: Pancreatic cancers depend on a non-canonical glutamine metabolism pathway
Authors: Lyssiotis Costas A. , Son Jaekyoung , Mancias Joesph D. , Ying Haoqiang , Cantley Lewis C. , Kimmelman Alec C.
Published: October 2015

Cancer cells exhibit metabolic dependencies that distinguish them from their normal counterparts. Among these addictions is an increased utilization of the amino acid glutamine (Gln) to fuel anabolic processes. Recently, we reported the identification of a non-canonical pathway of Gln utilization in human pancreatic cancer cells that is required for tumor growth. While most cells utilize glutamate dehydrogenase (GLUD1) to convert Gln-derived glutamate (Glu) into alpha-ketoglutarate (alpha-KG) in the mitochondria to fuel the tricarboxylic acid cycle, pancreatic cancer cells rely on a distinct pathway that integrates the mitochondrial and cytosolic aspartate aminotransferases GOT2 and GOT1. By generating alpha-KG from Glu (in conjunction with the conversion of oxaloacetate into aspartate), GOT2 fuels anaplerosis in place of GLUD1. The Asp created is released into the cytosol and acted on by GOT1. This is subsequently used through a series of reactions to yield cytosolic NADPH from malic enzyme. Importantly, we have demonstrated that pancreatic cancers are strongly dependent on this series of reactions to maintain redox homeostasis which enables proliferation. Herein, we detail the subcellular compartmentalization and consequences of the aforementioned reactions on pancreatic cancer metabolism. We have also investigated the essentiality of this pathway in other contexts and find that pancreatic cancers have a uniform and unique reliance on this pathway, which may provide novel therapeutic approaches to treat these refractory tumors.

Citation Format: Costas A. Lyssiotis, Jaekyoung Son, Joesph D. Mancias, Haoqiang Ying, Lewis C. Cantley, Alec C. Kimmelman. Pancreatic cancers depend on a non-canonical glutamine metabolism pathway. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr B45.
Abstract B50: Abrogating cholesterol esterification suppresses pancreatic cancer growth and metastasis mediated by caveolin-1
Authors: Li Junjie , Lee Seung-Young , Gu Dongsheng , Song Bing , Chen Shaoxiong , Konieczny Stephen , Ratliff Timothy , Liu Xiaoqi , Xie Jingwu , Cheng Ji-Xin
Published: October 2015

Pancreatic cancer is one of the most lethal human cancers due to the lack of early diagnosis and its high propensity for metastases. Recent advances in cancer metabolism research have manifested new promises for therapy. However, cholesterol metabolism in pancreatic cancer remains poorly understood. Here, by employing label-free Raman spectromicroscopy, we found an aberrant accumulation of cholesteryl ester (CE) in human pancreatic cancer tissues and cell lines, but not in normal ones. Our biochemical study revealed that accumulation of CE is a consequence of activated PI3K/Akt/mTOR pathway. Pharmaceutical blocking and genetic knockdown of the cholesterol esterification enzyme, acyl-CoA cholesterol acyltransferase-1 (ACAT-1), reduced pancreatic cancer cell proliferation, migration and invasion rate. In an orthotopic mouse model of pancreatic cancer, ACAT-1 inhibition significantly suppressed tumor growth and metastasis. Furthermore, we showed that ACAT-1 inhibition suppressed pancreatic cancer growth and metastasis by induction of intracellular free cholesterol toxicity and down-regulation of Akt and MAPK pathway mediated by caveolin-1. Collectively, our study opens a new opportunity for treating pancreatic cancer by targeting the altered cholesterol metabolism.

Citation Format: Junjie Li, Seung-Young Lee, Dongsheng Gu, Bing Song, Shaoxiong Chen, Stephen Konieczny, Timothy Ratliff, Xiaoqi Liu, Jingwu Xie, Ji-Xin Cheng. Abrogating cholesterol esterification suppresses pancreatic cancer growth and metastasis mediated by caveolin-1. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr B50.
Abstract B56: Inactivation of LKB1-AMPK pathway is mediated by inflammation in pancreatic cancer
Authors: Aggarwal Sita , Wang Qingxia , Giri Shailendra , Hansel William
Published: October 2015

Goal: The goal of this project is to determine if there is link between cancer cell metabolism and inflammation. LKB1is a known serine/threonine kinase tumor suppressor gene and it functions by sensing changes in cellular energy homeostasis and modulates anabolic and catabolic processes by activating its downstream kinase, AMP-activated protein kinase (AMPK). It is associated with Peutz-Jeghers syndrome, as well as various cancers including pancreatic cancer. Thus; it is a unique link between cell metabolism and inflammation.

Hypothesis: Our hypothesis is that LKB1-AMK succumbs to inactivation processes because of increased NF-κB expression in pancreatic cancer cells and is associated with increased pancreatic cancer growth.

Results: We tested five pancreatic cancer cells that express constitutive active NF-κB (pp65) and LKB1proteins by western blot analysis. In these cancer cells there was loss of active AMPK, phospho AMK (pAMPK) protein and its substrate pACC protein, suggesting a negative correlation between inflammation and loss of active AMPK. To strengthen this observation, we treated macrophage with LPS/IFNγ to create inflammatory environment and examined the protein levels of pp65, NF-κB regulated inflammatory gene (COX-2), pAMPK and pACC. We found that induction of pp65 and COX-2 are negatively correlated with pAMPK and pACC. To further support this observation we treated the pancreatic cancer cells with Metformin, a known activator of AMPK and our results clearly indicates that Metformin inhibits the proliferation of pancreatic cancer cells in a time-dependent manner. Metformin activates AMPK and ACC in pancreatic cancer cells. These data indicate that, compounds that activates LKB1-AMPK pathway can be beneficial in pancreatic cancer treatment.

Citation Format: Sita Aggarwal, Qingxia Wang, Shailendra Giri, William Hansel. Inactivation of LKB1-AMPK pathway is mediated by inflammation in pancreatic cancer. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr B56.
Abstract B72: Developing drug combinations to co-target pancreatic cancer and its supporting stroma
Authors: Carapuça Elisabete Florencio , Gemenetzidis Emilios , Feig Christine , Tuveson David , Kocher Hemant
Published: October 2015

Background: Pancreatic ductal adenocarcinoma (PDAC) is characterized by an intense desmoplastic stroma, due to the activation of pancreatic stellate cells (PSC). The activated PSC are characterized by a reduction of fat droplets, expression of α-smooth muscle actin (α-SMA), and an increased synthesis and secretion of several connective tissue components such as fibronectin (FN) and collagen type I. Aberrant stromal-epithelial interactions contribute to pancreatic cancer spread and metastasis raising the possibility that targeting the stroma may represent viable strategy for treating pancreatic cancer. Our group has shown that pancreatic cancer progression can be restrained via modulation of the stellate cells in the stroma.

Methods: Organotypic cultures (OT) were constructed to mimic human PDAC. Treatment of OT was performed to mimic human chemotherapy regimen cycles with all-trans retinoic acid (ATRA), targeting PSC, and the chemotherapeutic agent Gemcitabine (GEM), targeting pancreatic cancer cells (PCC). Furthermore, KPC mice (LSL-KrasG12D/+; LSL-Trp53R172H/+; Pdx-1-Cre) were treated with the combination of GEM and ATRA. Appropriate controls were used for both in vivo and in vitro assays using either drug alone or vehicle alone to dissect effect of individual drug. Both in vivo and in vitro assays were studied for various surrogate endpoints for chemotherapy efficacy.

Results:In the organotypic model, ATRA alone or in combination with GEM reduced cancer cell and stellate cell invasion. The same treatment also reduced cancer cell proliferation. Stellate cell activation, as measured by fibronectin production per stellate cell, was significantly reduced upon combination treatment with GEM/ATRA, in comparison to cultures treated with GEM or ATRA only. In the KPC mice model, ATRA alone or in combination with GEM caused stromal collapse. The same regimen treatment led to an increase in vascular density in the tumor area and a significant impairment of the tumor growth, when compared with mice treated with ATRA or GEM alone. The number of necrotic areas was also higher in tumors from mice treated with the combination treatment of GEM/ATRA. Further assessments are being carried out.

Conclusions:The combination treatment of all-trans retinoic acid and Gemcitabine may have a synergistic detrimental effect upon pancreatic cancer progression.

Citation Format: Elisabete Florencio Carapuça, Emilios Gemenetzidis, Christine Feig, David Tuveson, Hemant Kocher. Developing drug combinations to co-target pancreatic cancer and its supporting stroma. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr B72.
Abstract B78: Warfarin blocks Gas6-mediated Axl activation required for pancreatic tumor plasticity and metastasis
Authors: Kirane Amanda , Ludwig Kathleen W. , Haaland Gry , Sandal Tone , Ranaweera Renata , Toombs Jason E. , Sullivan Laura A. , Wang Miao , Sorrelle Noah , Dineen Sean P. , Dellinger Michael T. , Lorens James B. , Brekken Rolf A.
Published: October 2015

Warfarin, a vitamin K antagonist anti-coagulant in clinical use for over 50 years, is reported to exert anti-cancer effects. We hypothesized that the molecular mechanism underlying the observed anti-tumor effects of warfarin is unrelated to generalized anti-coagulation, but rather due to inhibition of the Axl receptor tyrosine kinase. Activation of Axl by its ligand Gas6, a vitamin K-dependent protein, is inhibited at doses of warfarin that do not affect coagulation. Here we document that inhibiting Gas6-mediated Axl activation with low dose warfarin blocks pancreatic cancer progression and spread. Warfarin and other Axl-targeting agents inhibit tumor progression and block spontaneous metastasis in multiple murine models of pancreatic cancer. Warfarin inhibited Axl-dependent tumor cell migration, invasiveness and proliferation while increasing apoptosis and sensitivity to chemotherapy. We demonstrate that Axl signaling is necessary for pancreatic tumor cell epithelial plasticity which is potently reversed by warfarin or selective Axl inhibition in vitro and in vivo. We anticipate Axl is a critical driver of pancreatic cancer progression and its inhibition with low dose warfarin or Axl-selective targeting agents may significantly improve outcome in patients.

Citation Format: Amanda Kirane, Kathleen W. Ludwig, Gry Haaland, Tone Sandal, Renata Ranaweera, Jason E. Toombs, Laura A. Sullivan, Miao Wang, Noah Sorrelle, Sean P. Dineen, Michael T. Dellinger, James B. Lorens, Rolf A. Brekken. Warfarin blocks Gas6-mediated Axl activation required for pancreatic tumor plasticity and metastasis. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr B78.
Abstract B83: Cannabinoids as an adjuvant therapy for pancreatic cancer
Authors: Hospodor Andy D.
Published: October 2015

In over 20 states, cancer patients have access to cannabinoids (aka medical marijuana) to treat symptoms of chemotherapy, such as nausea and lack of appetite. However, new evidence, both scientific and empirical, suggests that higher doses of cannabinoids may be an effective adjuvant alongside traditional chemotherapy agents, such as Gemcitibine. While daily dosages of 10 to 40mg are commonly used to control nausea, pancreatic cancer cells are known to over express the endo-cannabinoid receptor CB1 one hundred fold, requiring much higher dosages. Cannabinoids target different receptors than traditional chemotherapy agents with low combinatorial toxicity, and as such present a class of new treatments. In an n=1 study of a patient with stage IV pancreatic adeno-carcinoma, we augmented the standard Gemcitibine chemotherapy with balanced initial doses of 50mg THC and 50mg CBD that increased over a four week period to achieve a 12.5 mg/kg total cannabinoid dosage. Curiously, after ten days the patient stopped presenting signs of cannabinoid use, such as red eyes, slurred speech and clumsiness. However, the patient’s CA-19-9 marker increased from 8,800 ul/L at diagnosis to 25,500. Over the next four weeks, dosage of CBD was held constant and THC was increased to 1050mg daily for a combined dosage of 20mg/kg. At week 6, the CA-19-9 marker began decreasing and cannabinoid dosage was leveled off, although a higher dosage was planned for weeks 8-12. At week 15, CA-19-9 markers dropped to pre-diagnosis levels and a CAT scanned revealed shrinkage of the tumor. Rate of decrease in CA-19-9 exceeded previously published rates for patients with positive outcomes from Gemcitibine alone. Although many pancreatic cancer patients have access to cannabinoids, issues such as potency, purity and bio-availablity will impact future adjuvant cannabinoid therapies. We have addressed these issues with existing technology in the hopes of supporting large scale trials that will examine the efficacy of Gemcitibine + cannabinoid adjuvants in the treatment of pancreatic cancer.

Citation Format: Andy D. Hospodor. Cannabinoids as an adjuvant therapy for pancreatic cancer. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr B83.