bluuebunny/crossref_metadata_2025 huggingface dataset:
Bacteriological and Physical Quality of Locally Packaged Drinking Water in Kampala, Uganda
Authors: Halage Abdullah Ali , Ssemugabo Charles , Ssemwanga David K. , Musoke David , Mugambe Richard K. , Guwatudde David , Ssempebwa John C.
Published: October 2015

Objective. To assess the bacteriological and physical quality of locally packaged drinking water sold for public consumption.Methods. This was cross-sectional study where a total of 60 samples of bottled water from 10 brands and 30 samples of sachet water from 15 brands purchased randomly were analyzed for bacteriological contamination (total coliform and faecal coliform per 100 mL) using membrane filtrate method and reported in terms of cfu/100 mL.Results. Both bottled water and sachet water were not contaminated with faecal coliform. Majority (70%, 21/30) of the sachet water analyzed exceeded acceptable limits of 0 total coliforms per 100 mL set by WHO and the national drinking water standards. The physical quality (turbidity and pH) of all the packaged water brands analyzed was within the acceptable limits. There was statistically significant difference between the median count of total coliform in both sachet water and bottled water brands (U(24)=37.0,p=0.027).Conclusion. Both bottled water and sachet water were not contaminated with faecal coliforms; majority of sachet water was contaminated with total coliform above acceptable limits. Government and other stakeholders should consider intensifying surveillance activities and enforcing strict hygienic measures in this rapidly expanding industry to improve packaged water quality.
Unique Fixed Point Theorems for Generalized Contractive Mappings in Partial Metric Spaces
Authors: Mishra Lakshmi Narayan , Tiwari Shiv Kant , Mishra Vishnu Narayan , Khan Idrees A.
Published: October 2015

We establish some unique fixed point theorems in complete partial metric spaces for generalized weaklyS-contractive mappings, containing two altering distance functions under certain assumptions. Also, we discuss some examples in support of our main results.
High 15-F2t-Isoprostane Levels in Patients with a Previous History of Nonmelanoma Skin Cancer: The Effects of Supplementary Antioxidant Therapy
Authors: Almendra Freitas Betânia de Jesus e Silva de , Lloret Gustavo Rafaini , Visacri Marília Berlofa , Tuan Bruna Taliani , Amaral Lais Sampaio , Baldini Daniele , Sousa Vanessa Marcílio de , Castro Laís Lima de , Aguiar Jordana Rayane Sousa , Pincinato Eder de Carvalho , Mazzola Priscila Gava , Moriel Patricia
Published: October 2015

Background. Phase I of this study was aimed at comparing the profiles of oxidative stress biomarkers in patients with history of nonmelanoma skin cancer (NMSC), previously treated with surgery, to the healthy subjects. Phase II aimed to evaluate the effects of supplementary antioxidant therapy on the levels of biomarkers in the case group.Materials and Methods. In Phase I, oxidative stress biomarkers were measured in blood samples obtained from 24 healthy subjects and 60 patients with history of NMSC previously treated with surgery. In Phase II, the 60 patients with history of NMSC were randomized into two subgroups, one receiving placebo (n=34) and the other (n=26) receiving vitamin C, vitamin E, and zinc supplementation for 8 weeks, followed by reevaluation of biomarkers.Results. In Phase I, patients with history of NMSC showed increased plasma concentrations of all biomarkers, but only 15-F2t-isoprostane was significantly higher than in the healthy subjects. Risk of NMSC increased by 4% for each additional 1 pg/mL increase in 15-F2t-isoprostane. In Phase II, supplementation did not significantly reduce levels of oxidative stress biomarkers.Conclusion. Patients with history of NMSC had significantly high 15-F2t-isoprostane plasma levels; supplementation did not result in significant reduction of oxidative stress biomarkers. This trial was registered with ClinicalTrials.gov (IDNCT02248584).
The Clinical Value of Oxymatrine in Preventing Lamivudine Induced YMDD Mutation: A Meta-Analysis
Authors: He Min , Wu Yu , Wang Mengmeng , Chen Wenwen , Yuan Weian , Jiang Jian
Published: October 2015

Oxymatrine (OMTR) is widely used for the treatment of chronic hepatitis B (CHB) in China. Several reports revealed that combination of OMTR and lamivudine reduced the incidence of tyrosine- (Y-) methionine- (M-) aspartic acid- (D-) aspartic acid (D) (YMDD) mutations in CHB patients. The aim of this study was to evaluate the clinical value of oxymatrine in preventing lamivudine induced YMDD mutation using meta-analysis of data from published randomized controlled trials (RCTs) and to provide some useful information for clinical treatment and future research of YMDD mutation. The Cochrane Central Register of Controlled Trials, Medline, Science Citation Index, EMBASE, China National Knowledge Infrastructure, Wanfang Database, and China Biomedical Database were searched to identify RCTs that evaluated the incidence of YMDD-motif mutation to lamivudine therapy and lamivudine plus OMTR therapies in CHB patients. Data analysis was carried out with the use of RevMan 5.3.2. The literature search yielded 324 studies, and 16 RCTs matched the selection criteria. Overall, the incidence of YMDD mutation was significantly lower in patients treated with lamivudine plus OMTR than in patients treated with lamivudine alone (11.14% versus 28.18%; RR: 0.41; 95% CI: 0.33–0.52;p<0.05). The exact outcome needs to perform rigorously designed, multicenter, and large randomized controlled trials.
SAFM: An Adaptive Socially Aware Feedback Mechanism in Delay Tolerant Sensor Networks
Authors: Liu Yan , Wang Kun , Huang Guo , Qi Jin , Sun Yanfei
Published: October 2015

In Delay Tolerant Sensor Networks (DTSN), it is a challenge to ensure the delivery reliability, due to the lack of end-to-end path, intermittent connection, and high latency. In addition, the resource utilization is decreased because of the limited resources and a large number of redundant copies. To this end, this paper proposes an adaptive Socially Aware Feedback Mechanism (SAFM). In this mechanism, the historical information of the encountered nodes is utilized to construct social links which indicates the level of social relationship between nodes. In the feedback process, acknowledgements are forwarded to the nodes whose social link (SL) is higher than a given thresholdα. After getting the acknowledgements, nodes will delete the copies of messages which have been received by the destination nodes, so as to reduce the redundancy. This mechanism is to reach a tradeoff between overhead and delivery efficiency. In simulation, the thresholdαis obtained to reach the best performance of SAFM. Compared with active and passive receipt approaches in an acceptable range of delay, SAFM improves the delivery probability, decreases the buffer occupancy, and reduces the overhead.
Screen‐Printed Flexible Bandstop Filter on Polyethylene Terephthalate Substrate Based on Ag Nanoparticles
Authors: Dhakal Rajendra , Jung Younsu , Park Hyejin , Cho Gyoujin , Kim Nam Young
Published: October 2015

We present a low‐power, cost‐effective, highly reproducible, and disposable bandstop filter by employing high‐throughput screen‐printing technology. We apply large‐scale printing strategies using silver‐nanoparticle‐based ink for the metallization of conductive wires to fabricate a bandstop filter on a polyethylene terephthalate (PET) substrate. The filter exhibits an attenuation pole at 4.35 GHz with excellent in‐and‐out band characteristics. These characteristics reflect a rejection depth that is better than −25 dB with a return loss of −0.75 dB at the normal orientation of the PET substrate. In addition, the filter characteristics are observed at various bending angles (0°, 10°, and 20°) of the PET substrate with an excellent relative standard deviation of less than 0.5%. These results confirm the accuracy, reproducibility, and independence of the resonance frequency. This screen‐printing technology for well‐defined nanostructures is more favorable than other complex photolithographic processes because it overcomes signal losses due to uneven surface distributions and thereby reveals a homogeneous distribution. Moreover, the proposed methodology enables incremental steps in the process of producing highly flexible and cost‐effective printed‐electronic radio devices.
Worms Propagation Modeling and Analysis in Big Data Environment
Authors: He Song , Zhang Can , Guo Wei , Zhai Li-Dong
Published: October 2015

The integration of the Internet and Mobile networks results in huge amount of data, as well as security threat. With the fragile capacity of security protection, worms can propagate in the integration network and undermine the stability and integrity of data. The propagation of worm is a great security risk to massive amounts of data in the integration network. We propose a kind of worm propagating in big data environment named BD-Worm. BD-Worm consumes computing resources and gets privacy information of users, which causes huge losses to our working and living. This paper constructs an integration network topology model and designs the BD-Worm propagating in the big data environment. To analyze the propagation of BD-Worm, we conduct a simulation and provide some recommendations to contain the widespread of BD-Worm according to the simulation results.
Optimal Design of Stochastic Distributed Order Linear SISO Systems Using Hybrid Spectral Method
Authors: Duong Pham Luu Trung , Kwok Ezra , Lee Moonyong
Published: October 2015

The distributed order concept, which is a parallel connection of fractional order integrals and derivatives taken to the infinitesimal limit in delta order, has been the main focus in many engineering areas recently. On the other hand, there are few numerical methods available for analyzing distributed order systems, particularly under stochastic forcing. This paper proposes a novel numerical scheme for analyzing the behavior of a distributed order linear single input single output control system under random forcing. The method is based on the operational matrix technique to handle stochastic distributed order systems. The existing Monte Carlo, polynomial chaos, and frequency methods were first adapted to the stochastic distributed order system for comparison. Numerical examples were used to illustrate the accuracy and computational efficiency of the proposed method for the analysis of stochastic distributed order systems. The stability of the systems under stochastic perturbations can also be inferred easily from the moment of random output obtained using the proposed method. Based on the hybrid spectral framework, the optimal design was elaborated on by minimizing the suitably defined constrained-optimization problem.
Abstract A08: Activation of Wnt/β-catenin in acinar cells accelerates Kras-induced PDAC, while activation of Wnt signaling pathways in stroma induces mucinous cystic neoplasm
Authors: Sano Makoto , Driscoll David R. , DeJesus-Monge Wilfredo E. , Klimstra David S. , Lewis Brian C.
Published: October 2015

Pancreatic ductal adenocarcinoma (PDAC) commonly develops following activating mutations in the KRAS oncogene. Activation of the Wnt signaling pathway is also commonly observed in PDAC, yet whether Wnt ligand induced signaling promotes pancreatic tumorigenesis in vivo remains unclear. To ascertain the impact of postnatal activation of the Wnt signaling pathways in PDAC development, we combined the elastase-tva-based RCAS-TVA pancreatic cancer model with the established LSL-KrasG12D, Ptf1a-cre model. Delivery of RCAS viruses encoding β-cateninS37A and Wnt1 stimulated the progression of premalignant PanIN and PDAC development. Mice injected with RCAS-β-cateninS37A and Wnt1 had reduced survival relative to RCAS-GFP controls (log-rank test; p < 0.05). Immunohistochemical analysis demonstrated cytoplasmic and nuclear staining of β-catenin in Wnt1-induced PDAC, and enhanced staining for the Wnt target gene Axin2 in the tumor epithelium, but not the reactive stroma. Interestingly, we also found that female mice injected with RCAS-Wnt1, but neither RCAS-β-cateninS37A nor RCAS-GFP, developed mucinous cystic neoplasm (MCN). These lesions displayed stereotypical ovarian-like stroma that was positive for estrogen receptor (ER) and progesterone receptor (PR), but they lacked the typical mucinous epithelium observed in human MCN. Analysis of tissue specimens confirmed of activation of both the Wnt/β-catenin and PCP signaling pathways in the stroma, but not the epithelium of MCN lesions. Analysis of human MCN cases identified activation of these Wnt signaling pathways in the ovarian-like stroma, but not the cyst epithelium. Together, these data suggest that the Wnt/β-catenin signaling pathway in acinar cells stimulates Kras-induced PDAC development, while activation of Wnt signaling pathways in the stroma stimulates the development of the ovarian-like stroma and contributes to MCN formation in vivo.

Citation Format: Makoto Sano, David R. Driscoll, Wilfredo E. DeJesus-Monge, David S. Klimstra, Brian C. Lewis. Activation of Wnt/β-catenin in acinar cells accelerates Kras-induced PDAC, while activation of Wnt signaling pathways in stroma induces mucinous cystic neoplasm. [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 A08.
Abstract A100: Role of HER3 ligand-independent activation in EGFR resistance in pancreatic cancer
Authors: Buchsbaum Donald J. , Zhou Tong
Published: October 2015

The purpose of this study was to investigate the role of HER3 ligand-independent activation in EGFR resistance in pancreatic cancer. The expression and activation status of EGFR and HER3 were determined in a panel of 13 human pancreatic cancer cell lines by immunoprecipitation and Western blot analysis. To determine whether HER3 plays a central role in EGFR resistance, the effect of combination treatment with erlotinib and anti-HER3 on signaling pathways was examined in 2 pancreatic cancer cell lines. This was done using a novel anti-HER3 antibody (1A5) capable of inhibiting HER3 activation in a ligand-independent fashion, and a classic anti-HER3 antibody (3D4) primarily blocking ligand-induced HER3 activation. The MEK inhibitor trametinib was used to investigate EGFR and HER3 activation. Combination treatment studies in athymic nude mice bearing BxPC-3 xenografts involved anti-HER3, lapatinib, trametinib, and gemcitabine treatment. The majority of pancreatic cancer cell lines expressed high levels of total EGFR and HER3, and had variable levels of phospho-EGFR (Tyr1068) and phospho-HER3. Erlotinib treatment did not reduce the levels of phospho-EGFR. Although ligand-independent and ligand-dependent anti-HER3 antibodies did not alter the levels of phospho-EGFR, they did reduce the levels of phospho-AKT. Combination treatment with anti-HER3 antibodies and erlotinib or trametinib reduced the levels of phospho-EGFR and phospho-AKT. When MEK/ERK was inhibited by trametinib, both EGFR and HER3 were activated. Treatment of BxPC-3 xenografts with lapatinib, trametinib, anti-HER3, and gemcitabine produced the greatest inhibition of tumor growth as compared to any single agent or combinations of two or three agents. These results show that EGFR is expressed and highly activated in pancreatic cancer cell lines, but the cell lines are resistant to an EGFR inhibitor. They also suggest that ligand-independent activation of HER3 may lead to erlotinib resistance via the AKT pathway. These results reveal a novel mechanism by which HER3 is activated in a ligand-independent fashion via inhibition of the MEK/ERK pathway. This is an important observation as it indicates that HER3 ligand-independent activation must be inhibited when the MEK/ERK pathway is targeted. Overall, these results indicate that HER3 ligand-independent activation is a key target for overcoming EGFR resistance in pancreatic cancer cells, and suggest a combination strategy of anti-HER3 antibodies with either erlotinib or trametinib for the treatment of pancreatic cancer.

Citation Format: Donald J. Buchsbaum, Tong Zhou. Role of HER3 ligand-independent activation in EGFR resistance 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 A100.
Abstract A106: BRCA mutation sensitizes pancreatic tumors to treatment with cisplatin
Authors: Lohse Ines , Cao Pinjian , Ibrahimov Emin , Tsao Ming-Sound , Hedley David W.
Published: October 2015

Rationale: Recent clinical observations in pancreatic cancer suggest that cancers arising in germline BRCA1/2 mutation carriers are highly sensitive to Cisplatin chemotherapy.

Both BRCA1 and BRCA2 are required for DNA double-strand break repair by homologous recombination (HR). Platinum chemotherapy generates interstrand cross-links that can only be adequately repaired by HR-based DNA repair, and consequently BRCA1/2-deficient cells are highly sensitive to platinum chemotherapy both in vitro and in vivo.

With a strong biological rationale and favourable clinical observations, we aim to investigate whether BRCA mutation indeed sensitize to Cisplatin treatment and if the addition of the PARP inhibitor ABT-888 further reduces tumor growth in patient-derived pancreatic xenografts

Methods: Primary xenografts were derived from three patients with known BRCA2 germline mutations (2 from surgical resections, 1 from ascites fluid). All 3 patients experienced a major response when treated with cisplatin. These models were used to assess the in vivo sensitivity to the drugs Cisplatin, Gemcitabine and the PARP inhibitor ABT-888, all of which are being used in the clinic. Treatment sensitivities were compared to 2 primary xenografts that were BRCA w/t. For single treatments, animals were treated with 4mg/kg Cisplatin weekly, 100mg/kg Gemcitabine biweekly or 12.5mg/kg ABT-888 daily for 30 days. For the combination treatment, animals were treated with a single dose of 4mg/kg Cisplatin followed by 30 days of 12.5mg/kg ABT-888 daily.

Results: Preliminary results show no difference in tumor growth between BRCA2 wt and mt models was observed in response to treatment with ABT-888 alone. Treatment with cisplatin or gemcitabine on the other hand significantly reduced tumor growth and increased survival in all 3 BRCA2 mutated xenograft models, while being mostly ineffective in BRCA w/t tumors. The combination of Cisplatin and ABT-888 significantly reduced tumor growth when compared to ABT-888 alone.

Conclusions: The results suggest that BRCA1/2 mt pancreatic xenograft models are highly sensitive to cisplatin. The availability of these models facilitates “near-clinical” testing of alternative strategies for optimizing the individualized treatment of patients carrying these rare mutations, and for the exploration of protocols incorporating novel agents.

Citation Format: Ines Lohse, Pinjian Cao, Emin Ibrahimov, Ming-Sound Tsao, David W. Hedley. BRCA mutation sensitizes pancreatic tumors to treatment with cisplatin. [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 A106.
Abstract A112: Eradication of cancer stem-like cells in PDAC
Authors: Arumugam Thiruvengadam , Ramachandran Vijaya , Logsdon Craig
Published: October 2015

Background: Pancreatic Ductal Adenocarcinoma (PDAC) is resistant to conventional chemotherapy. Cancer Stem-Like Cells (CSLCs) are drug resistant and can act as tumor initiating cells. Evidence suggests that CSLCs can be selected by chemotherapy that targets the more sensitive somatic cancer cells. In the current study we found that Gem treatment can not only select CSLCs, but can also induce transformation of somatic cancer cells into CSLCs. We also observed that p21 is required to maintain CSLCs in a quiescent state. Methods: Cell growth, cell cycle and apoptosis were analyzed by using MTS and FACS analysis. ALDH and p21 were localized by immunohistochemistry and immunofluorescence. CLSCs were analyzed by ALDH assay, clonogenic in vitro assays and in vivo tumor initiation. Both in vitro and in vivo silencing of p21 was accomplished using nanoparticle coupled siRNA. Results: Gem treatment induced the p21 and led to a transient cytostasis and chemoresistance in PDAC cell lines. Analysis of resected tumor samples revealed that Gem treatment also induced p21 expression and ALDH positivity in tumors of Gem treated but not untreated patients. In vitro studies indicated that Gem induced the acquisition of a CSLC phenotype and the expression of pluripotent transcription factors (PFTs). Silencing of p21 blocked the both basal and Gem induced CSLC numbers, the maintenance of quiescence, and resistance to Gem in vitro. In vivo, silencing of p21 greatly increased the effectiveness of Gem treatments to inhibit tumor growth and did not increase toxicity. Conclusion: These data indicate that p21 maintains chemotherapy induced CSLCs quiescence and drug resistance such that targeting p21 in combination with cytotoxic therapies is beneficial in eradicating both basal and Gem transformed CSLCs.

Note: This abstract was not presented at the conference.

Citation Format: Thiruvengadam Arumugam, Vijaya Ramachandran, Craig Logsdon. Eradication of cancer stem-like cells in PDAC. [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 A112.
Abstract A121: Suppression of orthotopic pancreatic cancer growth by sulforaphane is associated with activation of FOXO transcription factors
Authors: Yu Wei , Srivastava Rakesh , Shankar Sharmila
Published: October 2015

FoxO (forkhead box O) transcription factors are crucial regulators of cell fate. This function of FoxO proteins relies on their ability to control diverse functions such as proliferation, differentiation, DNA repair and apoptosis. Constitutively active AKT and ERK in cancer cells have been shown to phosphorylate FoxO transcription factors (FKHR, FKHRL1 and AFX), which bind to protein 14-3-3 and sequester in the cytoplasm. In the absence of survival signals, FoxO proteins dephosphorylate, translocate to the nucleus and upregulate a series of target genes, thereby promoting cell cycle arrest and apoptosis. Sulforaphane a naturally occurring isothiocyanate, exerts anti cancer effects through diverse mechanisms. In this study we have shown that sulforaphane acts both by suppressing cell proliferation and inducing apoptosis in pancreatic tumors orthotopically implanted in nude mice. Sulforaphane regulates cell survival and cell death by modulating the expression of two interacting survival signaling pathways. The inhibition of PI3K/AKT and MEK/ERK pathways by sulforaphane resulted in the inhibition of cytoplasmic phosphorylation of FOXOs, and enhanced their nuclear translocation and transcriptional activities leading to apoptosis. Furthermore, deletion of FOXO1, FOXO3 and FOXO4 genes by shRNA abrogated sulforaphane-induced cell cycle arrest and apoptosis whereas the phosphorylation deficient triple mutants of FOXOs enhanced sulforaphane-induced FOXO transcriptional activity and apoptosis by nuclear translocation of FOXO. Sulforaphane-treated mice showed significant inhibition in tumor growth which was associated with reduced phosphorylation of ERK, PI3K, AKT, FOXO1 and FOXO3a, cyclin D1 and induction of FOXO’s target genes Bim, p21/CIP1, and p27/KIP1. These data suggest that inhibition of ERK and AKT pathways act together to activate FOXO transcription factors which are involved in sulforaphane-mediated pancreatic tumor growth suppression, thus supporting the use of sulforaphane as a chemopreventive agent for the treatment of pancreatic cancer.

Citation Format: Wei Yu, Rakesh Srivastava, Sharmila Shankar. Suppression of orthotopic pancreatic cancer growth by sulforaphane is associated with activation of FOXO transcription factors. [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 A121.
Abstract A20: Molecular dissection of pancreatic cancer invasion and metastasis
Authors: Chiou Shin-Heng , Winslow Monte
Published: October 2015

Pancreatic ductal adenocarcinoma (PDAC) is an almost uniformly fatal malignancy of the exocrine pancreas. Although several factors contribute to the poor prognosis of this disease, the ability of cancer cells to disseminate and establish inoperable metastases before diagnosis is a major impediment to successful therapy. Unfortunately, strategies that enable efficacious treatment or early detection of the disease do not exist, highlighting an urgent need for a critical understanding of PDAC progression and dissemination. To identify novel molecular mechanisms that drive metastasis, we compared the transcriptomes of “invasive” and “non-invasive” cancer cells isolated from tumors that are derived from a previously described autochthonous PDAC model (KrasLSL-G12D;p53LSL-R172H;Pdx1-cre or KPC mice). This mouse model was chosen because it recapitulates many aspects of the human disease, including cellular heterogeneity, abundant stromal responses, and great propensity for metastasis. To isolate pure PDAC cells, we first excluded the infiltrating, non-cancer cells by incorporating a Cre-reporter allele (R26LSL-Tomato) into the KPC mice. Our strategy to distinguish “invasive” from “non-invasive” cancer cells was based on our previous observations that the high mobility group AT-hook 2 protein (Hmga2), which is otherwise not expressed in most of adult tissues, is specifically expressed in cancer cells with mesenchymal phenotype. To label cancer cells that express Hmga2, we generated a conditional Hmga2-GFP reporter mouse. When a single Hmga2GFP allele is present in the KPC;R26LSL-Tom mice, we were able to sort both Hmga2-positive (GFP+Tomato+) and Hmga2–negative (GFP-Tomato+) cancer cells. Intravenous transplantations indicated that the GFP+ cancer cells have significantly higher metastatic ability. Furthermore, transcriptomic profiling of the sorted, un-passaged cells through RNA-Seq indicated that Hif1α activity is highly enriched in the invasive GFP+ cancer cells. Consistent with the RNA-Seq data, the expression of the Hif1α target Glut1 correlates with Hmga2 under immunohistochemical staining. We hypothesized that during PDAC progression, hypoxia induces the both up- and down-regulation of a set of genes, including both Hif1α-dependent and –independent ones, that are necessary to drive cancer metastasis. Future experiments will functionally interrogate, both in vitro and in vivo, the candidate genes selected based on presence of human orthologs, cross-examination with co-purified myofibroblast transcriptomic profiles, fold change, and novelty. Our study will help identify important molecular mechanisms that drive PDAC metastasis.

Citation Format: Shin-Heng Chiou, Monte Winslow. Molecular dissection of pancreatic cancer invasion 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 A20.
Abstract A22: CXCL12-CXCR4 chemotactic pathway modulates metastasis and perineural invasion in pancreatic cancer
Authors: Xu Qinhong , Duan Wanxing , Lei Jianjun , Ma Jiguang , Wu Erxi , Ma Qingyong
Published: October 2015

Perineural invasion (PNI) is considered as an alternative route for metastatic spread of pancreatic cancer cells; however the molecular changes leading to PNI are still poorly understood. In this study, we show that CXCL12/CXCR4 axis, which is one of the most widely studied chemokines signaling, plays a pivotal role in the neurotropism of pancreatic cancer cells to local peripheral nerves. We conducted a co-culture model, which used newborn rat dorsal root ganglia (DRG) and pancreatic cancer cells, and a sciatic nerve invasion model by nude mice. We provide in vitro and in vivo evidence to study the function of CXCL12/CXCR4 signaling in PNI progression and pathogenesis. The results showed that the activation of CXCL12/CXCR4 axis significantly increased the invasion of pancreatic cancer cells and promoted the outgrowth of DRG. The chemotaxis migration of pancreatic cancer cells to the neurites of DRG is evidently suppressed by blocking the pathway. In vivo analyses revealed that the abrogation of the activated signaling could inhibit tumor growth and invasion of the sciatic nerve toward the spinal cord. These data indicated that CXCL12/CXCR4 axis is involved in PNI, and inhibition of the signaling pathway may be a promising new therapeutic strategy for the recurrence and metastasis of pancreatic cancer.

Citation Format: Qinhong Xu, Wanxing Duan, Jianjun Lei, Jiguang Ma, Erxi Wu, Qingyong Ma. CXCL12-CXCR4 chemotactic pathway modulates metastasis and perineural invasion 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 A22.
Abstract A27: Redefining the role of Notch in acinar to ductal metaplasia
Authors: Halbrook Christopher J. , Crawford Howard C.
Published: October 2015

The EGFR and Notch signaling pathways have been widely implicated in relation to both chronic pancreatitis and pancreatic ductal adenocarcinoma in humans, however the link between the two pathways has remained obscure. Acinar to ductal metaplasia (ADM,) a phenomenon where acinar cells undergo a morphological change and begin expressing markers normally found only in ductal cells while losing markers typical of acinar cells, has been linked to both the Notch and EGFR signaling pathways. ADM is highly proliferative with the potential to develop into pancreatic intraepithelial neoplasia, a precursor lesion to pancreatic cancer. Recently we and others have shown that genetic ablation of EGFR in the pancreas effectively prevents acinar to ductal metaplasia in cerulein model of pancreatitis in mice, and prevents tumorigenesis driven by oncogenic Kras. Additionally, we have found that acinar cells harvested from EGFRf/f;Ptf1aCre/+ mice (EKO) mice are resistant to ADM in vitro upon cerulein treatment, or by the expression of oncogenic Kras. Activation of EGFR by treatment of WT collagen embedded acinar cell explants with the EGFR ligand TGF-α has previously been shown to induce ADM in a manner requiring Notch pathway activation. Furthermore, it has also been demonstrated that expression of Notch2 intracellular domain (N2ICD) is sufficient to induce ADM in WT acinar cells. To directly investigate the relationship of the EGFR, Kras, and Notch signaling pathways in ADM, we examined the effect of Notch signaling in acinar cells harvested from EKO mice. Interestingly, these acinar cells fail to transdifferentiate in vitro upon transduction of N2ICD in 3D culture; however the transdifferentiation event can be rescued by co-expression of oncogenic Kras with N2ICD in acinar cells lacking EGFR. These results indicate that EGFR is important in Notch induced ADM, however there are other pathways that possibly can be utilized by acinar cells expressing oncogenic Kras to drive ADM.

Citation Format: Christopher J. Halbrook, Howard C. Crawford. Redefining the role of Notch in acinar to ductal metaplasia. [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 A27.
Abstract A39: The activation of β1-integrin by type i collagen coupling with the Hedgehog pathway promotes the epithelial-mesenchymal transition in pancreatic cancer cells
Authors: Duan Wanxing , Ma Qingyong , Ma Jiguang , Xu Qinhong , Lei Jianjun , Wu Erxi
Published: October 2015

Pancreatic ductal adenocarcinoma (PDAC), one of the most lethal gastrointestinal cancers, is characterized by the excessive deposition of extracellular matrix (ECM) that has been thought to contribute to the malignant behaviour. However, the detailed mechanism and the contribution of excessive deposition of ECM in PDAC progression remain unclear. A better understanding of the mechanism involved in this process is essential for the design of new effective therapies. In this study, we demonstrated that pancreatic cancer cells exhibited increased proliferation and decreased apoptosis in response to type I collagen. In addition, exposed to type I collagen, PDAC cells lost the expression of E-cadherin and increased expression of mesenchymal markers, including N-cadherin and vimentin, which was correlated with enhanced cell migration and invasiveness. Conversely, the knockdown of β1-integrin abolished the effects induced by type I collagen. Further investigation revealed that type I collagen activates β1-integrin accompanied with significant up-regulation of Gli-1. siRNA specific to Gli-1 reversed the effects of type I collagen on PDAC invasion and epithelial-mesenchymal transition (EMT). These results suggest that there is cross-talk between the β1-integrin signaling pathway and the Hedgehog (HH) pathway in pancreatic cancer and the abnormal activation of the HH pathway plays a key role in the type I collagen-induced effects on pancreatic cancer. Therefore, our findings may have potential significance for the development of new therapeutic strategies to treat this highly aggressive malignancy.

Citation Format: Wanxing Duan, Qingyong Ma, Jiguang Ma, Qinhong Xu, Jianjun Lei, Erxi Wu. The activation of β1-integrin by type i collagen coupling with the Hedgehog pathway promotes the epithelial-mesenchymal transition 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 A39.
Abstract A48: CD4+ T lymphocyte ablation prevents pancreatic carcinogenesis in mice
Authors: Zhang Yaqing , Yan Wei , Mathew Esha , Bednar Filip , Wan Shanshan , Collins Meredith A. , Evans Rebecca A. , Welling Theodore H. , Vonderheide Robert H. , Magliano Marina Pasca di
Published: October 2015

This abstract is also being presented as a short talk in Session 6: Immunology. A full abstract is printed in the Proffered Abstracts section (PR11) of the Conference Proceedings.

Citation Format: Yaqing Zhang, Wei Yan, Esha Mathew, Filip Bednar, Shanshan Wan, Meredith A. Collins, Rebecca A. Evans, Theodore H. Welling, Robert H. Vonderheide, Marina Pasca di Magliano. CD4+ T lymphocyte ablation prevents pancreatic carcinogenesis in mice. [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 A48.
Abstract A54: Ly6Chi inflammatory monocytes mediate tumor regression in a mouse model of spontaneously arising pancreatic ductal adenocarcinoma
Authors: Gladney Whitney L. , Tooker Graham M. , Beatty Gregory L.
Published: October 2015

Macrophage infiltration into solid malignancies most often portends a poor prognosis. In pancreatic ductal adenocarcinoma (PDAC), macrophages dominate the leukocyte infiltrate with effector T lymphocytes remaining scarce. Strategies to restore productive immunosurveillance in PDAC have largely focused on inducing anti-tumor T cell immunity. However, we have previously shown in patients and a mouse model of PDAC that immune modulation with a CD40 agonist can induce macrophages to facilitate tumor regression. Thus, strategies that restore innate immunosurveillance may hold promise in the treatment of PDAC. To further investigate the role of macrophages as targets for anti-tumor immunotherapy, we utilized the KrasG12D; Trp53R172H; Pdx-1 Cre (KPC) genetically engineered mouse model of PDAC. We previously reported a role for liposomal targeted macrophages in facilitating tumor regression induced with CD40 therapy. However, unexpectedly we found by immunohistochemistry that macrophages targeted by liposomes do not infiltrate PDAC tumors in response to CD40 therapy. This finding suggested a role for additional leukocyte subsets in mediating the anti-tumor effect. Using immunohistochemistry, we found that systemic CD40 activation induced the infiltration of Ly6C+ myeloid cells into KPC tumors. Based on this finding, we hypothesized that macrophages may regulate the infiltration of Ly6Chi inflammatory monocytes, which are the critical effector myeloid cells mobilized in the peripheral blood by CD40 agonist therapy. In support of this hypothesis, we found that tumor regression induced with a CD40 agonist was abrogated by treatment with the anti-Ly6C/Ly6G RB6-8C5 depleting antibody. Flow cytometric analysis of peripheral blood revealed that RB6-8C5 and liposomes target distinct myeloid subsets. Whereas RB6-8C5 was found to deplete Ly6ChiCCR2+ inflammatory monocytes, CEL depleted Ly6Cneg myeloid cells. Our findings suggest that CD40-induced tumor regression in PDAC is mediated by inflammatory monocytes which infiltrate tumor lesions under the regulation of extra-tumoral macrophages.

Citation Format: Whitney L. Gladney, Graham M. Tooker, Gregory L. Beatty. Ly6Chi inflammatory monocytes mediate tumor regression in a mouse model of spontaneously arising 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 A54.
Abstract A73: De-convoluting therapeutic resistance in a pancreatic cancer model: Pharmacogenomic evaluation of intratumoral clonal heterogeneity
Authors: Vietsch Eveline E. , Simmons John K. , Peran Ivana , Stenstra Marianne , Mock Beverly A. , Wellstein Anton
Published: October 2015

Background: The duration of therapeutic response in pancreatic adenocarcinoma to both targeted therapies and conventional chemotherapeutics is abysmal, greatly contributing to the 5-year survival rate of this disease remaining in the single digits. Given the high proliferative rate of these tumors, and the frequent occurrence of mutations in genes critical for maintaining genomic integrity, we hypothesized that rapid therapeutic resistance may largely be the consequence of intratumoral heterogeneity present at the onset of therapy.

Materials and Methods: To address this question, an integrated genomic and pharmacologic survey was performed on a panel of clonal cell lines generated from a tumor arising in a Kras/Trp53 mutant mouse model (p48-Cre; LSL-KrasG12D; LSL-Trp53R172H).

Results: All lines screened maintained tumorigenicity upon allografting, and exhibited metastatic capacity. Whole exome sequencing confirmed that 94% of driver mutations found in the clonal lines were also present in the tumor. Importantly, each clonal line contains unique passenger mutations. Exposure of these lines to conventional chemotherapeutics in vitro (i.e. gemcitabine, doxorubicin, and vincristine) showed high variance in sensitivity, with 10-fold ranges of IC50s among the lines. Screening of the clonal cell lines with a kinase inhibitor library of 200 compounds, showed distinct vulnerabilities to targeted pathways between the lines. Gene expression profiling and pathway analysis highlighted variation in critical cellular pathways between the lines.

Conclusions: Our results in this model system implicate ab initio drug resistance in these heterogeneous tumors as a major contributor to the poor therapeutic outcomes in this disease. This applies to conventional chemotherapy as well as targeted inhibitors.

Citation Format: Eveline E. Vietsch, John K. Simmons, Ivana Peran, Marianne Stenstra, Beverly A. Mock, Anton Wellstein. De-convoluting therapeutic resistance in a pancreatic cancer model: Pharmacogenomic evaluation of intratumoral clonal heterogeneity. [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 A73.
Abstract A77: Investigating the role of ADAM10 in pancreatic tumor differentiation
Authors: Peverley Louise V. , Halbrook Christopher J. , Hall Jason C. , Ardito Christine M. , Crawford Howard C.
Published: October 2015

Pancreatic adenocarcinoma (PDAC) is the 4th most common cause of cancer related deaths in the United States and has a dismal 5-year survival rate of 6%. This prognosis is attributed the disease’s fast and asymptomatic progression to metastasis, leading to late diagnosis upon which time there are few treatment options available. The A Disintegrin and Metalloproteinase (ADAM) family are sheddase proteins known to regulate cell adhesion and function. This regulation can allow ADAMs to influence the ability of tumor cells to disseminate from the primary tumor and metastasize to distant organs. ADAM10, which is seen to be up-regulated in both chronic pancreatitis and PDAC, cleaves a variety of substrates including several cell adhesion molecules such as L1-CAM, N-Cadherin, and E-Cadherin. Using a conditional knockout for ADAM10 in the Kras+/G12D;Ptf1a+/Cre (KC) mouse model of pancreatic cancer, we have observed an absence of metastasis when ADAM10 is genetically ablated. To investigate the potential role that ADAM10 plays in this, we used a shRNA approach to knock-down ADAM10 expression in various human pancreatic cancer cells lines. Analysis of these cell lines suggests a partial restoration of a less aggressive, differentiated phenotype, consistent with the increased longevity of the ADAM10 knockout KC mice.

Citation Format: Louise V. Peverley, Christopher J. Halbrook, Jason C. Hall, Christine M. Ardito, Howard C. Crawford. Investigating the role of ADAM10 in pancreatic tumor differentiation. [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 A77.
Abstract A78: Profiling of miRNA interactions in pancreatic adenocarcinoma by Argonaute CLIP-seq suggests a highly dynamic repertoire of targets
Authors: Quann Kevin , Loher Phillipe , Clark Peter , Delgrosso Kathleen , Fortina Paolo , Jing Yi , Brody Jonathan , Rigoutsos Isidore
Published: October 2015

MicroRNAs (miRNAs) are primary post-transcriptional regulators of gene expression which operate by degrading or otherwise repressing translation of target transcripts containing a corresponding miRNA recognition element (MRE). MiRNAs exert their effects through recruitment of the Argonaute (Ago) silencing complex to MRE sites. Although disruption of miRNA expression profiles is characteristic of many disease states, the inherent biological complexity of these regulatory networks has limited the ability to exhaustively catalog miRNA target repertoires and their associated functional phenotypes for a given tissue or cell type. To address these issues in the context of pancreatic adenocarcinoma, we performed next generation sequencing of both short and long RNA species to profile expression levels of both miRNAs and potential target transcripts, respectively, in hTERT-HPNE and MIA PaCa-2 cell lines. Additionally, we deep-sequenced Argonaute-bound RNAs (Ago CLIP-seq). Our results indicate that although the transcriptional profiles of both cell lines are stable across replicates, the subset of MREs that are engaged at any time with miRNAs is highly dynamic and not necessarily commensurate with relative transcript abundance. Additionally, we found that most MREs are located in intergenic and intronic regions. Moreover, of the MREs that are in protein-coding transcripts, the majority exist outside the 3′ untranslated regions (3′UTRs), in the coding regions and the 5′UTRs. These results further suggest that standard models for miRNA interactions that are commonly utilized may not adequately capture the interactions that are at work in pancreatic cells. Taken together, these results highlight a newfound complexity of miRNA regulatory networks and suggest their functional relevance in a model of pancreatic adenocarcinoma.

Citation Format: Kevin Quann, Phillipe Loher, Peter Clark, Kathleen Delgrosso, Paolo Fortina, Yi Jing, Jonathan Brody, Isidore Rigoutsos. Profiling of miRNA interactions in pancreatic adenocarcinoma by Argonaute CLIP-seq suggests a highly dynamic repertoire of targets. [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 A78.
Abstract A81: A microRNA signature identified for chemoresistance and mesenchymal phenotype is also found in advanced pancreatic cancer
Authors: Freeman James W. , Bera Alakesh , Kolaparthi Venkatasubbarao
Published: October 2015

Recent studies link cancer cells that possess an epithelial to mesenchymal transition (EMT) and cancer stem cell properties with chemoresistance and metastatic potential. Here, we investigated the molecular bases of the chemoresistant mesenchymal phenotype (CRMP) with emphasis on identifying a micro-RNA (miRNA) signature in advanced pancreatic ductal adenocarcinoma (PDAC). We developed a gemcitabine resistant cell model from a PDAC cell line, BxPC3. This gemcitabine resistant cell line (BxPC3-GZR) showed a pronounced mesenchymal phenotype and expressed high levels of CD44 a marker found on stem cells and showed a highly significant increase in expression of nine miRNAs and decrease in eight miRNAs. Based on relevance to cancer and on validation by q-RT-PCR we chose six of the miRNAs (miR-100, miR-125b, miR-21, miR-205, miR-27b and miR-455-3p) as a signature to determine whether they were similarly deregulated in 43 advanced PDAC tumor specimens previously analyzed as part of the Total Cancer Genome Atlas (TCGA). A strong correlation was observed for five of the six miRNAs in the tumor specimens compared to normal pancreas tissue.

To assess the functional relevance we initially focused on miRNA-125b, which is over-expressed in both cellular CRMP and advanced PDAC. Knockdown of miRNA-125b in BxPC3-GZR and Panc-1 cells caused a partial reversal of the mesenchymal phenotype and enhanced response to gemcitabine. Moreover, RNA-seq data from each of 40 advanced PDAC tumor specimens from the TCGA data base indicate a negative correlation between expression of miRNA-125b and five of six potential target genes (BAP1, BBC3, NEU1, BCL2, STARD13). Thus far, two of these target genes, BBC3 and NEU1, that are tumor suppressor genes but not yet studied in PDAC, appear to be functional targets of miR-125b since knockdown of miR125b caused their up regulation. The results of this study suggests that CRMP is caused in part by deregulation of a specific set of miRNAs and that these miRNAs are also deregulated in advanced PDAC. These miRNAs and their molecular targets may serve as targets to enhance sensitivity to chemotherapy and reduce metastatic spread.

Citation Format: James W. Freeman, Alakesh Bera, Venkatasubbarao Kolaparthi. A microRNA signature identified for chemoresistance and mesenchymal phenotype is also found in advanced 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 A81.