bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 1848: Autocrine IGF1 signaling mediates the survival of pancreatic cancer cells following the ablation of oncogenes
Authors: Rajbhandari Nirakar 
Published: July 2017

Abstract
Pancreatic cancer is an extremely lethal disease, which is mostly associated with the gain-of-function mutation in KRAS gene. Due to a very high frequency of activating mutations within the KRAS gene, mutant KRAS is considered a rational therapeutic target in pancreatic cancer. In line with the existing idea that oncogenic KRAS is required for the maintenance of pancreatic cancer, we show a complete macroscopic regression of both primary and orthotopically transplanted tumors in our ligand-regulatable (Doxycycline) mouse model of KRASG12D-driven pancreatic cancer. This finding indicate that the expression, and provides a strong rationale for the development of KRAS targeted therapy for the treatment of pancreatic cancer.
However, in our current study, despite the complete macroscopic regression of PDACs upon downregulation of oncogenic KRAS, few cancer cells always survived and remained dormant for a protracted duration. These residual cancer cells were responsible for the rapid recurrence upon KRAS reactivation. Using a genome-wide gene expression (RNA-Seq) analysis of in vivo-derived bulk and residual cancer cells followed by biochemical analysis, we identified a significant increase in autocrine IGF-1/AKT signaling in residual cancer cells. We also identified IGF1 signaling as a common survival mechanism of residual cancer cells in c-MYC-driven pancreatic tumor model. Pharmacological inhibition of IGF-1R signaling significantly delayed the tumor recurrence in both the tumor models, suggesting the crucial role of IGF-1R signaling in the survival of cancer cells in the absence of oncogenic drivers. Our findings from animal models were also validated in human pancreatic cancer cell lines harboring KRAS mutations, by demonstrating a compensatory increase in IGF1 signaling in response to a conditional knockdown of KRAS in vitro and in vivo. Collectively, all our findings from mouse model and human cancer cell studies strongly indicate that residual cancer cells can survive in the absence of tumor driving oncogenes by upregulation of autocrine IGF1 signaling loop. Thus, targeting oncogenic drivers along with IGF-1R signaling might be an effective strategy for prevention of tumor recurrence in pancreatic cancer.
Citation Format: Nirakar Rajbhandari. Autocrine IGF1 signaling mediates the survival of pancreatic cancer cells following the ablation of oncogenes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1848. doi:10.1158/1538-7445.AM2017-1848
Abstract 1850: Development of a NOTCH1 loss of function and PIK3CA mutant transgenic model of HNSCC
Authors: Devenport Samantha N. , Michmerhuizen Nicole L. , Leonard Elizabeth , Jewell Brittany , Swanson Jacob , Wong Sunny , Carey Thomas E. , Brenner J Chad 
Published: July 2017

Abstract
Head and neck squamous cell carcinoma (HSNCC) is a debilitating disease with a poor 5-year survival rate. The use of in vivo models to study tumorigenesis and to identify potential targeted therapies, especially those that work in combination with immune checkpoint inhibitors, is essential in improving overall patient care. However, the overall number of HNSCC transgenic models with recurrent genetic lesions identified by the HNSCC TCGA project has been limited. For example, TCGA data has shown both Notch1 loss of function mutations and PIK3CA activating mutations as some of the most common in HNSCC, but bi-genic models of these lesions do not yet exist. Here, we have designed a model which utilizes K14-CreERT to drive a bi-genic model with Notch1flox and PIK3CAH1047R mutations in epithelial compartments. Characterization of this line both in the context of spontaneous and carcinogen induced tumor formation is a tool which can be utilized to better understand common mutations in HNSCC. Immunohistochemistry confirms the overexpression of PIK3CA in tamoxifen induced mice. Furthermore, early characterization of this model with chronic treatment of the smoking analogue 4-Nitroquinoline N-oxide (4NQO) in drinking water shows tumor formation on the tongue and surrounding head and neck regions in as little as 12-16 weeks. Hematoxylin and Eosin staining confirmed the squamous tumor formation, while Ki67 staining showed enhanced proliferation of the transformed cells. In the future, this model can be used to study tumor formation over time and in response to targeted inhibitors and common therapies that are being advanced as companion diagnostic strategies for either NOTCH1 deficient or PIK3CA aberrant HNSCC tumors. Further detailed characterization of this model will allow for a deeper understanding of the mechanisms which drive HNSCC and will translate to improved patient care.
Citation Format: Samantha N. Devenport, Nicole L. Michmerhuizen, Elizabeth Leonard, Brittany Jewell, Jacob Swanson, Sunny Wong, Thomas E. Carey, J Chad Brenner. Development of a NOTCH1 loss of function and PIK3CA mutant transgenic model of HNSCC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1850. doi:10.1158/1538-7445.AM2017-1850
Abstract 1865: Enhancing the in vivo detection of cancer by manipulating magnetic fields applied to tumor targeting superparamagnetic iron oxide nanoparticles
Authors: Karaulanov Todor , Vreeland Erika C. , Gomez Andrew , Minser Kayla E. , Weldon Caroline L. , Anderson William H. , Nettles Christopher , Paciotti Giulio 
Published: July 2017

Abstract
Superparamagnetic Relaxometry (SPMR) is combination technology for the early detection of cancer. Conceptually, PEGylated superparamagnetic iron oxide (Fe3O4) nanoparticles (NPs) coupled with a tumor targeting monoclonal antibody are systemically administered and target solid tumors by both passive (EPR) and active (receptor targeting) mechanisms. Once bound to the target cells, the NPs are magnetized by a brief, low field magnetic pulse to create macroscopic magnetization. Once the field is removed, the particle’s magnetization decays and is measurable by superconducting quantum interference device (SQUID) detectors. The pattern of decay, known as Néel relaxation, exhibits a difference in latency specific to bound nanoparticles and differs from the Brownian decay exhibited by free/unbound particles. As a proof of concept, we developed PEGylated NPs that are covalently bound to an anti-Her-2 monoclonal antibody. In vitro, the nanoconstruct exhibits specific binding to the Her-2 overexpressing BT-474 breast cancer cells, with little to no binding to Her-2 negative MCF-7cells. Similar patterns of selective targeting were observed in vivo.
To improve the specific detection of SPMR signals in tumors we developed a novel system that selectively enhances the magnetic signal at tumor sites and reduces the contribution of similar signals at off target sites such as the liver and spleen. For these studies, we created phantoms of varying strength to mimic tumor and non-specific signals. We observed that by creating non-homogenous excitation magnetic field patterns, we reduced the contribution of the non-specific signals by an order of magnitude, effectively increasing the signal to noise ratio of the tumor signal. These results are clinically relevant and support the use of SPMR in the detection of small tumors in cancer patients.
Citation Format: Todor Karaulanov, Erika C. Vreeland, Andrew Gomez, Kayla E. Minser, Caroline L. Weldon, William H. Anderson, Christopher Nettles, Giulio Paciotti. Enhancing the in vivo detection of cancer by manipulating magnetic fields applied to tumor targeting superparamagnetic iron oxide nanoparticles [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1865. doi:10.1158/1538-7445.AM2017-1865
Abstract 1869: Improved image-guided surgical resection of glioblastoma with [18F]-fluoroethyltyrosine Cerenkov luminescence imaging
Authors: Lewis David Y. , Mair Richard , Wright Alan J. , Allinson Kieren , Lyons Scott K. , Booth Tom , Bielik Robert , Soloviev Dmitry , Brindle Kevin M. 
Published: July 2017

Abstract
The ability of a surgeon to completely resect a tumor is directly related to outcome in high- and low-grade gliomas. However current intraoperative navigational tools are useful only in a subset of glioma patients and do not detect the full extent of disease.
We modelled orthotopic brain tumors by stereotactically implanting human U87, rat F98 and C6 glioblastoma cells into the forebrains of rats. We show here that a new hybrid PET-Cerenkov luminescence imaging approach using O-(2-[18F]fluoroethyl)-L-tyrosine (FET) can accurately delineate tumor margins pre- and intra-operatively. We demonstrate consistency in the successful localisation and quantification of tumor burden using PET and Cerenkov luminescence imaging. The Cerenkov signal in individual tumors was directly proportional to the signal detected in corresponding FET PET scans (y = 1.06x - 0.01; R2 = 0.98; p &lt; 0.0001) and subsequent autoradiography indicated equivalence between modalities. Cerenkov luminescence was better able to discriminate tumor from healthy brain tissue than the current ‘gold standard’ for intraoperative mapping, 5-ALA (5-aminolevulinic acid), indicated by a greater area under the ROC curve in human xenograft (0.968 ± 0.003 vs. 0.893 ± 0.019; p = 0.003) and syngeneic rat glioma models (0.970 ± 0.010 vs. 0.774 ± 0.046; p = 0.006). The quantitative accuracy of Cerenkov luminescence enabled us to determine a threshold of 2.1 x 102 p-1 sec-1 cm-2 sr-1 MBq-1 that separated U87 human glioblastoma and normal brain tissue, more precisely guiding tumor excision than 5-ALA. At the optimal threshold the specificity for detecting syngeneic rat and human xenograft gliomas was better with FET Cerenkov than 5-ALA (91.1 ± 2.7 % vs. 67.2 ± 5.2 %; p = 0.007 and 91.2 ± 1.0 % vs. 82.9 ± 1.8 %; p = 0.005 respectively). We confirmed and extended these findings at higher spatial resolution on cryosections using FET autoradiography and 5-ALA confocal microscopy, with FET demonstrating higher specificity and sensitivity for tumor detection than 5-ALA.
FET PET-Cerenkov luminescence imaging has the potential for guiding resections in a much broader range of glioma patients than current approaches. Previous clinical experience with FET offers a facile route for clinical translation of this technology.
Citation Format: David Y. Lewis, Richard Mair, Alan J. Wright, Kieren Allinson, Scott K. Lyons, Tom Booth, Robert Bielik, Dmitry Soloviev, Kevin M. Brindle. Improved image-guided surgical resection of glioblastoma with [18F]-fluoroethyltyrosine Cerenkov luminescence imaging [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1869. doi:10.1158/1538-7445.AM2017-1869
Abstract 1880: Bulk lung cancer cell migration is more common than single cell migration and regulated by different genes
Authors: Popper Helmut H. , Eidenhammer Sylvia 
Published: July 2017

Abstract
Introduction: There are two different forms how tumor cells migrate: single cell or small cell cluster movement as it is seen in small cell carcinoma, and movement by large clusters of organized cells as seen most often in adenocarcinoma or squamous cell carcinoma. This latter migration form is not understood. Drosophila border cells forming wings migrate in large cell complexes similar to what is seen in the carcinomas and the genes identified in these cells might regulate the same process in carcinomas. Methods: 30 cases of pulmonary squamous cell and adenocarcinomas were selected based on the identification of large tumor cell clusters visible within the stroma as well as in blood vessels. Immunohistochemistry was done for receptor of activated C kinase (Rack1), brinker (brk), mother against dpp (mad), and saxophone (sax), proteins shown to be responsible for bulk cell movement in drosophila development. In addition immunohistochemistry was also done for Src-kinase, Twist, Snail, and TGFβ1 Tyrosine kinase substrate 5 (Tks5), E-cadherin, SARI (suppressor of AP-1), and vimentin, all known to be associated with epithelial-to-mesenchymal transition (EMT) and formation of invadopodia. Results and Conclusion: Most well differentiated pulmonary carcinomas migrate in large cell clusters, for example acinar adenocarcinomas form nicely structured acini deep within the stroma and even within blood vessels. These carcinomas do not undergo classical EMT. Proteins expressed by the four genes (Rack1, brk, mad, and sax) associated with border cell movement in drosophila could also be identified in pulmonary carcinomas and might coordinate bulk cell movement. Other members of TGF-beta signaling cascade were identified. Inhibition of Src by Rack1 may be important for border cell migration and cluster cohesion maintenance. Proteins usually seen in single tumor cell migration, such as vimentin (a sign of EMT) could not be proven in the tumor cell clusters. Findings of this study show that similar mechanisms are working in pulmonary carcinomas and that bulk cell migration is probably another way of metastasis. Further investigation using cell culture system and genetically designed adenocarcinomas expressing these genes should prove our findings and contribute in understanding migration of carcinoma bulk complexes.
Citation Format: Helmut H. Popper, Sylvia Eidenhammer. Bulk lung cancer cell migration is more common than single cell migration and regulated by different genes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1880. doi:10.1158/1538-7445.AM2017-1880
Abstract 1882: Tankyrase-binding protein TNKS1BP1 regulates cancer cell invasion
Authors: Ohishi Tomokazu , Yoshida Haruka , Katori Masamichi , Migita Toshiro , Muramatsu Yukiko , Miyake Mao , Ishikawa Yuichi , Saiura Akio , Iemura Shun-ichiro , Natsume Tohru , Seimiya Hiroyuki 
Published: July 2017

Abstract
Tankyrase, a member of poly(ADP-ribose) polymerase (PARP) family, catalyzes addition of long PAR chains onto the acceptor proteins, such as TRF1, a telomere-binding protein, and Axin, a repressor of Wnt/β-catenin signaling. Tankyrase-mediated PARylation of TRF1 and Axin represses the biological functions of these proteins, leading to enhanced telomere elongation by telomerase and upregulation of Wnt/β-catenin signaling, respectively. Thus, tankyrase is a multifunctional protein that supports oncogenic properties of cancer cells. Given that tankyrase has a large protein-protein interaction platform called ANK repeat clusters, and is broadly distributed to various intracellular loci, including telomeres, nucleoplasm, nuclear pore complexes, cytoplasm, Golgi, and spindle poles, this protein seems to have a yet unidentified function. In the present study, we explored the function of a novel tankyrase-binding protein called TNKS1BP1 and elucidated its contribution to regulating cancer cell invasion. Since TNKS1BP1 co-localizes with the actin filaments, we first examined the effect of genetic manipulation of TNKS1BP1 expression on cell invasion. We found that TNKS1BP1 depletion by small interfering RNAs increased the invasive capacity of human fibrosarcoma cells, whereas its overexpression decreased the cell invasion. In TNKS1BP1-depleted cells, actin filament dynamics, focal adhesion and lamellipodia ruffling were increased with activation of the ROCK-LIMK-cofilin pathway, which promotes cell motility. Importantly, tankyrase overexpression reproduced the phenotype of TNKS1BP1-depleted cells and enhanced cell invasion in a PARP activity-dependent manner. Under approval by Institutional Review Board of Japanese Foundation for Cancer Research, we performed immunohistochemical analysis of clinical pancreatic cancer. We found that TNKS1BP1 protein expression is decreased in invasive regions of the tumors. Taken together, these observations suggest that the tankyrase-TNKS1BP1 axis constitutes a post-translational modulator of cell invasion and its aberration promotes cancer malignancy.
Citation Format: Tomokazu Ohishi, Haruka Yoshida, Masamichi Katori, Toshiro Migita, Yukiko Muramatsu, Mao Miyake, Yuichi Ishikawa, Akio Saiura, Shun-ichiro Iemura, Tohru Natsume, Hiroyuki Seimiya. Tankyrase-binding protein TNKS1BP1 regulates cancer cell invasion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1882. doi:10.1158/1538-7445.AM2017-1882
Abstract 1887: Untethering heterochromatin: how loss of HP1a enhances cell invasion by altering nuclear envelope integrity
Authors: Hale Tracy K. , Bond Sarah , Wheeler David 
Published: July 2017

Abstract
Malignant cell invasion is accompanied by complex changes in nuclear shape and organisation. The onset of invasion correlates with the loss of HP1a in many solid tumours including those of the thyroid, kidney, colon and breast, while in cancer cell lines HP1a suppresses invasive potential. In normal cells HP1a maintains the condensation of transcriptionally silent heterochromatin and sequesters it at the inner periphery of the nuclear envelope; an event critical for the maintenance of nuclear stability and envelope rigidity. This role for HP1a leads us to hypothesise that the un-tethering of heterochromatin from the nuclear periphery that would occur after loss of HP1 causes a remodelling of nuclear envelope that enhances cellular invasion. If true this would explain how the nucleus, the largest and most rigid cellular organelles, becomes malleable enough to squeeze through interstitial spaces in the surrounding tissue during metastatic invasion. In support of this hypothesis we observed a 44% increase in the invasive potential of the poorly invasive MCF7 breast cells when HP1a is knocked down. Lamin A staining and electron microscopy also confirmed that these HP1a knockdown cells had the expected alterations in nuclear morphology and loss of heterochromatin at the nuclear periphery. Furthermore the loss of HP1 was correlated with a decrease in the mechanical stability of the nuclei. The significant enrichment (p-val 6.7x10-8) of nuclear envelope proteins shown by RNAseq analysis of transcripts that are differentially expressed in the MCF7 versus HP1a knock-down cells, suggests this loss of nuclear envelope integrity is associated with alterations to its composition. The most striking change identified in the nuclear envelope of cells lacking HP1a was the loss of two Nesprin1 isoforms. While reintroduction of HP1a in highly invasive MDA-MB-231 cells shows the return of these isoforms to the nuclear envelope. As the Nesprin1 isoforms act as signalling scaffolds connecting to the cytoskeleton or reaching into the nucleus, they represent a means of modulating nuclear malleability. Together these findings suggest that when loss of HP1a increases invasive potential there is a corresponding disruption to the nuclear periphery that is a weakness of these cells that could be exploited.
Citation Format: Tracy K. Hale, Sarah Bond, David Wheeler. Untethering heterochromatin: how loss of HP1a enhances cell invasion by altering nuclear envelope integrity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1887. doi:10.1158/1538-7445.AM2017-1887
Abstract 1888: 3D matrix confinement triggers vascular mimicry through a conserved migratory and transcriptional response
Authors: Ortiz Daniel , Tsui Brian , Goshia Tyler , Ricker Colleen , Carter Hannah , Fraley Stephanie I. 
Published: July 2017

Abstract
An initial step in solid tumor metastasis involves the migration of tumor cells through extracellular matrix. Several cancer cell migration strategies exist in vivo, and the local properties of collagen fibers are implicated in modulating migration behaviors. Yet, individual tumor cells also display heterogeneity in their intrinsic ability to migrate and metastasize. It remains unclear to what extent intrinsic and extrinsic heterogeneity contribute to the emergence of distinct migration phenotypes and whether certain migration phenotypes contribute more to metastasis than others. To study this, we generated 3D collagen matrices of varying densities and monitored single cancer cell migration in these matrices with time-lapse microscopy. We observed a collagen density threshold at 2.5mg/ml, above which 86% of MDA-MB-231 breast cancer cells transition from single mesenchymal migration to collective cell migration, with a 50% increase in persistence after cell division. After seven days, these collectively migrating cells created networks coated with basement membrane molecules resembling a clinical phenotype known as vascular mimicry (VM).The remaining 14% of cells migrated randomly and eventually formed spheroids. HT-1080 fibrosarcoma cells also responded similarly, migrating persistently and forming cellular networks. Next we sought to identify the physical feature of high-density collagen driving VM. Neither hypoxia or matrix stiffness was sufficient to induce VM. However, PEG-induced matrix confinement triggered VM network formation. RNA sequencing revealed collectively migrating cells up-regulated a conserved transcriptional program significantly enriched for annotations of vascular development and motility regulation processes. This gene module predicted survival in human tumor transcriptome datasets. Our results suggest that the VM phenotype arises in a subpopulation of cells from a conserved transcriptional and migratory response to confinement in 3D collagen.
Note: This abstract was not presented at the meeting.
Citation Format: Daniel Ortiz, Brian Tsui, Tyler Goshia, Colleen Ricker, Hannah Carter, Stephanie I. Fraley. 3D matrix confinement triggers vascular mimicry through a conserved migratory and transcriptional response [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1888. doi:10.1158/1538-7445.AM2017-1888