bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 2357: Novel transgenic animal model of salivary gland tumors
Authors: Cruz-Monserrate Zobeida , Ji Baoan , El-Naggar Adel K. , Logsdon Craig D. 
Published: August 2012

Abstract
Background: Salivary gland malignancies represent 1-2% of human head and neck cancers with approximately 3,300 new cases per year in the United States. Surgery is the best treatment, however must tumors are too advanced at discovery and are unresectable. Furthermore, many surgeries are not margin negative and thus they recur. In addition, advanced tumors metastasize, which makes them fatal. The lack of research tools and the limited number of cases per year makes it difficult for investigators to study the development and progression of these tumors. The aim of this study was to characterize a novel inducible mouse model of salivary gland tumors, which develops by the activation of oncogenic K-RasG12V. Methods: We developed transgenic mice with Cre regulated mutant K-RasG12D and a specific tamoxifen regulated Cre (Ela-CreER). Double transgenic animals and littermate controls were treated with tamoxifen over 3 consecutive days and after 3, 8, and 15 days they were sacrificed and analyzed histologically. Results: Tamoxifen fed animals with mutant K-RasG12D expression in the salivary gland develop tumors with intense fibrosis and inflammatory cell infiltration. Histologically the tumors resembled human high grade salivary sarcomas. Conclusions: Our results show the development of a new animal model to study the role of K-Ras in the progression of salivary gland tumors and could be a useful tool for future salivary gland tumor studies. In particular it should serve as a useful preclinical model to test for drugs against inflammatory response pathways induced by activated K-RasG12V in salivary gland tumors.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2357. doi:1538-7445.AM2012-2357
Abstract 2358: ERK1/2 regulation of CD44 modulates aggressiveness in a new mouse model of oral cancer
Authors: Uppaluri Ravindra , Judd Nancy , Winkler Ashley , Law Jonathan , Murillo-Sauca Oihana , Sunwoo John 
Published: August 2012

Abstract
Carcinogen-induced oral cavity squamous cell carcinoma (OSCC) causes significant morbidity and mortality and constitutes a global health challenge. To gain further insight into this disease, six unique C57BL/6 mouse OSCC cell lines were generated from 7,12-dimethylbenz(≥)anthracene (DMBA) induced murine primary OSCCs. The cell lines were designated as mouse oral cancer (MOC1, 2, 7, 10, 22 and 23) and 5/6 (excluding MOC23) formed tumors when transplanted into immunocompetent wild-type (WT) mice. Analyses of tumor growth in mice showed that MOC2, MOC7 and MOC10 grew more rapidly and metastasized to regional lymph nodes, while MOC1 and MOC22 grew much slower and did not metastasize. This aggressive growth was correlated with ERK1/2 activation, which in addition, was found to induce CD44 expression- a molecule whose expression is associated with EMT and putative cancer stem cells. Inhibiting MEK, the upstream activator of ERK1/2, led to decreased CD44 expression and promoter activity and also decreased cellular migration and invasion. Conversely, enforced activation of MEK1 led to enhanced CD44 expression and promoter activity. CD44 was required for the aggressive growth since reduction of CD44 levels significantly attenuated in vitro migration and in vivo tumor formation of MOC2 and MOC10 cell lines. These results in the mouse model were extended to freshly resected human OSCC where a strict relationship between ERK1/2 phosphorylation and CD44 expression was also identified. Thus, using a novel immunocompetent mouse model, we identify CD44 as an essential mediator of the aggressive tumor-promoting effects of ERK1/2, which highlight the potential efficacy of targeting this molecular pathway in head and neck cancers.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2358. doi:1538-7445.AM2012-2358
Abstract 2361: Establishing a patient-derived heterotransplant mouse model of head and neck squamous carcinoma (HNSCC)
Authors: Peng Shaohua , Sen Banibrata , Mazumdar Tuhina , Myers Jeffrey , Bell Diana , Williams Michelle , El-Naggar Adel , Johnson Faye M. 
Published: August 2012

Abstract
There are approximately 47,000 new cases of head and neck cancer diagnosed in the United States each year. The survival rate has not improved significantly in the past 30 years. The development of new therapies for HNSCC and the understanding of its biology both depend upon clinically relevant animal models. There are several existing animal models for HNSCC that include chemically-induced cancer models, syngeneic models using animal cancer cells, transgenic mice, and xenograft models using cultured human HNSCC cell lines injected into immunocompromised mice, either subcutaneously or orthotopically. An increasingly promising xenograft model, the heterotransplant model, is developed by surgically implanting tumor tissue directly from a patient into an immunocompromised mouse. The resulting tumor is serially passaged in vivo and never cultured on plastic. We have transplanted 20 HNSCC primary tumors from untreated patients directly into mice that included 17 tongue tumors, one maxillary gingival tumor, and two from the floor of the mouth. Although several tumors grew initially in mice, only 2 of 20 (10%) established tumors that could be serially passaged and used for therapeutic and mechanistic studies. One cell line has been established from a tongue heterotransplant (HOSC1). The two established heterotransplants maintained the histological appearance of the original tumors. To test the biological and molecular signaling response of HNSCC to targeted therapy, we utilized one heterotransplant that was passaged into 40 mice. Both the Src inhibitor dasatinib and the JAK inhibitor INCB16562 modestly inhibited tumor growth; the combination was significantly more effective than the single agents. Likewise, the tumors treated with the combination had significantly more apoptosis and less proliferation than control tumors. Consistent with our published in vitro results, Src inhibition did not result in STAT3 inhibition, but JAK inhibition abrogated STAT3 activation. Src was inhibited in vivo by dasatinib. Our results demonstrate that the heterotransplant model of HNSCC has promise as an in vivo model to test the efficacy of anti-cancer drugs. The low “take rate” is problematic but will be addressed in the future by intra-operative biopsies and larger tumor specimens.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2361. doi:1538-7445.AM2012-2361
Abstract 2363: Comparison and characterization of two orthotopic glioblastoma in vivo mouse models with human U87 and LN-229 cells using in vivo bioluminescence imaging and magnetic resonance imaging (MRI)
Authors: Lingnau Andreas , Hoffmann Steffen , Weidensteiner Claudia , Reichardt Wilfried , Kording Fabian , Obodozie-Schaefer Cynthia , Schaechtele Christoph 
Published: August 2012

Abstract
Glioblastoma is the most common and most aggressive type of malignant brain tumors. The prognosis is poor, with a median survival time of several months only. Despite steady progress in treatment of glioblastomas this tumor entity is still not curable. Thus, there is an urgent need for the development of novel effective therapies, and for appropriate in vivo models to characterize them. Most often novel antiglioblastoma drugs are tested in subcutaneous xenograft mouse models using various human or murine glioblastoma cell lines. To generate more relevant, orthotopic brain cancer in vivo models, we stably transduced the human glioblastoma cell lines U-87 and LN-229 with fire fly luciferase suitable for in vivo bioluminescence imaging. To initiate orthotopic growth, nude mice were anesthetized and placed in a stereotactic fixation device. Through a burr hole cells were implanted intracranially using a Hamilton syringe. Once to twice a week we used bioluminescence imaging to continually monitor tumor growth in vivo. However, as magnetic resonance imaging (MRI) is the most relevant tool to monitor oncological therapy in glioblastomas clinically, we adapted this translational aspect and analysed the mice in parallel using a dedicated animal MRI System. MRI offers detailed information about growth characteristics, size, blood supply and interaction with the surrounding tissue of the tumor. To achieve this, we performed T2-weighted imaging, and diffusion weighted imaging (DWI) weekly to visualise the tumors as well as necrosis and edemas. The use of both methods allowed independent and complementary characterization of the tumors. When exponential growth of the orthotopic tumors was observed, and the tumors reached critical sizes necropsy was done. In vivo bioluminescence imaging revealed only a very dominant signal in the region of the brain where the primary tumor was located. To address potential metastases in more detail we analysed a set of different resected organs and tissues for in vitro luciferase activity followed by extensive histological examination. Currently, we test different anti-glioblastoma agents in these orthotopic models to evaluate an antitumoral effect as well as a potential reduction of the edemas comparing the results in both models.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2363. doi:1538-7445.AM2012-2363
Abstract 2367: Neural progenitor cells deficient in BAX and BAK manifest progressive hyperplasia and tumorigenesis
Authors: Katz Samuel G. , Fisher Jill K. , Bronson Roderick T. , Ligon Keith L. , Walensky Loren D. 
Published: August 2012

Abstract
The pro-apoptotic BCL-2 family proteins BAX and BAK serve as essential gatekeepers of the intrinsic apoptotic pathway and, when activated, transform into pore-forming homo-oligomers that permeabilize the mitochondrial outer membrane. Deletion of Bax and Bak causes marked resistance to many death stimuli in a variety of cell types. Bax−/−Bak−/− mice are predominantly non-viable and survivors exhibit multiple developmental abnormalities characterized by cellular excess, including accumulation of neural progenitor cells in the periventricular, hippocampal, cerebellar, and olfactory bulb regions of the brain. To explore the long-term pathophysiologic consequences of BAX/BAK deficiency in the central nervous system, we generated Bak−/− mice with conditional deletion of Bax in Nestin-positive cells. Aged mice manifest progressive brain enlargement with a profound accumulation of NeuN- and Sox2-positive neural progenitor cells within the subventricular zone niche. One-third of the mice develop frank masses comprised of the progenitor neurons, and in 20% of these cases, more aggressive, hypercellular tumors emerged. Interestingly, 60% of NestinCreBaxfl/flBak−/− mice harbor high-grade tumors within the testis interstitium, a peripheral site of Nestin expression. This mouse model of apoptotic blockade highlights the constitutive role of BAX/BAK in long-term regulation of Nestin-positive progenitor cell pools, with loss of function predisposing to adult-onset tumorigenesis.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2367. doi:1538-7445.AM2012-2367
Abstract 2367A: Understanding the role of stem-like tumor cells in mouse models of high-grade gliomas
Authors: Barrett Lindy E. , Benezra Robert 
Published: August 2012

Abstract
High-grade gliomas (WHO grade III-IV) are typified by poor therapeutic response and rapid lethality. Since the discovery of glioma cells with properties reminiscent of neural stem cells, there has been a great deal of interest in understanding their contributes to tumor growth and therapeutic resistance. Self-renewal is the defining characteristic of both normal and cancer stem cells, and it has been hypothesized that glioma cells with self-renewal capacity contribute disproportionately to tumor growth compared to other, more differentiated lineages. However, analyses are complicated by the lack of reliable markers to definitively identify and functionally characterize each distinct cell lineage. In the normal neurogenic niche, ID (Inhibitor of DNA-binding) genes regulate self-renewal and multipotency of adult neural stem cells. Here, using mouse models of high-grade glioma driven by PDGF- or mutKRAS, we show that high Id1 expression (Id1high) identifies self-renewing, multipotent tumor cells. By contrast, low Id1 expression (Id1low) identifies progenitor-like cells with proliferative potential but limited self-renewal capacity. While Id1high cells generate tumors upon orthotopic transplantation, Id1low cells do so with shorter latency and higher penetrance. Further, eliminating tumor cell self-renewal through targeted deletion of ID genes has modest effects on overall survival, while knockdown of the bHLH transcription factor, Olig2, within the Id1low population, results in a significant survival benefit. Together, these data highlight an important distinction between self-renewal capacity and tumor growth potential in two mouse models of gliomagenesis, underscoring the importance of non-stem cell lineages in disease progression.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2367A. doi:1538-7445.AM2012-2367A
Abstract 2371: Circulating cancer associated cells co-express epithelial and hematopoietic markers in metastatic breast cancer (MBC) patients (pts)
Authors: Lustberg Maryam B. , Balasubramanian Priya , Miller Brandon , Villa Alejandra Garcia , Xue Wei , Wu Yongqi , Chalmers Jeffery J. , Shapiro Charles L. 
Published: August 2012

Abstract
Background: Circulatingtumor cells (CTCs) are most commonly isolatedby using positive selection enrichment targeting the epithelial cell adhesion activating molecule (EpCAM). Using positive selection, a CTC is defined as EpCAM and cytokeratins (CK) positive (+) and CD45 negative (-). However, other rare cancer associated cells (RCACs) including EpCAM - and/or CD45 + cells have been reported (van de Stolpe, 2011). In order to investigate these RCACs, a prospective study in MBC using multi-parameter flow cytometry and immunocytochemistry (ICC) was undertaken. Methods:Forty blood samples from MBC pts were collected prior to initiation of a new line of chemotherapy, after one cycle, or at time of progression. Twenty one (52%) samples were from pts with estrogen receptor (ER) -, progesterone receptor (PR) -, and HER2neu non-overexpressing, or triple negative breast cancer (TNBC); nineteen (47%) were from pts with ER/PR +, HER2neu nonoverexpressing disease. Blood was processed using immunomagnetic negative depletion (Yang, 2009). Multiparameter, flow cytometry analysis was conducted prior to, and after depletion of CD45 + cells. Multistep, sequential labeling and fixation for surface markers was performed, followed by permeablizition for CK. ICC staining for EpCAM, CD45, CK 8/ 18/19 and DAPI was performed. Results: Either very low or no CK + events were present in blood samples from healthy volunteers (n=5). Various post-enrichment events were identified. These populations were also present by ICC with confocal microscopy. Conclusions: In addition to CTCs, RCACS that are CD45 + and/or EpCAM - are detectable in MBC pts and more frequently present in TNBC pts. These populations, only detectable by negative depletion, may be clinically significant as ongoing studies evaluate the predictive capabilities of blood based biomarkers.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2371. doi:1538-7445.AM2012-2371
Abstract 2375: Rapid unbiased enrichment (negative selection) of circulating non-hematopoietic tumor cells directly from whole blood
Authors: Peters Carrie , Fadum Jodie , Woodside Steve , McQueen Karina , Thomas Terry 
Published: August 2012

Abstract
There is increasing interest in analyzing circulating non-hematopoietic tumor cells (CTC) in peripheral blood to evaluate disease progression or response to treatment; however, CTC enrichment is required prior to most analytic procedures. The ideal enrichment method would be rapid, permit a high recovery of viable CTC, and would be independent of the expression of specific epithelial cell surface markers, since CTCs in the peripheral blood may be undergoing EMT (epithelial mesenchymal transition) and may not express epithelial markers. RosetteSep™ CD45 depletion of hematopoietic cells directly from whole blood meets these criteria. However, RosetteSep™ enrichment of CTC involves density gradient centrifugation, which entails careful layering of the sample over the density gradient medium and careful pipetting to remove the enriched cells after centrifugation. Centrifugation must be performed with the brake off to avoid disturbing the enriched cell layer, further lengthening the process. SepMate™, a centrifugation tube with a specialized insert, was developed to minimize mixing of the sample with the density gradient medium, thus allowing rapid layering of the sample on the density gradient medium and easy pouring off of the enriched cells after centrifugation. We compared CTC enrichment using RosetteSep™ and the standard tubes and protocol with RosetteSep™ using SepMate™ tubes and reduced cocktail incubation and spin times on 5 donor whole blood samples seeded with ∼1% CAMA cells. Purity of viable (PI negative) CTC obtained with SepMate™ with RosetteSep™ was 85 ± 7%; purity of CTC obtained with RosetteSep™ alone was 91 ± 5% (no significant difference, paired t test, p=0.050). Purity of CTC obtained with density gradient centrifugation only (no RosetteSep™), either with or without SepMate™, was 4 ± 2%. There was no significant difference in the recovery of enriched CTC under any of the conditions tested (RosetteSep™ ± SepMate™, SepMate™ alone, density gradient separation alone, Tukey-Kramer test, p&gt;0.05). CTC enrichment was accomplished in &lt;40 min using SepMate™ with RosetteSep™. Simplifying the layering and layer removal step makes the entire process easily scalable to processing multiple samples simultaneously. Utilizing this method, CTCs can be enriched directly from whole blood without bias regarding their surface antigen expression. Large samples can be rapidly volume-reduced in preparation for detailed examination in a microfluidic device. Finally, enriched CTC are not labeled with antibodies or beads; there is nothing to interfere with subsequent further enrichment, culture, or evaluation.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2375. doi:1538-7445.AM2012-2375
Abstract 2382: SOX17 promoter methylation in CTC and cell free DNA isolated from plasma of breast cancer patients
Authors: Chimonidou Maria , Strati Areti , Malamos Nikos , Georgoulias Vasilis , Lianidou Evi S. 
Published: August 2012

Abstract
Introduction: Molecular characterization of Circulating Tumor Cells (CTC) is a hot topic nowadays. SOX17 plays a very critical role in the regulation of development and stem/precursor cell function, at least partly through repression of Wnt pathway activity. Silencing of SOX17 due to its promoter methylation is a frequent event and may contribute to aberrant activation of Wnt signaling in breast cancer. We have recently shown that the promoter of this gene is methylated in CTC (Chimonidou et al, Clin Chem 2011). The aim of the present study was to evaluate whether SOX17 promoter methylation in CTC, is associated with the methylation pattern of this gene in matched cell free DNA isolated from plasma of breast cancer patients. Patients and methods: We firstly developed a highly sensitive and specific Methylation Specific Real-time PCR method for SOX17. The methylation status of SOX17 was examined in paired specimens of DNA isolated from CTC and cell free DNA (cfDNA) circulating in plasma of the same individuals. 58 patients with operable breast cancer, 21 patients with verified metastasis, and 12 healthy individuals used as controls were enrolled in our study. For CTC analysis, DNA was extracted from EpCAM positive immunomagnetically isolated CTC fraction, while cfDNA was isolated from 200μL of plasma from the same individuals. DNA extracted from isolated CTC and cfDNA was modified by a Sodium Bisulfite (SB) conversion reaction and subjected to methylation specific real time PCR. Results: In CTC, promoter methylation of SOX17 was observed in 22/58 (37.9%) of patients with operable breast cancer, 12/21 (57.1%) of patients with verified metastasis and 1/12 (8.3%) of healthy individuals. In the matched plasma samples, promoter methylation of SOX17 was observed in 23/58 (39.6%) of patients with operable breast cancer, 11/21 (52.4%) of patients with verified metastasis and 1/12 (8.3%) in healthy individuals. By comparing these results we found that promoter methylation of SOX17 in CTC was significantly correlated with promoter methylation of SOX17 in cell free DNA isolated from plasma of the same patients (P&lt;0.005). Conclusion: We show for the first time that promoter methylation of SOX17 in CTC, is associated with the methylation pattern of this gene in matched cell free DNA isolated from plasma of breast cancer patients. Our findings suggest a new dimension to the origin of cell free DNA and indicate a correlation between cell free DNA and CTC.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2382. doi:1538-7445.AM2012-2382