bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 2339: Specific binding of modified ZD 6474 (Vandetanib) monomer and its dimer with VEGF receptor 2
Authors: Kim Yoo-Shin , Li Feng , O'neill Brian Edward , Li King CP , Li Zheng 
Published: August 2012

Abstract
Introduction: Tumor angiogenesis is an important component of cancer biology driven in part by the thesis that tumor vessel growth is a necessary requirement for tumor growth. Angiogenesis does not only depend on endothelial cell invasion and proliferation: it also requires pericyte coverage of vascular sprouts for vessel stabilization. These processes are coordinated by vascular endothelial growth factor (VEGF). A significant portion of research on tumor angiogenesis has focused on VEGF and its blockage with the expectation that dramatic results would be demonstrated in cancer patients as previously documented in animal models. Vandetanib, also known as ZD6474, is an antagonist of the vascular endothelial growth factor (VEGF) receptor-2 (VEGFR-2) and the epidermal growth factor receptor (EGFR or HER1 or ErbB1). It is an orally bioavailable small molecule tyrosine kinase inhibitor of multiple growth factors, and is now available in the US for the treatment of metastatic medullary thyroid cancer (MTC). Methods: ZD 6474 monomer was purchased modified to add a fluorescent dye (6-FAM). Its coupled ZD 6474 dimer was also prepared using a PEG linker, similarly with FAM fluorescent dye. The two compounds were compared in a series of in vitro studies using human endothelial cell (HUVECs) and several cancer cell lines. We first looked at VEGFR binding affinity and specificity with cell uptake and blocking study. Then, the effects on cellular viability and angiogenesis were compared using with tubular formation of HUVECs in vitro, also matrigel plug assay, and bio-distribution test on VEGF over expressed U87 human glioma tumor model in vivo. Results: Imaging of ZD 6474 dimer showed much better binding and uptake in HUVECs and other VEGFR expressing cells than ZD 6474 monomer, including during systemic delivery to tumors. However, the therapeutic and anti-angiogenic effects were mixed, with most tests showing the dimer to have same or weaker effects than the monomer. Conclusion: This study provides a rational for the evaluation of dimeric ZD 6474 as a potential imaging agent. Paradoxically, it also demonstrates that the enhanced receptor binding achieved by multivalency does not always translate into enhanced therapeutic effectiveness. Keyword: Vandetanib (ZD 6474), anti-angiogenesis, VEGFR
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 2339. doi:1538-7445.AM2012-2339
Abstract 2351: Identification of somatic mutations in esophageal squamous cell carcinoma and corresponding xenograft by next-generation sequencing
Authors: Fang Douglas D. , Gao Yibo , Xu Qiang , Sun Hongye , Zhang Bin , Chen Zhaoli , Chan Chi-Chung , He Jie 
Published: August 2012

Abstract
The genomes of all cancer cells carry somatic mutations, including both passenger and driver mutations. Driver mutations, which are implicated in oncogenesis, are most likely preserved in xenografted tumor cells in immunedeficient mice. Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive carcinomas in the gastrointenstinal tract. It is prevalent in the developing world and associated with substantial morbidity and mortality. Molecular mechanisms contributing to initiation and progression of ESCC are still poorly understood. Systematic identification of genetic variations and putative driver mutations may lead to understanding of pathogenesis of the disease. In this study, using next-generation sequencing we performed exome sequencing of eight paired Chinese esophageal squamous cell carcinoma and xenograft. Comparing with control genomes obtained from case-matched peripheral blood cells, we identified a wide variety of somatic variations in both primary and xenograft tumors, including TP53, RGMA, MUC4, TCEAL6, PRSS3, etc. Moreover, we found that mouse sequences accounted for a significant fraction of sequence reads from xenograft samples. Excluding these mouse sequences significantly improved the accuracy of mutation detection in xenograft samples. Overall, our findings shed a light on important somatic mutations involved in ESCC. In addition, comparison between primary and xenograft tumors may lead to identification of driver mutations that confer growth advantage. These mutations represent therapeutic opportunities for development of targeted therapy.
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 2351. doi:1538-7445.AM2012-2351
Abstract 237: Novel applications of pSIVA, a new polarity sensitive phosphatidylserine (PS) apoptosis/cell death probe
Authors: Stein Lisa S. , Quintel Payton D. , Krajewski Stan , Rosenberg Jonathan S. , Singh Sujay K. 
Published: August 2012

Abstract
pSIVA is a newly developed Annexin B12 based polarity sensitive probe for monitoring exposed PS, a hallmark of apoptosis. A unique feature of pSIVA is that it fluoresces (green channel) only when bound to PS, and hence no wash steps are needed to remove unbound probe. This attribute is enabling the development of new methodologies not previously possible with classical Annexin V conjugates, which fluoresce irrespective of whether or not they are bound to PS. In this study we developed a flow cytometry protocol whereby pSIVA is added directly to cell culture media, avoiding the use of buffers. The protocol eliminates unforeseen perturbation or negative effects that standard buffers can have on sensitive cell types. Multicolor methodology that employed pSIVA-labeled cells along with intracellular markers was developed for flow cytometry and microscopy platforms. A model using primary mouse neurons labeled with pSIVA, DAPI and MAP2 (neuronal marker) indicated pSIVA stained the cell body of spontaneously dying neurons but stained both the cell body and degenerating axons in staurosporine treated neurons. These results suggest that mechanisms of PS exposure may vary between different apoptotic processes, including spontaneous versus induced apoptosis. They also suggest pSIVA has potential for elucidating new pathways of PS exposure heretofore not possible with existing reagents.
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 237. doi:1538-7445.AM2012-237
Abstract 2380: Detecting human circulating endothelial cells using the acoustic focusing cytometer
Authors: Anderson April , Haataja Kristi , Bradford Jolene A. 
Published: August 2012

Abstract
Circulating endothelial cells (CECs) are mature cells shed from blood vessel walls during the natural process of endothelial cell turnover. Elevated levels of CECs have been reported in a host of pathological conditions including cardiovascular disorders, infectious diseases, immune disorders, post-transplantation analysis, and cancer. In cancer research, CECs have been suggested as a noninvasive biomarker for angiogenic activity, providing insight into tumor regrowth, resistance to chemotherapy, early recurrence and metastasis formation during or after chemotherapy. In healthy individuals, CECs are reported to be present in very low numbers: 0.01%-0.0001% of all peripheral blood mononuclear cells. Flow cytometry offers the necessary collection and analysis capabilities for detection of CECs, but is subject to numerous technical challenges. In comparison to traditional hydrodynamic-focusing cytometers, the Attune® Acoustic Focusing Cytometer, with its fast acquisition times and increased precision, overcomes the technological hurdles involved in analyzing CECs. Here we present a method for detecting human circulating endothelial cells using the Attune® Acoustic Focusing Cytometer. The method includes a number of conventional ways to improve rare event detection: a blocking step, a viability stain (SYTOX® AADvanced™ Dead Cell Stain), and the use of a dump channel to eliminate unwanted cells and decrease background fluorescence. The challenge of collecting a large enough number of events in a reasonable amount of time is met by using a collection rate of 1000 µL/min with the Attune® cytometer. This setting enables the collection of more than 4,000,000 live white blood cell (WBC) events in just 35 minutes; the acquisition time using a traditional hydrodynamic-focusing cytometer would be 10-12 times longer, close to 6 hours. Furthermore, this method delivers additional time savings by eliminating wash steps to avoid sample loss and employing a simpler sample preparation method; details and specific panels designed for both the blue/violet and blue/red Attune® cytometer configurations are outlined.
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 2380. doi:1538-7445.AM2012-2380
Abstract 239: A novel multimeric protein scaffold stimulates apoptotic signaling through TRAILR2
Authors: Chen Hong , Swers Jeffery , Inigo Ivan , Carrasco Rosa A. , Grinberg Luba , Wang Lin , Leow Ching-Ching , Xiao Zhan , Wu Herren , Hollingsworth Bob , Baca Manuel , Tice David A. 
Published: August 2012

Abstract
TRAILR2 (DR5, TNFRSF10B) is a member of the TNF-receptor superfamily that mediates programmed cell death following stimulation with its ligand. Binding of homotrimeric ligand TRAIL to TRAILR2 induces oligomerization of the receptors and triggers the apoptotic pathway through induction of caspases. Although TRAILR2 is found to be expressed in a number of normal cell types it is routinely found at high levels in many cancer types. Since TRAIL has been shown to preferentially induce apoptosis in cancer cells versus normal cells, several TRAIL receptor agonists including monoclonal antibodies as well as the ligand itself, are currently in clinical development. Here, we describe a novel protein scaffold (Tn3) based on a fibronectin type-III domain from the protein Tenascin that was engineered to specifically agonize TRAILR2. Connecting TRAILR2-binding Tn3 domains together significantly improved the in vitro potency of the molecule in several cancer cell models. For example, a hexameric TRAILR2-binding Tn3 construct has an EC50 of 0.5 pM in a 72 hour cell viability assay with Colo-205 cells. This is approximately 2 logs better than TRAIL. Furthermore, a subset of TRAIL-resistant cancer cell lines derived from multiple tissues of origin is sensitive to the multimeric Tn3. The improved potency over TRAIL was demonstrated in colorectal cancer xenograft models. In addition, tumor regression was also observed at doses as low as 0.3 mg/kg. These results suggest that a multimeric Tn3 protein scaffold targeting TRAILR2 has more potent anti-tumor activity in vitro and in vivo compared than the natural ligand.
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 239. doi:1538-7445.AM2012-239
Abstract 2393: Isolation and characterization of circulating tumor cells in a mouse model of colorectal cancer
Authors: Das Avisnata , Whitcomb Tiffany L. , Allen Joshua E. , Dicker David T. , Peters Kristi L. , El-Deiry Wafik S. 
Published: August 2012

Abstract
Circulating tumor cells (CTCs) are indicative of disease burden in metastatic colorectal cancer (mCRC) and high counts are believed to adversely affect outcome. However there has been a lack of suitable mouse models to study CTCs in mCRC. Here we report the development of an orthotopic model of mCRC in athymic nude mice from which we have successfully isolated and enumerated CTCs using the FDA-approved Veridex Cellsearch technology (Table 1). So far we have injected 5 mice with a million cells each of the human CRC cell line DLD-1 within the layers of the cecal wall for tumor xenografts to grow. 200 microL of blood has been collected every 2 weeks, till the endpoint of 16 weeks or a humane endpoint, from the medial saphenous vein of the mouse for CTC detection. In our protocol, human leucocyte filters are used as a RBC source. The blood is centrifuged at 800 G for 10 minutes in a CellSave tube, the serum removed and replaced by an equal volume of PBS. Mouse blood is transferred to this tube after collection. Efforts are on to show CTCs from mice injected with tumor cells labeled with a suitable cellular dye like Cellvue. At the endpoint, after humanely euthanizing a mouse, the cecum and organs are analyzed for possible secondary spread (liver, lungs, mesenteric lymph nodes) following resection and preservation. H/E staining is performed for evidence of primary or metastatic tumor tissue. Positive tissue samples are further analysed using immunostaining for stem cell markers and prognostic markers CD133, CD26, ALDH1, Mcl-1, EFGR, Ki67. We are analyzing isolated CTCs for expression of these markers and note the extent of concordance. The mouse model should help to understand the role of CTCs in evaluating metastasis as well as to validate the use of CTCs as tools for “liquid biopsy” of tumors. Table 1. CTC counts in the mice at different time points from injection of cells. Mouse 4 is the negative control mouse of the cohort which received injection of normal saline instead of cancer cell suspension. * denotes clotted sample.

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 2393. doi:1538-7445.AM2012-2393
Abstract 2402: TGF beta-mediated epithelial to mesenchymal transition in non small cell lung cancer: effects on stemness, invasiveness and chemotherapy sensitivity
Authors: Pore Milind M. , Buikema Lianne , Hiltermann TJN , Kruyt FAE 
Published: August 2012

Abstract
The developmental program of epithelial to mesenchymal transition (EMT) can be activated in tumor cells and is implicated in the metastatic spread of tumor cells. EMT leads to loss of cell adhesion and increased motility of cells and can be detected by down regulation of epithelial makers such as E-cadherin and gain of mesenchymal ones such as vimentin and fibronectin. Interestingly, EMT has also been implicated in enhancing stemness properties of tumor cells and in causing chemotherapy resistance. The aim of this study is to examine the invasive, stem-ness and chemotherapy sensitive properties of mesenchymal and epithelial Non-small cell lung cancer (NSCLC) cells. In particular we use a TGF beta-inducible EMT model of A549 cells. A pannel of NSCLC cell lines, A549, H460, H322, SW1573, H1650 and H1299 were explored for epithelial (EpCAM. E-cadherin) and mesenhymal markers (N- cadherin, Vimentin and Fibronectin). Only A549 cells exhibit epithelial characteristics while remaning cell lines were either mesenchymal in nature or weekly expressing epithelial markers. Treatment of A549 cells with TGFbeta induced EMT as confirmed by loss of epithelial and gain of mesenchymal markers by FACS and WB analysis. This process was independent of Src since knockdown of Src did not effect EMT activation. Other kinases are currently evaluated for mediating EMT in this model. A549 mesenchymal cells (M) cells were somewhat more resistant to cisplatin and paclitaxel compared to parental A549 cells, whereas no marked difference in the response to proapoptotic TRAIL was found. Furthermore, using wound healing assays A549M cells showed higher rates of migration. Possible effects of EMT on stem cell properties in A549 cells were studied next. A549M cells displayed enhanced spheroid formation potential when cultured in serum free Neurobasal media (NBM) that was associated with an increase in Sox-2 expression. To further explore stemness of A549(M) cells, currently the expression of stem cell markers such as CD133, CD24, CD44 is examined. In conclusion, our results thus far suggest that in A549 NSCLC cells, induction of EMT by TGF beta results in chemoresistance, higher migratory potential and increased stem cell properties. The in-vitro results observed will be extended by in-vivo assays. For this purpose we are establishing orthotopic NSCLC mice 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 2402. doi:1538-7445.AM2012-2402
Abstract 2405: Loss of TBK1 induces an epithelial-mesenchymal transition through upregulation of Slug in the breast cancer cell lines
Authors: Yang Kyung-Min , Kim WonJoo , Jung YunShin , Kim Seong-Jin 
Published: August 2012

Abstract
Estrogen receptor alpha (ER alpha) is a key regulator of proliferation and differentiation in mammary epithelium through their well-documented effects on transcription and represents a crucial prognostic indicator and therapeutic target in breast cancer. Here, we show that loss of TBK1 in ER alpha positive breast cancer cells causes an epithelial-mesenchymal transition (EMT). We found that TBK1 is downregulated in ER alpha negative breast tumors by analyzing published microarray data sets, suggesting that TBK1 might regulate ER alpha expression. To investigate this hypothesis, we made the ER alpha positive breast cancer cell lines stably expressing TBK1-specific shRNA. Knockdown of TBK1 decreased E-cadhrein expression (epithelial marker) and increased N-cadherin, vimentin, fibronectin expression (mesenchymal marker). Additionally, loss of TBK1 in ER alpha positive breast cancer cell lines leads to the downregulation of ER alpha expression. Interestingly, ER alpha repression by knockdown of TBK1 induced the upregulation of transcriptional repressor Slug, a master regulator of EMT. Because ER alpha expression is suppressed by loss of TBK1, it is suggested that TBK1 plays a role in the inverse correlation between Slug and ER alpha. Our findings indicate that loss of TBK1 expression is associated in between ER alpha expression status and invasive growth of breast cancer.
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 2405. doi:1538-7445.AM2012-2405
Abstract 2407: Snail 1 regulates invasion through uPA-uPAR and MMP-9 signaling in prostate cancer cells
Authors: Randle Diandra D. , Clarke Shineka , Odero-Marah Valerie 
Published: August 2012

Abstract
Epithelial-mesenchymal transition (EMT) is a process by which cancer cells acquire mesenchymal properties, such as induction of N-cadherin, while epithelial-associated genes like E-cadherin are lost. This enables the cells to be more invasive, migratory and metastatic. Factors that can induce EMT include growth factors like transforming growth factor -α (TGF-β) and epidermal growth factor (EGF), and transcription factors like Snail1. Snail1-induced EMT promotes migration and invasion and we hypothesized that this may be mediated by urokinase (uPA) and its receptor (uPAR) activities. uPA, a serine protease, may be activated by integrin engagement to bind to its receptor, uPAR, and initiate a signaling cascade that regulates a variety of biological pathways including invasion. Since Snail1 can induce matrix metalloproteinases (MMP 2 and 9) which are also involved in cell invasion, we also examined MMP activity. Androgen-dependent LNCaP, and 22Rv1 and androgen-independent ARCaP human prostate cancer (PC) cells were stably transfected with empty vector control (Neo) or constitutively active Snail1 which led to increased cell migration and invasion. The levels of Snail1, uPA, and uPAR were measured by Western Blot analysis. uPA activity in conditioned media was measured using the Elisa uPA activity assay kit. Additionally, cells were treated with MAPK inhibitor, UO126, at set time points. Gelatin zymography analysis was utilized to detect MMP-9 activity in the conditioned media. Currently, ARCaP-Snail cells are being transiently transfected with uPAR siRNA to assay for the effects of uPAR knockdown on uPA and MMP activity. The data suggests that overexpression of Snail1 increased uPA and uPAR protein levels, while uPA activity was elevated in conditioned media from LNCaP, 22Rv1 and ARCaP cells. Also, MAPK inhibited MAPK expression in the cell and decreased uPA activity. In addition gelatin zymography showed higher MMP 9 activity in ARCaP-Snail overexpressing cells that was inhibited by MAPK inhibitor. Therefore, Snail-mediated cell migration and invasion in human prostate cancer cells may occur via the regulation of uPA and uPAR activities in addition to MMPs.
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 2407. doi:1538-7445.AM2012-2407
Abstract 2467: Acidic pericellular pH increases contribution of cathepsin B to invasiveness of a human breast carcinoma cell line
Authors: Rothberg Jennifer M. , Bogyo Mathew S. , Sloane Bonnie F. 
Published: August 2012

Abstract
Among the non-cellular microenvironmental factors that may contribute to malignancy of solid tumors is an acidic peritumoral pH (pHe). We have shown that this induces secretion of the lysosomal cysteine protease, cathepsin B. The object of the present study was to further examine the effect of a slightly acidic pericellular pH (i.e., pHe 6.8) on degradation of collagen IV and the activity and secretion of proteolytic enzymes, in particular cathepsin B. For these studies, we used: 1) a highly malignant human breast carcinoma line, MDA-MB-231-RFP; 2) a 3D reconstituted basement membrane overlay culture model; 3) a live cell confocal microscopy assay for imaging proteolysis and detecting active cathepsin B via an activity based probe, GB123; 4) a protocol for quantification of proteolysis on a per cell basis; 5) and fluorometric real-time and plate-reader assays for measuring cathepsin B activity. The live cell proteolysis assay confirmed that degradation of collagen IV by the MDA-MB-231 cells was consistently higher at a slightly acidic pHe and was decreased by a highly selective cathepsin B inhibitor, CA074. A dramatic increase in cathepsin B secretion from MDA-MB-231 cells was observed upon exposure to an acidic pHe, as assessed by assays of conditioned media and analysis of secretion in real-time. Our results are consistent with the hypothesis by Gillies and colleagues of “acid-mediated invasion” in tumors and suggest a role for cathepsin B in promoting degradation of collagen IV and thereby tumor invasiveness in the acidic peritumoral microenvironment.
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 2467. doi:1538-7445.AM2012-2467