bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 4743: Exosomes in motion: Visualizing cancer metastasis via the Synaptotagmin C2B domain
Authors: Saludes Jonel , Morton Leslie , Ghosh Nilanjan , Beninson Lida , Chapman Edwin , Fleshner Monika , Yin Hang 
Published: August 2012

Abstract
Exosomes play pivotal roles in intercellular communication and cancer progression. Recent findings have shown exosomes to incite proangiogenesis and prepare lymph nodes as remote niches for accumulation and migration of melanoma cells. Exosomes present a highly curved morphology with a size range of ∼30-100 nm that is distinct from other lipid vesicles. Furthermore, exosomes have the potential as a general metastasis biomarker since their increased secretion in the peripheral blood has been correlated with cancer metastasis. Since aqueous suspensions of exosomes cannot be seen by conventional optical methods, we hypothesized that a molecular probe that binds to exosomes could be a novel tool for detecting these vesicles. We aim to develop a minimally-invasive diagnostic tool to detect and measure secreted exosomes as biomarkers of cancer metastasis that may help clinicians and patients decide on an appropriate therapeutic action. Taking a cue from nature and using solid phase ‘Click’ chemistry as a technique for peptide modification, we created a fluorophore-tagged cyclic peptide based on the membrane penetrating C2B domain of Synaptotagmin I. We investigated the peptide-lipid interactions using synthetic liposomes as preliminary models of exosomes through a combination of spectroscopic techniques. We found that the peptide probe was selective for highly curved liposomes (d &lt;100 nm) and does not bind to low curvature liposomes (d &gt;100 nm). We tested blood plasma samples from rat models to find out if our preliminary findings would translate to the detection of exosomes. Our results showed that blood plasma treated with the peptide probe showed fluorescence intensity that was remarkably higher than the untreated peptide, which indicated binding to exosomes. Furthermore, we used a real time nanoparticle tracking analysis system to visualize the exosomes in a dynamic and physiologically-relevant medium. The peptide-treated exosomes were detected as fast-moving, fluorescent particles even in the complex matrix of blood plasma. This technique provided us with a platform to study the size distribution and concentration of exosomes in blood plasma. We have created a peptide probe that selectively binds to exosomes from an animal model. The investigation of the exosome binding property of this probe on clinically relevant samples is ongoing.
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 4743. doi:1538-7445.AM2012-4743
Abstract 4746: Structural studies of human glioma pathogenesis-related protein 1(GLIPR1)
Authors: Asojo Oluwatoyin A. , Koski Raymond A. , Bonafé Nathalie 
Published: August 2012

Abstract
Human glioma pathogenesis-related protein 1 (GLIPR1) is a membrane protein that is highly upregulated in brain cancers but barely detectable in normal brain tissue. GLIPR1 is composed of a signal peptide, to direct its secretion, a conserved cysteine-rich CAP (cysteine-rich secretory protein, antigen 5, pathogenesis related-1) domain, and a transmembrane domain. Phase I/II clinical trial involving direct injection of neoadjuvant GLIPR1 prior to radical prostatectomy are underway (IND #13033). GLIPR1 gene therapy has been shown to be anti-metastatic in an orthotopic mouse model of prostate cancer. GLIPR1 is also currently being investigated for glioblastoma targeted therapy. We present here crystal structures of a truncated soluble domain of the human GLIPR1 protein, sGLIPR1, solved by molecular replacement (MR) using a truncated polyalanine model of the CAP domain of stecrisp, a snake venom CRISP (cysteine-rich secretory protein), in PHASER. The correct MR solution could only be obtained by removing all loops in the search model. While, the native structure was refined to 1.85 Å, that of the Zn2+ complex was refined to 2.2 Å. The latter structure reveals that the putative binding cavity coordinates Zn2+ similarly to snake venom CRISPs which are involved in Zn2+-dependent mechanisms of inflammatory modulation. Both sGLIPR1 structures have extensive flexible loop / turn regions and unique charge distributions that were not observed in any of the previously reported CAP protein structures. We also propose a model for the structure of the full-length, membrane-bound GLIPR1.
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 4746. doi:1538-7445.AM2012-4746
Abstract 4748: Molecular targets of quinolinone derivatives with anticancer activity
Authors: Rylova Gabriela , Dzubak Petr , Janostakova Anna , Frydrych Ivo , Konecny Petr , Holub Dusan , Ozdian Tomas , Dolezal Dalibor , Soural Miroslav , Hlavac Jan , Hajduch Marian 
Published: August 2012

Abstract
Currently, we are testing chemical libraries of quinolinone derivatives, compounds with high selective cytotoxic activity. These compounds, derived from quinolone antibiotics, are well known for their antibacterial, antiprotozoal, cytotoxic and immunosuppressive effects. 2-phenyl-3-hydroxy-4(1H)-quinolinones were tested by MTT assay for cytotoxic activity and some of them proved IC50 values in sub-micromolar concentrations. Cell cycle and DNA/RNA synthesis were further analysed by flow cytometry. The accumulation of cells was observed predominantly in G1 phase together with significant DNA and RNA synthesis inhibition. The most active derivative was tested in in vivo cancer mice model with using hollow fibres. Hollow fibres were filled by leukemic CEM cell line and were implanted subcutaneously and intraperitoneally to mice. Afterwards, mice were treated by tested compound. Hollow fibres were after 14 days taken from mice and surviving cells were tested by cytotoxic MTT assay. activity of tested quinolinone was comparable to doxorubicin. For protein targets identification, we have synthesized biotinylated molecules of original derivatives. Biotinylated derivatives were immobilized on the surface of streptavidin coated magnetic beads and whole complex (magnetic bead-streptavidin-biotin-quinolinone) was incubated with total cellular lysate of the CEM cell line. Thereafter non-bonded proteins were washed-out and specifically bonded proteins were separated on SDS-PAGE gel. Following silver-staining of the gel we identified sample lines with specifically bonded proteins to biotinylated compound and negative control. Specific proteins were cut off from the gel and trypsinized to get peptides for protein identification by MS analysis (LC-MS/MS and LC-MALDI). Identified targets are proteins associated with translational regulation, glucose metabolism and cytoskeleton. Potential targets were validated by western blot and by other assays (reporter cell models, kinase and enzymatic assays, evaluation in vitro transcription and translation). The work was supported by grants: LC07017, CZ.1.07/2.3.00/20.0009 coming from European Social Fund. Infrastructural part of this project (Institute of Molecular and Translational Medicine) was supported from the Operational Programme Research and Development for Innovations (project CZ.1.05/2.1.00/01.0030).
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 4748. doi:1538-7445.AM2012-4748
Abstract 4755: The role of a pair of cysteine residues in the redox properties of human ribonucleotide reductase small subunits hp53R2 and hRRM2
Authors: Zhou Bingsen , Su Leila , Hu Shuya , Yen Yun 
Published: August 2012

Abstract
Ribonucleotide reductase (RNR) is a cell cycle protein regulating intracellular redox state, which is a critical mediator and metabolic modulator of cellular functions such as cell signaling, gene expression, proliferation, and apoptosis. Human RNR has two small subunits hp53R2 and hRRM2, which by themselves play important roles in regulating cellular redox state. Our previous studies have shown that hRRM2 and hp53R2 have different redox properties, where hp53R2 is an antioxidant defending oxidative stress while hRRM2 tends to be an oxidant. Many proteins consist of cysteine residues which have a sulfhydryl group with a labile proton, making it an ideal “receptor” through the reversibility of the thiol/disulfide redox couple. In this work we have found human RNR small subunits possess a conserved CXXXC motif, C270XXXC274 in hRRM2 and C232XXXC236 in hp53R2, close to Tyr162-hRRM2/Tyr124-hp53R2. Our mutagenesis study indicated this motif is linked with the redox properties of hp53R2 and hRRM2. The cysteines were mutated to serine and alanine respectively and the redox state of the mutants were monitored by the fluorescence assays of carboxy-H2DCFDA oxidation. Electron paramagnetic resonance spectroscopy (EPR) and enzyme activity assays were also carried out for the radical stability and enzyme activity.
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 4755. doi:1538-7445.AM2012-4755
Abstract 4756: YM155 suppresses survivin expression by disrupting the ILF3/p54nrb transcription factor complex
Authors: Nakamura Naoto , Yamauchi Tomohiro , Hiramoto Masashi , Yuri Masatoshi , Naito Masanori , Takeuchi Masahiro , Yamanaka Kentaro , Nakahara Takahito , Kita Aya , Kinoyama Isao , Matsuhisa Akira , Sasamata Masao , Yokota Hiroyuki , Kawabata Shigeki , Furuichi Kiyoshi 
Published: August 2012

Abstract
Survivin, a member of the anti-apoptosis proteins family, is highly expressed in all primary tumor types, and is responsible for cancer progression and drug resistance in many types of cancer. YM155, a small chemical compound, selectively suppressed the expression of survivin and induced apoptosis in cancer cells both in vitro and in vivo. However, the mechanisms underlying the suppression of survivin expression by YM155 are unknown. In order to identify the molecular targets and analyze the drug mechanism of action, affinity purification was performed using an active analogue of YM155. We identified interleukin enhancer-binding factor 3 (ILF3) as the binding target of YM155. From the complex analysis of ILF3 and survivin promoter sequence, we also found that ILF3 forms a complex with p54nrb transcription factor, and then binds to the survivin promoter. Overexpression of ILF3 enhanced survivin promoter activity, which was attenuated by YM155 in a concentration-dependent manner. Furthermore, the ILF3/p54nrb complex was disrupted by YM155, thus dispersing the components in the nucleus.In conclusion, our study suggests that binding to ILF3 by YM155 causes the dissociation of the ILF3/p54nrb complex, thus inhibits ILF3 dependent survivin expression.
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 4756. doi:1538-7445.AM2012-4756
Abstract 4757: Design and optimization of linked nucleic acid (LNA) probes to detect the c-MYC G-quadruplex
Authors: Gaerig Vanessa C. , Jin Xi , Tabrizian Tahmineh , Danford Forest L. , Brooks Tracy A. 
Published: August 2012

Abstract
The c-MYC oncogene is upregulated in almost 80% of cancers, and in some cases is the causative oncogenic factor. It is regulated at the transcriptional level with up to 90% initiating at the P1 and P2 promoters. The NHE III1 element regulates this region, which consists of a unique guanine-rich string of DNA capable of adopting at least three topologies: single stranded, double stranded (ds) and the non-B-DNA G-quadruplex (G4) structure. G4s are formed when two or more tetrads stack, each comprised of four guanines bonded by Hoogsteen hydrogen bonds, stabilized with monovalent cations. Putative G4 forming regions have at least four runs of three or more consecutive guanines separated by varying nucleotides that comprise the loop structures. The c-MYC G4 structure has been elucidated to involve guanine runs 1α4 (G41-4) or 2Δ5 (G42-5) (of six total runs) in a parallel formation. Regulatory proteins have been identified, and small molecule compounds are under investigation to stabilize the G4 element and downregulate c-MYC expression. In parallel to these efforts, we are developing linked nucleic acid (LNA)-biotin bridge probes to be used as diagnostic tools to identify these formations in biopsies in order to inform therapeutic regimens. Molecular models of the two G4 isoforms were used to determine the distance occupied by the secondary structure to be between 16.4α16.6 angstroms; various length nucleic acid sequences flanking a 17.7α30 angstrom linker were screened and optimized. Probes were shown to be structure specific - either for the c-MYC G41-4 (probe 1a) or the G42-5 (probe 1b) - by EMSA analysis. The probes were amenable to internal biotinylation for ongoing pull-down assays, but truncation of the 5′-complementary sequence limited affinity. Interestingly, the LNA probes thermally stabilized the c-MYC G4 in a unique pattern and are also being examined for their potential therapeutic efficacy. Experiments are underway to show that these hybrid probes will bind intracellularly and show the frequency of G4 formation in quiescent versus activated cells, and following treatment with c-MYC G4-interactive compounds. Through these works, we highlight for the first time that a ‘FISH’-type probe can be developed and used to selectively detect the formation of the c-MYC G4 in vitro. Up to 80% cancer patients overexpress c-MYC and are candidates for G4-targeted therapies currently under development. The developed probes will be of great utility as companion diagnostics in selecting patients for G4-therapeutics and truly personalized medicine.
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 4757. doi:1538-7445.AM2012-4757
Abstract 4767: Reaction of singlet oxygen with hydrazone prodrugs for the photochemical release of N-nitrosoamine drugs
Authors: Ghogare Ashwini A. 
Published: August 2012

Abstract
Very few visible-light activated photocleavable groups are available for drug delivery applications. Our research was interested in assessing the visible-light photolability of hydrazone C=N bonds via a Type II (singlet oxygen) dye-sensitized oxygenation reaction. We have explored the photooxidized cleavage of N-nitrosoamine by-products from N-methylbenzophenone phenylhydrazone and methylenehydrazine model compounds. The former was studied by gas chromatography mass spectrometry and the latter by density functional theory calculations (DFT). We quantified benzophenone that arose from the phenylhydrazone photooxidation. The DFT calculations predicted a low energy route to C=N bond fragmentation via a [2+2] pathway and an 1,2,3-dioxazetidine reactive intermediate. The reaction was predicted to occur in stepwise process via zwitterionic intermediates prior to forming the dioxazetidine, and cleavage to the nitrosamine product. Further studies are underway regarding the photolytic and hydrolytic stability of the hydrazone C=N bond to give better insight including structure-activity relationships, of singlet oxygen triggered photo-release of nitrosoamines.
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 4767. doi:1538-7445.AM2012-4767
Abstract 4774: LC-MS/MS detection of the dansyl-modified biologically active CDK inhibitor VMY-1-103 using an in vivo model system
Authors: Sirajuddin Paul , Das Sudeep , Ringer Lymor , Salinas Patricia , Rodriguez Olga , Moasser Bahram , Yenugonda Venkata M. , Albanese Christopher , Brown Milton 
Published: August 2012

Abstract
The development of new small molecule kinase inhibitors as cancer therapeutic drugs has placed increased emphasis on determining the mechanism of action of the new compounds preclinically, such as in genetically engineered mice or using human tissue xenografts. The ability to accurately measure the pharmacokinetics and pharmacodynamics of new compounds is often hampered by the lack of suitable platforms to measure serum and tissue distribution with high sensitivity and specificity. We have recently developed a novel dansylated cyclin dependent kinase inhibitor called VMY-1-103 (VMY) that has purvalanol B as its base compound. We established that VMY was significantly more effective in blocking cell cycle progression and inducing apoptosis than purvalanol B. Since dansylation is frequently used to enhance mass spectrometry-based quantitative analyses, we hypothesized that this modality could similarly be used to evaluate the tissue distribution of VMY in mouse models. In the current study, we developed a rapid liquid phase-extraction of VMY and purvalanol B from mouse tissue and validated a sensitive liquid chromatography-tandem mass spectrometry based assay to quantify tissue delivery of these compounds in vivo. Comparisons of the standard curves for VMY versus Purvalanol B revealed a greater than 7.7-fold increase in sensitivity for VMY. Using both the ND-2 SmoA1, a genetically engineered mouse model of medulloblastoma, and normal mice, we quantified tissue delivery by mass spectrometry as well as Area Under the Curve (AUC) analysis by integrating the peak intensity normalized by an internal standard. Our analyses revealed that VMY delivered intraperitoneally at 20mg/kg was found at its highest concentration in serum 4 hours after injection. We further established that VMY was distributed in multiple tissues, including pancreas and prostate at varying levels and, importantly, we establish that VMY was able to traverse an intact blood-brain barrier as it was detected in the brain and cerebellum of normal mice. Purvalanol B delivered in the same manner as VMY was found at significantly lower levels in all tissues examined and unlike VMY, we failed to detect purvalanol B in brain or and cerebellar tissue. The significance of this study illustrates that a biologically active compound can be modified by dansylation and exhibit both increased sensitivity to mass spectrometry and enhanced bioavailability and tissue delivery, including the brain, in vivo. We also define a simple mass spectrometry-based tissue and serum assay.
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 4774. doi:1538-7445.AM2012-4774
Abstract 4777: Computational strategies for finding protein targets of flavonoids
Authors: Chen Hanyong , Yao Ke , Nadas Janos , Bode Ann M. , Malakhova Margarita , Oi Naomi , Lubet Ronald A. , Dong Zigang 
Published: August 2012

Abstract
Plant-based polyphenols (i.e., phytochemicals) have been used as treatments for human ailments for centuries. The mechanisms of action of these plant-derived medicines are a now major topic of investigation. Thousands of phytochemicals have been isolated, and a certain number of them have shown activities or effects on different disease models. Using conventional approaches to select the best or group of the best chemicals for studying the effectiveness in treating or preventing disease is extremely challenging. We have developed and used computational-based methodologies that provide an efficient and inexpensive tools to gain further understanding of the anticancer and therapeutic effects exerted by polyphenols. Computational strategies involving virtual screening, shape and pharmacophore analysis and molecular docking have been used to select chemicals that target a particular protein or enzyme and to determine potential protein targets for well-characterized as well as for novel polyphenols.
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 4777. doi:1538-7445.AM2012-4777
Abstract 478: Does ICAM-2 contribute to the metastatic phenotype of pancreatic cancer cells
Authors: Garcia Patrick L. , Yoon Karina J. 
Published: August 2012

Abstract
Pancreatic Cancer (PC) is the 10th most diagnosed cancer and the 4th leading cause of cancer related deaths in the United States, and of those deaths, approximately 90% are due to metastatic disease. Metastasis involves many different proteins and pathways, but one family of proteins, cell adhesion molecules (CAMs) have been implicated in the metastatic process. CAMs are membrane bound glycoproteins involved in cell adhesion to other cells or the extracellular matrix. A specific protein within the CAM superfamily is intercellular adhesion molecule 2 (ICAM-2), which was shown to be expressed in leukocytes and vascular endothelium. Previously, our lab reported a novel function for ICAM-2 in neuroblastoma (NB) cells. ICAM-2 expression correlated with decreased cell motility in vitro, a decreased capacity to form disseminated tumors in vivo in an experimental metastasis model, and coincided with a favorable prognosis in primary tumor samples. The objective of our current study is to examine if these findings could be expanded to other types of solid tumors. Interestingly, in a preliminary screen for ICAM-2 expression, we detected ICAM-2 expression in other types of solid tumors, including PC cell lines. We detected RNA and protein expression of ICAM-2 in two cell lines (BxPC-3 and CFPAC-1), while ICAM-2 expression was not detectable in Panc-1 cells. Next, we wanted to determine if the absence of ICAM-2 expression correlated with increased colony formation in anchorage independent growth in soft agar assay, which was previously reported to be an in vitro indicator of either tumorigenic or metastatic potential. Surprisingly, ICAM-2 expressing PC cells showed significantly (p&lt;0.001) decreased colony growth compared to non-ICAM-2 expressing cells. Currently, we are i) evaluating functional differences between ICAM-2 expressing and non-ICAM-2 expressing PC cell lines, and ii) producing a stable transfected Panc-1 cell line over-expressing ICAM-2 to further assess its potential role in metastasis. This work was supported by UAB - comprehensive cancer center - young supporters board - new faculty development award 2010.
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 478. doi:1538-7445.AM2012-478