bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 2494: Identification of mithramycin analogues with increased potency and more selective inhibition of EWS-FLI1 for the treatment of Ewing sarcoma
Authors: Gebregiorgis Meti , Woldemichael Girma , He Min , Kang Min H. , Núñez Luz E. , Morís Francisco , Smith Malcolm A. , Helman Lee J. , Grohar Patrick J. 
Published: August 2012

Abstract
Background: Ewing Sarcoma Family Tumors (ESFT) is characterized by a chromosomal translocation, most commonly, between chromosomes 11 and 22, resulting in the fusion of the EWS and FLI1 genes. The fusion protein EWS-FLI1 is known to function as a constitutively activated transcription factor responsible for the oncogenic phenotype of ESFT. The identification of potent and specific inhibitors of EWS-FLI1 offers the hope of improved outcomes for ESFT patients. We have recently identified mithramycin, an antineoplastic antibiotic produced by Streptomyces plicatus, as a potent inhibitor of EWS-FLI1. In this report, we have investigated a series of mithramycin structural analogs in an effort to find compounds with better pharmacological properties. Methods: We evaluated the relative effects of the mithramycin analogs on ESFT viability using MTS, XTT and IncuCyte® real time cell confluence assays. The compounds were screened against a panel of pediatric cell lines within the Pediatric Preclinical Testing Program (PPTP) to evaluate selectivity. Western blot analysis and luciferase assays were used to determine the effects on EWS-FLI1 downstream target expression. Results: The mithramycin analogs 6 and 16 exhibit better potency and improved selectivity relative to mithramycin for both cell viability and downstream target inhibition. Furthermore, compound 6 is known to have a higher 200mg/kg maximum tolerated dose (MTD) relative to the 5 mg/kg MTD of mithramycin in xenograft models. Conclusions: In comparison to the drug mithramycin, we have shown that some of its structural analogs display better pharmacological properties such as increased potency and more specificity for ESFT cells. These results indicate that studies of analogs of DNA binding drugs are an important aspect of transcription factor drug development. We are working to further characterize the mechanism of these analogs and evaluate them in an in vivo model. The ultimate goal would be to translate these compounds to the clinic and improve therapeutic outcomes in patients with ESFT.
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 2494. doi:1538-7445.AM2012-2494
Abstract 2495: Sepiapterin reductase interacts with Ornithine Decarboxylase and regulates neuroblastoma proliferation
Authors: Lange Ingo , Koomoa Dana-Lynn T. , Bachmann Andre S. 
Published: August 2012

Abstract
Ornithine Decarboxylase (ODC) is a key, rate-limiting enzyme in mammalian polyamine biosynthesis that is upregulated in various types of cancer including neuroblastoma (NB). MYCN is a transcription factor and proto-oncogene that has been shown to be a key prognostic factor associated with advanced stage NB. ODC is a transcriptional target of MYCN, and has been found to play a critical role in NB progression. Previous studies have shown that inhibition of ODC through drugs such as alpha-difluoromethylornithine (DFMO) depletes intracellular polyamine pools and induces G1 cell cycle arrest. Our previous studies have shown that the anti-proliferative effect of DFMO in NB involves upregulation of the cyclin dependent kinase inhibitor p27 and downregulation of MYCN. In a search for novel regulators of ODC, we recently discovered that sepiapterin reductase (SPR), a key enzyme in the biosynthesis of tetrahydrobiopterin, binds to ODC and may regulate ODC activity through a novel mechanism. Co-immunoprecipitation experiments using NB cell lysates show that ODC interacts with SPR. In addition, immunofluorescence staining and laser-scanning confocal microscopy confirm the co-localization of ODC and SPR. Furthermore, downregulation of SPR expression using siRNA targeting SPR results in significant inhibition of NB proliferation, without affecting ODC protein levels. These results suggest that the interaction between SPR and ODC may be critically important to ODC activity and function and may constitute a novel mechanism for the regulation of NB proliferation. This interaction may play a critical role in fundamental physiological and pathophysiological processes including the development and progression of NB. Understanding the novel interaction between ODC and SPR might play a crucial role for the development of new drugs targeting SPR for the treatment of NB and other MYC/ODC-driven diseases.
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 2495. doi:1538-7445.AM2012-2495
Abstract 2502: Next-generation sequencing: Integrated exotome analysis in human multiple neuroblastoma
Authors: Hiyama Eiso , Hiyama Keiko 
Published: August 2012

Abstract
Background: Although multifocal neuroblastoma (NBL) is rare, its susceptibility is due to germline aberration and this predisposition gene may also be involved in sporadic neuroblastoma tumorigenesis. Sequence capture enrichment strategies and massively parallel next generation sequencing (NGS) were used for gene discovery because of their alterations. Methods: Out of approximately 500 NBL samples, 10 samples derived from 5 multifocal neuroblastoma cases were analyzed by a method for whole-exome sequencing coupling Agilent whole-exome capture to the Illumina DNA-sequencing platform. Using this technology, we investigated consistent point-mutations and insertions-deletions in these cases. Then, we analyzed the expression levels of these candidate genes in 298 sporadic NBL samples. Results: Among these 5 cases, one case showed ALK mutation in both of his multifocal tumors and germline mutation of ALK exon 23 (F1174L) was identified. The remaining 4 cases showed 57 candidate loci with consistent point-mutations and insertions-deletions including NBPF family genes and cell division cycle protein (CDC) genes. The expression levels of these candidate genes revealed that two genes were significantly decreased in these multifocal NBL tumors, except for one ALK mutated case. Then, we examined the expression levels of these two genes in sporadic NBL tumors. The expression levels of these candidate genes were significantly low in 34 and 59 NBL tumors, respectively but the low expression of both genes were detected in only two NBL tumors.Conclusions: Whole-exome sequencing using NGS in multifocal neuroblastoma revealed several candidate germline-mutated genes including ALK in such NBL-susceptibility cases. The expression levels of these genes also indicated that heterogeneous subtypes exist in sporadic NBLs. NGS can be used in research and diagnostic settings to screen for mutations and deletion/insertion in number of loci in genetically heterogeneous neuroblastoma. Further NGS analysis provided important candidates of indicators for diagnostic and therapeutic targets for NBLs.
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 2502. doi:1538-7445.AM2012-2502
Abstract 2504: Defining the contribution of the extracellular domain of ICAM-2 to the non metastatic phenotype of neuroblastoma cells using chimeric fusion proteins
Authors: Feduska Joseph M. , Yoon Karina J. 
Published: August 2012

Abstract
Neuroblastoma (NB) is the most common extracranial pediatric cancer, accounting for 15% of all childhood cancer deaths. Recently, our lab reported the novel finding of ICAM-2 expression in NB cell lines and primary NB tumor cells. Interestingly, ICAM-2-expressing NB cells exhibited decreased motility in vitro and decreased metastatic potential in vivo. In these ICAM-2-expressing non-metastatic NB cells, the cytoplasmic domain of ICAM-2 interacted with β-actinin, which in turn interacted with actin, leading to subsequent redistribution of actin fibers to a non-motile state. The goal of the current study is determining the potential role of the ICAM-2 extracellular domain in NB metastasis development. Therefore, we constructed a series of chimeric fusion proteins, one of which consists of the extra cellular domain of CD89 with the transmembrane and cytoplasmic domains of ICAM-2 (CD89αED). CD89 is the receptor for IgA, and bears striking similarity to ICAM-2 in terms of size (287AA vs. 275AA, respectively) and structure. Both are immunoglobulin superfamily members with two Ig-like domains, six extracellular N-glycosylation sites, and short cytoplasmic domains. Furthermore, there is no literature implicating CD89 in cancer progression. This construct was stably transfected into a non-ICAM-2 expressing SK-N-AS NB cell line, and protein expression was confirmed by flow cytometry and western blot. Our preliminary data showed distinct phenotypic differences between NB cells stably transfected with the CD89αED construct compared to wild type ICAM-2. In scratch assays, CD89αED cells showed faster migration ability than ICAM-2 wt (75% vs. 50% wound closure) at 72 hour time points. Furthermore, in anchorage-independent colony growth in soft agar, CD89αED cells formed a significantly (P &lt; 0.001) higher number of colonies compared to ICAM-2 wt. Ongoing work focuses on determining the effect of CD89αED on F-actin modification and regulation of potential downstream signaling pathways. This work was supported by the 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 2504. doi:1538-7445.AM2012-2504
Abstract 2514: CSPG4 as a target of antibody-based immunotherapy for malignant mesothelioma
Authors: Zeyana Rivera , Ferrone Soldano , Wang Xinhui , Sandro Jube , Yang Haining , Gaudino Giovanni , Carbone Michele 
Published: August 2012

Abstract
Malignant mesothelioma (MM) is an aggressive tumor, resistant to conventional therapies, with median survival of 1 year from diagnosis. The lack of effective therapies available prompted us to implement antibody-based immunotherapy against novel targets and to investigate possible synergies with chemotherapy on MM. CSPG4 is involved in the onset and progression of melanoma and other tumors, as well as in neo-angiogenesis. CSPG4-specific monoclonal antibodies (mAb) have shown anti-tumor effects in both preclinical and clinical trials of melanoma. We hypothesized that targeting CSPG4 with a CSPG4-specific mAb would have therapeutic efficacy against MM. We found that chondroitin sulphate proteoglycan 4 (CSPG4) was aberrantly expressed in 6 out of 8 MM cell lines and in 24 out of 40 MM biopsies, with minimal expression in surrounding non-malignant cells. The expression of CSPG4 in MM was higher upon engagement of extracellular matrix components (ECM) and was associated with increased MM cell viability and motility. Silencing of CSPG4 expression by siRNAs supported this functional significance of CSPG4 in MM. Consistently, the CSPG4-specific mAb TP41.2 inhibited MM cell attachment to the ECM, resulting in decreased phosphorylation of FAK and AKT, decreased expression of cyclin D1 and apoptosis. Moreover, TP41.2 significantly reduced MM cell motility, migration and invasiveness, and inhibited MM growth in soft agar. TP41.2 prevented the outgrowth of human MM tumors in SCID mice and inhibited the growth of established MM xenografts, resulting in significantly extended survival of tumor-bearing mice. These results represent a novel approach for CSPG4 mAb-based immunotherapy of MM. Combinatorial strategies with chemotherapeutic agents and with mAbs targeting c-Met related receptor are ongoing, aimed at translating CSPG4-specific mAb into clinical setting.
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 2514. doi:1538-7445.AM2012-2514
Abstract 2527: Antibody-dependent cellular cytotoxicity of cetuximab against colorectal cancer cells with wild-type and mutant KRAS
Authors: Nakadate Yusuke , Kitamura Yuka , Tamura Tomohide , Koizumi Fumiaki 
Published: August 2012

Abstract
Cetuximab is a chimeric IgG1 monoclonal antibody (mAb) that targets the extracellular domain of epidermal growth factor receptor (EGFR). In addition to direct EGFR inhibition, antibody-dependent cellular cytotoxicity (ADCC) is considered to be an important mechanism of action of cetuximab. Recently, KRAS mutations in tumors have been shown to be a negative predictive factor for response to cetuximab treatment for colorectal cancer (CRC). KRAS activating mutations constitutively transduce RAS/RAF/MEK/ERK pathway signaling, which theoretically cannot be suppressed by inhibition of the upstream receptor through the use of cetuximab. Thus, KRAS mutations potentially contribute to the resistance to the direct inhibitory effect of cetuximab. However, the influence of KRAS mutations on cetuximab induced ADCC is not fully understood. In this study, we investigated cetuximab-mediated ADCC against human CRC lines, HCT116 and DLD-1, which carry mutated KRAS, and their derivative cell lines, HKh2 and DKO-4 respectively, in which the mutated KRAS allele was deleted by targeted disruption (KRAS wild-type). Peripheral blood mononuclear cells (PBMCs) from healthy volunteers and NK92, a natural killer cell line, exogenously expressing Fcα3A (CD16a) were used as effector cells. We first determined the growth-inhibitory effect of cetuximab alone using a WST-8 assay. Growth inhibition was observed only in KRAS wild-type cell lines, but its effect was only slight. In a standard short-term (4hr) ADCC assay that mainly evaluated lytic activity via perforin/granzyme, ADCC activities were exhibited to a similar extent against CRC cell lines regardless of the KRAS mutation status. We also examined a long-term (24hr) ADCC assay under the perforin-inhibited condition to evaluate the death receptor ligand-induced apoptosis, which is another major mechanism of ADCC. In this assay, cetuximab-mediated ADCC was induced in wild-type but not mutant KRAS cell lines. Similar to a previous report, Hkh2 and DKO-4 displayed a higher sensitivity to recombinant human Fas ligand (FasL) and TRAIL than did HCT116 and DLD-1, respectively. Furthermore, blocking experiments with neutralizing antibodies revealed that induction of apoptosis via Fas-FasL interaction is involved in perforin-independent cetuximab-mediated ADCC against KRAS wild-type cells. In conclusion, these results suggest that mutated KRAS may contribute to the resistance to the antitumor effects of cetuximab not only through direct receptor inhibition but also through ADCC mediated by Fas-FasL interaction.
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 2527. doi:1538-7445.AM2012-2527
Abstract 2529: A monoclonal anti-Globo H antibody, VK9 can mediate CDC/ADCC and inhibit adhesion of Globo H+ cancer cells to extracellular matrix
Authors: Hung Jung-Tung , Cheng Jing-Yan , Wu Chia-Cheng , Yu Alice L. 
Published: August 2012

Abstract
Globo H is a hexasaccharides expressed on many carcinomas including breast, pancreas, prostate, and stomach, with limited expression on normal tissue. Monoclonal antibodies against glycan, such as CH14.18 GD2-specific antibody, have been proven to be a promising strategy for cancer therapy. Here we evaluated the biological activity and potential application of VK9, a murine IgG3 anti-Globo H antibody. FACS analysis showed that VK9 bound to MCF7 cells in a dose dependent manner at 0.01 - 30 μg/mL. It does not bind to GH (-) cell lines, including AU565 and MDA-MB-231. The specificity of VK9 as determined by glycan array of 87 printed carbohydrates revealed binding of VK9 to three glycans (Globo H, BB4, and BB3) only, without reactivity to Gb5 or sialyl-Gb5. Investigation of the biological activity of VK9 showed no obvious effects on the proliferation of MCF7 cells. However, VK9 inhibited adhesion of MCF7 cell on fibronectin (83.5 ± 1.3%, p = 0.001) or laminin (70.5 ± 2.8%, p = 0.001), but not BSA (85.6 ± 0.2%, p = 0.08) or collagen IV (105.1 ± 2%, p = 0.37), when compared to IgG3 isotype control. Moreover, VK9 was able to mediate CDC against MCF7 cells. It could also induce ADCC of human IL-2 activated peripheral blood mononuclear cells at an E/T of 6.25-100. Furthermore, we cloned the Fab region of VK9 to generate a mouse-human chimeric anti-Globo H antibody, cVK9. The binding affinity of cVK9 was similar to VK9 at concentration range of 6.25 - 50 ug/mL by ELISA analysis. In conclusion, VK9 could not only mediate ADCC and CDC but also inhibit adhesion of MCF7 cell on fibronectin and laminin. Thus, VK9 have the potential as therapeutic antibody for Globo H expressing carcinoma.
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 2529. doi:1538-7445.AM2012-2529
Abstract 2530: Long-term tumor regression induced by a novel antibody drug conjugate that targets 5T4, an oncofetal antigen expressed on tumor-initiating cells
Authors: Sapra Puja , DiJoseph John , Damelin Marc , Dougher Maureen , Narayanan Bitha , Khandke Kiran , Lucas Judy , Golas Jon , Tchistiakova Lioudmila , Leal Mauricio , Hu George , Maderna Andreas , Marquette Kimberly , Loganzo Frank , Dushin Russell , O'Donnell Christopher J. , Abraham Robert , Gerber Hans-Peter 
Published: August 2012

Abstract
Antibody-drug conjugates (ADCs) represent a promising therapeutic modality for the clinical management of cancer. We have developed a novel ADC that targets 5T4 (also known as TPBG), a tumor-associated antigen that rapidly internalizes. In preclinical models of NSCLC, 5T4 was identified as a marker of undifferentiated tumorigenic cells that express properties of tumor-initiating cells (TICs) and was associated with a highly proliferating (Ki67 positive) cell phenotype. Based on the biological properties of 5T4, we designed the ADC by conjugating an internalizing humanized anti-5T4 antibody (Ab), A1, to the tubulin inhibitor monomethylauristatin F via a maleimidocaproyl (mc) linker (A1mcMMAF) with a drug/antibody ratio of ∼ 4. The A1 Ab has a Kd of 0.9 nM against the 5T4 antigen, binds to a broad range of 5T4 expressing cell lines, and rapidly internalizes (66% internalized within 4h). As an ADC, A1mcMMAF retains similar properties to the unconjugated Ab. In vitro, A1mcMMAF exhibited potent and target-specific cytotoxic activity against a panel of 5T4+ cell lines with an IC50 of 5 ng Ab/ml against high 5T4 expressing cells. In vivo, A1mcMMAF exhibited potent anti-tumor activity in all five tumor models tested (with a broad range of 5T4 expression) and caused long-term regressions monitored up to 100 days after the last dose. Strikingly, animals were cured of disease in every model with doses as low as 3 mg Ab/kg Q4d x 4. In a lung cancer patient-derived xenograft in which 5T4 is not uniformly expressed, but instead is preferentially expressed on the less differentiated sub-population of tumor cells, A1mcMMAF treatment resulted in sustained tumor regression. This result highlights the clinical potential of ADCs that target aggressive cell subpopulations such as TICs. In exploratory safety studies, A1mcMMAF exhibited no overt toxicities when administered at 10 mg Ab/kg/cycle x 2 to cynomolgus monkeys and had a half-life of ∼5 days. The encouraging efficacy and safety data of the conjugate resulting in high therapeutic index in preclinical models warrants further clinical testing of this ADC.
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 2530. doi:1538-7445.AM2012-2530
Abstract 2532: Integrated therapeutic antibody development at the National Research Council of Canada
Authors: Jaramillo Maria Luz , O'Connor-McCourt Maureen 
Published: August 2012

Abstract
Advances in genomics and antibody engineering have enabled the development of an innovative class of targeted therapies to provide new treatment options for diseases with significant unmet medical needs such as cancer. Therapeutic antibodies represent one of the fastest growing classes of medications with sales anticipated to exceed $30 billion globally by 2012. The NRC has built a chain of cutting edge technology platforms needed to discover, engineer and produce therapeutic monoclonal antibodies with the goal of partnering with industrial and academic centers to advance research and development of this important class of therapeutics. Target Identification- To establish and validate the technology platform, tumor targets for candidate therapeutic antibody production were identified using a combination of proteomics, transcriptomics and bioinformatic approaches. Out of these lists, approximately 40 tumor targets were selected (known therapeutic antibody targets were excluded), and over 2,000 antibodies of mouse and camelid origin were then generated against these targets. Antibody generation- Once identified, the recombinant target protein of interest can be produced using the NRC's high efficiency cell expression platforms in CHO or HEK293 cells and purified protein used for immunization or panning. For targets which are difficult to express or purify, the capabilities for direct immunization with plasmid DNA constructs provides another option. Clone selection is carried out by ELISA and typically 50 antibodies/target are identified for further characterization. Antibody characterization and validation- The affinities of the antibodies are determined by SPR biosensor analysis. Reverse phase protein arrays and Western blot analysis on protein mixes and cell lines allow the characterization of the specificity of the antibodies. Epitope mapping can be carried out so that representative antibodies from each epitope bin can be selected for further validation in appropriate cell-based assays (many of which are established at NRC) and animal models. Therapeutic antibody Optimization, Bioprocessing and Biomanufacturing- Therapeutic antibodies selected for development can be further optimized using antibody engineering technologies to humanize them and/or modify their glycosylation patterns to improve their effector function, pharmacokinetics, solubility and stability as well as reduce their immunogenicity. The NRC platform for large scale protein production has the capacity to manufacture up to 13.5 g of commercial grade antibody using serum free, low endotoxin media in a cGMP certified CHO cell line which is ready for transfer to CMOs or other industrial partners.
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 2532. doi:1538-7445.AM2012-2532