bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract LB-7: Design and development of a novel series of orally active, selective PI3Kp110β/δ inhibitors for the treatment of cancer
Authors: Shuttleworth Stephen J. 
Published: May 2015

Abstract
The phosphatidylinositide 3-kinases (PI3Ks) have emerged as attractive therapeutic targets for the treatment of cancer. The majority of PI3K inhibitors currently in clinical development primarily target either all four class I enzymes (p110α, β, δ and γ) with limited selectivity, or are pan-class I/mTOR dual inhibitors. Over recent years, a switch of focus to more selective PI3K inhibitors for the treatment of specific tumor types has occurred. Of particular note, p110b has been reported to be the principal isoform in driving PTEN-deficient tumorigenesis; additionally, high levels of p110δ expression in solid tumor cells have been shown to suppress PTEN activity, generating cellular sensitivity to p110δ inhibition through PTEN activation. Moreover, PI3K pathway activation in certain PTEN-null solid tumors has been shown to be mediated by both the p110β and p110δ catalytic subunits, suggesting the potential of a dual-selective p110β/δ inhibitor in this setting. During the past 12 months, the discovery of activating mutant forms of both p110β and p110δ has been reported. The strategy outlined in this presentation centres on the design and development of a new class of orally-active small molecules that selectively inhibit p110β and p110δ, and which display high degrees of specificity over protein kinases and other lipid kinases. Moreover, a spectrum of p110β/δ selectivity has been achieved in this series, which has facilitated interrogation of preferred isoform inhibition profiles required to confer tumor growth inhibition; additionally, by tuning selectivity over the other class I isoforms, elimination of the mechanism-related toxicities associated with the pan-class I inhibitors currently in the clinic can be realized, making such agents potentially more conducive to combination therapy. In vitro and in vivo therapy data for advanced lead compounds will be disclosed.
Citation Format: Stephen J. Shuttleworth. Design and development of a novel series of orally active, selective PI3Kp110β/δ inhibitors for the treatment of cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-7. doi:10.1158/1538-7445.AM2014-LB-7
Abstract LB-74: The NLR-related protein NWD1 is associated with prostate cancer and modulates androgen receptor signaling
Authors: Correa Ricardo G. , Krajewska Maryla , Ware Carl F. , Gerlic Motti , Reed John C. 
Published: May 2015

Abstract
Prostate cancer (PCa) is among the leading causes of cancer-related death in men. Androgen receptor (AR) signaling plays a seminal role in prostate development and homeostasis, and dysregulation of this pathway is intimately linked to prostate cancer pathogenesis and progression. Here, we identify the cytosolic NLR-related protein NWD1 as a novel modulator of AR signaling. We determined that expression of NWD1 becomes elevated during prostate cancer progression, based on analysis of primary tumor specimens. Experiments with cultured cells showed that NWD1 expression is up-regulated by the sex-determining region Y (SRY) proteins. Gene silencing by short hairpin RNA (shRNA), in conjunction with transcriptional profiling, showed that NWD1 is required for expression of PDEF (prostate-derived Ets factor), which is known to bind and co-regulate AR. Of note, NWD1 modulates AR protein levels. Silencing NWD1 in PCa cell lines reduces the levels of androgen-stimulated accumulation of nuclear AR and suppresses activity of androgen-driven reporter genes. NWD1 knockdown potently suppressed growth of androgen-dependent LNCaP prostate cancer cells, thus showing its functional importance in an AR-dependent tumor cell model. Proteomics analysis suggested that NWD1 associates with various molecular chaperones commonly related to AR complexes. Altogether, our data suggest a role for tumor-associated over-expression of NWD1 in the dysregulation of AR signaling in PCa.
Citation Format: Ricardo G. Correa, Maryla Krajewska, Carl F. Ware, Motti Gerlic, John C. Reed. The NLR-related protein NWD1 is associated with prostate cancer and modulates androgen receptor signaling. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-74. doi:10.1158/1538-7445.AM2014-LB-74
Abstract LB-75: Oct7 is expressed in human gliomas and correlates with malignancy grade
Authors: Rahman Mohummad Aminur , Leiss Lina , Saed Halala S. , Gjerde Christiane H. , Lellahi Mohammad S. , Mutlu Ercan , Enger Per Øyvind 
Published: May 2015

Abstract
INTRODUCTION: The transcription factor Oct 7 (also called POU3f2/Brn2) is expressed during neurogenesis, and constitutes the CNS equivalent of Oct 4, a critical regulator of induced pluripotent stem cells. Moreover, data suggest its expression is regulated by hypoxia, and Oct 7 expression has been reported in malignant melanoma of the skin. Since both melanomas and CNS-malignancies arise in organs of neuroectodermal origin, we investigated whether human gliomas expressed Oct7.
MATERIAL & METHODS: We performed immunohistochemistry of 150 grade II-IV gliomas from our tumor bank, and subsequently performed western blots of 20 glioma samples. In addition, we performed flow cytometry analysis of Oct 7 expression in 5 acutely dissociated tumors. Using lentiviral transfection we established Oct7 overexpression in a panel of constitutively negative glioma cell lines, as well as knock-down in an Oct7 positive glioma cell line, to investigate the effect of Oct 7 expression on proliferation, migration and differentiation.
RESULTS: Immunohistochemistry showed that Oct7 was almost uniformly expressed in human gliomas, although at a varying degree. Microscopy revealed a predominantly nuclear staining pattern, but cytoplasmic immunopositivity for Oct7 could also be detected in some tumors. Both western blot and flow cytometry confirmed expression of Oct7 in human gliomas. With two independent observers we obtained a nuclear staining index for all tumors, with 61% positive nuclei in GBM specimens, which was significantly higher than for grade II (37%) and grade III (36%) tumors (p= 0.0001). Moreover, ongoing studies suggest that overexpression of Oct7 increases the proportion of cells in G2/M phase of the cell cycle, suggesting that this transcription factor has a role in regulating tumor cell proliferation, and hence possibly overall tumor aggressiveness. Ongoing studies aim at further elucidating the multiple roles of Oct7 in brain tumor progression.
Citation Format: Mohummad Aminur Rahman, Lina Leiss, Halala S. Saed, Christiane H. Gjerde, Mohammad S. Lellahi, Ercan Mutlu, Per Øyvind Enger. Oct7 is expressed in human gliomas and correlates with malignancy grade. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-75. doi:10.1158/1538-7445.AM2014-LB-75
Abstract LB-76: Absolute single-molecule sensitive NGS by SPLITSEQ: a new ctDNA analysis tool
Authors: Lebofsky Ronald , Madic Jordan , Saliou Adrien , Bidard Francois-Clement , Lantz Olivier , Stern Marc-Henri , Pierga Jean-Yves 
Published: May 2015

Abstract
Circulating tumor DNA (ctDNA) analysis requires absolute single molecule sensitivity, since only a few copies of the mutation may be present per blood draw. Recent developments in next-generation sequencing (NGS) sample preparation have improved the relative sensitivity to detect &lt;0.01% variants in background. However, when the total number of input mutant molecules falls below 10, these improvements have not translated into the absolute sensitivity required to sequence these rare templates. Here we develop and present SPLITSEQ, a novel microfluidics and NGS-based method that combines 0.01% fractional sensitivity with absolute single copy input sensitivity in an excess of background DNA. We provide multiplexed performance data on mutations in KRAS codons 12 and 13 and BRAF V600E, targets that are currently being developed as circulating predictive and prognostic biomarkers in colorectal and other cancers. Using reconstituted DNA solutions from mutant and normal cell lines ranging from 0.01% to 10% mutated allele fractions, we detected the sequence of approximately 0.2, 2, and 20 nominal mutated KRAS and BRAF inputs total in 10 000X background. Single copy numbers were supported by droplet digital PCR (ddPCR) data, an orthogonal single-molecule sensitive technique. Lastly, we confirm the specificity of the technique by screening wild-type DNA only and finding a false positive rate significantly lower than ddPCR. Moreover, in comparison with digital PCR, SPLITSEQ is easily amenable to high levels of multiplexing and detects non-recurrent mutations in tumor suppressors along the length of the sequence. Since the only requirement is a single PCR-amplifiable template, SPLITSEQ fills an unmet need in ctDNA detection, providing biomarkers from hereto unanalyzable liquid biopsies containing rare mutants.
Citation Format: Ronald Lebofsky, Jordan Madic, Adrien Saliou, Francois-Clement Bidard, Olivier Lantz, Marc-Henri Stern, Jean-Yves Pierga. Absolute single-molecule sensitive NGS by SPLITSEQ: a new ctDNA analysis tool. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-76. doi:10.1158/1538-7445.AM2014-LB-76
Abstract LB-77: The Met receptor tyrosine kinase drives signaling through EGFR and ErbB3 in Met-amplified non-small-cell lung cancer
Authors: Stern Yaakov E. , Lai Andrea Z. , Park Morag 
Published: May 2015

Abstract
Receptor tyrosine kinases are canonically activated by dimerization induced by the binding of a cognate ligand. This leads to autophosphorylation of the receptor molecules by their intrinsic kinase domains and the recruitment of intracellular protein complexes to initiate signaling. In many human cancers, receptor tyrosine kinases are aberrantly activated to promote proliferative signaling, thus driving tumor growth. The MET proto-oncogene is amplified in approximately 5% of non-small-cell lung cancers (NSCLC), a disease in which aberrant signaling through the epidermal growth factor receptor (EGFR) or the anaplastic lymphoma kinase is known to be oncogenic. The Met receptor tyrosine kinase is overexpressed and constitutively active in cell lines derived from MET-amplified tumors, and Met activity is required for proliferation. Furthermore, Met activity is sufficient to promote the phosphorylation of EGFR and its homologs ErbB2 and ErbB3 in the presence of inhibitors targeting EGFR, ErbB2, and Src family kinases. We show that Met utilizes the EGFR, ErbB2 and ErbB3 proteins as scaffolds to broaden downstream oncogenic signaling and promote cancer cell proliferation. The contribution of EGFR and its homologs to Met signaling in NSCLC will be presented with a focus on ErbB family kinases required for proliferation in MET-amplified NSCLC. Understanding the mechanisms by which Met drives proliferative signaling in NSCLC will become crucial as Met-targeted therapies become available in the clinic.
Citation Format: Yaakov E. Stern, Andrea Z. Lai, Morag Park. The Met receptor tyrosine kinase drives signaling through EGFR and ErbB3 in Met-amplified non-small-cell lung cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-77. doi:10.1158/1538-7445.AM2014-LB-77
Abstract LB-78: Effects of rapamycin and fasting-cycles therapy on differential stress resistance and sensitization in breast cancer mouse models
Authors: Biase Stefano D. , Brandorst Sebastian , Wei Min , Longo Valter 
Published: May 2015

Abstract
Short-term starvation (STS) has been shown to be effective in both protection of normal cell and tissues and the sensitization of a variety of tumors during chemotherapy treatment. This condition of protection/sensitization of different cell types under the same condition has been named differential stress resistance (DSR). Although the effects of fasting have been mainly attributed to reduced glucose and circulating IGF1 levels, the involvement of signaling genes regulated by glucose and growth factors in these effects of fasting remain poorly understood.
In this study we have administered the mTor inhibitor rapamycin in combination with STS and with the chemotherapy drug doxorubicin to shed light on the role of mTOR in the STS response and on its role in mediating DSR.
In a mouse allograft model for breast cancer (4T1) we show that STS and rapamycin have an additive effect in reducing tumor progression, which confirms the possibility that STS-mediated effects on cancer cells are not due to the up-regulation of mTOR. Surprisingly, we observed that the administration of rapamycin during chemotherapy sensitizes the mice to the drug leading to an increased mortality. However, this sensitizing effect could be reversed by STS.
In summary, the combination of mTor inhibition by rapamycin and STS have additive effects in retarding breast cancer tumor growth and also prevent the chemotherapy-dependent sensitization of normal cells caused by rapamycin alone. Because rapamycin is used for the treatment of certain tumors in humans, these results may have important implications for the safety of therapies using a combination of rapamycin and chemotherapy and indicate that the combination of Tor inhibitors and STS should be tested clinically.
Citation Format: Stefano Di Biase, Sebastian Brandorst, Min Wei, Valter Longo. Effects of rapamycin and fasting-cycles therapy on differential stress resistance and sensitization in breast cancer mouse models. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-78. doi:10.1158/1538-7445.AM2014-LB-78
Abstract LB-80: Exome sequencing of murine p53-knockout T-cell lymphomas reveals Pten loss and Cdk6 amplification as key steps toward cellular transformation
Authors: Dudgeon Crissy , Chan Chang , Sun Yvonne , Levine Arnold J. 
Published: May 2015

Abstract
Loss of the tumor suppressor, p53, occurs in over 50% of cancers. The ability for p53 to protect the cell from tumorigenesis is based on its ability to induce cell cycle arrest, apoptosis, and senescence following genotoxic stress. Furthermore, genetic deletion of p53 in mice gives rise to spontaneous thymic (T-cell) lymphomas and sarcomas. In this study, we used the p53-knockout (KO) mouse as a model for progression of tumorigenesis. We first analyzed genomic DNA of p53-KO and WT normal thymus at various ages and p53-KO thymic lymphomas using TCRβ sequencing, allowing us to determine the clonality of the T cell repertoire. These data suggest that p53-KO thymic lymphomas were mostly oligoclonal, with some tumors comprising of a dominant clone. We further analyzed tumors with dominant clones for genomic instability by exome sequencing. Sequencing analysis revealed that there were many non-synonymous mutations occurring in each tumor, but with no similarities between tumors. On the other hand, all of the murine tumors had deletion of Pten and amplification of Cdk6. This is in stark contrast to what is seen in most human T cell lymphoblastic leukemias, which have activating mutations in Notch1 and loss of Arf. Interestingly, loss of Pten not only occurred in all tumors, but also in most, if not all, clones in the tumor. This suggests that Pten loss is an early event driving T cell transformation in a p53-KO background. Using this data, we found the somatic mutation rate in the tumors to be 1000-fold greater than the germline mutation rate. Loss of p53 also caused chromosomal abnormalities as seen with increased copy number variations. Taken together, our work suggests that, with initial loss of p53, the path to T cell tumorigenesis is vastly different from that of human tumors. Without p53, the somatic genome increases in mutation rate and copy number variations, thus solidifying p53's role as guardian of the genome.
Citation Format: Crissy Dudgeon, Chang Chan, Yvonne Sun, Arnold J. Levine. Exome sequencing of murine p53-knockout T-cell lymphomas reveals Pten loss and Cdk6 amplification as key steps toward cellular transformation. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-80. doi:10.1158/1538-7445.AM2014-LB-80
Abstract LB-81: Conditional deletion of the tumor suppressor Hic1 results in aneuploidy and single-step transformation
Authors: Szczepny Anette , McKenzie Lisa , Jayesekara Samantha , Russell Prue , Wright Gavin , Baylin Stephen B. , Rossello Fernando J. , Cain Jason E. , Watkins David N. 
Published: May 2015

Abstract
HIC1 is a zinc-finger transcriptional repressor frequently targeted for deletion and/or epigenetic gene silencing in cancer. In cancer cell lines, re-expression of HIC1 results in the downregulation of target genes thought to promote context-dependent tumor growth, including Sirt1, Atoh1, Efna1 and components of the WNT and STAT3 signalling pathway.
In mouse embryonic fibroblasts, we now show that deletion of a conditional loxP allele of Hic1 results in immediate growth arrest without significant overexpression of Hic1 target genes, followed by a prolonged period of cellular quiescence. After several weeks, we then observed the spontaneous emergence of rapidly growing clones that fulfil all the criteria for transformation, associated with aneuploidy and recurrent copy number alterations. By contrast, conditional deletion of p53 using the same experimental protocol resulted in prompt immortalisation without transformation, and a stable tetraploid karyotype resembling that seen in NIH-3T3 cells. These data suggest that inactivation of Hic1 in cells undergoing replication stress in tissue culture can induce complete transformation associated with marked genomic instability.
To test this hypothesis in vivo, we employed the inhaled adenoviral Cre recombinase model in order to direct loxP recombination to the airway epithelium of adult mice. As previously described by other groups, Cre activation of a conditional oncogenic KRasG12D mutant resulted in the appearance of multiple lung adenomas within 6-8 weeks following viral inhalation. By contrast, mice carrying this KRasG12D allele, as well as homozygous for the conditional Hic1lox knockout allele, developed highly aggressive adenocarcinomas with prominent pleomorphic and micropapillary histology. These data suggest a novel tumour suppressor role for HIC1 in maintaining genomic stability in replicating cells. HIC1 is known to interact with components of the SWI/SNF and PRC2 complexes, which help maintain genomic integrity by re-establishing constitutive heterochromatin following DNA replication. We therefore speculate that loss of HIC1 function may phenocopy recently described mutations in components of these chromatin-remodelling complexes such as ARID1A and BRG1.
Citation Format: Anette Szczepny, Lisa McKenzie, Samantha Jayesekara, Prue Russell, Gavin Wright, Stephen B. Baylin, Fernando J. Rossello, Jason E. Cain, David N. Watkins. Conditional deletion of the tumor suppressor Hic1 results in aneuploidy and single-step transformation. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-81. doi:10.1158/1538-7445.AM2014-LB-81
Abstract LB-96: A novel blood preservation system to study oncogenic signaling pathway biomarkers by flow cytometry in leukemia/lymphoma clinical trials
Authors: Pahuja Anil , Saci Abdel , Sarikonda Shyam , Graber Armin , Lee Benjamin , Lameh Jelveh , Tangri Shabnam , Dakappagari Naveen 
Published: May 2015

Abstract
Propelled by the advent of new technologies and an evolving regulatory landscape, the desire to personalize cancer treatments has never been greater. There is a critical need to reliably evaluate target inhibition and pharmacodynamic activity of investigational drugs in biologically relevant compartments. However, the ability to fulfill such a task in global clinical trials is complicated by varying technical expertise available at clinical sites and considerations about specimen stability for centralized laboratory analysis. We developed a novel formalin-based preservation method that enables specimen stabilization in a single step, requiring less than 20 minutes, without the need for specialized training or instrumentation. Stabilized specimens can be frozen for shipping and batched analysis at a later time point, in a specialized laboratory. Using this preservation method, we developed a flow assay enabling identification of multiple cell-types, and quantification of intracellular biomarkers in target cellular compartments, in both the peripheral blood (PB) and bone marrow (BM). We present pharmacodynamic (PD) data for a novel anticancer investigational agent intended for acute myeloid leukemia and multiple myeloma and its effect on multiple target biomarkers of the PI3K signaling pathway, including phosphorylation of the S6 ribosomal protein (S6). Our novel fixation method allowed detection of pS6 modulation in a dose dependent manner in both tumor cells and PB or BM in response to the novel investigational agent. Assay sensitivity and concordance were evaluated by comparing flow assay with western blot analysis, with each assay performed at a different site using the same batched frozen samples; exceptional preservation of phosphorylated proteins for more than 72 hours could be observed, when frozen immediately following fixation. In conclusion, our novel preservation method enables reliable quantification of signaling biomarkers in centralized laboratories at different time points post sample (PB or BM) acquisition requiring minimal processing at collection sites.
Citation Format: Anil Pahuja, Abdel Saci, Shyam Sarikonda, Armin Graber, Benjamin Lee, Jelveh Lameh, Shabnam Tangri, Naveen Dakappagari. A novel blood preservation system to study oncogenic signaling pathway biomarkers by flow cytometry in leukemia/lymphoma clinical trials. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-96. doi:10.1158/1538-7445.AM2014-LB-96