bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 4547: High-throughput screen to identify compounds targeted to embryonal rhabdomyosarcoma harboring mutant HRAS using cells derived from a pediatric Costello syndrome patient.
Authors: Cartledge Donna M. , Drake Katherine M. , Gripp Karen W. , Sol-Church Katia , Kolb E. Anders , Napper Andrew D. 
Published: August 2014

Abstract
Costello syndrome (CS) is a disorder caused by HRAS gene mutations. Substitutions in glycine residues at positions 12 or 13 of the HRAS gene lead to aberrant activation of the guanine-nucleotide binding protein, HRAS. Homozygous expression of mutant HRAS predisposes pediatric patients to early onset of cancer, especially embryonal rhabdomyosarcoma (ERMS), while heterozygosity at this locus results in non-malignant abnormalities. Since the mid 1970’s there has been only a modest increase in the 5-year survival rate for ERMS in the United States to no more than 70%, so new treatment strategies are needed. To address this need, we have acquired, propagated, and banked patient-derived ERMS cells harboring a homozygous p.G12A substitution and have used these cells to develop a high-throughput screening (HTS) assay to discover compounds that selectively kill cells bearing homozygous HRAS mutation. The assay employs luminescent detection of ATP using CellTiter-Glo to quantify cell viability. Cell number, growth conditions, and compound delivery were optimized to obtain a robust 72-hr cell growth assay. The potent cytotoxic agent dactinomycin was used to ensure reproducible sensitivity of the assay. The assay was validated for HTS by pilot screening of a library of 2,000 known drugs and bioactive natural products, and hits were confirmed by retesting in dose-response. Confirmed active compounds were tested for selectivity for ERMS harboring homozygous mutant HRAS in a panel of patient-derived and purchased cell lines: RD, an ERMS line not driven by HRAS mutation; RH36, a mutant HRAS (p.Q61K) ERMS line that is not derived from CS; fibroblasts derived from CS patients with heterozygous HRAS mutations (CS242, p.G12A and CS066, p.G12S), and normal fibroblasts. In future work, compounds identified by HTS as displaying selectivity for homozygous mutant HRAS-expressing ERMS cells will be evaluated in pairwise combinations and also in combination with currently used chemotherapeutics. Targeting mutant HRAS-activated cell growth could direct the design of a novel therapeutic strategy for treatment of children with ERMS.
Citation Format: Donna M. Cartledge, Katherine M. Drake, Karen W. Gripp, Katia Sol-Church, E. Anders Kolb, Andrew D. Napper. High-throughput screen to identify compounds targeted to embryonal rhabdomyosarcoma harboring mutant HRAS using cells derived from a pediatric Costello syndrome patient. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4547. doi:10.1158/1538-7445.AM2013-4547
Abstract 4556: NOSH-aspirin is a potent inhibitor of colon cancer cell growth: effects of positional isomerism.
Authors: Eschbach Erin K. , MacKessack-Leitch Andrew C. , Vannini Federica , Kodela Ravinder , Chattopadhyay Mitali , Kashfi Khosrow 
Published: August 2014

Abstract
Background: We recently reported the synthesis of NOSH-aspirin, a novel hybrid capable of releasing both nitric oxide (NO) and hydrogen sulfide (H2S). In NOSH-aspirin, the two moieties that release NO and H2S are covalently linked at the 1, 2 positions of acetyl salicylic acid, ie ortho-NOSH-aspirin. Here we compared the cell growth inhibitory properties of ortho-NOSH-aspirin to that of the 1,3 (meta-NOSH-aspirin) and the 1,4 (para-NOSH-aspirin) positional isomers. We also incorporated electron donating/withdrawing groups about the bezyl ring in order to evaluate the effect of substitution on stability and biological activity of these novel compounds. Methods: Cell line: HT-29 and HCT 15 human colon adenocarcimoa; Cell growth: MTT; Cell cycle phase distribution: Flow cytometry; Apoptosis: subdiploid (sub-G0/G1) peak in DNA content histograms; Proliferation: PCNA; ROS: measured hydrogen peroxide and super oxide by flow cytometry using DCFDA and DHE dyes. Results: All positional isomers of NOSH-aspirin were potent growth inhibitors of both cell lines. The IC50s for growth inhibition in nM at 24h were, HT-29: ortho-NOSH-ASA (0.04 ± 0.011), meta-NOSH-ASA (0.24 ± 0.11), para-NOSH-ASA (0.46 ± 0.17); significance between the groups were: o vs m P&gt;0.05, o vs p P&lt;0.01, m vs p P&gt;0.05; HCT 15: ortho-NOSH-ASA (0.062 ± 0.006), meta-NOSH-ASA (0.092 ± 0.004), para-NOSH-ASA (0.37 ± 0.04); significance between the groups were: o vs m P&gt;0.05, o vs p P&lt;0.001, m vs p P&lt;0.001. Electron donating/withdrawing groups significantly affected these IC50s. All positional isomers qualitatively had similar effects on proliferation, apoptosis, and caused G0/G1 cell cycle arrest in both colon cancer cell lines. The underlying mechanism for these observations appeared to be mediated through generation of intracellular H2O2 and superoxide anions as pretreatment of cells with N-acetylcysteine, partially blocked these effects. Conclusions: Positional isomerism affects the potency of NOSH-aspirin and offers a platform for drug design. Further, NOSH-aspirin merits further evaluation as an anti-cancer agent.
Citation Format: Erin K. Eschbach, Andrew C. MacKessack-Leitch, Federica Vannini, Ravinder Kodela, Mitali Chattopadhyay, Khosrow Kashfi. NOSH-aspirin is a potent inhibitor of colon cancer cell growth: effects of positional isomerism. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4556. doi:10.1158/1538-7445.AM2013-4556
Abstract 4568: Rapid assessment of TORC1 suppression predicts responsiveness to RAF and MEK inhibition in BRAF mutant melanoma.
Authors: Corcoran Ryan B. , Rothenberg Stephen M. , Hata Aaron N. , Faber Anthony C. , Winokur Daniel , Piris Adriano , Nazarian Rosalynn M. , Brown Ronald D. , Godfrey Jason T. , Mino-Kenudson Mari , Settleman Jeffrey , Wargo Jennifer A. , Flaherty Keith T. , Haber Daniel A. , Engelman Jeffrey A. 
Published: August 2014

Abstract
The clinical development and potent efficacy of selective RAF and MEK inhibitors has transformed the treatment of the ∼50% of melanoma patients whose tumors harbor BRAF mutations. However, a substantial percentage of these patients fail to respond to therapy, and all who respond eventually develop resistance. We found that suppression of TORC1 activity, as measured by decreases in ribosomal protein S6 phosphorylation (P-S6) in response to RAF or MEK inhibitors, was a highly effective predictor of sensitivity in BRAF mutant melanoma cell lines in vitro and in mouse xenografts. TORC1 and P-S6 were suppressed in response to RAF or MEK inhibitors in sensitive but not resistant melanoma cells, despite robust suppression of the MAPK pathway by these inhibitors. Notably, suppression of P-S6 levels, as assessed by immunohistochemistry in paired biopsies obtained from BRAF mutant melanoma patients before and during treatment, was associated with significantly improved progression-free survival. Finally, we show that changes in P-S6 levels specifically in tumor cells can be readily monitored by multiplexed, quantitative immunofluorescence microscopy of fine needle aspiration biopsies obtained from patients before and during the first two weeks of BRAF inhibitor therapy. This provides a minimally invasive means for monitoring the efficacy of treatment in real time, before changes in tumor volume are apparent on traditional radiographs. Together, these results establish changes in P-S6 levels with therapy as a robust biomarker to guide the treatment of patients with BRAF mutant melanoma, and present a powerful methodology for monitoring changes in potentially any signaling pathway in response to therapy in patients.
Citation Format: Ryan B. Corcoran, Stephen M. Rothenberg, Aaron N. Hata, Anthony C. Faber, Daniel Winokur, Adriano Piris, Rosalynn M. Nazarian, Ronald D. Brown, Jason T. Godfrey, Mari Mino-Kenudson, Jeffrey Settleman, Jennifer A. Wargo, Keith T. Flaherty, Daniel A. Haber, Jeffrey A. Engelman. Rapid assessment of TORC1 suppression predicts responsiveness to RAF and MEK inhibition in BRAF mutant melanoma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4568. doi:10.1158/1538-7445.AM2013-4568
Abstract 4595: Activating mutations in the NT5C2 nucleotidase gene drive chemotherapy resistance in relapsed ALL.
Authors: Tzoneva Gannie , Perez-Garcia Arianne , Carpenter Zachary , Khiabanian Hossein , Tosello Valeria , Allegretta Maddalena , Paietta Elisabeth , Racevkis Janis , Rowe Jakob M. , Tallman Martin S. , Paganin Maddalena , Hoff Jana , Kirschner-Schwabe Renate , Palomero Teresa , Rabadan Raul , Ferrando Adolfo 
Published: August 2014

Abstract
Acute lymphoblastic leukemia (ALL) is an aggressive hematological tumor resulting from the malignant transformation of lymphoid progenitors. Despite intensive chemotherapy, 20% of pediatric and over 50% of adult ALL patients fail to achieve a complete remission or relapse after intensified chemotherapy, making disease relapse and resistance to therapy the most significant challenge in the treatment of this disease. Using whole exome sequencing, here we identify mutations in NT5C2, a 5’-nucleotidase enzyme responsible for inactivation of nucleoside analog chemotherapy drugs, in 20/103 (19%) relapse T-ALLs and in 1/35 (3%) relapse B-precursor ALLs analyzed. NT5C2 mutant proteins show increased nucleotidase activity in vitro and conferred resistance to chemotherapy with 6-mercaptopurine and 6-thioguanine when expressed in ALL lymphoblasts. These results support a prominent role for activating mutations in NT5C2 and increased nucleoside analog metabolism in disease progression and chemotherapy resistance in ALL.
Citation Format: Gannie Tzoneva, Arianne Perez-Garcia, Zachary Carpenter, Hossein Khiabanian, Valeria Tosello, Maddalena Allegretta, Elisabeth Paietta, Janis Racevkis, Jakob M. Rowe, Martin S. Tallman, Maddalena Paganin, Jana Hoff, Renate Kirschner-Schwabe, Teresa Palomero, Raul Rabadan, Adolfo Ferrando. Activating mutations in the NT5C2 nucleotidase gene drive chemotherapy resistance in relapsed ALL. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4595. doi:10.1158/1538-7445.AM2013-4595
Abstract 4610: Small molecule inhibitors of membrane-bound MCL-1 and BCL-2.
Authors: Patel Luv G. , Paranal Ronald M. , Ryan Jeremy , Sarosiek Kristopher , Bradner James E. , Letai Anthony 
Published: August 2014

Abstract
Small molecule inhibitors of membrane-bound MCL-1 and BCL-2
Mcl-1 and Bcl-2 are anti-apoptotic members of the Bcl-2 family of proteins. These proteins sequester activators of Bax-Bak oligomerization and inhibit the subsequent mitochondrial depolarization. Knockdown of anti-apoptotic Bcl-2 family proteins has induced apoptosis in a variety of cancers, signifying that these malignancies are dependent on these proteins for survival. Thus, their inhibition by small molecules is an emerging strategy in cancer therapy. While Bcl-2 specific and pan-inhibitors have emerged, there remains a dearth of molecules that effectively inhibit Mcl-1. In fact, increased Mcl-1 expression is a common mechanism of resistance to these therapies.
Previous efforts to identify small molecules that inhibit MCL-1 or BCL-2 function have exploited assays using soluble, truncated, bacterially-expressed recombinant proteins. Since in vivo MCL-1 and BCL-2 exist at full length and are membrane bound, we thought we could improve the identification of biologically active small molecules by screening in a more physiologically relevant environment. It is likely that membrane association affects the structure and access of binding sites. We have therefore developed a screening assay to assess inhibition of full-length Mcl-1 and Bcl-2 in a membrane-bound state. The screen identified compounds that selectively permeabilize membranes whose integrity depends on either MCL-1 or BCL-2. The screen was optimized for high-throughput 384-well format. Positive controls for screening were peptides representing the BH3 domains of Bad and Noxa, known to be selective inhibitors of Bcl-2 and Mcl-1, respectively. We screened &gt;70,000 compound wells. These compounds include an assortment of known bioactives, natural product extract mixtures, and commercial library compounds. We have identified several lead compounds from the primary screen and have validated their performance in biochemical and biological assays.
Citation Format: Luv G. Patel, Ronald M. Paranal, Jeremy Ryan, Kristopher Sarosiek, James E. Bradner, Anthony Letai. Small molecule inhibitors of membrane-bound MCL-1 and BCL-2. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4610. doi:10.1158/1538-7445.AM2013-4610
Abstract 4616: Oncogenic c- and N-Myc disrupt circadian rhythm.
Authors: Altman Brian J. , Hsieh Annie , Gouw Arvin , Venkataraman Anand , Li Bo , Bellovin David , Simon M. Celeste , Felsher Dean , Hogenesch John , Dang Chi V. 
Published: August 2014

Abstract
Circadian rhythms are regulated by feedback loops comprising a network of factors that regulate Clock-associated genes. Chronotherapy seeks to take advantage of altered circadian rhythms in some cancers to better time administration of treatments to increase efficacy and reduce toxicity. Taking advantage of cancers that have substantially different circadian rhythms, or are ‘out of phase’, with normal tissues, could open a wide therapeutic window to make them vulnerable to chemotherapy or targeted drugs at different times than normal tissue. However, there is currently no basis to identify which cancers have disrupted circadian rhythms and would be amenable to chronotherapy. c- and N-Myc are oncogenic transcription factors translocated or amplified in many cancers. While the role of Myc in circadian rhythm is currently unknown, it may affect circadian rhythm by binding to the same E-box promoter regions used by the central regulators of circadian rhythm, Clock/Bmal1. Additionally, Myc increases NAD+ levels through upregulation of NAMPT, and NAD+ is a crucial cofactor in the activity of the circadian regulator Sirt1. Thus, we hypothesized that Myc may disrupt circadian rhythm through two mechanisms: inappropriate engagement of E-box promoters and also upregulation of NAMPT leading to dysregulated Sirt1 activity.
Here we show in neuroblastoma, osteosarcoma, and hepatocellular carcinoma cells that overexpressed Myc specifically upregulated the negative circadian regulator Rev-erbα, which in turn decreased expression of Bmal1. Inhibition of NAMPT downstream of Myc upregulation also led to major perturbations in circadian gene expression, suggesting a role for NAD modulation downstream of Myc in disruption of circadian rhythm. Importantly, My-expressing cells showed dramatically disrupted circadian oscillations, which could be partially rescued by inhibiting expression of Rev-erbα. Together, these data suggest that Myc-driven cancers have altered circadian oscillation due to upregulation of Rev-erbα and NAMPT, and that cancers driven by Myc may thus be good candidates for chronotherapy.
We thank the following funding sources: NIH R01CA051497, R01CA57341, LLS 636311
Citation Format: Brian J. Altman, Annie Hsieh, Arvin Gouw, Anand Venkataraman, Bo Li, David Bellovin, M. Celeste Simon, Dean Felsher, John Hogenesch, Chi V. Dang. Oncogenic c- and N-Myc disrupt circadian rhythm. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4616. doi:10.1158/1538-7445.AM2013-4616
Abstract 4621: The histone methyltransferase EZH2 catalytic activity is required for cell growth in diffuse large B-cell lymphoma.
Authors: Audia James E. , Trojer Patrick , Garapaty Shivani , Lan Fei , Balasubramanian Vidya , Chan Eric , Hatton Charles , Campbell Robert , Cummings Richard , Normant Emmanuel , Bryant Barbara , Albrecht Brian , Harmange Jean Christophe , Dakin Les , Gehling Victor , Nasveschuk Chris , Vaswani Rishi , Cook Andrew 
Published: August 2014

Abstract
Lysine methyltransferases and demethylases were identified as transcriptional co-regulators functioning by either preserving particular chromatin methylation states or by controlling placement and removal of histone lysine methylation marks to promote dynamic changes in gene expression. The development of small molecule methyltransferase and demethylase inhibitors provides a novel approach to affect the regulation of transcription, and thus potentially allowing interference with aberrant transcriptional programs as observed, for instance, in cancer.
Enhancer of Zeste Homolog 2 (EZH2), the major histone H3 lysine 27 (K27) methyltransferase, is widely implicated in tumor progression. The presence of a recurrent mutation of a single tyrosine residue in the EZH2 catalytic domain in germinal center B-cell like diffuse large B-cell lymphoma (GCB-DLBCL) and follicular lymphoma suggests that these cancers might be dependent on altered EZH2 molecular function, the mutation facilitating the conversion of an H3K27 di-methylated to a tri-methylated state. Inhibition of the EZH2 catalytic activity will provide a new therapeutic approach to treat human cancers, especially lymphomas carrying activating mutations.
Constellation has identified, characterized and optimized potent, selective and reversible EZH2 small molecule inhibitors as well as studied the biological impact of such inhibition. We find that pharmacological inhibition of EZH2 causes selective cell viability defects with cell lines harboring EZH2 mutations being the most sensitive. Our EZH2 inhibitors potently engage the target in vivo and exhibit efficacy in lymphoma xenograft models. Genome-wide mapping of EZH2 and H3K27me3 sites in the absence and presence of the compound revealed that the EZH2 inhibitor caused significant changes to the local chromatin modification landscape, however only a subset of these alterations translated into gene expression changes. The discovery of additional contexts that define sensitivity to EZH2 inhibitors will be discussed.
Citation Format: James E. Audia, Patrick Trojer, Shivani Garapaty, Fei Lan, Vidya Balasubramanian, Eric Chan, Charles Hatton, Robert Campbell, Richard Cummings, Emmanuel Normant, Barbara Bryant, Brian Albrecht, Jean Christophe Harmange, Les Dakin, Victor Gehling, Chris Nasveschuk, Rishi Vaswani, Andrew Cook. The histone methyltransferase EZH2 catalytic activity is required for cell growth in diffuse large B-cell lymphoma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4621. doi:10.1158/1538-7445.AM2013-4621
Abstract 4622: Targeting MYCN in Neuroblastoma by BET Bromodomain Inhibition.
Authors: Puissant Alexandre , Frumm Stacey M. , Alexe Gabriela , Bassil Christopher F. , Qi Jun , Chanthery Yvan H. , Nekritz Erin A. , Zeid Rhamy , Gustafson W. Clay , Greninger Patricia , Garnett Matthew J. , McDermott Ultan , Benes Cyril H. , Kung Andrew L. , Weiss William A. , Bradner James E. , Stegmaier Kimberly 
Published: August 2014

Abstract
Bromodomain inhibition comprises a promising therapeutic strategy in cancer, particularly for hematologic malignancies. To date, however, genomic biomarkers to direct clinical translation have been lacking. We conducted a cell-based screen of genetically-defined cancer cell lines using a prototypical inhibitor of BET (bromodomain and extra-terminal domain) bromodomains. Integration of genetic features with chemosensitivity data revealed a robust correlation between MYCN amplification and sensitivity to bromodomain inhibition. We characterized the mechanistic and translational significance of this finding in neuroblastoma, a childhood cancer with frequent amplification of MYCN. Genome-wide expression analysis demonstrated downregulation of the MYCN transcriptional program accompanied by suppression of MYCN transcription, and a BET Bromodomain inhibitor was found to displace BRD4 from the MYCN promoter region in neuroblastoma cell lines. Functionally, bromodomain-mediated inhibition of MYCN impaired growth and induced apoptosis in neuroblastoma. BRD4 knock-down phenocopied these effects, establishing BET bromodomains as transcriptional regulators of MYCN. BET inhibition conferred a significant survival advantage in three in vivo neuroblastoma models, providing a compelling rationale for developing BET bromodomain inhibitors in patients with neuroblastoma.
Citation Format: Alexandre Puissant, Stacey M. Frumm, Gabriela Alexe, Christopher F. Bassil, Jun Qi, Yvan H. Chanthery, Erin A. Nekritz, Rhamy Zeid, W. Clay Gustafson, Patricia Greninger, Matthew J. Garnett, Ultan McDermott, Cyril H. Benes, Andrew L. Kung, William A. Weiss, James E. Bradner, Kimberly Stegmaier. Targeting MYCN in Neuroblastoma by BET Bromodomain Inhibition. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4622. doi:10.1158/1538-7445.AM2013-4622