bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 1658: Proteolytic processing pathways for topoisomerase covalent complexes
Authors: Sun Yilun , Nitiss Karin C. , Nitiss John L. 
Published: August 2015

Abstract
DNA topoisomerase II (Top2) is the target of several important anti-cancer agents, including doxorubicin and etoposide. Clinically active Top2 agents, termed Top2 poisons, act by blocking the enzyme reaction at a step where the protein is covalently bound to DNA. This leads to the accumulation of Top2/DNA complexes that act as DNA damaging agents that can trigger cell death. Surviving Top2-induced damage likely requires the repair of the enzyme induced damage and has been hypothesized to include pathways that proteolyze the protein bound to DNA followed by nucleolytic removal of the remaining peptide that is bound to DNA by a phosphotyrosyl linkage. This model of repair suggests that inhibition of proteolysis would lead to elevated levels of intact Top2/DNA complexes, and increased sensitivity to Top2 poisons such as etoposide. We have tested this model using the proteasome inhibitor carfilzomib in a pediatric rhabdomyosarcoma cell line (Rh30). We found that carfilzomib enhanced cell killing by etoposide, and that co-treatment of Rh30 cells with carfilzomib led to increases in both Top2 alpha and Top2 beta covalent complexes. These results suggest that proteasomal degradation of both Top2 isoforms is important for repairing DNA damage arising from etoposide. We are also interested in identifying the determinants of Top2 degradation following treatment with etoposide, especially proteins that recognize the trapped enzyme as DNA damage. We used a yeast genetic model system to address this question. We showed that the proteasome inhibitor MG132 greatly enhanced the sensitivity of yeast cells to etoposide, and that co-treatment of MG132 and etoposide led to elevated levels of Top2/DNA complexes compared to etoposide alone. We found that deletion of the human RNF4 homolog Slx5/Slx8 (a SUMO dependent ubiquitin ligase) also leads to an increase in Top2 covalent complexes induced by etoposide. We found that deletion of the genes encoding either Slx5 or Slx8 along with the repair protein Tdp1 led to much higher levels of cell killing compared to single deletions. These results suggest that there are at least two independent pathways for repairing Top2 damage, one dependent on Slx5/Slx8 dependent protein degradation and a second pathway dependent on nucleolytic removal of Top2. We suggest that Slx5/Slx8 plays a role in targeting Top2 for degradation following etoposide treatment. Our results also provide a rationale for the combination of a proteasome inhibitor with etoposide as an approach of increasing the efficacy of etoposide.
Citation Format: Yilun Sun, Karin C. Nitiss, John L. Nitiss. Proteolytic processing pathways for topoisomerase covalent complexes. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1658. doi:10.1158/1538-7445.AM2015-1658
Abstract 1673: Galunisertib combined with sorafenib affects proliferation, EMT and delays tumor growth in mice and in hepatocellular carcinoma (HCC) patient samples ex vivo
Authors: Tijeras-Raballand Annemilai , Serova Maria , Neuzillet Cindy , Albuquerque Miguel , Colnot Nathalie , Barral Matthias , Dohan Anthony , Barral Matthias , Bonnin Philippe , Pocard Marc , Paradis Valérie , Raymond Eric , Faivre Sandrine , de Gramont Armand 
Published: August 2015

Abstract
Introduction: The TGF-β pathway that has been associated with hepatocellular carcinoma (HCC) progression, can be targeted by galunisertib, a selective ATP-mimetic TGF-β receptor (TβR)-I inhibitor currently under clinical investigation in HCC patients after sorafenib failure or ineligible for sorafenib treatment. Our study aimed to investigate the tumor effects of galunisertib with or without sorafenib in different models of HCC and in freshly grown HCC specimens from patients.
Material and methods: Transgenic mice developing stage-defined HCC were treated for 12 weeks (W) with either vehicle, sorafenib (30mg/kg), galunisertib (100mg/kg) or sorafenib plus galunisertib. Human hepatocarcinoma HUH7 cells were subcutaneously injected in nude mice and treated daily with either vehicle, sorafenib (60mg/kg) or sorafenib combined with galunisertib (100mg/kg). Ex vivo experiments were realized in surgical specimens from HCC patients that were cut into 300μM and grown in specific media. Slices were randomly exposed to galunisertib (10μM), sorafenib (5μM) and sorafenib plus galunisertib for 48h. At the end of treatments, tumor samples were analyzed by IF or IHC.
Results: In transgenic mice, the number of liver tumor macronodules was significantly lower in all treatment arms compared to control placebo (p3 fold decrease in proliferation (Ki67 expression) and 3-5 fold increase in apoptosis induction (caspase-3 expression).
Conclusion: In vivo and ex vivo, TGF-β signalling inhibition using galunisertib in combination with sorafenib in HCC models showed promising data on downstream signaling pathway, angiogenesis and tumor growth inhibition and may prevent sorafenib-induced EMT.
Citation Format: Annemilai Tijeras-Raballand, Maria Serova, Cindy Neuzillet, Miguel Albuquerque, Nathalie Colnot, Matthias Barral, Anthony Dohan, Matthias Barral, Philippe Bonnin, Marc Pocard, Valérie Paradis, Eric Raymond, Sandrine Faivre, Armand de Gramont. Galunisertib combined with sorafenib affects proliferation, EMT and delays tumor growth in mice and in hepatocellular carcinoma (HCC) patient samples ex vivo. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1673. doi:10.1158/1538-7445.AM2015-1673
Abstract 1677: Annexin A2 antibody inhibits the progression of triple-negative and herceptin-resistant breast cancer by blocking epidermal growth factor receptor functions
Authors: Chaudhary Pankaj , Gibbs Lee Daniel , Vishwanatha Jamboor K. 
Published: August 2015

Abstract
Short Description:
Annexin A2 (AnxA2), a calcium-dependent phospholipid binding protein, is abundantly present at the surface of triple-negative and Herceptin-resistant breast cancer cells. Interactions between cell-surface AnxA2 and tyrosine kinase receptors have an important role in the tumour microenvironment and act together to enhance tumour growth. The mechanism supporting this role is still unknown.
Methods:
Triple-negative (MDA-MB-231) and Herceptin-resistant (JIMT-1) breast cancer cell lines were grown in complete DMEM and DMEM/F12 medium respectively, in a humidified incubator at 37°C with 5% CO2. The membrane function of AnxA2 was blocked by incubating cells with anti-AnxA2 antibodies. Western blotting, immunoprecipitation, immunofluorescence, 1-(4,5-Dimethylthiazol-2-yl)-3,5-diphenylformazan (MTT), flow cytometry, Clonogenic, and wound-healing assays were performed in this study
Results:
We demonstrate that in triple-negative and Herceptin-resistant breast cancer cells a large amount of AnxA2 is specifically translocated to the outer membrane domain. In addition, AnxA2 interacts with extracellular domain of epidermal growth factor receptor (EGFR) at the cell surface and has an important role in cancer cell proliferation and migration by modulating EGFR functions. Blocking AnxA2 function at the cell surface by anti-AnxA2 antibody suppressed the EGF-induced EGFR tyrosine phosphorylation and internalization by blocking its homodimerization. Furthermore, addition of AnxA2 antibody significantly inhibited the EGFR-dependent PI3K-AKT and Raf-MEK-ERK downstream pathways under both EGF-induced and basal growth conditions, resulting in lower cell proliferation and migration.
Conclusions: These studies indicate that association of AnxA2 with EGFR in the membrane domain might play a positive regulatory role in keeping EGFR signaling events in an activated state in triple negative and Herceptin-resistant breast cancer thus making AnxA2 an important therapeutic target.
Citation Format: Pankaj Chaudhary, Lee Daniel Gibbs, Jamboor K. Vishwanatha. Annexin A2 antibody inhibits the progression of triple-negative and herceptin-resistant breast cancer by blocking epidermal growth factor receptor functions. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1677. doi:10.1158/1538-7445.AM2015-1677
Abstract 1692: Antibody-drug conjugates to target cell surface TACE-cleaved amphiregulin in breast cancer
Authors: Jenkins Edmund C. , Levano Kelly S. , Jung Eric H. , Levy Matthew , Kenny Paraic A. 
Published: August 2015

Abstract
Approximately 70% of breast cancer cases are Estrogen Receptor (ER) positive. In many cases, these patients are well-served by endocrine therapies such as tamoxifen and aromatase inhibitors, however the emergence of endocrine-resistant disease in up to 40% of these patients is a major clinical concern. This necessitates treatment with more toxic chemotherapies which are often successful at delaying tumor progression, but are not curative.
Recent work from our group and others has demonstrated that Amphiregulin, an Epidermal Growth Factor Receptor (EGFR) ligand, is a critical effector of ER signaling in both normal development and breast cancer pathogenesis, and is expressed in both endocrine-sensitive and endocrine-resistant breast cancer. Like other EGFR ligands, Amphiregulin is proteolytically processed at the cell surface to release a soluble EGFR-binding signaling domain and a residual cell-associated stalk. In this project, we are developing antibodies that selectively recognize the residual transmembrane Amphiregulin cleavage product with the goal of developing antibody-drug conjugates with which to selectively target tumor cells with high levels of Amphiregulin shedding.
We have generated six humanized antibodies that recognize the cell-associated neo-epitope revealed following the TACE-mediated proteolytic release of Amphiregulin. Using both flow Cytometry and immunofluorescence, we demonstrate that these antibodies selectively recognize cleaved over full-length Amphiregulin in estrogen receptor positive breast cancer cells. Conjugation of these antibodies with a pH-sensitive dye, pHrodo, demonstrates robust and rapid antibody internalization in live cells. Conjugation of these antibodies with monomethyl auristatin E results in the disruption of the microtubule network of breast cancer cells followed by cell death. We propose that these agents may have utility in the treatment of breast and other cancers in which Amphiregulin expression and processing play a prominent role.
This study is supported by the Department of Defense Breast Cancer Research Program (W81XWH-14-1-0294).
Citation Format: Edmund C. Jenkins, Kelly S. Levano, Eric H. Jung, Matthew Levy, Paraic A. Kenny. Antibody-drug conjugates to target cell surface TACE-cleaved amphiregulin in breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1692. doi:10.1158/1538-7445.AM2015-1692
Abstract 1694: Preclinical evaluation of a novel bispecific targeted toxin for the treatment of sarcomas
Authors: Borgatti Antonella , Winter Amber , Stuebner Kathleen , Koopmeiners Joseph , Modiano Jaime F. , Vallera Daniel 
Published: August 2015

Abstract
Introduction: EGFuPA is a bispecific ligand-targeted toxin consisting of epidermal growth factor (EGF) and urokinase (uPA) on the same molecule with truncated Pseudomonas exotoxin. The toxin was mutated to remove amino acids recognized by B-cells. EGFuPA is uniquely designed to simultaneously target EGF receptors (EGFR) and/or urokinase receptors (uPAR) on tumor cells and uPAR in the microenvironment. EGFuPA is safe and effective in laboratory animals and has excellent in vitro activity against sarcomas. Because EGFuPA crosses species platforms, an adaptive phase 1/2 study was undertaken using canine hemangiosarcoma (HSA) as a model of a highly aggressive, metastatic vascular sarcoma. We hypothesized that six-month survival would exceed 50% for dogs enrolled. Canine HSA is a tumor derived from blood vessel forming cells, which can overexpress both uPAR and EGFR rendering it an excellent target for the drug. It bears similarity to human angiosarcoma.
Methods: Enrollment began in November 2012. Dogs with histologically confirmed, non-metastatic stage-I or II splenic HSA were eligible after splenectomy. EGFuPA was administered intravenously for one cycle on Days 1, 3, and 5. Adjuvant doxorubicin was given according to standard of care (SOC) protocols starting seven days after the last dose of EGFuPA.
Results: EGFuPA was detectable in the systemic circulation 5 minutes post-infusion with clearance by 15 minutes. The drug was well tolerated with self-limiting, reversible hypovolemia at the highest dose. Thus far, 50 μg/kg appears to be the optimal dose. When compared to a historical control group of 19 dogs treated with SOC between 2008 and 2011, median survival is significantly longer for all 16 dogs treated with EGFuPA (SRCBST group, 240 vs. 129 days, p = 0.03) and for the 10 dogs in the Optimal Dose group (MS not reached, p = 0.01). Six-month survival for the Optimal Dose group was 65%. Overall survival at 400 days was 7% for the SOC group, 32.7% for the SRCBST group, and 56% for the Optimal Dose group. Outcomes were not affected by the presence of neutralizing antibodies.
Conclusions: A biologically active dose of EGFuPA was established and found to be safe in companion dogs with HSA in the minimal residual disease setting. The unique nature of its bispecific targeting and the observed significant, biologic activity warrants consideration of EGFuPA for a phase 1 study for drug-refractory sarcomas in human patients.
Citation Format: Antonella Borgatti, Amber Winter, Kathleen Stuebner, Joseph Koopmeiners, Jaime F. Modiano, Daniel Vallera. Preclinical evaluation of a novel bispecific targeted toxin for the treatment of sarcomas. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1694. doi:10.1158/1538-7445.AM2015-1694
Abstract 1713: IL-24 inhibits lung cancer cell migration and invasion by disrupting the SDF-1/CXCR4 signaling axis
Authors: Panneerselvam Janani , Jin Jiankang , Shanker Manish , Lauderdale Jason , Bates Jonathan , Wang Qi , Zhao Daniel , Archibald Stephen , Hubin Timothy , Ramesh Rajagopal 
Published: August 2015

Abstract
Introduction
The stromal cell derived factor (SDF)-1/chemokine receptor (CXCR)-4 signaling pathway plays a key role in lung cancer metastasis. Therefore, disrupting the SDF-1/CXCR4 signaling axis will reduce the incidence of lung metastasis. In the present study we investigated whether interleukin (IL)-24 can inhibit the SDF-1/CXCR4 axis and suppress lung cancer cell migration and invasion in vitro. Further, the efficacy of IL-24 in combination with CXCR4 antagonists was investigated.
Methods
Human H1299 lung tumor cell line was stably transfected with a tetracycline-inducible plasmid vector carrying the IL-24. Upon addition of doxycycline (Dox; 1μg/ml), cells were induced to express IL-24 protein. The expression levels of CXCR4 and its downstream molecular mechanisms in H1299 cells were analyzed. The inhibitory effect of IL-24 on SDF-1/CXCR4 axis is determined by RT-qPCR, western blot, luciferase reporter assay, flow-cytometry and immuno-cytochemistry and the consequence of its inhibition on cell migration, and invasion.
Results
Endogenous CXCR4 protein expression levels varied among four human lung cancer cell lines with H1299 cells showing the highest expression. Doxycycline-induced IL-24 expression in the H1299-IL-24 cell line resulted in reduced CXCR4 mRNA and protein expression. IL-24 post-transcriptionally regulated CXCR4 mRNA expression by decreasing the half-life of CXCR4 mRNA (&gt;40%). Associated with CXCR4 inhibition was the reduced protein expression of pAKTS473, pmTORS2448, pPRAS40T246 and HIF-1α. IL-24 inhibited tumor cell migration and invasion both in the presence and absence of the CXCR4 agonist, SDF-1. However, the combinatorial effect of either IL-24 combined with CXCR4 inhibitors (AMD3100, SJA5) or with CXCR4 siRNA demonstrated enhanced inhibitory activity on tumor cell migration.
Conclusions
Our study results demonstrate that IL-24 inhibits lung tumor cell migration and invasion by disrupting the SDF-1/CXCR4 signaling pathway and exhibits enhanced anti-metastatic activity when combined with CXCR4 inhibitors.
Citation Format: Janani Panneerselvam, Jiankang Jin, Manish Shanker, Jason Lauderdale, Jonathan Bates, Qi Wang, Daniel Zhao, Stephen Archibald, Timothy Hubin, Rajagopal Ramesh. IL-24 inhibits lung cancer cell migration and invasion by disrupting the SDF-1/CXCR4 signaling axis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1713. doi:10.1158/1538-7445.AM2015-1713
Abstract 1740: Allosteric Hsp70-family inhibitors as targeted anticancer therapeutics
Authors: Koren John , Xu Chao , Rodina Anna , Shrestha Liza , Taldone Tony , Chiosis Gabriela 
Published: August 2015

Abstract
Background: Hsp70, a molecular chaperone responsible, in part, for the folding of nascent peptides following translation, has been implicated as a survival factor and a poor prognostic marker in cancer cells. These pro-cancer mechanisms originate in the ability of Hsp70 to preserve and maintain oncogenic and transformative proteins responsible for the cancer phenotype. Hsp70 is a stress response protein such that expression increases under proteomic/proteotoxic stress events. This increased expression is also evident in cancer cells, an environment under proteomic stress brought on by transformation, and is known to be protective against programmed cell death.
Hypothesis: We predict that by interrupting the chaperoning capacity of Hsp70 through allosteric inhibition, we can destabilize oncogenic proteins dependent on Hsp70 for structure and function. Additionally, as Hsp70 is a survival factor, we believe that a loss of Hsp70 activity will result in cancer specific cell death both in vitro and in vivo.
Approach: Using chemical tools, primarily novel allosteric Hsp70 inhibiting small molecules, we will determine the fate of oncogenic proteins dependent on Hsp70 for stability. We will also examine the cellular response to the disruption of cancer-specific networks which require Hsp70. In vivo tumor models will be used to examine the pharmacokinetics and pharmacodynamics of small molecule Hsp70 inhibitors and to evaluate the therapeutic potential of Hsp70 inhibition.
Significance: The stress response machinery is responsible for the stability of proteins, maintenance of signaling pathways, and evasion from programmed cell death while a cell is under stress; stressors including oncogenic transformation. These pathways maintained by the molecular chaperones have been directly linked to deleterious cancer phenotypes including aggressiveness and the emergence of therapeutic resistances. Targeted therapeutics, and uniquely those targeting the molecular chaperone system, can provide therapeutic options capable of ablating the specific mechanisms involved in proteomic stability and cell survival unique to each tumor cell; effects which can be delivered with minimal effect to normal tissue. This work highlights the potential for therapeutics targeting Hsp70 as anti-cancer agents.
Citation Format: John Koren, Chao Xu, Anna Rodina, Liza Shrestha, Tony Taldone, Gabriela Chiosis. Allosteric Hsp70-family inhibitors as targeted anticancer therapeutics. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1740. doi:10.1158/1538-7445.AM2015-1740
Abstract 1757: The new molecular target therapy of Hsp90 inhibition in esophageal squamous cell carcinoma
Authors: Yamamura Masahiro , Nohno Tsutomu , Yamauchi Akira , Katase Naoki , Okawaki Makoto , Sawaki Akira , Matsumoto Hideo , Hirai Toshihiro , Yamaguchi Yoshiyuki 
Published: August 2015

Abstract
Heat shock protein 90 (HSP90) has numerous cellular functions, including promotion of proper protein folding, and stabilizes a number of oncogenic proteins, many of which are overexpressed in cancers. The objective of this study is to evaluate an antitumor effect of HSP90 inhibitor, AUY922, in esophageal squamous cell carcinoma(ESCC) cell lines. ESCC cell lines were treated with AUY922 to examine the effect on proliferation assay, apoptosis assay, Western blotting, and chemotaxis assay. AUY922 inhibited cell proliferation in ESCC cells in a dose- and time-dependent manner. Growth inhibitory effect of AUY922 for ESCC cells was higher than CDDP. With flowcytometry and immunostaining, we showed that AUY922 induced apoptosis in ESCC cells and inhibited chemotaxis of ESCC cells. These antitumor effects of AUY922 were due to inhibition of cell proliferation through suppression of phosphorylation of the client proteins. The HSP90 inhibitor is useful as an antitumor drug in ESCC by inhibiting proliferation of ESCC cells through novel mechanism.
Citation Format: Masahiro Yamamura, Tsutomu Nohno, Akira Yamauchi, Naoki Katase, Makoto Okawaki, Akira Sawaki, Hideo Matsumoto, Toshihiro Hirai, Yoshiyuki Yamaguchi. The new molecular target therapy of Hsp90 inhibition in esophageal squamous cell carcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1757. doi:10.1158/1538-7445.AM2015-1757
Abstract 1761: Small molecule restoration of wildtype structure and function of mutant p53 using a novel zinc metallochaperone based mechanism
Authors: Yu Xin , Blanden Adam R. , Narayanan Sumana , Jayakumar Lalithapriya , Lubin David , Augeri David J. , Kimball S. David , Loh Stewart N. , Carpizo Darren R. 
Published: August 2015

Abstract
NSC319726 (ZMC1) is a small molecule that reactivates mutant p53 by restoration of WT structure/function to the most common p53 missense mutant (p53-R175H). We investigated the mechanism by which ZMC1 reactivates p53-R175H and provide evidence that ZMC1: 1) restores WT structure by functioning as a zinc-metallochaperone, providing an optimal concentration of zinc to facilitate proper folding; 2) increases cellular reactive oxygen species that transactivate the newly conformed p53-R175H (via post-translational modifications), inducing an apoptotic program. We not only demonstrate that this zinc metallochaperone function is possessed by other zinc-binding small molecules, but that it can reactivate other p53 mutants with impaired zinc binding. This represents a novel mechanism for an anti-cancer drug and a new pathway to drug mutant p53.
Citation Format: Xin Yu, Adam R. Blanden, Sumana Narayanan, Lalithapriya Jayakumar, David Lubin, David J. Augeri, S. David Kimball, Stewart N. Loh, Darren R. Carpizo. Small molecule restoration of wildtype structure and function of mutant p53 using a novel zinc metallochaperone based mechanism. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1761. doi:10.1158/1538-7445.AM2015-1761