bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 3521: Glutamine metabolic inhibition synergizes with L-asparaginase in MYCN-amplified neuroblastoma
Authors: Maxwell Micah J. , Poore Brad , Hanaford Allison , Alt Jesse , Rais Rana , Slusher Barbara S. , Eberhart Charles G. , Raabe Eric H. 
Published: August 2018

Abstract
Neuroblastoma is the most common extracranial solid tumor in children. Though it accounts for about 10% of pediatric cancers, it is disproportionately responsible for 15% of pediatric cancer deaths. MYCN is amplified in 20% of neuroblastomas and correlates with adverse outcome. MYCN is involved in the maintenance of cancer stem cells, as well as in driving tumor cell growth, proliferation and tumorigenesis. Attempts to inhibit MYCN directly have been largely unsuccessful. MYCN is known to drive tumor cell reliance on glutamine for cellular metabolism. 6-Diazo-5-oxo-L-norleucine (DON) is a well-characterized glutamine analogue that inhibits glutamine metabolism by irreversibly inactivating multiple glutamine-utilizing enzymes. DON was well tolerated in a previous phase I clinical trial in pediatric patients, but it has never been systematically tested in neuroblastoma patients. We show that MYCN-amplification confers sensitivity to DON therapy in in vitro models of neuroblastoma, and that DON administered by intraperitoneal injection twice weekly significantly reduces flank tumor volume in orthotopic mouse models of MYCN-amplified neuroblastoma (mean tumor volume 1715 mm3 vs. 207 mm3 in control animals, p-value = 0.00017 by t-test). We have also developed an orally bioavailable DON prodrug, JHU083, and we found that this drug administered orally three times weekly was similarly able to suppress neuroblastoma tumor growth in mice (mean tumor volume 1,115 mm3 vs. 217 mm3 in control animals, p-value = 0.0000088 by t-test). In metabolic flux experiments, tracing glutamine and glucose donation of 13C and 15N via liquid chromatography/mass spectrometry, DON prevents asparagine synthesis, depleting intracellular asparagine levels by 40% compared to control treated cells (p-value = 0.006). DON combined with L-asparaginase synergistically inhibits growth of MYCN-amplified neuroblastoma cell lines (CI = 0.25 by the Chou-Talalay method, indicating strong synergy; p-value = 0.00011). We conclude that DON depletes cellular pools of asparagine, and combination therapy with DON and L-asparaginase synergistically inhibits the growth of MYCN-amplified neuroblastoma. These studies provide the preclinical justification for potential clinical trials for the use of DON or DON prodrugs in combination with L-asparaginase as new therapeutic options for patients with MYCN-amplified neuroblastoma.
Citation Format: Micah J. Maxwell, Brad Poore, Allison Hanaford, Jesse Alt, Rana Rais, Barbara S. Slusher, Charles G. Eberhart, Eric H. Raabe. Glutamine metabolic inhibition synergizes with L-asparaginase in MYCN-amplified neuroblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3521.
Abstract 3536: SENP1 is a p53 deSUMOylating enzyme and its depletion induces p53 activity
Authors: Dai Mushui , Chauhan Krishna , Chen Yingxiao , Sun Xiao-Xin 
Published: August 2018

Abstract
SUMOylation plays important roles in diverse cellular processes by regulating protein-protein interaction, protein localization, trafficking, stability and activity. p53 can by SUMOyalted at lysine (K) 384. Yet, how SUMOylation regulates p53 activity remain unclear. SUMOylation can be revered by a group of proteins called deSUMOylating enyzme including the SUMO specific protease (SENP) family proteins. How p53 is regulated by deSUMOylation is also not well understood. Here, we show that SENP1 directly interacts with and desumoylates p53 in cells and in vitro. Depletion of SENP1 by siRNA-mediated knockdown drastically increased the p53 transactivation activity without inducing p53 protein levels, resulting p53-depndent cell cycle arrast. Further, SENP1 knockdown significantly promoted p53 transactivation activity in cells following DNA damage. Additionally, we found that SENP1 binds to and deSUMOylates PML and aborageted the enhancing effect of PML on p53 SUMOylation. Thus, SNEP1 is novel p53 desumoylating enzyme that regulates p53 activity but not its stability.
Citation Format: Mushui Dai, Krishna Chauhan, Yingxiao Chen, Xiao-Xin Sun. SENP1 is a p53 deSUMOylating enzyme and its depletion induces p53 activity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3536.
Abstract 3539: Establishing ubiquitylation patterns in cells: Efficient monitoring of oncogenic ubiquitylation activity
Authors: Foote Peter K. , Lu Xiaolong , Singh Rajesh 
Published: August 2018

Abstract
Cells regulate their internal functions by the ubiquitylation of many key proteins, especially onco-proteins and tumor suppressors. As a result, ubiquitin proteasome system (UPS) substrates and the relevant UPS enzymes have been identified as attractive anti-cancer targets. However, traditional methods for monitoring ubiquitylation patterns, including by immunoprecipitation coupled with immunoblot analysis (IP/IB) or by mass spectrometry methods, are either insensitive, low throughput, or highly intensive. Here, we describe three Tandem Ubiquitin Binding Entity (TUBE)-based assays, UbiTest, HT-UbiTest, and UbiQuant S, which provide a platform to efficiently detect ubiquitylation of anti-cancer targets. UbiTest is an immunoblot-based assay, which can be used to easily identify ubiquitlyated proteins. Compared to traditional ubiquitin IP/IB, this assay avoids epitope masking of antibodies caused by ubiquitin modification. HT-UbiTest extends this concept using a TUBE pulldown followed by two-antibody detection in a 96-well plate, and allows high-throughput absolute quantification of a target of interest. UbiQuant S is a high-throughput assay to quantify ubiquitylation status in cells or tissue. Ubiquitylated proteins are identified by energy transfer between AlphaLISA bead-labeled TUBE and antibody against the endogenous protein of interest in a homogenous plate-based assay. Furthermore, we have extended these technologies to identify K63- and K48-linked poly-ubiquitylated proteins using poly-ubiquitin linkage-selective TUBEs. Several prominent therapeutic targets in oncology and immuno-oncology have been used to verify these assays, including Cbl-b and its substrates, p53, and USP7. The efficiency and sensitivity of these assays have wide applications in drug discovery targeting ubiquitylation-dependent signaling pathways. Examples using DUB and ubiquitin ligase inhibitors illustrate the power of this system. These novel assays are versatile tools for understanding the role of ubiquitylation in cancer treatment, and provide platforms to monitor disease biomarkers in response to drug action.
Citation Format: Peter K. Foote, Xiaolong Lu, Rajesh Singh. Establishing ubiquitylation patterns in cells: Efficient monitoring of oncogenic ubiquitylation activity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3539.
Abstract 3542: Missense mutations in USE1 promote lung tumorigenesis
Authors: Lee Peter C. W. 
Published: August 2018

Abstract
The UBA6-USE1 enzyme cascade is a poorly characterized arm of the ubiquitin-proteasome system. We found that UBA6 and USE1 proteins are frequently overexpressed in lung cancer patients (83.01% and 92.45%, respectively; n = 106). Stable overexpression of UBA6 or USE1 significantly increased cell proliferation, migration, and invasiveness in lung cancer cells and xenograft models, whereas their knockdown significantly reduced cell proliferation, migration, and invasion. USE1 has a conserved D-box domain and the level of the protein was regulated by the anaphase-promoting complex through its interaction with CDC20 and CDH1. Furthermore, several missense mutations in USE1 identified in patients prolong the half-life and stability of the protein. Our findings reveal novel roles for USE1 in lung cancer and the possible use of USE1 as a novel biomarker and therapeutic target for lung cancer treatment.
Citation Format: Peter C. W. Lee. Missense mutations in USE1 promote lung tumorigenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3542.
Abstract 3543: USP7 inhibitor P5091 inhibits esophageal squamous cell carcinoma growth by inducing NOXA-mediated apoptosis
Authors: Hu Tao , Zhang Jing-Yang , Sha Bei-Bei , Li Miao-Miao , Liu Xing-Ge , Zhang Yi , Dong Zi-Ming , Li Pei , Chen Ping 
Published: August 2018

Abstract
Recently, deubiquitinase USP7/HAUSP was reported to be an attractive anti-cancer target. However, its expression and role in esophageal cancer remain elusive. Here, immunohistochemistry and western blot assay were used to detect the expression of USP7/HAUSP in esophageal squamous cell carcinoma (ESCC) tissues. Specific inhibitor P5091 was used to inhibit the activity of USP7 and explore the role and mechanism of USP7 in KYSE450, KYSE510 and KYSE30 ESCC cell lines.
Result: Staining-intensity analysis by immunohistochemistry demonstrated that USP7 was expressed higher in ESCC tissues compared with their corresponding adjacent tissues (P&lt;0.01), which was confirmed by western blot analysis. CCK-8 assay, colony formation assay and tumor growth assay in subcutaneous transplantation tumor model indicated that P5091 could significantly inhibit ESCC cell growth in vitro and in vivo. Moreover, P5091 induced apoptosis by triggering unfolded protein reaction, accumulating the protein of ATF4 and thus transcriptionally upregulating the expression of NOXA.
Conclusion: These results showed that P5091 effectively inhibited ESCC cell growth in vitro and in vivo and supported the clinical investigation of P5091 for the treatment of ESCC.
Keywords: P5091, esophageal squamous cell carcinoma, ATF4, apoptosis, NOXA
* T H and J-Y Z contributed to this work equally.
Citation Format: Tao Hu, Jing-Yang Zhang, Bei-Bei Sha, Miao-Miao Li, Xing-Ge Liu, Yi Zhang, Zi-Ming Dong, Pei Li, Ping Chen. USP7 inhibitor P5091 inhibits esophageal squamous cell carcinoma growth by inducing NOXA-mediated apoptosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3543.
Abstract 3548: EPAC-RAP1, the alternative cyclic AMP signaling pathway, regulates cell cycle progression in primary melanoma cells
Authors: Krishnan Aishwarya , Prabhakar Kirthana , Ndiaye Mary , Ahmad Nihal , Rodriguez Carlos Ivan , Setaluri Vijayasaradhi 
Published: August 2018

Abstract
Cyclic AMP (cAMP) is an important second messenger that acts as a key mediator in a wide range of cellular pathways. In melanocytes, the G-Protein Coupled Receptor (GPCR) Melanocortin-1-Receptor (MC1R), an important regulator of melanocyte proliferation and melanogenesis, activates cAMP signaling. Polymorphisms in MC1R lead to cAMP signaling impairments which are accompanied by higher risk for melanoma development. Despite the importance of cAMP signaling in melanocytes, very little is known about its role in melanoma. Exchange Protein directly Activated by cAMP (EPAC) constitutes an alternative pathway to cAMP signaling and is known to mediate the crosstalk between the cAMP and MAPK pathways. In this study, we show that pharmacological inhibition of EPAC, delays cell cycle progression and inhibits the growth of human primary melanoma cells. Flow cytometry and western blot analysis of cell cycle proteins showed that inhibition of EPAC arrests cells in G1-S and delays their mitotic progression. Paradoxically, inhibition of EPAC also caused an increase in AKT phosphorylation, suggesting a cell survival response elicited upon the cell cycle arrest caused by inhibition of EPAC allows continued survival of primary melanoma cells. Inhibition of EPAC in metastatic melanoma cells, on the other hand, stimulated their growth. These data show differential role of EPAC in primary and metastatic melanoma cells and provide a basis for targeting EPAC for prevention of cutaneous melanoma progression.
Citation Format: Aishwarya Krishnan, Kirthana Prabhakar, Mary Ndiaye, Nihal Ahmad, Carlos Ivan Rodriguez, Vijayasaradhi Setaluri. EPAC-RAP1, the alternative cyclic AMP signaling pathway, regulates cell cycle progression in primary melanoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3548.
Abstract 3551: Lipid raft integrity is essential for metastasis and chemoresistance properties of CD133+ cancer stem cells in pancreatic cancer
Authors: Gupta Vineet K. , Sharma Nikita S. , Kesh Kousik , Dauer Patrcia , Nomura Alice , Giri Bhuwan , Dudeja Vikas , Saluja Ashok , Banerjee Sulagna 
Published: August 2018

Abstract
Pancreatic cancer remains a significant health burden associated with limited patient survival and poses a major therapeutic challenge. Among cancer cells, Cancer stem cells (CSCs) are instrumental in inducing chemoresistance and metastasis in pancreatic cancer. CD133 has been identified as a CSC surface marker in several malignancies including pancreatic cancer. However, the functional role of CD133 in CSCs still not clear. The present study investigates the role of caveolar lipid raft integrity in functional properties of CD133+ CSCs. Current study showed first time that CD133 localizes to caveolar lipid rafts in pancreatic cancer cells, and associates with Caveolin1 (Cav-1) and cholesterol to form an integral signaling complex which drives the downstream processes of chemoresistance and metastasis. Further analysis showed that the integrity of the lipid-raft is crucial for maintenance of the functional properties of pancreatic CSCs, and its disruption leads to increased chemo-sensitivity to chemotherapeutic compound paclitaxel both in vitro as well as in vivo. Additionally, disruption of lipid raft results in decreased invasiveness and metastatic ability of the cells by deregulation of FAK signaling. The study also reveals that pancreatic cancer cells that lack the CSC population marker, CD133, did not respond to lipid raft disruption. Our results indicated that targeting the lipid-raft integrity in pancreatic cancer can specifically eradicate the CD133+ CSCs in pancreatic tumors, leading to a better prognosis for the disease.
Citation Format: Vineet K. Gupta, Nikita S. Sharma, Kousik Kesh, Patrcia Dauer, Alice Nomura, Bhuwan Giri, Vikas Dudeja, Ashok Saluja, Sulagna Banerjee. Lipid raft integrity is essential for metastasis and chemoresistance properties of CD133+ cancer stem cells in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3551.
Abstract 3565: T cell receptor signaling-responsive single chain IL-12 and IL-15 superagonist nanogel “backpacks” to enhance adoptive cell therapy in solid tumors
Authors: Fichter Michael 
Published: August 2018

Abstract
Adoptive cell therapy (ACT) using patient-derived tumor-specific T cells is a promising approach for cancer treatment especially for the treatment of hematological malignancies. However, therapeutic approaches using ACT in patients with solid tumors, such as hepatocellular carcinoma (HCC), has not shown substantially improved clinical outcomes in particular due to immunosuppressive tumor microenvironments. Therefore, strategies to enhance ACT T cell functionality in vivo and to overcome the immunosuppressive microenvironments in solid tumors are strongly needed. We developed a strategy combining nanomedicine with ACT, based on the chemical conjugation of cytokine-loaded nanoparticles (NPs) as synthetic “backpacks” to the surfaces of live lymphocytes for adoptive therapy. Novel protein nanoparticles were synthesized by crosslinking of single chain IL-12 (scIL-12)- or IL-15 superagonist through disulfide-containing crosslinkers, forming nanogels that when bound to the surface of T cells, release the supporting cytokines in response to antigen receptor signaling-mediated changes in cell surface redox state. This TCR-mediated drug release allowed drug delivery to the T cells to be focused in tumors and tumor-draining lymph nodes. Coupling of cytokine nanogels to T cell membranes induced significant cell activation in terms of interferon-γ production or proliferation in a concentration-dependent manner. Antigen-specific CD8+ T cells “backpacked” with scIL-12 or IL-15SA nanogels were capable of substantial tumor cell killing in a B16F10 melanoma cancer model in vivo, while avoiding lethal systemic toxicities triggered by systemically-administered immunomodulatory cytokines. Ongoing studies are seeking to apply this approach in HCC, and this approach bears the potential for the development of successful immunotherapeutic strategies against this and other solid tumors where effective treatment options are still lacking.
Citation Format: Michael Fichter. T cell receptor signaling-responsive single chain IL-12 and IL-15 superagonist nanogel “backpacks” to enhance adoptive cell therapy in solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3565.
Abstract 3580: Enhancing adoptive cell therapies through exogenous regulation
Authors: Richardson Celeste , Elpek Kutlu , Ols Michelle , Kassum Tariq , Shamah Steve 
Published: August 2018

Abstract
Adoptive cell therapy with chimeric antigen receptor (CAR) modified T cells has demonstrated remarkable clinical efficacy in the treatment of certain B cell malignancies and more recently in multiple myeloma. However, in solid tumors, CAR-T therapy has been far less successful, likely due to the lack of robust CAR-T cell expansion, the immunosuppressive microenvironment, and clonal heterogeneity within these tumors. The trafficking of CAR-T cells to tumor sites provides an opportunity for selective delivery of cargo that can enhance CAR-T cell activity at the site of the tumor. Interleukin-12 (IL12) and membrane tethered interleukin-15 (mbIL15) have previously been shown to enhance CAR-T activity, yet the unregulated expression of either compromises safety and/or efficacy. The Obsidian Therapeutics platform equips engineered immune cells with new functionalities whose activity can be regulated via the administration of FDA-approved small-molecule drugs, putting dosing control back in the hands of the treating physician. We utilize small, fully human protein sequences called destabilizing domains (DDs) that confer reversible destabilization to a fused target protein. In the absence of ligand the fusion protein is degraded, whereas the presence of small molecule ligand restores expression and functionality. Furthermore, stabilization is titratable with small molecule ligand dose, providing finely tuned control over target protein expression and function. We have applied our technology to create DD-IL12 and DD-mbIL15 “cassettes” that provide exogenous regulation of cytokine activity when transduced into CAR-Ts for enhanced cellular function. We describe here the successful implementation of the DD technology in engineered primary human T cells and show small-molecule ligand controlled regulation of DD-IL12 and DD-mbIL15 protein expression in vivo in mouse models. These data demonstrate the feasibility of exogenous control over protein expression in primary human T cells for the development of next-generation CAR-T cell products with enhanced efficacy and more favorable safety profiles.
Citation Format: Celeste Richardson, Kutlu Elpek, Michelle Ols, Tariq Kassum, Steve Shamah. Enhancing adoptive cell therapies through exogenous regulation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3580.
Abstract 3589: Preclinical evaluation of mesothelin-specific T cell receptor (TCR) fusion constructs (TRuC™s) utilizing the signaling power of the complete TCR complex: A new opportunity for solid tumor therapy
Authors: Ding Jian , Patel Ekta , Tavares Patrick , Quinn Justin , Choudhary Rashmi , Le Bonnie , Kiner Olga , Weiler Solly , Getts Daniel R. , Baeuerle Patrick , Hofmeister Robert 
Published: August 2018

Abstract
Despite success in treating hematological malignancies, T cells expressing chimeric antigen receptors (CARs) have shown poor efficacy in solid tumor indications. The poor utility of CARs is thought to be due to a number of factors including T cell exhaustion and a lack of persistence. Utilizing only the CD3ζ chain of six distinct T cell receptor subunits in combination with a costimulatory domain, the CARs bypass the natural TCR signaling complex. The failure to initiate and harness a complete TCR response is arguably a primary underlying factor preventing CAR-T cell success in solid tumor indications. Here, we present a novel T cell engineering platform: T Cell Receptor Fusion Constructs (TRuC™s), which target tumors in a MHC non-restricted fashion. Unlike CARs, the constructs integrate into the TCR complex, harnessing the full potential of natural T cell activation, effector function and regulation. Here we demonstrate preclinical evidence underscoring the efficacy of TRuC™-T cells re-programmed to target the solid tumor antigen mesothelin (TC-210). TC-210 showed robust anti-tumor activity in vitro and in vivo in mesothelioma, lung and ovarian tumor models. Surprisingly, this activity was associated with less proinflammatory cytokine production compared to CAR-T cells with the same binder and was supported by strong TRuC™-T cell persistence. Taken together, mesothelin targeting TRuC™-T cells have potent anti-tumor activity and present a promising approach for treating mesothelin-expressing solid tumors.
Citation Format: Jian Ding, Ekta Patel, Patrick Tavares, Justin Quinn, Rashmi Choudhary, Bonnie Le, Olga Kiner, Solly Weiler, Daniel R. Getts, Patrick Baeuerle, Robert Hofmeister. Preclinical evaluation of mesothelin-specific T cell receptor (TCR) fusion constructs (TRuC™s) utilizing the signaling power of the complete TCR complex: A new opportunity for solid tumor therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3589.