bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 533: XIAP BIR domain suppresses miR-200a expression and subsequently promotes EGFR protein translation and anchorage-independent growth of bladder cancer cell
Authors: Liao Xin , Huang Chao , Li Jingxia , Huang Chuanshu 
Published: July 2017

Abstract
The X-linked inhibitor of apoptosis protein (XIAP) is a well-known potent apoptosis suppressor, and also participates in cancer cell biological behaviors, therefore attracting great attentions as a potential antineoplastic therapeutic target for past years. We found here that lacking of XIAP expression resulted in a remarkable suppression of EGFR expression, consequently leading to the deficient of anchorage-independent cell growth. Further study demonstrated that BIR domain of XIAP was crucial for regulating the EGFR translation by suppressing the transcription and expression of miR-200a. Mechanistic studies indicated that BIR domain activated the PP2A activity by decreasing the phosphorylation of PP2A at Tyr307 in its catalytic subunit, PP2A-C. Such activated PP2A prevented the deviant phosphorylation and activation of MAPK kinases/MAPKs, their downstream effector c-Jun, and in turn inhibiting transcription of c-Jun-regulated the miR-200a. Collectively, our study uncovered a novel function of BIR domain of XIAP in regulating the EGFR translation, providing significant insight into the understanding of the XIAP overexpression in the cancer development and progression, further offering a new theoretical support for using XIAP BIR domain and EGFR as targets for cancer therapy.
Citation Format: Xin Liao, Chao Huang, Jingxia Li, Chuanshu Huang. XIAP BIR domain suppresses miR-200a expression and subsequently promotes EGFR protein translation and anchorage-independent growth of bladder cancer cell [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 533. doi:10.1158/1538-7445.AM2017-533
Abstract 5332: ISG15 knockdown inhibits growth of pancreatic cancer
Authors: Burks Julian , Smith Jill 
Published: July 2017

Abstract
Background: Pancreatic ductal adenocarcinoma (PDAC) is a deadly disease driven by mutated KRAS with an average survival of only 3-6 months from the time of diagnosis. Interferon-Stimulated Gene 15 (ISG15) is a 15 kDa protein induced by Type I interferons (IFN-α and IFN-β) and is a member of the ubiquitin-like superfamily of proteins. The ISG15 pathway is highly elevated in various malignancies where it has been shown to stabilize KRAS protein expression. However, very little is known about the role of the ISG15 pathway in PDAC. The purpose of this project is to investigate the expression and proliferative effects of the ISG15 pathway in PDAC.
Methods: The ISG15 knockdown cells were created using the CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) gene editing system. ISG15 was stably knocked-down in murine Panc02 pancreatic cancer cells by transfection with an ISG15 CRISPR construct from Genscript (pSpCas9 BB-2A-Puro (PX459)) and treated with media containing puromycin (2 μg/ml) for selection. Knockdown was confirmed by RT-PCR. The effect of ISG15 knockdown on PDAC cell growth in vitro was determined by comparing viable cell counts on wild-type and ISG15 knockdown Panc02 cells 48 hours after plating. The effect of ISG15 knockdown on pancreatic tumorigenesis was determined by subcutaneous inoculation of syngeneic immune competent C57BL/6 mice with 1x106 Panc02 wild-type or ISG15 knockdown cells. Tumor volumes were measured weekly and after 3 weeks the mice were euthanized, tumors dissected and weighed.
Results: ISG15 CRISPR treated cells had a 50% reduction in ISG15 mRNA expression as compared to wild-type cells. ISG15 knockdown in Panc02 PDAC cells significantly reduced cell growth as compared to wild-type cells (p=0.030). Tumors formed from ISG15 knockdown Panc02 cells significantly had a 74% reduction in tumor volume (p=0.031) and 78% reduction in tumor weight (p=0.029) as compared to wild-type cells.
Conclusion: The ISG15 pathway contributes to PDAC by increasing cell growth and the tumorigenic potential of pancreatic cancer cells. Ultimately, strategies to target the ISG15 pathway may lead to improved survival for patients diagnosed with PDAC.
Supported by: NIH T32CA00968 grant
Citation Format: Julian Burks, Jill Smith. ISG15 knockdown inhibits growth of pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5332. doi:10.1158/1538-7445.AM2017-5332
Abstract 5333: Monoubiquitination inhibits the actin bundling activity of fascin
Authors: Lin Shengchen , Lu Shuang , Mulaj Mentor , Fang Bin , Keeley Tyler , Wan Lixin , Hao Jihui , Muschol Martin , Sun Jianwei , Yang Shengyu 
Published: July 2017

Abstract
Fascin is the most frequently upregulated actin regulatory protein in metastatic tumors. The elevated expression levels of fascin universally correlate with poor clinical course and shorter survival across different cancer types. It is believed that fascin promotes cancer cell migration and invasion by crosslinking actin filaments into bundles. However, the molecular mehcanisms underlying the regulation of fascin bundling activity are not completely understood. In this study we examine the regulation of Fascin activity by monoubiquitination. IP and LC-MS/MS was used to identify the posttranslational modification of Fascin A novel chemical monoubiquitination method was employed to synthesize monoubiquitinated Fascin. The monoubiquitinated fascin was purified, and the effect of monoubiquitination on fascin bundling activity was determined using low speed sedimentation assay, fluorescence microscopy and transmission electron microscopy. Here we identified monoubiquitination as a novel mechanism that regulates fascin bundling activity and dynamics. The monoubiquitination sites were identified to be K247 and K250, two residues located in a positive charge patch at the actin binding site 2 (ABS2) of fascin. Using a chemical ubiquitination method, we synthesized chemically monoubiquitinated fascin (mUb-fascin) and determined the effects of monoubiquitination on fascin bundling activity and dynamics. Our data demonstrated that monoubiquitination decreased the fascin bundling EC50, delayed the initiation of bundle assembly and accelerated the disassembly of existing bundles. By analyzing the electrostatic properties on the solvent accessible surface of fascin, we proposed that monoubiquitination introduced steric hindrance to interfere with the interaction between actin filaments and the positively charged patch at ABS2. Mutation of the monoubiquitination sites (K247 and K 250) to arginine inhibited fascin monoubiquitination and enhanced pro-migration ability of fascin, supporting the notion that monoubiquitination inhibit fascin activity. We also identified Smurf1 as an E3 ligase regulating the monoubiquitination of fascin. Our findings revealed a previously unidentified regulatory mechanism for fascin, which will have important implications for the understanding of actin bundle regulation under physiological and pathological conditions.
Citation Format: Shengchen Lin, Shuang Lu, Mentor Mulaj, Bin Fang, Tyler Keeley, Lixin Wan, Jihui Hao, Martin Muschol, Jianwei Sun, Shengyu Yang. Monoubiquitination inhibits the actin bundling activity of fascin [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5333. doi:10.1158/1538-7445.AM2017-5333
Abstract 5335: Dissecting the ubiquitin pathway using homogenous and sensitive bioluminescent assay
Authors: Goueli Said A. , Hsiao Kevin , Mondal Subhanjan 
Published: July 2017

Abstract
Post-translational modification of target proteins by ubiquitin (Ub) and ubiquitin-like (Ubl) proteins is a fundamental mechanism for regulating protein functions and protein stability thus affecting diverse cellular processes. Several ubiquitin-like (Ubl) molecules have been identified including SUMO, NEDD8, ATG8/15 and ISG15 which share the ubiquitin fold Ub/Ubl proteins are conjugated to lysine residues in substrate proteins through an ATP-dependent enzymatic cascade involving E1-activating enzyme, E2-conjugating enzyme and E3-ligase. To mark proteins for degradation, multiple ubiquitins are covalently attached to produce a Lys48 linked poly-ubiquitin chain. The poly-ubiquitinated proteins are recognized by the 26S proteasome system and deubiquitinated and destroyed. Substrates with ubiquitin chains linked through Lys 6, 11, 27, 29, 33 also regulate protein degradation. Substrates marked with mono-ubiquitination or Lys63 ubiquitin chains are involved in cell signaling independent of degradative functions. Many diseases are associated with dysfunction of ubiquitin signaling, with the E3 ligase class of enzymes are considered to be the most important target. However, in recent years, evidence have accumulated demonstrating the significance of E2 class of enzymes where mutations and impairment of this class lead to severe diseases states including chromosomal instability, cancer predisposition, neurological syndromes, and immunological disorders. Thus, in addition to E3, E2 group of enzymes represent important class of therapeutic targets. To address the need for developing drugs targeting these enzymes, we have developed a novel assay that can be used to screen for modulators of these enzymes by taking advantage of the first ubiquitin activating enzyme E1 which activates free Ub forming a high-energy thioester bond between E1’s active site Cys and the C-terminus of Ub, generating AMP and pyrophosphate (PPi) as products of the reaction. We monitor the activity of these enzymes by determining the concentration of AMP generated in the reactions in a luminescence-based assay. Our assay interrogate not only E1 but also E2 and E3 in a very robust and sensitive manner. The assay is homogenous, bioluminescent, and show a very high signal to background in a very selective manner for each class of the ubiquitin pathway. The assay was successfully tested for ubiquitination, SUMOlyation and Neddylation reactions and thus can be used for screening of enzymes targeting these pathways.
Citation Format: Said A. Goueli, Kevin Hsiao, Subhanjan Mondal. Dissecting the ubiquitin pathway using homogenous and sensitive bioluminescent assay [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5335. doi:10.1158/1538-7445.AM2017-5335
Abstract 5336: Characterization of selective covalent inhibitors of USP7
Authors: Wang Feng , Wu Jian , Wang Liqing , Sokirniy Ivan , Wang Hui , Grove Charles , Nguyen Phuong , Bregnard Thomas , Weinstock Joseph , Mattern Michael , Hancock Wayne , Bezsonova Irina , Kumar Suresh 
Published: July 2017

Abstract
The ubiquitin-specific protease 7 (USP7) has emerged as an attractive therapeutic target owing to its critical roles in several cancer signaling pathways as well as its essential role in maintaining Foxp3+ T-regulatory cell (Treg) functions. Pharmacological inhibition of USP7 using Progenra’s small molecule inhibitors resulted in direct anti-tumor activity as well as the unleashing of anti-tumor immunity by suppressing Treg functions. However, the precise mechanism of action these compounds was not well characterized. Using a combination of NMR spectroscopy, mass spectrometry, and single amino acid substitution approaches, we have now demonstrated that our USP7 inhibitors specifically target the catalytic cleft of USP7 and covalently modify its active site cysteine (Cys223). Pharmacokinetic studies revealed sustained irreversible USP7 inhibition after short term inhibitor treatment as well as subsequent changes in the level and ubiquitylation of various pharmacodynamic markers, including the Treg lineage specific transcription factor Foxp3. Detailed knowledge of the mechanism of USP7 inhibition has allowed us to incorporate rational design strategies into the lead optimization to obtain improved
molecules that will serve as the basis of a new class of anti-cancer immunotherapy agents.
Citation Format: Feng Wang, Jian Wu, Liqing Wang, Ivan Sokirniy, Hui Wang, Charles Grove, Phuong Nguyen, Thomas Bregnard, Joseph Weinstock, Michael Mattern, Wayne Hancock, Irina Bezsonova, Suresh Kumar. Characterization of selective covalent inhibitors of USP7 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5336. doi:10.1158/1538-7445.AM2017-5336
Abstract 5337: USP26 regulates TGF-β signaling by deubiquitinating and stabilizing SMAD7
Authors: Eichhorn Pieter J.A. , Lui Sarah , Iyengar Prasanna , Jaynes Patrick 
Published: July 2017

Abstract
The amplitude of transforming growth factor-β (TGF-β) signal is tightly regulated to ensure appropriate physiological responses. As part of negative feedback loop SMAD7, a direct transcriptional target of downstream TGF-β signaling, acts as a scaffold to recruit the E3 ligase SMURF2 to target the TGF-β receptor complex for ubiquitin mediated degradation. Here we identify the deubiquitinating enzyme USP26 as a novel integral component of this negative feedback loop. We demonstrate that TGF-β rapidly enhances the expression of USP26 and reinforces SMAD7 stability by limiting the ubiquitin mediated turnover of SMAD7. Conversely, knockdown of USP26 rapidly degrades SMAD7 resulting in TGF-β receptor stabilization and enhanced levels of p-SMAD2. Clinically, loss of USP26 correlates with high TGF-β activity and confers poor prognosis in glioblastoma. Our data identify USP26 as a novel negative regulator of the TGF-β pathway and suggests that loss of USP26 expression may be an important factor in glioblastoma pathogenesis.
Citation Format: Pieter J.A. Eichhorn, Sarah Lui, Prasanna Iyengar, Patrick Jaynes. USP26 regulates TGF-β signaling by deubiquitinating and stabilizing SMAD7 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5337. doi:10.1158/1538-7445.AM2017-5337
Abstract 5339: Molecular phylogenetic classification of human papillomaviruses and cancer associated genes: In correlation with cervical cancer manifestation
Authors: Idoko John , Faruk Mohammed , Yaro Jigo , Enemari James , Akpulu Peter 
Published: July 2017

Abstract
Human papillomaviruses (HPVs) are a diverse group of small double stranded Deoxyribonucleic acid viruses implicated in many malignancies including cervical cancer. The viruses are also attributed to premalignant epithelial lesions in this disease. Cervical cancer is a leading course of morbidity and mortality in African women and beyond. We aimed to study the molecular phylogenetic classification of HPVs and cervical cancer associated genes in relation with tumour manifestation. Phylogenetic tree was constructed based on nucleotide sequence alignments using ClustalX 2.1 algorithms to classify 31 different HPV DNA virus types and 10 cervical cancer associated genes. Study of immunohistochemistry markers associated with cervical cancer pathology was performed. The nucleotide sequences used include HPV- 1 (V01116), HPV-14 (D90261), HPV-20 (D90262), HPV-21 (D90263), HPV-25 (D90264), HPV-5 (M22961), HPV-47 (M32305), HPV-8 (M12737), HPV-2 (X55964), HPV-57 (X55965), HPV-6: X00203), HPV-11 (M14119), HPV-13 (X62843), HPV-43 (HE962420.1 E6 gene), HPV-44 (U31788.1), HPV-42 (HE820226.1 E6 gene for E6 protein), HPV-16 (K02718), HPV 16 (KJ869425.1 E6 and E7 variants), HPV-35 (M74117), HPV-31 (J04353), HPV-52 (KJ869430.1), HPV-33 (M12732), HPV-58 (D90400), HPV-51 (M62877), HPV-18 (X05015), HPV-45 (M27363), HPV-39 (M38185), (ME180, M73258), HPV 16 (KJ869425.1 E6 and E7 variants), Ki-67 (NM_002417.4), p53 (AB082923.1), EGFR (NM_005228.3), MYC (M25803.1), KRAS (EF471957.1), TGF-B (AF254794.1) and RB (AH002963.2) genes. The resulting phylogenetic tree provides a conventional classification of the HPVs and the cancer genes into groups encompassing the known tissue tropism and oncogenic potential of each gene type associated with the disease. The implications of a phylogenetic taxonomy on the diagnostic detection of HPVs as they relate to cervical cancer associate genes are shown to be important in disease management.
Citation Format: John Idoko, Mohammed Faruk, Jigo Yaro, James Enemari, Peter Akpulu. Molecular phylogenetic classification of human papillomaviruses and cancer associated genes: In correlation with cervical cancer manifestation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5339. doi:10.1158/1538-7445.AM2017-5339
Abstract 5341: HPV16 E6 oncoprotein modulates the DPPIV/CD26 in primary keratinocytes
Authors: Beckenkamp Aline , Prati Bruna , Maria-Engler Silvya Stuchi , Lenz Guido , Pilger Diogo André , Pierulivo Enrique Mario , Buffon Andréia 
Published: July 2017

Abstract
Cervical cancer is related to the persistent infection by high-risk human papillomavirus (HPV) subtypes, such as types 16 and 18. The E6 and E7 oncoproteins significantly contribute to the carcinogenic potential of high-risk HPV, through the degradation of p53 and pRb, respectively. The exoprotease dipeptidyl peptidase IV (DPPIV) also known as CD26, is a multifunctional protein involved in several processes related to cancer. DPPIV/CD26 has an intrinsic peptidase activity, able to degrade some bioactive peptides and chemokines, thereby regulating cell migration, proliferation and survival. It has been reported that the reduction in DPPIV/CD26 expression is associated with tumor progression in different types of cancer. Moreover, studies in cervical cancer samples and cell lines point to a reduction in the expression of this protein. However, there are no studies addressing the relationship between HPV infection and DPPIV/CD26 expression. We analyzed the influence of HPV oncoproteins on DPPIV/CD26 expression in human keratinocyte transduced with E6, E7 and E6E7. We observed that HPV16 E6 expression is associated to a reduction in DPPIV/CD26 expression at mRNA and protein levels, whereas HPV16 E7 does not affect DPPIV/CD26 expression. HPV16 E6E7 co-expression leads to a reduction in DPPIV/CD26 expression similar to that found in E6 transduced cells. In addition, we note a more pronounced reduction in DPPIV/CD26 expression in immortalized cells expressing E6E7. Furthermore, keratinocytes expressing HPV16 E6 mutant sequence and HPV11 E6, that do not bind to E6AP and do not degrade p53, have no effect on DPPIV/CD26 expression. Our results suggest that the HPV16 E6 oncoprotein can downregulates DPPIV/CD26. In addition, preliminary results suggest that modulation of DPPIV/CD6 mediated by E6 can be dependent on degradation of p53, since HPV16 E6 mutant and low-risk HPV E6 were not able to affect CD26 expression. Furthermore, the process of cell immortalization also appears to be related to the reduction of DPPIV/CD26 expression. Therefore, these results indicate that HPV oncoproteins promote imbalance DPPIV/CD26 expression which may be relate to cervical carcinogenesis.
Citation Format: Aline Beckenkamp, Bruna Prati, Silvya Stuchi Maria-Engler, Guido Lenz, Diogo André Pilger, Enrique Mario Pierulivo, Andréia Buffon. HPV16 E6 oncoprotein modulates the DPPIV/CD26 in primary keratinocytes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5341. doi:10.1158/1538-7445.AM2017-5341
Abstract 5343: The HIV shell protein Gp120 stimulates U87 glioma cell proliferation through the activation of glycolysis
Authors: Valentin-Guillama Gabriel , Lopez Sheila , Perez Jose , Cubano Luis , Chorna Natalia , Harrison Jeffrey , Boukli Nawal , Kucheryavykh Lilia 
Published: July 2017

Abstract
Patients infected with human immunodeficiency virus (HIV) are more prone to develop cancers, including glioblastomas (GBM). The median survival of GBM patients with HIV is significantly shorter compared to HIV-negative GBM patients, despite the fact that they receive the same treatments. This indicates that HIV infection is associated with more aggressive tumor behavior and with treatment resistance. Taking into account that HIV itself is not found in GBM specimens, the nature of the GBM-HIV association remains poorly understood and the underlying molecular mechanism is still unknown. Here we study the effect of Gp120, a glycoprotein found in the HIV shell, on GBM cell growth and chemotherapeutic resistance. U87 glioma cells were used in this study. Flow cytometry analyses based on 7-aminoactinomycin D staining and viability assays were used for identification of cell cycle, proliferation rates, and resistance to temozolomide (TMZ). Combined proteomics, metabolomics, and western blot approaches together with colorimetric pyruvate kinase activity assays were used for evaluation of metabolic pathways. U87 cells treated with Gp120 (200ng/ml) for 10 days showed higher proliferation rates and increased cell survival in response to treatment with TMZ (100µM) compared to un-treated cells. Quantitative proteomics studies using isobaric tags and western blot analysis identified expression up-regulation of several glycolytic enzymes, including enolase 2, pyruvate kinase, hexokinase, and glyceraldehyde 3-phosphate dehydrogenase in Gp120 treated U87 cells. Additionally, metabolite analysis revealed an increase of pyruvate, amino acid and lipid synthesis, together with reduction of protein degradation, in response to treatment with Gp120. In summary, we demonstrated that Gp120 promoted proliferation and resistance to TMZ in U87 cells through the activation of glycolysis, resulting in increased protein and lipid synthesis This research was made possible by NIH grant numbers: 1SC2GM102040, R25GM110513, INBRE-PR NIH Grant 8P20GM103475, the UCC RCMI Biomedical Proteomics Facility grant G12MD007583 and US Department of Education Grant number P031S130068.
Citation Format: Gabriel Valentin-Guillama, Sheila Lopez, Jose Perez, Luis Cubano, Natalia Chorna, Jeffrey Harrison, Nawal Boukli, Lilia Kucheryavykh. The HIV shell protein Gp120 stimulates U87 glioma cell proliferation through the activation of glycolysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5343. doi:10.1158/1538-7445.AM2017-5343