bluuebunny/crossref_metadata_2025_split huggingface dataset:
Foamy Virus Nuclear RNA Export Is Distinct from That of Other Retroviruses
Authors: Bodem Jochen , Schied Tanja , Gabriel Richard , Rammling Matthias , Rethwilm Axel 
Published: December 2010

ABSTRACT
Most retroviruses express all of their genes from a single primary transcript. In order to allow expression of more than one gene from this RNA, differential splicing is extensively used. Cellular quality control mechanisms retain and degrade unspliced or partially spliced RNAs in the nucleus. Two pathways have been described that explain how retroviruses circumvent this nuclear export inhibition. One involves a constitutive transport element in the viral RNA that interacts with the cellular mRNA transporter proteins NXF1 and NXT1 to facilitate nuclear export. The other pathway relies on the recognition of a viral RNA element by a virus-encoded protein that interacts with the karyopherin CRM1. In this report, we analyze the protein factors required for the nuclear export of unspliced foamy virus (FV) mRNA. We show that this export is CRM1 dependent. In contrast to other complex retroviruses, FVs do not encode an export-mediating protein. Cross-linking experiments indicated that the cellular protein HuR binds to the FV RNA. Inhibition studies showed that both ANP32A and ANP32B, which are known to bridge HuR and CRM1, are essential for FV RNA export. By using this export pathway, FVs solve a central problem of viral replication.
Identification of Two Functional Domains within the Arenavirus Nucleoprotein
Authors: Levingston Macleod Jesica M. , D'Antuono Alejandra , Loureiro Maria Eugenia , Casabona Juan Cruz , Gomez Guillermo A. , Lopez Nora 
Published: December 2010

ABSTRACT

Tacaribe virus (TCRV) belongs to the
Arenaviridae
family. Its bisegmented negative-stranded RNA genome encodes the nucleoprotein (N), the precursor of the envelope glycoproteins, the polymerase (L), and a RING finger matrix (Z) protein. The 570-amino-acid N protein binds to viral RNA, forming nucleocapsids, which are the template for transcription and replication by the viral polymerase. We have previously shown that the interaction between N and Z is required for assembly of infectious virus-like particles (VLPs) (J. C. Casabona et al., J. Virol. 83:7029-7039, 2009). Here, we examine the functional organization of TCRV N protein. A series of deletions and point mutations were introduced into the N-coding sequence, and the ability of the mutants to sustain heterotypic (N-Z) or homotypic (N-N) interactions was analyzed. We found that N protein displays two functional domains. By using coimmunoprecipitation studies, VLP incorporation assays, and double immunofluorescence staining, the carboxy-terminal region of N was found to be required for N-Z interaction and also necessary for incorporation of N protein into VLPs. Moreover, further analysis of this region showed that the integrity of a putative zinc-finger motif, as well as its amino-flanking sequence (residues 461 to 489), are critical for Z binding and N incorporation into VLPs. In addition, we provide evidence of an essential role of the amino-terminal region of N protein for N-N interaction. In this regard, using reciprocal coimmunoprecipitation analysis, we identified a 28-residue region predicted to form a coiled-coil domain (residues 92 to 119) as a newly recognized molecular determinant of N homotypic interactions.
Phosphorylation and Polyubiquitination of Transforming Growth Factor β-Activated Kinase 1 Are Necessary for Activation of NF-κB by the Kaposi's Sarcoma-Associated Herpesvirus G Protein-Coupled Receptor
Authors: Bottero Virginie , Kerur Nagaraj , Sadagopan Sathish , Patel Kinjan , Sharma-Walia Neelam , Chandran Bala 
Published: December 2010

ABSTRACT
Kaposi's sarcoma-associated herpesvirus (KSHV) G protein-coupled receptor (vGPCR) protein has been shown to induce several signaling pathways leading to the modulation of host gene expression. The hijacking of these pathways facilitates the viral life cycle and leads to tumorigenesis. In the present work, we show that transforming growth factor β (TGF-β)-activated kinase 1 (TAK1) is an important player in NF-κB activation induced by vGPCR. We observed that the expression of an inactive TAK1 kinase mutant (TAK1M) reduces vGPCR-induced NF-κB nuclear translocation and transcriptional activity. Consequently, the expression of several NF-κB target genes normally induced by vGPCR was blocked by TAK1M expression, including interleukin 8 (IL-8), Gro1, IκBα, COX-2, cIAP2, and Bcl2 genes. Similar results were obtained after downregulation of TAK1 by small interfering RNA (siRNA) technology. The expression of vGPCR recruited TAK1 to the plasma membrane, and vGPCR interacts with TAK1. vGPCR expression also induced TAK1 phosphorylation and lysine 63-linked polyubiquitination, the two markers of the kinase's activation. Finally, inhibition of TAK1 by celastrol inhibited vGPCR-induced NF-κB activation, indicating this natural compound could be used as a potential therapeutic drug against KSHV malignancies involving vGPCR.
Cell-Associated Viral Burden Provides Evidence of Ongoing Viral Replication in Aviremic HIV-2-Infected Patients
Authors: Soares Rui S. , Tendeiro Rita , Foxall Russell B. , Baptista António P. , Cavaleiro Rita , Gomes Perpétua , Camacho Ricardo , Valadas Emília , Doroana Manuela , Lucas Margarida , Antunes Francisco , Victorino Rui M. M. , Sousa Ana E. 
Published: December 2010

ABSTRACTViremia is significantly lower in HIV-2 than in HIV-1 infection, irrespective of disease stage. Nevertheless, the comparable proviral DNA burdens observed for these two infections indicate similar numbers of infected cells. Here we investigated this apparent paradox by assessing cell-associated viral replication. We found that untreated HIV-1-positive (HIV-1+) and HIV-2+individuals, matched for CD4 T cell depletion, exhibited similargagmRNA levels, indicating that significant viral transcription is occurring in untreated HIV-2+patients, despite the reduced viremia (undetectable to 2.6 × 104RNA copies/ml). However,tatmRNA transcripts were observed at significantly lower levels in HIV-2+patients, suggesting that the rate ofde novoinfection is decreased in these patients. Our data also reveal a direct relationship ofgagandtattranscripts with CD4 and CD8 T cell activation, respectively. Antiretroviral therapy (ART)-treated HIV-2+patients showed persistent viral replication, irrespective of plasma viremia, possibly contributing to the emergence of drug resistance mutations, persistent hyperimmune activation, and poor CD4 T cell recovery that we observed with these individuals. In conclusion, we provide here evidence of significant ongoing viral replication in HIV-2+patients, further emphasizing the dichotomy between amount of plasma virus and cell-associated viral burden and stressing the need for antiretroviral trials and the definition of therapeutic guidelines for HIV-2 infection.
Phylogeography of West Nile Virus: from the Cradle of Evolution in Africa to Eurasia, Australia, and the Americas
Authors: May Fiona J. , Davis C. Todd , Tesh Robert B. , Barrett Alan D. T. 
Published: December 2010

ABSTRACTWest Nile virus (WNV) is the most widely distributed of the encephalitic flaviviruses and is a major cause of encephalitis, with isolates obtained from all continents, apart from Antarctica. Subsequent to its divergence from the other members of the Japanese encephalitis virus complex, presumably in Africa, WNV has diverged into individual lineages that mostly correspond with geographic distribution. Here we elucidate the phylogeography and evolutionary history of isolates from lineage 1 of WNV. Interestingly, there are many examples of the same amino acid having evolved independently on multiple occasions. In Africa, WNV exists in an endemic cycle, whereas it is epidemic in Europe, being reintroduced regularly from Africa either directly (in western Europe) or via the Middle East (in eastern Europe). Significantly, introduction into other geographic areas has occurred on one occasion only in each region, leading to subsequent establishment and expansion of the virus in these areas. Only one endemic genotype each is present in India and Australia, suggesting that WNV was successfully introduced into these locations once only. Each introduction occurred many centuries ago, probably due to trade and exploration during the 19th century. Likewise, in the Americas, WNV was successfully introduced in 1999 and subsequently became endemic across most temperate regions of North America (NA). In contrast to previous suggestions, an isolate from the epidemic in Israel in 1998 was not the direct progenitor of the NA epidemic; rather, both epidemics originated from the same (unknown) location.
Functional Characterization of Kaposi's Sarcoma-Associated Herpesvirus Open Reading Frame K8 by Bacterial Artificial Chromosome-Based Mutagenesis
Authors: Wang Yan , Sathish Narayanan , Hollow Charles , Yuan Yan 
Published: December 2010

ABSTRACT

The open reading frame K8 of Kaposi's sarcoma-associated herpesvirus (KSHV) encodes a basic leucine zipper (bZip) protein that binds to the origin of viral DNA replication and is an integral component of viral lytic DNA replication complex. Moreover, K8 physically interacts with replication and transcription activator (RTA) and represses its transactivation activity on several viral promoters. To investigate the role of this protein in viral life cycle, we constructed two K8-null recombinant mutant viruses (BAC-ΔK8 and BAC-stopK8) by using a bacterial artificial chromosome (BAC) system. Latent viral infection can be reconstituted in 293T and BJAB cells with wild-type and the K8-null recombinant viruses by introducing the cloned viral genomes into the cells. When the cells carrying these viruses were induced with 12-
O
-tetradecanoylphorbol-13-acetate (TPA) and sodium butyrate, no significant difference was seen in overall viral gene expression between wild-type and K8-null viruses, with lytic DNA replication still active in the latter. However, 293T cells harboring K8-null mutant viruses, either BAC-ΔK8 or BAC-stopK8, displayed lower copy numbers of latent KSHV genome in comparison with wild-type viruses. Furthermore, although K8 deficiency appeared to not affect infectivity when K8-null viruses were used to infect 293T, primary human microvascular dermal endothelial and human foreskin fibroblast cells, they exhibited much lower viral genome copy numbers in all types of cell compared to wild-type viruses. Taken together, these data suggest a possible role of K8 in abortive lytic DNA replication occurring in early stages of
de novo
infection or in the maintenance of latent viral genomes.
Molecular Mechanism of MART-1+/A*0201+ Human Melanoma Resistance to Specific CTL-Killing Despite Functional Tumor–CTL Interaction
Authors: Jazirehi Ali R. , Baritaki Stavroula , Koya Richard C. , Bonavida Benjamin , Economou James S. 
Published: December 2010

Abstract
Durable responses in metastatic melanoma patients remain generally difficult to achieve. Adoptive cell therapy (ACT) with ex vivo engineered lymphocytes expressing high affinity T-cell receptors (TCRα/β) for the melanoma antigen MART-127–35/HLA-A*0201 [recognized by F5 cytotoxic T lymphocytes (F5 CTL)] has been found to benefit certain patients. However, many other patients are inherently unresponsive and/or relapse for unknown reasons. To analyze the basis for the acquired resistance and strategies to reverse it, we established F5 CTL–resistant (R) human melanoma clones from relatively sensitive parental lines under selective F5 CTL pressure. Surface MART-127–35/HLA-A*0201 in these clones was unaltered and F5 CTLs recognized and interacted with them similar to the parental lines. Nevertheless, the R clones were resistant to F5 CTL killing, exhibited hyperactivation of the NF-κB survival pathway, and overexpression of the antiapoptotic genes B cell lymphoma protein 2 (Bcl-2), Bcl-2 related gene (long alternatively spliced variant of Bcl-x gene; Bcl-xL), and myeloid cell differentiation 1 (Mcl-1). Sensitivity to F5 CTL-killing could be increased by pharmacological inhibition of the NF-κB pathway, Bcl-2 family members, or the proteasome, the latter of which reduced NF-κB activity and diminished antiapoptotic gene expression. Specific gene-silencing (by siRNA) confirmed the protective role of antiapoptotic factors by reversing R clone resistance. Together, our findings suggest that long-term immunotherapy may impose a selection for the development of resistant cells that are unresponsive to highly avid and specific melanoma-reactive CTLs, despite maintaining expression of functional peptide:MHC complexes, due to activation of antiapoptotic signaling pathways. Though unresponsive to CTL, our results argue that resistant cells can be resensitized to immunotherapy with coadministration of targeted inhibitors to antiapoptotic survival pathways. Cancer Res; 71(4); 1406–17. ©2010 AACR.
Targeting RNA Polymerase I with an Oral Small Molecule CX-5461 Inhibits Ribosomal RNA Synthesis and Solid Tumor Growth
Authors: Drygin Denis , Lin Amy , Bliesath Josh , Ho Caroline B. , O'Brien Sean E. , Proffitt Chris , Omori Mayuko , Haddach Mustapha , Schwaebe Michael K. , Siddiqui-Jain Adam , Streiner Nicole , Quin Jaclyn E. , Sanij Elaine , Bywater Megan J. , Hannan Ross D. , Ryckman David , Anderes Kenna , Rice William G. 
Published: December 2010

AbstractDeregulated ribosomal RNA synthesis is associated with uncontrolled cancer cell proliferation. RNA polymerase (Pol) I, the multiprotein complex that synthesizes rRNA, is activated widely in cancer. Thus, selective inhibitors of Pol I may offer a general therapeutic strategy to block cancer cell proliferation. Coupling medicinal chemistry efforts to tandem cell- and molecular-based screening led to the design of CX-5461, a potent small-molecule inhibitor of rRNA synthesis in cancer cells. CX-5461 selectively inhibits Pol I–driven transcription relative to Pol II–driven transcription, DNA replication, and protein translation. Molecular studies demonstrate that CX-5461 inhibits the initiation stage of rRNA synthesis and induces both senescence and autophagy, but not apoptosis, through a p53-independent process in solid tumor cell lines. CX-5461 is orally bioavailable and demonstrates in vivo antitumor activity against human solid tumors in murine xenograft models. Our findings position CX-5461 for investigational clinical trials as a potent, selective, and orally administered agent for cancer treatment. Cancer Res; 71(4); 1418–30. ©2010 AACR.
B7-H1 Overexpression Regulates Epithelial–Mesenchymal Transition and Accelerates Carcinogenesis in Skin
Authors: Cao Yujia , Zhang Lu , Kamimura Yosuke , Ritprajak Patcharee , Hashiguchi Masaaki , Hirose Sachiko , Azuma Miyuki 
Published: December 2010

Abstract
B7-H1 (CD274) is a T-cell coinhibitory molecule that is also often induced on human carcinoma cells, where its expression has been implicated in immune escape. Under inflammatory conditions, B7-H1 is also inducible in normal epithelial cells but little is known about its involvement in conversion of normal cells to tumor cells. Here, we show that skin-specific expression of B7-H1 accelerates inflammatory carcinogenesis in a methylcholantrene (MCA)-induced model of squamous cell carcinoma (SCC). Inflammatory responses induced by MCA or phorbol ester TPA were clearly inhibited in B7-H1 transgenic mice (B7-H1tg mice). Antibody-mediated blockade of either B7-H1 or the related molecule PD-1 revealed that their ability to limit inflammation relied on ligand interactions made by B7-H1 or PD-1. Skin keratinocytes derived from B7-H1tg mice exhibited constitutive reduction of E-cadherin, and SCC induced in B7-H1tg mice also showed loss of E-cadherin along with elevated expression of the transcription factors Slug and Twist that drive epithelial–mesenchymal transition (EMT). Our results indicate that upregulation of B7-H1 in skin epithelial cells promotes EMT and accelerates carcinogenesis, revealing insights into the significance of B7-H1 overexpression on solid tumor cells and hinting at a close relationship between EMT and immune escape signaling pathways in cancer. Cancer Res; 71(4); 1235–43. ©2010 AACR.
Induction of Monocyte Chemoattractant Protein-1 and Interleukin-10 by TGFβ1 in Melanoma Enhances Tumor Infiltration and Immunosuppression
Authors: Díaz-Valdés Nancy , Basagoiti María , Dotor Javier , Aranda Fernando , Monreal Iñaki , Riezu-Boj José Ignacio , Borrás-Cuesta Francisco , Sarobe Pablo , Feijoó Esperanza 
Published: December 2010

AbstractMelanoma progression is associated with the expression of different growth factors, cytokines, and chemokines. Because TGFβ1 is a pleiotropic cytokine involved not only in physiologic processes but also in cancer development, we analyzed in A375 human melanoma cells, the effect of TGFβ1 on monocyte chemoattractant protein-1 (MCP-1) and interleukin-10 (IL-10) expression, two known factors responsible for melanoma progression. TGFβ1 increased the expression of MCP-1 and IL-10 in A375 cells, an effect mediated by the cross-talk between Smad, PI3K (phosphoinositide 3-kinase)/AKT, and BRAF-MAPK (mitogen activated protein kinase) signaling pathways. Supernatants from TGFβ1-treated A375 cells enhanced MCP-1–dependent migration of monocytes, which, in turn, expressed high levels of TGF,β1, bFGF, and VEGF mRNA. Moreover, these supernatants also inhibited functional properties of dendritic cells through IL-10–dependent mechanisms. When using in vitro, the TGFβ1-blocking peptide P144, TGFβ1-dependent Smad3 phosphorylation, and expression of MCP-1 and IL-10 were inhibited. In vivo, treatment of A375 tumor–bearing athymic mice with P144 significantly reduced tumor growth, associated with a lower macrophage infiltrate and decreased intratumor MCP-1 and VEGF levels, as well as angiogenesis. Finally, in C57BL/6 mice with B16-OVA melanoma tumors, when administered with immunotherapy, P144 decreased tumor growth and intratumor IL-10 levels, linked to enhanced activation of dendritic cells and natural killer cells, as well as anti-OVA T-cell responses. These results show new effects of TGFβ1 on melanoma cells, which promote tumor progression and immunosuppression, strongly reinforcing the relevance of this cytokine as a molecular target in melanoma. Cancer Res; 71(3); 812–21. ©2011 AACR.
Fes Tyrosine Kinase Expression in the Tumor Niche Correlates with Enhanced Tumor Growth, Angiogenesis, Circulating Tumor Cells, Metastasis, and Infiltrating Macrophages
Authors: Zhang Shengnan , Chitu Violeta , Stanley E. Richard , Elliott Bruce E. , Greer Peter A. 
Published: December 2010

Abstract
Fes is a protein tyrosine kinase with cell autonomous oncogenic activities that are well established in cell culture and animal models, but its involvement in human cancer has been unclear. Abundant expression of Fes in vascular endothelial cells and myeloid cell lineages prompted us to explore roles for Fes in the tumor microenvironment. In an orthotopic mouse model of breast cancer, we found that loss of Fes in the host correlated with reductions in engrafted tumor growth rates, metastasis, and circulating tumor cells. The tumor microenvironment in Fes-deficient mice also showed reduced vascularity and fewer macrophages. In co-culture with tumor cells, Fes-deficient macrophages also poorly promoted tumor cell invasive behavior. Taken together, our observations argue that Fes inhibition might provide therapeutic benefits in breast cancer, in part by attenuating tumor-associated angiogenesis and the metastasis-promoting functions of tumor-associated macrophages. Cancer Res; 71(4); 1465–73. ©2010 AACR.
Regulatory Role of mir-203 in Prostate Cancer Progression and Metastasis
Authors: Saini Sharanjot , Majid Shahana , Yamamura Soichiro , Tabatabai Laura , Suh Seong O. , Shahryari Varahram , Chen Yi , Deng Guoren , Tanaka Yuichiro , Dahiya Rajvir 
Published: December 2010

Abstract
Purpose: Advanced metastatic prostate cancer (PCa) is a fatal disease, with only palliative therapeutic options. Though almost 80% of cases of metastatic PCa present bone metastasis, our current understanding of the molecular mechanisms that govern this metastatic dissemination remains fragmentary. The main objective of the present study was to identify microRNA (miRNA) genes that regulate metastatic PCa.
Experimental Design: miRNA expression profiling was done in human prostate cell lines to identify dysregulated miRNA components of advanced PCa. miR-203 expression was assessed in prostate carcinoma cell lines and clinical specimens by real-time PCR and in situ hybridization. To assess the biological significance of miR-203, miR-203 was reexpressed in bone metastatic PCa cell lines followed by in vitro and in vivo functional assays.
Results: miR-203 expression is specifically attenuated in bone metastatic PCa suggesting a fundamental antimetastatic role for this miRNA. Reintroduction of miR-203 in bone metastatic PCa cell lines suppresses metastasis via inhibition of several critical steps of the metastatic cascade including epithelial-mesenchymal transition, invasion, and motility. Ectopic miR-203 significantly attenuated the development of metastasis in a bone metastatic model of PCa. Importantly, miR-203 regulates a cohort of pro-metastatic genes including ZEB2, Bmi, survivin, and bone-specific effectors including Runx2, a master regulator of bone metastasis.
Conclusions: miR-203 is an “antimetastatic” miRNA in PCa that acts at multiple steps of the PCa metastatic cascade via repression of a cohort of prometastatic targets. miR-203 may be an attractive target for therapeutic intervention in advanced PCa. Clin Cancer Res; 17(16); 5287–98. ©2011 AACR.
Development and Validation of the Atrial Fibrillation Effect on QualiTy-of-Life (AFEQT) Questionnaire in Patients With Atrial Fibrillation
Authors: Spertus John , Dorian Paul , Bubien Rosemary , Lewis Steve , Godejohn Donna , Reynolds Matthew R. , Lakkireddy Dhanunjaya R. , Wimmer Alan P. , Bhandari Anil , Burk Caroline 
Published: December 2010

Background—
Atrial fibrillation (AF) has a deleterious impact on health-related quality-of-life (HRQoL), but measuring this outcome is difficult. A comprehensive, validated, disease-specific questionnaire to measure the spectrum of QoL domains affected by AF and its treatment is not available. We developed and validated a 20-item questionnaire, Atrial Fibrillation Effect on QualiTy-of-life (AFEQT), in a 6-center, prospective, observational study.

Methods and Results—
Factor analyses established 4 conceptual domains (Symptoms, Daily Activities, Treatment Concern, and Treatment Satisfaction) from which individual domain and global scores were calculated. Participants from 6 centers completed the AFEQT at baseline, at month 1, and at month 3. Psychometric analyses included internal consistency and known-group validity. Test-retest reliability was assessed by comparing 1-month changes in scores among those with no change in therapy. Effect size was used to assess responsiveness after intervention. Among 219 patients age 62±11.9 years, 94% completed the AFEQT at baseline and 3 months; 66% had paroxysmal, 24% persistent, 5% longstanding persistent, and 5% permanent AF. Internal consistency was >0.88 for all scales. Lower AFEQT scores were observed with increased AF severity, categorized as asymptomatic, mild, moderate and severe, respectively: 71.2±20.6, 71.3±19.2, 57.9±19.0, and 42.0±21.2. Intraclass correlations for Overall, Symptoms, Daily Activities, Treatment Concern, and Satisfaction scores were 0.8, 0.5, 0.8, 0.7, and 0.7, respectively. Changes in 3-month scores were larger after ablation than with pharmacological adjustments, and both were greater than those observed in stable patients.

Conclusions—
This initial validation of AFEQT supports its use as an outcome in studies and a means to clinically follow patients with AF.