bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mutational Inactivation of Herpes Simplex Virus 1 MicroRNAs Identifies Viral mRNA Targets and Reveals Phenotypic Effects in Culture
Authors: Flores Omar , Nakayama Sanae , Whisnant Adam W. , Javanbakht Hassan , Cullen Bryan R. , Bloom David C. 
Published: March 2013

ABSTRACT
Herpes simplex virus 1 (HSV-1), a ubiquitous human pathogen, expresses several viral microRNAs (miRNAs). These, along with the latency-associated transcript, represent the only viral RNAs detectable in latently infected neuronal cells. Here, for the first time, we analyze which HSV-1 miRNAs are loaded into the RNA-induced silencing complex (RISC), the key effector of miRNA function. Only 9 of the 17 reported HSV-1 miRNAs, i.e., miR-H1 to miR-H8 plus miR-H11, were found to actually load into the RISC. Surprisingly, this analysis also revealed that HSV-1 miRNAs loaded into the RISC with efficiencies that differed widely; <1% of the miR-H1-3p miRNA detectable in HSV-1-infected cells was loaded into the RISC. Analysis of HSV-1 mutants individually lacking the viral miR-H2, miR-H3, or miR-H4 miRNA revealed that loss of these miRNAs affected the rate of replication of HSV-1 in neuronal cells but not in fibroblasts. Analysis of mRNA and protein expression, as well as assays mapping viral miRNA binding sites in infected cells, showed that endogenous HSV-1 miR-H2 binds to viral ICP0 mRNA and inhibits its expression, while endogenous miR-H4 inhibits the expression of the viral ICP34.5 gene. In contrast, no viral mRNA target for miR-H3 could be detected, even though miR-H3, like miR-H4, is perfectly complementary to ICP34.5 mRNA. Together, these data demonstrate that endogenous HSV-1 miRNA expression can significantly alter viral replication in culture, and they also identify two viral mRNA targets for miR-H2 and miR-H4 that can partially explain this phenotype.
Guanine-Nucleotide Exchange Factor RCC1 Facilitates a Tight Binding between the Encephalomyocarditis Virus Leader and Cellular Ran GTPase
Authors: Petty Ryan V. , Palmenberg Ann C. 
Published: March 2013

ABSTRACT

The leader (L) protein of encephalomyocarditis virus (EMCV) shuts off host cell nucleocytoplasmic trafficking (NCT) by inducing hyperphosphorylation of nuclear pore proteins. This dramatic effect by a nonenzymatic protein of 6 kDa is not well understood but clearly involves L binding to cellular Ran GTPase, a critical factor of active NCT. Exogenous GDP and GTP are inhibitory to L-Ran binding, but the guanine-nucleotide exchange factor RCC1 can relieve this inhibition. In the presence of RCC1, L binds Ran with a

K
D

(equilibrium dissociation constant) of ∼3 nM and reaches saturation within 20 min. The results of fluorescently tagged nucleotide experiments suggest that L-Ran interactions affect the nucleotide-binding pocket of Ran.
A Comparison of Murine Leukemia Viruses That Escape from Human and Rhesus Macaque TRIM5αs
Authors: Ohkura Sadayuki , Stoye Jonathan P. 
Published: March 2013

ABSTRACT
To better understand the binding mechanism of TRIM5α to retrovirus capsid, we had previously selected N-tropic murine leukemia virus (N-MLV) mutants escaping from rhesus macaque TRIM5α (rhTRIM5α) by passaging the virus in rhTRIM5α-expressing cells and selecting for nonrestricted variants. To test the commonality of the findings from the rhTRIM5α study, we have now employed a similar genetic approach using human TRIM5α (huTRIM5α). Consistent with the rhTRIM5α study, the mapped huTRIM5α escape mutations were distributed across the capsid exterior, confirming the extended binding surface between virus and restriction factor. Compared to the results of the previous study, fewer escape mutations were identified, with particular mutants being repeatedly selected. Three out four huTRIM5α escape variants showed resistance to all primate TRIM5αs tested, but two of them sacrificed viral fitness, observations that were not made in the rhTRIM5α study. Moreover, differences in amino acid changes associated with escape from hu- and rhTRIM5αs suggested a charge dependence of the restriction by different TRIM5αs. Taken together, these results suggest that the recognition of the entire capsid surface is a general strategy for TRIM5α to restrict MLV but that significantly different specific interactions are involved in the binding of TRIM5α from different species to the MLV capsid core.
The ULb′ Region of the Human Cytomegalovirus Genome Confers an Increased Requirement for the Viral Protein Kinase UL97
Authors: Wang Depeng , Li Gang , Schauflinger Martin , Nguyen Christopher C. , Hall Ellie D. , Yurochko Andrew D. , von Einem Jens , Kamil Jeremy P. 
Published: March 2013

ABSTRACT

We report a requirement for the viral protein kinase UL97 in human cytomegalovirus (HCMV) replication that maps to the ULb′ region of the viral genome. A UL97-null (Δ97) mutant of strain TB40/E, which encodes a full-length ULb′ region, exhibited replication defects, particularly in production of cell-free virus, that were more severe than those seen with a Δ97 mutant of laboratory strain AD169, which harbors extensive deletions in its ULb′ region. These differences were recapitulated with additional HCMV strains by treatment with a UL97 kinase inhibitor, 1-(β-
l
-ribofuranosyl)-2-isopropylamino-5,6-dichlorobenzimidazole (maribavir). We observed lower levels of viral DNA synthesis and an increased requirement for UL97 in viral late gene expression in strains with full-length ULb′ regions. Analysis of UL97-deficient TB40/E infections by electron microscopy revealed fewer C-capsids in nuclei, unusual viral particles in the cytoplasmic assembly compartment, and defective viral nuclear egress. Partial inhibition of viral DNA synthesis caused defects in production of cell-free virus that were up to ∼100-fold greater than those seen with cell-associated virus in strains TB40/E and TR, suggesting that UL97-dependent defects in cell-free virus production in strains with full-length ULb′ regions were secondary to DNA synthesis defects. Accordingly, a chimeric virus in which the ULb′ region of TB40/E was replaced with that of AD169 showed reduced effects of UL97 inhibition on viral DNA synthesis, late gene expression, and production of cell-free virus compared to parental TB40/E. Together, these results argue that the ULb′ region encodes a factor(s) which invokes an increased requirement for UL97 during viral DNA synthesis.
Sigma-1 Receptor Regulates Early Steps of Viral RNA Replication at the Onset of Hepatitis C Virus Infection
Authors: Friesland Martina , Mingorance Lidia , Chung Josan , Chisari Francis V. , Gastaminza Pablo 
Published: March 2013

ABSTRACT

Hepatitis C virus (HCV) genome replication is thought to occur in a membranous cellular compartment derived from the endoplasmic reticulum (ER). The molecular mechanisms by which these membrane-associated replication complexes are formed during HCV infection are only starting to be unraveled, and both viral and cellular factors contribute to their formation. In this study, we describe the discovery of nonopioid sigma-1 receptor (S1R) as a cellular factor that mediates the early steps of viral RNA replication. S1R is a cholesterol-binding protein that resides in lipid-rich areas of the ER and in mitochondrion-associated ER membranes (MAMs). Several functions have been ascribed to this ER-resident chaperone, many of which are related to Ca
2+
signaling at the MAMs and lipid storage and trafficking. Downregulation of S1R expression by RNA interference (RNAi) in Huh-7 cells leads to a proportional decrease in susceptibility to HCV infection, as shown by reduced HCV RNA accumulation and intra- and extracellular infectivity in single-cycle infection experiments. Similar RNAi studies in persistently infected cells indicate that S1R expression is not rate limiting for persistent HCV RNA replication, as marked reduction in S1R in these cells does not lead to any decrease in HCV RNA or viral protein expression. However, subgenomic replicon transfection experiments indicate that S1R expression is rate limiting for HCV RNA replication without impairing primary translation. Overall, our data indicate that the initial steps of HCV infection are regulated by S1R, a key component of MAMs, suggesting that these structures could serve as platforms for initial RNA replication during HCV infection.
Pandemic influenza in Papua New Guinea: a modelling study comparison with pandemic spread in a developed country
Authors: Milne George J , Baskaran Pravin , Halder Nilimesh , Karl Stephan , Kelso Joel 
Published: March 2013

ObjectivesThe possible occurrence of a highly pathogenic influenza strain is of concern to health authorities worldwide. It is known that during past influenza pandemics developing countries have experienced considerably higher death rates compared with developed countries. Furthermore, many developing countries lack appropriate pandemic preparedness plans. Mathematical modelling studies to guide the development of such plans are largely focused on predicting pandemic influenza spread in developed nations. However, intervention strategies shown by modelling studies to be highly effective for developed countries give limited guidance as to the impact which an influenza pandemic may have on low-income countries given different demographics and resource constraints. To address this, an individual-based model of a Papua New Guinean (PNG) community was created and used to simulate the spread of a novel influenza strain. The results were compared with those obtained from a comparable Australian model.DesignA modelling study.SettingThe towns of Madang in PNG (population ∼35 000) and Albany (population ∼30 000) in Australia.Outcome measuresDaily and cumulative illness attack rates in both models following introduction of a novel influenza strain into a naive population, for an unmitigated scenario and two social distancing intervention scenarios.ResultsThe unmitigated scenario indicated an approximately 50% higher attack rate in PNG compared with the Australian model. The two social distancing-based interventions strategies were 60–70% less effective in a PNG setting compared with an Australian setting.ConclusionsThis study provides further evidence that an influenza pandemic occurring in a low-income country such as PNG may have a greater impact than one occurring in a developed country, and that PNG-feasible interventions may be substantially less effective. The larger average household size in PNG, the larger proportion of the population under 18 and greater community-wide contact all contribute to this feature.
Study protocol for a randomised controlled double-blinded trial of the dose-dependent efficacy and safety of primaquine for clearance of gametocytes in children with uncomplicated falciparum malaria in Uganda
Authors: Eziefula Alice Chijioke , Staedke Sarah G , Yeung Shunmay , Webb Emily , Kamya Moses , White Nicholas J , Bousema Teun , Drakeley Chris 
Published: March 2013

ObjectivesFor the purpose of blocking transmission ofPlasmodium falciparummalaria from humans to mosquitoes, a single dose of primaquine is recommended by the WHO as an addition to artemisinin combination therapy. Primaquine clears gametocytes but causes dose-dependent haemolysis in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Evidence is needed to inform the optimal dosing of primaquine for malaria elimination programmes and for the purpose of interrupting the spread of artemisinin-resistant malaria. This study investigates the efficacy and safety of reducing doses of primaquine for clearance of gametocytes in participants with normal G6PD status.Methods and analysisIn this prospective, four-armed randomised placebo-controlled double-blinded trial, children aged 1–10 years, weighing over 10 kg, with haemoglobin ≥8 g/dl and uncomplicatedP falciparummalaria are treated with artemether lumefantrine and randomised to receive a dose of primaquine (0.1, 0.4 or 0.75 mg base/kg) or placebo on the third day of treatment. Participants are followed up for 28 days. Gametocytaemia is measured by quantitative nucleic acid sequence-based analysis on days 0, 2, 3, 7, 10 and 14 with a primary endpoint of the number of days to gametocyte clearance in each treatment arm and secondarily the area under the curve of gametocyte density over time. Analysis is for non-inferiority of efficacy compared to the reference dose, 0.75 mg base/kg. Safety is assessed by pair-wise comparisons of the arithmetic mean (±SD) change in haemoglobin concentration per treatment arm and analysed for superiority to placebo and incidence of adverse events. Ethics and dissemination Approval was obtained from the ethical committees of Makerere University School of Medicine, the Ugandan National Council of Science and Technology and the London School of Hygiene and Tropical Medicine.ResultsThese will be disseminated to inform malaria elimination policy, through peer-reviewed publication and academic presentations.
From IEDs to AIDS? Detection of HIV in human corpses by rapid screening tests after suspected intentional transmission in terrorist attacks
Authors: Frickmann Hagen , Wulff B , Loderstædt U , Hagen R M , Sturm D , Polywka S 
Published: March 2013

ObjectivesWe evaluated the feasibility of intentional transmission of HIV by means of suicide bombing and rape as a terrorist tactic in asymmetric conflicts by evaluating the recognised optimum conditions for biological warfare. We also estimated the suitability of a fourth-generation rapid test for HIV detection in the blood of dead terrorists killed in the completion of their mission.MethodsThe feasibility of deliberate transmission of HIV for terroristic ends was evaluated on the basis of published experience from passive biological warfare research. In addition, blood from four recently deceased HIV-positive patients and four HIV-negative control corpses, stored at 4°C in a mortuary, was analysed at 12, 24, 36 and 48 h postmortem by rapid serological testing.ResultsThe feasibility of HIV infection for terroristic purposes was established. The fourth-generation HIV rapid test we evaluated identified all HIV-positive samples and was negative for all HIV-negative samples.ConclusionsRapid HIV testing from the remains of dead terrorists in the deployed military environment is possible. Samples should be acquired quickly, basic sample preparation is advisable and consequent decisions concerning postexposure prophylaxis should take into account the diagnostic gap in early infections.
Myeloid-Derived Suppressor Cells as a Vehicle for Tumor-Specific Oncolytic Viral Therapy
Authors: Eisenstein Samuel , Coakley Brian A. , Briley-Saebo Karen , Ma Ge , Chen Hui-ming , Meseck Marcia , Ward Stephen , Divino Celia , Woo Savio , Chen Shu-Hsia , Pan Ping-Ying 
Published: March 2013

AbstractOne of the several impediments to effective oncolytic virus therapy of cancer remains a lack of tumor-specific targeting. Myeloid-derived suppressor cells (MDSC) are immature myeloid cells induced by tumor factors in tumor-bearing hosts. The biodistribution kinetics of MDSC and other immune cell types in a murine hepatic colon cancer model was investigated through the use of tracking markers and MRI. MDSCs were superior to other immune cell types in preferential migration to tumors in comparison with other tissues. On the basis of this observation, we engineered a strain of vesicular stomatitis virus (VSV), an oncolytic rhabdovirus that bound MDSCs and used them as a delivery vehicle. Improving VSV-binding efficiency to MDSCs extended the long-term survival of mice bearing metastatic colon tumors compared with systemic administration of wild-type VSV alone. Survival was further extended by multiple injections of the engineered virus without significant toxicity. Notably, direct tumor killing was accentuated by promoting MDSC differentiation towards the classically activated M1-like phenotype. Our results offer a preclinical proof-of-concept for using MDSCs to facilitate and enhance the tumor-killing activity of tumor-targeted oncolytic therapeutics. Cancer Res; 73(16); 5003–15. ©2013 AACR.
Loss of TGF-β Adaptor β2SP Activates Notch Signaling and SOX9 Expression in Esophageal Adenocarcinoma
Authors: Song Shumei , Maru Dipen M. , Ajani Jaffer A. , Chan Chia-Hsin , Honjo Soichiro , Lin Hui-Kuan , Correa Arlene , Hofstetter Wayne L. , Davila Marta , Stroehlein John , Mishra Lopa 
Published: March 2013

Abstract
TGF-β and Notch signaling pathways play important roles in regulating self-renewal of stem cells and gastrointestinal carcinogenesis. Loss of TGF-β signaling components activates Notch signaling in esophageal adenocarcinoma, but the basis for this effect has been unclear. Here we report that loss of TGF-β adapter β2SP (SPNB2) activates Notch signaling and its target SOX9 in primary fibroblasts or esophageal adenocarcinoma cells. Expression of the stem cell marker SOX9 was markedly higher in esophageal adenocarcinoma tumor tissues than normal tissues, and its higher nuclear staining in tumors correlated with poorer survival and lymph node invasion in esophageal adenocarcinoma patients. Downregulation of β2SP by lentivirus short hairpin RNA increased SOX9 transcription and expression, enhancing nuclear localization for both active Notch1 (intracellular Notch1, ICN1) and SOX9. In contrast, reintroduction into esophageal adenocarcinoma cells of β2SP and a dominant-negative mutant of the Notch coactivator mastermind-like (dnMAN) decreased SOX9 promoter activity. Tumor sphere formation and invasive capacity in vitro and tumor growth in vivo were increased in β2SP-silenced esophageal adenocarcinoma cells. Conversely, SOX9 silencing rescued the phenotype of esophageal adenocarcinoma cells with loss of β2SP. Interaction between Smad3 and ICN1 via Smad3 MH1 domain was also observed, with loss of β2SP increasing the binding between these proteins, inducing expression of Notch targets SOX9 and C-MYC, and decreasing expression of TGF-β targets p21(CDKN1A), p27 (CDKN1B), and E-cadherin. Taken together, our findings suggest that loss of β2SP switches TGF-β signaling from tumor suppression to tumor promotion by engaging Notch signaling and activating SOX9. Cancer Res; 73(7); 2159–69. ©2013 AACR.
Common Genetic Polymorphisms Modify the Effect of Smoking on Absolute Risk of Bladder Cancer
Authors: Garcia-Closas Montserrat , Rothman Nathaniel , Figueroa Jonine D. , Prokunina-Olsson Ludmila , Han Summer S. , Baris Dalsu , Jacobs Eric J. , Malats Nuria , De Vivo Immaculata , Albanes Demetrius , Purdue Mark P. , Sharma Sapna , Fu Yi-Ping , Kogevinas Manolis , Wang Zhaoming , Tang Wei , Tardón Adonina , Serra Consol , Carrato Alfredo , García-Closas Reina , Lloreta Josep , Johnson Alison , Schwenn Molly , Karagas Margaret R. , Schned Alan , Andriole Gerald , Grubb Robert , Black Amanda , Gapstur Susan M. , Thun Michael , Diver William Ryan , Weinstein Stephanie J. , Virtamo Jarmo , Hunter David J. , Caporaso Neil , Landi Maria Teresa , Hutchinson Amy , Burdett Laurie , Jacobs Kevin B. , Yeager Meredith , Fraumeni Joseph F. , Chanock Stephen J. , Silverman Debra T. , Chatterjee Nilanjan 
Published: March 2013

Abstract
Bladder cancer results from the combined effects of environmental and genetic factors, smoking being the strongest risk factor. Evaluating absolute risks resulting from the joint effects of smoking and genetic factors is critical to assess the public health relevance of genetic information. Analyses included up to 3,942 cases and 5,680 controls of European background in seven studies. We tested for multiplicative and additive interactions between smoking and 12 susceptibility loci, individually and combined as a polygenic risk score (PRS). Thirty-year absolute risks and risk differences by levels of the PRS were estimated for U.S. males aged 50 years. Six of 12 variants showed significant additive gene–environment interactions, most notably NAT2 (P = 7 × 10−4) and UGT1A6 (P = 8 × 10−4). The 30-year absolute risk of bladder cancer in U.S. males was 6.2% for all current smokers. This risk ranged from 2.9% for current smokers in the lowest quartile of the PRS to 9.9% for current smokers in the upper quartile. Risk difference estimates indicated that 8,200 cases would be prevented if elimination of smoking occurred in 100,000 men in the upper PRS quartile compared with 2,000 cases prevented by a similar effort in the lowest PRS quartile (Padditive = 1 × 10−4). Thus, the potential impact of eliminating smoking on the number of bladder cancer cases prevented is larger for individuals at higher than lower genetic risk. Our findings could have implications for targeted prevention strategies. However, other smoking-related diseases, as well as practical and ethical considerations, need to be considered before any recommendations could be made. Cancer Res; 73(7); 2211–20. ©2012 AACR.
Trop-2 Promotes Prostate Cancer Metastasis By Modulating β1 Integrin Functions
Authors: Trerotola Marco , Jernigan Danielle L. , Liu Qin , Siddiqui Javed , Fatatis Alessandro , Languino Lucia R. 
Published: March 2013

Abstract
The molecular mechanisms underlying metastatic dissemination are still not completely understood. We have recently shown that β1 integrin-dependent cell adhesion to fibronectin and signaling is affected by a transmembrane molecule, Trop-2, which is frequently upregulated in human carcinomas. Here, we report that Trop-2 promotes metastatic dissemination of prostate cancer cells in vivo and is abundantly expressed in metastasis from human prostate cancer. We also show here that Trop-2 promotes prostate cancer cell migration on fibronectin, a phenomenon dependent on β1 integrins. Mechanistically, we demonstrate that Trop-2 and the α5β1 integrin associate through their extracellular domains, causing relocalization of α5β1 and the β1-associated molecule talin from focal adhesions to the leading edges. Trop-2 effect is specific as this molecule does not modulate migration on vitronectin, does not associate with the major vitronectin receptor, αvβ3 integrin, and does not affect localization of αvβ3 integrin as well as vinculin in focal adhesions. We show that Trop-2 enhances directional prostate cancer cell migration, through modulation of Rac1 GTPase activity. Finally, we show that Trop-2 induces activation of PAK4, a kinase that has been reported to mediate cancer cell migration. In conclusion, we provide the first evidence that β1 integrin-dependent migratory and metastatic competence of prostate cancer cells is enhanced by Trop-2. Cancer Res; 73(10); 3155–67. ©2013 AACR.
The Multifaceted Role of the Microenvironment in Liver Metastasis: Biology and Clinical Implications
Authors: Van den Eynden Gert G. , Majeed Ali W. , Illemann Martin , Vermeulen Peter B. , Bird Nigel C. , Høyer-Hansen Gunilla , Eefsen Rikke Løvendahl , Reynolds Andrew R. , Brodt Pnina 
Published: March 2013

AbstractThe liver is host to many metastatic cancers, particularly colorectal cancer, for which the last 2 decades have seen major advances in diagnosis and treatment. The liver is a vital organ, and the extent of its involvement with metastatic disease is a major determinant of survival. Metastatic cells arriving in the liver via the bloodstream encounter the microenvironment of the hepatic sinusoid. The interactions of the tumor cells with hepatic sinusoidal and extrasinusoidal cells (endothelial, Kupffer, stellate, and inflammatory cells) determine their fate. The sinusoidal cells can have a dual role, sometimes fatal to the tumor cells but also facilitatory to their survival and growth. Adhesion molecules participate in these interactions and may affect their outcome. Bone marrow–derived cells and chemokines also play a part in the early battle for survival of the metastases. Once the tumor cells have arrested and survived the initial onslaught, tumors can grow within the liver in 3 distinct patterns, reflecting differing host responses, mechanisms of vascularization, and proteolytic activity. This review aims to present current knowledge of the interactions between the host liver cells and the invading metastases that has implications for the clinical course of the disease and the response to treatment. Cancer Res; 73(7); 2031–43. ©2013 AACR.