bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deep Sequencing Reveals Mutagenic Effects of Ribavirin during Monotherapy of Hepatitis C Virus Genotype 1-Infected Patients
Authors: Dietz Julia , Schelhorn Sven-Eric , Fitting Daniel , Mihm Ulrike , Susser Simone , Welker Martin-Walter , Füller Caterina , Däumer Martin , Teuber Gerlinde , Wedemeyer Heiner , Berg Thomas , Lengauer Thomas , Zeuzem Stefan , Herrmann Eva , Sarrazin Christoph 
Published: March 2013

ABSTRACTThe preeminent mode of action of the broad-spectrum antiviral nucleoside ribavirin in the therapy of chronic hepatitis C is currently unresolved. Particularly under contest are possible mutagenic effects of ribavirin that may lead to viral extinction by lethal mutagenesis of the hepatitis C virus (HCV) genome. We applied ultradeep sequencing to determine ribavirin-induced sequence changes in the HCV coding region (nucleotides [nt] 330 to 9351) of patients treated with 6-week ribavirin monotherapy (n= 6) in comparison to placebo (n= 6). Baseline HCV RNA levels maximally declined on average by −0.8 or −0.1 log10IU/ml in ribavirin- versus placebo-treated patients. No general increase in rates of nucleotide substitutions in ribavirin-treated patients was observed. However, more HCV genome positions with high G-to-A and C-to-U transition rates were detected between baseline and treatment week 6 in ribavirin-treated patients in comparison to placebo-treated patients (rate of 0.0041 transitions per base pair versus rate of 0.0022 transitions per base pair;P= 0.049). Similarly, the sensitive detection of low-frequency minority variants by statistical filtering indicated significantly more positions with G-to-A and C-to-U transitions in ribavirin-treated patients than in placebo-treated patients (rate of 0.0331 transitions versus rate of 0.0186 transitions per G/C-containing position at baseline;P= 0.018). In contrast, non-ribavirin-associated A-to-G and U-to-C transitions were not enriched in the ribavirin group (P= 0.152). We conclude that ribavirin exerts a mutagenic effect on the virus in patients with chronic hepatitis C by facilitating G-to-A and C-to-U nucleotide transitions.
MDA5 Localizes to Stress Granules, but This Localization Is Not Required for the Induction of Type I Interferon
Authors: Langereis Martijn A. , Feng Qian , van Kuppeveld Frank J. 
Published: March 2013

ABSTRACT
Virus infection can initiate a type I interferon (IFN-α/β) response via activation of the cytosolic RNA sensors retinoic acid-inducible gene-I (RIG-I) and melanoma differentiation-associated gene 5 (MDA5). Furthermore, it can activate kinases that phosphorylate eukaryotic translation initiation factor 2α (eIF2α), which leads to inhibition of (viral) protein translation and formation of stress granules (SG). Most viruses have evolved mechanisms to suppress these cellular responses. Here, we show that a mutant mengovirus expressing an inactive leader (L) protein, which we have previously shown to be unable to suppress IFN-α/β, triggered SG formation in a protein kinase R (PKR)-dependent manner. Furthermore, we show that infection of cells that are defective in SG formation yielded higher viral RNA levels, suggesting that SG formation acts as an antiviral defense mechanism. Since the induction of both IFN-α/β and SG is suppressed by mengovirus L, we set out to investigate a potential link between these pathways. We observed that MDA5, the intracellular RNA sensor that recognizes picornaviruses, localized to SG. However, activation of the MDA5 signaling pathway did not trigger and was not required for SG formation. Moreover, cells that were unable to form SG—by protein kinase R (PKR) depletion, using cells expressing a nonphosphorylatable eIF2α protein, or by drug treatment that inhibits SG formation—displayed a normal IFN-α/β response. Thus, although MDA5 localizes to SG, this localization seems to be dispensable for induction of the IFN-α/β pathway.
The Receptor Attachment Function of Measles Virus Hemagglutinin Can Be Replaced with an Autonomous Protein That Binds Her2/
neu
While Maintaining Its Fusion-Helper Function
Authors: Rasbach Anke , Abel Tobias , Münch Robert C. , Boller Klaus , Schneider-Schaulies Jürgen , Buchholz Christian J. 
Published: March 2013

ABSTRACT

Cell entry of enveloped viruses is initiated by attachment to the virus receptor followed by fusion between the virus and host cell membranes. Measles virus (MV) attachment to its receptor is mediated by the hemagglutinin (H), which is thought to produce conformational changes in the membrane fusion protein (F) that trigger insertion of its fusion peptide into the target cell membrane. Here, we uncoupled receptor attachment and the fusion-helper function of H by introducing Y481A, R533A, S548L, and F549S mutations into the viral attachment protein that made it blind to its normal receptors. An artificial receptor attachment protein specific for Her2/
neu
was incorporated into the membranes of pseudotyped lentivirus particles as a separate transmembrane protein along with the F protein. Surprisingly, these particles entered efficiently into Her2/
neu
-positive SK-OV-3 as well as CHO-Her2 cells. Cell entry was independent of endocytosis but strictly dependent on the presence of H. H-specific monoclonal antibodies, as well as a mutation in H interfering with H/F cooperation, blocked cell entry. The particles mediated stable and specific transfer of reporter genes into Her2/
neu
-positive human tumor cells also
in vivo
, while exhibiting improved infectivity and higher titers than Her2/
neu
-targeted vectors displaying the targeting domain on H. Extending the current model of MV cell entry, the data suggest that receptor binding of H is not required for its fusion-helper function but that particle-cell contact in general may be sufficient to induce the conformational changes in the H/F complex and activate membrane fusion.
TMPRSS2 Activates the Human Coronavirus 229E for Cathepsin-Independent Host Cell Entry and Is Expressed in Viral Target Cells in the Respiratory Epithelium
Authors: Bertram Stephanie , Dijkman Ronald , Habjan Matthias , Heurich Adeline , Gierer Stefanie , Glowacka Ilona , Welsch Kathrin , Winkler Michael , Schneider Heike , Hofmann-Winkler Heike , Thiel Volker , Pöhlmann Stefan 
Published: March 2013

ABSTRACT

Infection with human coronavirus 229E (HCoV-229E) is associated with the common cold and may result in pneumonia in immunocompromised patients. The viral spike (S) protein is incorporated into the viral envelope and mediates infectious entry of HCoV-229E into host cells, a process that depends on the activation of the S-protein by host cell proteases. However, the proteases responsible for HCoV-229E activation are incompletely defined. Here we show that the type II transmembrane serine proteases TMPRSS2 and HAT cleave the HCoV-229E S-protein (229E-S) and augment 229E-S-driven cell-cell fusion, suggesting that TMPRSS2 and HAT can activate 229E-S. Indeed, engineered expression of TMPRSS2 and HAT rendered 229E-S-driven virus-cell fusion insensitive to an inhibitor of cathepsin L, a protease previously shown to facilitate HCoV-229E infection. Inhibition of endogenous cathepsin L or TMPRSS2 demonstrated that both proteases can activate 229E-S for entry into cells that are naturally susceptible to infection. In addition, evidence was obtained that activation by TMPRSS2 rescues 229E-S-dependent cell entry from inhibition by IFITM proteins. Finally, immunohistochemistry revealed that TMPRSS2 is coexpressed with CD13, the HCoV-229E receptor, in human airway epithelial (HAE) cells, and that CD13
+
TMPRSS2
+
cells are preferentially targeted by HCoV-229E, suggesting that TMPRSS2 can activate HCoV-229E in infected humans. In sum, our results indicate that HCoV-229E can employ redundant proteolytic pathways to ensure its activation in host cells. In addition, our observations and previous work suggest that diverse human respiratory viruses are activated by TMPRSS2, which may constitute a target for antiviral intervention.
Patients who call emergency ambulances for primary care problems: a qualitative study of the decision-making process
Authors: Booker Matthew J , Simmonds Rosemary L , Purdy Sarah 
Published: March 2013

BackgroundTelephone calls for emergency ambulances are rising annually, increasing the pressure on ambulance resources for clinical problems that could often be appropriately managed in primary care.ObjectiveTo explore and understand patient and carer decision making around calling an ambulance for primary care-appropriate health problems.MethodsSemistructured interviews were conducted with patients and carers who had called an ambulance for a primary care-appropriate problem. Participants were identified using a purposive sampling method by a non-participating research clinician attending ‘999’ ambulance calls. A thematic analysis of interview transcripts was undertaken.ResultsA superordinate theme, patient and carer anxiety in urgent-care decision making, and four subthemes were explored: perceptions of ambulance-based urgent care; contrasting perceptions of community-based urgent care; influence of previous urgent care experiences in decision making; and interpersonal factors in lay assessment and management of medical risk and subsequent decision making.ConclusionsMany calls are based on fundamental misconceptions about the types of treatment other urgent-care avenues can provide, which may be amenable to educational intervention. This is particularly relevant for patients with chronic conditions with frequent exacerbations. Callers who have care responsibilities often default to the most immediate response available, with decision making driven by a lower tolerance of perceived risk. There may be a greater role for more detailed triage in these cases, and closer working between ambulance responses and urgent primary care, as a perceived or actual distance between these two service sectors may be influencing patient decision making on urgent care.
Teaching medical students to recognise their strengths and limitations in leadership, teamwork and communication by military led tutorials
Authors: Clark James , Hall T Falconer , O'Mahony K 
Published: March 2013

ObjectivesThe General Medical Council has stipulated that greater importance must be placed on undergraduate students developing their ability to lead and work effectively as part of a team. Wales Universities’ Officer Training Corps have attempted to meet this requirement through a third year interactive tutorial which aims to encourage students to recognise their strengths and limitations in the six outcomes of leadership, teamwork, accountability, management, feedback and communication.Methods16 tutorial groups of 10–15 students were each led by one officer who divided the tutorial group into three teams. The teams worked on complex planning exercises with an intrateam constructive feedback discussion to raise students’ awareness of their strengths and limitations as individuals during the task, as perceived by others.ResultsThe student perception was that all six learning outcomes were achieved by the session. 163 students returned feedback questionnaires and learning outcomes 1–4 were felt to have been addressed effectively or very effectively by 90%, 91%, 90% and 86% respondents, respectively. The fifth and sixth outcomes were less well achieved with only 66% and 64% respondents agreeing that the outcomes were achieved effectively or very effectively.ConclusionsStudents commended the instructor's demonstration of leadership and the novel teaching method but improvements could be made in reinforcing why these skills are important.
Genetic Susceptibility to Triple-Negative Breast Cancer
Authors: Stevens Kristen N. , Vachon Celine M. , Couch Fergus J. 
Published: March 2013

Abstract
Triple-negative breast cancers (TNBC), defined by the absence of estrogen receptor, progesterone receptor, and HER-2 expression, account for 12% to 24% of all breast cancers. TNBC is associated with early recurrence of disease and poor outcome. Germline mutations in the BRCA1 and BRCA2 breast cancer susceptibility genes have been associated with up to 15% of TNBC, and TNBC accounts for 70% of breast tumors arising in BRCA1 mutation carriers and 16% to 23% of breast tumors in BRCA2 carriers. Whether germline mutations in other breast cancer susceptibility genes also predispose to TNBC remains to be determined. Common variation in a subset of the 72 known breast cancer susceptibility loci identified through genome-wide association studies and other large-scale genotyping efforts have also been associated with risk of TNBC (TOX3, ESR1, RAD51L1, TERT, 19p13.1, 20q11, MDM4, 2p24.1, and FTO). Furthermore, variation in the 19p13.1 locus and the MDM4 locus has been associated with TNBC, but not other forms of breast cancer, suggesting that these are TNBC-specific loci. Thus, TNBC can be distinguished from other breast cancer subtypes by a unique pattern of common and rare germline predisposition alleles. Additional efforts to combine genetic and epidemiologic data are needed to better understand the etiology of this aggressive form of breast cancer, to identify prevention and therapeutic targets, and to impact clinical practice through the development of risk prediction models. Cancer Res; 73(7); 2025–30. ©2012 AACR.
ATF3 Suppresses Metastasis of Bladder Cancer by Regulating Gelsolin-Mediated Remodeling of the Actin Cytoskeleton
Authors: Yuan Xiangliang , Yu Liang , Li Junhua , Xie Guohua , Rong Tingting , Zhang Liang , Chen Jianhua , Meng Qiaohong , Irving Aaron T. , Wang Die , Williams Elizabeth D. , Liu Jun-Ping , Sadler Anthony J. , Williams Bryan R.G. , Shen Lisong , Xu Dakang 
Published: March 2013

Abstract
Bladder cancer is associated with high recurrence and mortality rates due to metastasis. The elucidation of metastasis suppressors may offer therapeutic opportunities if their mechanisms of action can be elucidated and tractably exploited. In this study, we investigated the clinical and functional significance of the transcription factor activating transcription factor 3 (ATF3) in bladder cancer metastasis. Gene expression analysis revealed that decreased ATF3 was associated with bladder cancer progression and reduced survival of patients with bladder cancer. Correspondingly, ATF3 overexpression in highly metastatic bladder cancer cells decreased migration in vitro and experimental metastasis in vivo. Conversely, ATF3 silencing increased the migration of bladder cancer cells with limited metastatic capability in the absence of any effect on proliferation. In keeping with their increased motility, metastatic bladder cancer cells had increased numbers of actin filaments. Moreover, ATF3 expression correlated with expression of the actin filament severing protein gelsolin (GSN). Mechanistic studies revealed that ATF3 upregulated GSN, whereas ATF3 silencing reduced GSN levels, concomitant with alterations in the actin cytoskeleton. We identified six ATF3 regulatory elements in the first intron of the GSN gene confirmed by chromatin immunoprecipitation analysis. Critically, GSN expression reversed the metastatic capacity of bladder cancer cells with diminished levels of ATF3. Taken together, our results indicate that ATF3 suppresses metastasis of bladder cancer cells, at least in part through the upregulation of GSN-mediated actin remodeling. These findings suggest ATF3 coupled with GSN as prognostic markers for bladder cancer metastasis. Cancer Res; 73(12); 3625–37. ©2013 AACR.
Interleukin-1β Promotes Skeletal Colonization and Progression of Metastatic Prostate Cancer Cells with Neuroendocrine Features
Authors: Liu Qingxin , Russell Mike R. , Shahriari Kristina , Jernigan Danielle L. , Lioni Mercedes I. , Garcia Fernando U. , Fatatis Alessandro 
Published: March 2013

Abstract
Despite the progress made in the early detection and treatment of prostate adenocarcinoma, the metastatic lesions from this tumor are incurable. We used genome-wide expression analysis of human prostate cancer cells with different metastatic behavior in animal models to reveal that bone-tropic phenotypes upregulate three genes encoding for the cytokine interleukin-1β (IL-1β), the chemokine CXCL6 (GCP-2), and the protease inhibitor elafin (PI3). The Oncomine database revealed that these three genes are significantly upregulated in human prostate cancer versus normal tissue and correlate with Gleason scores ≥7. This correlation was further validated for IL-1β by immunodetection in prostate tissue arrays. Our study also shows that the exogenous overexpression of IL-1β in nonmetastatic cancer cells promotes their growth into large skeletal lesions in mice, whereas its knockdown significantly impairs the bone progression of highly metastatic cells. In addition, IL-1β secreted by metastatic cells induced the overexpression of COX-2 (PTGS2) in human bone mesenchymal cells treated with conditioned media from bone metastatic prostate cancer cells. Finally, we inspected human tissue specimens from skeletal metastases and detected prostate cancer cells positive for both IL-1β and synaptophysin while concurrently lacking prostate-specific antigen (PSA, KLK3) expression. Collectively, these findings indicate that IL-1β supports the skeletal colonization and metastatic progression of prostate cancer cells with an acquired neuroendocrine phenotype. Cancer Res; 73(11); 3297–305. ©2013 AACR.
Temozolomide-Mediated DNA Methylation in Human Myeloid Precursor Cells: Differential Involvement of Intrinsic and Extrinsic Apoptotic Pathways
Authors: Wang Haiyan , Cai Shanbao , Ernstberger Aaron , Bailey Barbara J. , Wang Michael Z. , Cai Wenjing , Goebel W. Scott , Czader Magdalena B. , Crean Colin , Suvannasankha Attaya , Shokolenkoc Inna , Wilson Glenn L. , Baluyut Arthur R. , Mayo Lindsey D. , Pollok Karen E. 
Published: March 2013

Abstract
Purpose: An understanding of how hematopoietic cells respond to therapy that causes myelosuppression will help develop approaches to prevent this potentially life-threatening toxicity. The goal of this study was to determine how human myeloid precursor cells respond to temozolomide (TMZ)-induced DNA damage.
Experimental Design: We developed an ex vivo primary human myeloid precursor cells model system to investigate the involvement of cell-death pathways using a known myelosuppressive regimen of O6-benzylguanine (6BG) and TMZ.
Results: Exposure to 6BG/TMZ led to increases in p53, p21, γ-H2AX, and mitochondrial DNA damage. Increases in mitochondrial membrane depolarization correlated with increased caspase-9 and -3 activities following 6BG/TMZ treatment. These events correlated with decreases in activated AKT, downregulation of the DNA repair protein O6-methylguanine–DNA methyltransferase (MGMT), and increased cell death. During myeloid precursor cell expansion, FAS/CD95/APO1(FAS) expression increased over time and was present on approximately 100% of the cells following exposure to 6BG/TMZ. Although c-flipshort, an endogenous inhibitor of FAS-mediated signaling, was decreased in 6BG/TMZ–treated versus control, 6BG-, or TMZ alone–treated cells, there were no changes in caspase-8 activity. In addition, there were no changes in the extent of cell death in myeloid precursor cells exposed to 6BG/TMZ in the presence of neutralizing or agonistic anti-FAS antibodies, indicating that FAS-mediated signaling was not operative.
Conclusions: In human myeloid precursor cells, 6BG/TMZ–initiated apoptosis occurred by intrinsic, mitochondrial-mediated and not extrinsic, FAS-mediated apoptosis. Human myeloid precursor cells represent a clinically relevant model system for gaining insight into how hematopoietic cells respond to chemotherapeutics and offer an approach for selecting effective chemotherapeutic regimens with limited hematopoietic toxicity. Clin Cancer Res; 19(10); 2699–709. ©2013 AACR.
Infection and Cancer: Revaluation of the Hygiene Hypothesis
Authors: Oikonomopoulou Katerina , Brinc Davor , Kyriacou Kyriacos , Diamandis Eleftherios P. 
Published: March 2013

AbstractSeveral studies have shown that persistent infections and inflammation can favor carcinogenesis. At the same time, certain types of pathogens and antitumor immune responses can decrease the risk of tumorigenesis or lead to cancer regression. Infectious agents and their products can orchestrate a wide range of host immune responses, through which they may positively or negatively modulate cancer development and/or progression. The factors that direct this dichotomous influence of infection-mediated immunity on carcinogenesis are not well understood. Even though not universal, several previous reports have investigated the inverse link of pathogen-induced “benign” inflammation to carcinogenesis and various other pathologies, ranging from autoimmune diseases to allergy and cancer. Several models and ideas are discussed in this review, including the impact of decreased exposure to pathogens, as well as the influence of pathogen load, the timing of infection, and the type of instigated immune response on carcinogenesis. These phenomena should guide future investigations into identifying novel targets within the microbial and host proteome, which will assist in the development of cancer therapeutics and vaccine remedies, analogous to earlier efforts based on helminthic components for the prevention and/or treatment of several pathologies. Clin Cancer Res; 19(11); 2834–41. ©2013 AACR.
Discovery of a Novel Orally Active Small-Molecule gp130 Inhibitor for the Treatment of Ovarian Cancer
Authors: Xu Shili , Grande Fedora , Garofalo Antonio , Neamati Nouri 
Published: March 2013

Abstract
Interleukin (IL)-6 and Stat3 play key roles in ovarian cancer progression. However, the role of glycoprotein 130 (gp130), the signal transducer of this signaling axis, is not well-established. Currently, there are no small-molecule inhibitors of gp130 under clinical development. In this study, we show that gp130 is an attractive drug target in ovarian cancer due to its role in promoting cancer progression via the activation of its downstream Stat3 signaling. We also present preclinical studies of SC144, the first-in-class orally active small-molecule gp130 inhibitor. SC144 shows greater potency in human ovarian cancer cell lines than in normal epithelial cells. SC144 binds gp130, induces gp130 phosphorylation (S782) and deglycosylation, abrogates Stat3 phosphorylation and nuclear translocation, and further inhibits the expression of downstream target genes. In addition, SC144 shows potent inhibition of gp130 ligand–triggered signaling. Oral administration of SC144 delays tumor growth in a mouse xenograft model of human ovarian cancer without significant toxicity to normal tissues. Mol Cancer Ther; 12(6); 937–49. ©2013 AACR.