bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Burkholderia thailandensis Acyl-Homoserine Lactone-Independent Orphan LuxR Homolog That Activates Production of the Cytotoxin Malleilactone
Authors: Truong Thao T. , Seyedsayamdost Mohammad , Greenberg E. Peter , Chandler Josephine R. 
Published: August 2015

ABSTRACT

Burkholderia thailandensis
has three acyl-homoserine lactone (AHL) LuxR-LuxI quorum-sensing circuits and two orphan LuxR homologs. Orphans are LuxR-type transcription factors that do not have cognate LuxI-type AHL synthases. One of the orphans, MalR, is genetically linked to the
mal
gene cluster, which encodes enzymes required for production of the cytotoxic polyketide malleilactone. Under normal laboratory conditions the
mal
gene cluster is silent; however, antibiotics like trimethoprim induce
mal
transcription. We show that trimethoprim-dependent induction of the
mal
genes requires MalR. MalR has all of the conserved amino acid residues characteristic of AHL-responsive LuxR homologs, but in
B. thailandensis
, MalR activation of malleilactone synthesis genes is not responsive to AHLs. MalR can activate transcription from the
mal
promoter in
E. coli
without addition of AHLs or trimethoprim. Expression of
malR
in
B. thailandensis
is induced by trimethoprim. Our data indicate that MalR binds to a
lux
box-like element in the
mal
promoter and activates transcription of the
mal
genes in an AHL-independent manner. Antibiotics like trimethoprim appear to activate
mal
gene expression indirectly by somehow activating
malR
expression. MalR activation of the
mal
genes represents an example of a LuxR homolog that is not a receptor for an AHL quorum-sensing signal. Our evidence is consistent with the idea that
mal
gene activation depends solely on sufficient transcription of the
malR
gene.

IMPORTANCE
LuxR proteins are transcription factors that are typically activated by acyl-homoserine lactone (AHL) signals. We demonstrate that a conserved LuxR family protein, MalR, activates genes independently of AHLs. MalR is required for transcription of genes coding for synthesis of the cytotoxic polyketide malleilactone. These genes are not expressed when cells are grown under normal laboratory conditions. In laboratory culture, MalR induction of malleilactone requires certain antibiotics, such as trimethoprim, which increase
malR
expression by an unknown mechanism. At sufficient levels of
malR
expression, MalR functions independently of any external signal. Our findings show that MalR is an activator of the silent malleilactone biosynthesis genes and that MalR functions independently of AHLs.
The Bacterial Tyrosine Kinase Activator TkmA Contributes to Biofilm Formation Largely Independently of the Cognate Kinase PtkA in Bacillus subtilis
Authors: Gao Tantan , Greenwich Jennifer , Li Yan , Wang Qi , Chai Yunrong 
Published: August 2015

ABSTRACT

In
Bacillus subtilis
, biosynthesis of exopolysaccharide (EPS), a key biofilm matrix component, is regulated at the posttranslational level by the bacterial tyrosine kinase (BY-kinase) EpsB. EpsB, in turn, relies on the cognate kinase activator EpsA for activation. A concerted role of a second BY-kinase–kinase activator pair, PtkA and TkmA, respectively in biofilm formation was also indicated in previous studies. However, the exact functions of PtkA and TkmA in biofilm formation remain unclear. In this work, we show that the kinase activator TkmA contributes to biofilm formation largely independently of the cognate kinase, PtkA. We further show that the biofilm defect caused by a Δ
tkmA
mutation can be rescued by complementation by
epsA
, suggesting a functional overlap between TkmA and EpsA and providing a possible explanation for the role of TkmA in biofilm formation. We also show that the importance of TkmA in biofilm formation depends largely on medium conditions; the biofilm defect of Δ
tkmA
is very severe in the biofilm medium LBGM (lysogenic broth [LB] supplemented with 1% [vol/vol] glycerol and 100 μM MnSO
4
) but marginal in another commonly used biofilm medium, MSgg (5 mM potassium phosphate [pH 7.0], MOPS [100 mM morpholinepropanesulfonic acid] [pH 7.0], 2 mM MgCl
2
, 700 μM CaCl
2
, 50 μM MnCl
2
, 50 μM FeCl
3
, 1 μM ZnCl
2
, 2 μM thiamine, 0.5% glycerol, 0.5% glutamic acid, 50 μg/ml tryptophan, 50 μg/ml threonine, and 50 μg/ml phenylalanine). The molecular basis for the medium dependence is likely due to differential expression of
tkmA
and
epsA
in the two different media and complex regulation of these genes by both Spo0A and DegU. Our studies provide genetic evidence for possible cross talk between a BY-kinase activator (TkmA) and a noncognate kinase (EpsB) and an example of how environmental conditions may influence such cross talk in regulating biofilm formation in
B. subtilis
.

IMPORTANCE
In bacteria, biosynthesis of secreted polysaccharides is often regulated by bacterial tyrosine kinases (BY-kinases). BY-kinases, in turn, rely on cognate kinase activators for activation. In this study, we investigated the role of a BY-kinase activator in biofilm formation in
Bacillus subtilis
. We present evidence that different BY-kinase activators may functionally overlap each other, as well as an example of how activities of the BY-kinase activators may be highly dependent on environmental conditions. Our study broadens the understanding of the complexity of regulation of the BY-kinases/kinase activators and the influence on bacterial cell physiology.
Self-referral psychological treatment centre for young adults: a 2-year observational evaluation of routine practice before and after treatment
Authors: Halje Karin , Timpka Toomas , Tylestedt Petra , Adler Anna-Karin , Fröberg Lena , Schyman Tommy , Johansson Kristoffer , Dahl Katarina 
Published: August 2015

ObjectivesTo examine a self-referral psychological service provided to young adults with regard to effects on anxiety, depression and psychological distress and to explore client factors predicting non-adherence and non-response.DesignObservational study over a 2-year period.SettingYoung Adults Centre providing psychological services by self-referral (preprimary care) to Linköping, Åtvidaberg, and Kinda municipalities (combined population 145 000) in Östergötland county, Sweden.Participants607 young adults (16–25 years of age); 71% females (n=429).InterventionIndividually scheduled cognitive behavioural therapy delivered in up to six 45 min sessions structured according to an assessment of the client's mental health problems: anxiety, depression, anxiety and depression combined, or decreased distress without specific anxiety or depression.Primary outcome measuresPre–post intervention changes in psychological distress (General Health Questionnaire-12, GHQ-12), Hospital Anxiety and Depression Scale Anxiety/Depression (HADS-A/D).Results192 clients (32.5%) discontinued the intervention on their own initiative and 39 clients (6.6%) were referred to a psychiatric clinic during the course of the intervention. Intention-to-treat analyses including all clients showed a medium treatment effect size (d=0.64) with regard to psychological distress, and small effect sizes were observed with regard to anxiety (d=0.58) and depression (d=0.57). Restricting the analyses to clients who adhered to the agreed programme, a large effect size (d=1.26) was observed with regard to psychological distress, and medium effect sizes were observed with regard to anxiety (d=1.18) and depression (d=1.19). Lower age and a high initial HADS-A score were the strongest risk factors for non-adherence, and inability to concentrate and thinking of oneself as a worthless person increased the risk for discontinuation.ConclusionsWe conclude that provision of psychological services to young people through a self-referral centre has potential to improve long-term mental health in communities, but management of non-adherence remains a central challenge.
Diagnostic performance of S100B protein serum measurement in detecting intracranial injury in children with mild head trauma
Authors: Manzano Sergio , Holzinger Iris Bachmann , Kellenberger Christian J , Lacroix Laurence , Klima-Lange Dagmar , Hersberger Martin , La Scala Giorgio , Altermatt Stefan , Staubli Georg 
Published: August 2015

ObjectiveTo assess the accuracy of S100B serum level to detect intracranial injury in children with mild traumatic brain injury.MethodsA multicenter prospective cohort study was carried out in the paediatric emergency departments of three tertiary hospitals in Switzerland between January 2009 and December 2011. Participants included children aged <16 years with a mild traumatic brain injury (GCS ≥13) for whom a head CT was requested by the attending physician. Venous blood was obtained within 6 h of the trauma in all children for S100B measurement before a head CT was performed. As the S100B value was not available during the acute care period, the patient's management was not altered. The main measures were protein S100B value and the CT result.Results20/73 (27.4%) included children had an intracranial injury detected on CT. S100B receiver operating characteristics area under the curve was 0.73 (95% CI 0.60 to 0.86). With a 0.14 µg/L cut-off point, S100B reached an excellent sensitivity of 95% (95% CI 77% to 100%) and 100% (95% CI 81% to 100%) in all children and in children aged >2 years, respectively. The specificity, however, was 34% (95% CI 27% to 36%) and 37% (95% CI 30% to 37%), respectively.ConclusionsS100B has an excellent sensitivity but poor specificity. It is therefore an accurate tool to help rule out an intracranial injury but cannot be used as the sole marker owing to its specificity. Used with clinical decision rules, S100B may help to reduce the number of unnecessary CT scans.
Tissue factor is unregulated in microvascular endothelial cells of patients with heart failure
Authors: Reichman-Warmusz Edyta , Domal-Kwiatkowska Dorota , Matysiak Natalia , Kurek Józef , Spinczyk Dominik , Dudek Damian , Helewski Krzysztof , Wojnicz Romuald 
Published: August 2015

AimsSeveral lines of evidence point to hypercoagulability as an important factor for heart failure (HF) pathogenesis.MethodsWe hypothesised that endothelial tissue factor (TF) expression reflects altered tissue haemostasis which is related to the severity of HF. Accordingly, we investigated TF expression in the biopsies of 60 patients with HF and 22 without HF. In addition, we assessed the relationship between endothelial TF expression and clinical markers of HF severity.ResultsThe control subjects without HF presented absent or weak TF expression in few microvessels, while the endomyocardial biopsies of patients with HF, capillary vessels presented both weak and severe staining patterns by immunohistochemistry usually with regional distribution. This was collaborated by the immune electron microscopic study. The severe microvessel TF antigen expression was found in 11 (18.3%) patients with HF. The endothelial TF expression was inversely associated with left ventricular ejection fraction (r=−0.42, p=0.001) and positively with N-terminal brain natriuretic peptide (r=0.36, p<0.023), markers of HF severity.ConclusionsRegional upregulation of the TF in the capillary endothelial cells suggests local myocardial thrombogenicity. Furthermore, the relationship between endothelial TF and HF severity would be keeping in line with the hypothesis that an altered tissue haemostasis is most profoundly expressed in patients with severe HF. Weak TF expression found in several microvessels of the biopsy specimens patients without HF pathology might be potentially related to a low basal level of activation of the clotting system in normal individuals.
Risk of recurrence estimates with IHC4+C are tolerant of variations in staining and scoring: an analytical validity study
Authors: Dodson Andrew , Zabaglo Lila , Yeo Belinda , Miller Keith , Smith Ian , Dowsett Mitch 
Published: August 2015

AimsThe IHC4+C score combines assessment of oestrogen receptor (ER), progesterone receptor (PgR), HER2 and Ki67 with clinicopathological parameters to identify the risk of distant disease recurrence in patients with breast cancer, so, aiding treatment decision-making on adjuvant chemotherapy. Despite low cost and wide availability, the reported use of IHC4+C remains limited; one explanation for this is the perception that immunohistochemistry (IHC)-based methods and assessment of them lack precision, reproducibility and portability. We examined the effects of decentralised testing and easily reproducible estimate-based scoring methods on IHC4+C scores to determine its suitability for wider adoption.MethodsSections from a breast cancer tissue micro-array (TMA) were distributed to three centres undertaking diagnostic breast cancer IHC. Centres stained sections using their standard procedures, and returned them for central assessment. The results were compared with those obtained at IHC4+C's originating hospital (Royal Marsden Hospital (RMH)). In parallel, TMA sections stained at RMH were scored by a variety of simplified non-counting-based methods. The results were compared with those produced using counting.ResultsThere was a high degree of correlation between individual IHC results produced by external centres and those of RMH (r: 0.797–0.982), and between risk of distant recurrence scores derived from them (r: 0.972–0.984). Scoring methods for ER and PgR could be adapted to require less precision without significantly affecting correlation with counted results (r: 0.933 and 0.980, respectively), but correlation between estimating and counting for Ki67 was poorer (r: 0.855).ConclusionsIHC4+C is tolerant of variation in staining and scoring methods. Although additional confirmatory comparative studies are required, these data support use of IHC4+C in clinical practice outside RMH.
A Quantitative System for Studying Metastasis Using Transparent Zebrafish
Authors: Heilmann Silja , Ratnakumar Kajan , Langdon Erin M. , Kansler Emily R. , Kim Isabella S. , Campbell Nathaniel R. , Perry Elizabeth B. , McMahon Amy J. , Kaufman Charles K. , van Rooijen Ellen , Lee William , Iacobuzio-Donahue Christine A. , Hynes Richard O. , Zon Leonard I. , Xavier Joao B. , White Richard M. 
Published: August 2015

Abstract
Metastasis is the defining feature of advanced malignancy, yet remains challenging to study in laboratory environments. Here, we describe a high-throughput zebrafish system for comprehensive, in vivo assessment of metastatic biology. First, we generated several stable cell lines from melanomas of transgenic mitfa-BRAFV600E;p53−/− fish. We then transplanted the melanoma cells into the transparent casper strain to enable highly quantitative measurement of the metastatic process at single-cell resolution. Using computational image analysis of the resulting metastases, we generated a metastasis score, μ, that can be applied to quantitative comparison of metastatic capacity between experimental conditions. Furthermore, image analysis also provided estimates of the frequency of metastasis-initiating cells (∼1/120,000 cells). Finally, we determined that the degree of pigmentation is a key feature defining cells with metastatic capability. The small size and rapid generation of progeny combined with superior imaging tools make zebrafish ideal for unbiased high-throughput investigations of cell-intrinsic or microenvironmental modifiers of metastasis. The approaches described here are readily applicable to other tumor types and thus serve to complement studies also employing murine and human cell culture systems. Cancer Res; 75(20); 4272–82. ©2015 AACR.
The miR-146b-3p/PAX8/NIS Regulatory Circuit Modulates the Differentiation Phenotype and Function of Thyroid Cells during Carcinogenesis
Authors: Riesco-Eizaguirre Garcilaso , Wert-Lamas León , Perales-Patón Javier , Sastre-Perona Ana , Fernández Lara P. , Santisteban Pilar 
Published: August 2015

Abstract
The presence of differentiated thyroid cells in thyroid cancer is critical for the antitumor response to radioactive iodide treatment, and loss of the differentiated phenotype is a key hallmark of iodide-refractory metastatic disease. The role of microRNAs (miRNA) in fine-tuning gene expression has become a major regulatory mechanism by which developmental and pathologic processes occur. In this study, we performed next-generation sequencing and expression analysis of eight papillary thyroid carcinomas (PTC) to comprehensively characterize miRNAs involved in loss of differentiation. We found that only a small set of abundant miRNAs is differentially expressed between PTC tissue and normal tissue from the same patient. In addition, we integrated computational prediction of potential targets and mRNA sequencing and identified a master miRNA regulatory network involved in essential biologic processes such as thyroid differentiation. Both mature products of mir-146b (miR-146b-5p and -3p) were among the most abundantly expressed miRNAs in tumors. Specifically, we found that miR-146b-3p binds to the 3′-untranslated region of PAX8 and sodium/iodide symporter (NIS), leading to impaired protein translation and a subsequent reduction in iodide uptake. Furthermore, our findings show that miR-146b and PAX8 regulate each other and share common target genes, thus highlighting a novel regulatory circuit that governs the differentiated phenotype of PTC. In conclusion, our study has uncovered the existence of a miR-146b-3p/PAX8/NIS regulatory circuit that may be exploited therapeutically to modulate thyroid cell differentiation and iodide uptake for improved treatment of advanced thyroid cancer. Cancer Res; 75(19); 4119–30. ©2015 AACR.
Selective Inhibition of Parallel DNA Damage Response Pathways Optimizes Radiosensitization of Glioblastoma Stem-like Cells
Authors: Ahmed Shafiq U. , Carruthers Ross , Gilmour Lesley , Yildirim Salih , Watts Colin , Chalmers Anthony J. 
Published: August 2015

Abstract
Glioblastoma is the most common form of primary brain tumor in adults and is essentially incurable. Despite aggressive treatment regimens centered on radiotherapy, tumor recurrence is inevitable and is thought to be driven by glioblastoma stem-like cells (GSC) that are highly radioresistant. DNA damage response pathways are key determinants of radiosensitivity but the extent to which these overlapping and parallel signaling components contribute to GSC radioresistance is unclear. Using a panel of primary patient-derived glioblastoma cell lines, we confirmed by clonogenic survival assays that GSCs were significantly more radioresistant than paired tumor bulk populations. DNA damage response targets ATM, ATR, CHK1, and PARP1 were upregulated in GSCs, and CHK1 was preferentially activated following irradiation. Consequently, GSCs exhibit rapid G2–M cell-cycle checkpoint activation and enhanced DNA repair. Inhibition of CHK1 or ATR successfully abrogated G2–M checkpoint function, leading to increased mitotic catastrophe and a modest increase in radiation sensitivity. Inhibition of ATM had dual effects on cell-cycle checkpoint regulation and DNA repair that were associated with greater radiosensitizing effects on GSCs than inhibition of CHK1, ATR, or PARP alone. Combined inhibition of PARP and ATR resulted in a profound radiosensitization of GSCs, which was of greater magnitude than in bulk populations and also exceeded the effect of ATM inhibition. These data demonstrate that multiple, parallel DNA damage signaling pathways contribute to GSC radioresistance and that combined inhibition of cell-cycle checkpoint and DNA repair targets provides the most effective means to overcome radioresistance of GSC. Cancer Res; 75(20); 4416–28. ©2015 AACR.
Intratumoral Heterogeneity in EGFR-Mutant NSCLC Results in Divergent Resistance Mechanisms in Response to EGFR Tyrosine Kinase Inhibition
Authors: Soucheray Margaret , Capelletti Marzia , Pulido Inés , Kuang Yanan , Paweletz Cloud P. , Becker Jeffrey H. , Kikuchi Eiki , Xu Chunxiao , Patel Tarun B. , Al-shahrour Fatima , Carretero Julián , Wong Kwok-Kin , Jänne Pasi A. , Shapiro Geoffrey I. , Shimamura Takeshi 
Published: August 2015

Abstract
Non–small cell lung cancers (NSCLC) that have developed resistance to EGF receptor (EGFR) tyrosine kinase inhibitor (TKI), including gefitinib and erlotinib, are clinically linked to an epithelial-to-mesenchymal transition (EMT) phenotype. Here, we examined whether modulating EMT maintains the responsiveness of EGFR-mutated NSCLCs to EGFR TKI therapy. Using human NSCLC cell lines harboring mutated EGFR and a transgenic mouse model of lung cancer driven by mutant EGFR (EGFR-Del19-T790M), we demonstrate that EGFR inhibition induces TGFβ secretion followed by SMAD pathway activation, an event that promotes EMT. Chronic exposure of EGFR-mutated NSCLC cells to TGFβ was sufficient to induce EMT and resistance to EGFR TKI treatment. Furthermore, NSCLC HCC4006 cells with acquired resistance to gefitinib were characterized by a mesenchymal phenotype and displayed a higher prevalence of the EGFR T790M mutated allele. Notably, combined inhibition of EGFR and the TGFβ receptor in HCC4006 cells prevented EMT but was not sufficient to prevent acquired gefitinib resistance because of an increased emergence of the EGFR T790M allele compared with cells treated with gefitinib alone. Conversely, another independent NSCLC cell line, PC9, reproducibly developed EGFR T790M mutations as the primary mechanism underlying EGFR TKI resistance, even though the prevalence of the mutant allele was lower than that in HCC4006 cells. Thus, our findings underscore heterogeneity within NSCLC cells lines harboring EGFR kinase domain mutations that give rise to divergent resistance mechanisms in response to treatment and anticipate the complexity of EMT suppression as a therapeutic strategy. Cancer Res; 75(20); 4372–83. ©2015 AACR.
Enhanced Chemokine Receptor Recycling and Impaired S1P1 Expression Promote Leukemic Cell Infiltration of Lymph Nodes in Chronic Lymphocytic Leukemia
Authors: Patrussi Laura , Capitani Nagaja , Martini Veronica , Pizzi Marco , Trimarco Valentina , Frezzato Federica , Marino Filippo , Semenzato Gianpietro , Trentin Livio , Baldari Cosima T. 
Published: August 2015

Abstract
Lymphocyte trafficking is orchestrated by chemokine and sphingosine 1-phosphate (S1P) receptors that enable homing and egress from secondary lymphoid organs (SLO). These receptors undergo rapid internalization and plasma membrane recycling to calibrate cellular responses to local chemoattractants. Circulating chronic lymphocytic leukemia (CLL) cells display an abnormal increase in the surface levels of the homing receptors CCR7 and CXCR4 concomitant with low S1P receptor 1 (S1P1) expression. In this study, we investigated the role of receptor recycling on CXCR4/CCR7 surface levels in CLL cells and addressed the impact of quantitative alterations of these receptors and S1P1 on the ability of leukemic cells to accumulate in SLOs. We show that recycling accounts, to a major extent, for the high levels of surface CXCR4/CCR7 on CLL cells. In addition, increased expression of these receptors, together with S1P1 deficiency, is detectable not only in circulating leukemic cells, but also in SLOs of CLL patients with lymphoadenopathy. We further provide evidence that ibrutinib, a Btk inhibitor that promotes mobilization of leukemic cells from SLOs, normalizes the imbalance between CXCR4/CCR7 and S1P1. Taken together, our results highlight the relevance of chemokine and S1P receptor recycling in CLL pathogenesis and clinical outcome. Cancer Res; 75(19); 4153–63. ©2015 AACR.