174 research outputs found

    Sodium channel-inhibiting drugs and survival of breast, colon and prostate cancer: a population-based study

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    Metastasis is the leading cause of cancer-related deaths. Voltage-gated sodium channels (VGSCs) regulate invasion and metastasis. Several VGSC-inhibiting drugs reduce metastasis in murine cancer models. We aimed to test the hypothesis that patients taking VGSC-inhibiting drugs who developed cancer live longer than those not taking these drugs. A cohort study was performed on primary care data from the QResearch database, including patients with breast, bowel or prostate cancer. Cox proportional hazards regression was used to compare the survival from cancer diagnosis of patients taking VGSC-inhibiting drugs with those not exposed to these drugs. Median time to death was 9.7 years in the exposed group and 18.4 years in the unexposed group, and exposure to these medications significantly increased mortality. Thus, exposure to VGSC-inhibiting drugs associates with reduced survival in breast, bowel and prostate cancer patients. This finding is not consistent with the preclinical data. Despite the strengths of this study including the large sample size, the study is limited by missing information on potentially important confounders such as cancer stage, co-morbidities and cause of death. Further research, which is able to account for these confounding issues, is needed to investigate the relationship between VGSC-inhibiting drugs and cancer survival

    Dynamic interaction of PTP mu with multiple cadherins in vivo

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    There is a growing body of evidence to implicate reversible tyrosine phosphorylation as an important mechanism in the control of the adhesive function of cadherins. We previously demonstrated that the receptor protein tyrosine phosphatase PTP mu associates with the cadherin-catenin complex in various tissues and cells and, therefore, may be a component of such a regulatory mechanism (Brady-Kalnay, S.M., D.L. Rimm, and N.K. Tonks. 1995. J. Cell Biol. 130:977-986). In this study, we present further characterization of this interaction using a variety of systems. We observed that PTP mu interacted with N-cadherin, E-cadherin, and cadherin-4 (also called R-cadherin) in extracts of rat lung. We observed a direct interaction between PTP mu, and E-cadherin after coexpression in Sf9 cells. In WC5 cells, which express a temperature-sensitive mutant form of v-Src, the complex between PTP mu and E-cadherin was dynamic, and conditions that resulted in tyrosine phosphorylation of E-cadherin were associated with dissociation of PTP mu from the complex. Furthermore, we have demonstrated that the COOH-terminal 38 residues of the cytoplasmic segment of E-cadherin was required for association with PTP mu in WC5 cells. Zondag et al. (Zondag, G., W. Moolenaar, and M. Gebbink. 1996. J. Cell Biol. 134: 1513-1517) have asserted that the association we observed between PTP mu and the cadherin-catenin complex in immunoprecipitates of the phosphatase arises from nonspecific cross-reactivity between BK2, our antibody to PTP mu, and cadherins. In this study we have confirmed our initial observation and demonstrated the presence of cadherin in immunoprecipitates of PTP mu. obtained with three antibodies that recognize distinct epitopes in the phosphatase. In addition, we have demonstrated directly that the anti-PTP mu antibody BK2 that we used initially did not cross-react with cadherin. Our data reinforce the observation of an interaction between PTP mu, and E-cadherin in vitro and in vivo, further emphasizing the potential importance of reversible tyrosine phosphorylation in regulating cadherin function

    Wind-Powered Wheel Locomotion, Initiated by Leaping Somersaults, in Larvae of the Southeastern Beach Tiger Beetle (Cicindela dorsalis media)

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    Rapid movement is challenging for elongate, soft-bodied animals with short or no legs. Leaping is known for only a few animals with this “worm-like” morphology. Wheel locomotion, in which the animal's entire body rolls forward along a central axis, has been reported for only a handful of animals worldwide. Here we present the first documented case of wind-powered wheel locomotion, in larvae of the coastal tiger beetle Cicindela dorsalis media. When removed from their shallow burrows, larvae easily can be induced to enter a behavioral sequence that starts with leaping; while airborne, larvae loop their body into a rotating wheel and usually either “hit the ground rolling” or leap again. The direction larvae wheel is closely related to the direction in which winds are blowing; thus, all our larvae wheeled up-slope, as winds at our study site consistently blew from sea to land. Stronger winds increased both the proportion of larvae wheeling, and the distance traveled, exceeding 60 m in some cases. In addition, the proportion of larvae that wheel and the distance traveled by wheeling larvae are significantly greater on smooth sandy beaches than on beach surfaces made rough and irregular by pedestrian, equestrian, and vehicular traffic. Like other coastal species of tiger beetles, C. dorsalis media has suffered major declines in recent years that are clearly correlated with increased human impacts. The present study suggests that the negative effects of beach traffic may be indirect, preventing larvae from escaping from predators using wheel locomotion by disrupting the flat, hard surface necessary for efficient wheeling

    A novel Nav1.5-dependent feedback mechanism driving glycolytic acidification in breast cancer metastasis

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    The authors wish to acknowledge the roles of the Breast Cancer Now Tissue Bank in collecting and making available the samples and data, and the patients who have generously donated their tissues and shared their data to be used in the generation of this publication. The authors also thank Prof. Miles Whittington (Hull-York Medical School, UK), Dr. John Davey and Dr. Katherine Newling (Technology Facility, University of York, UK), and Prof. Lýdia Vargová (Charles University, Czechia) for providing invaluable advice. For the purpose of open access, a Creative Commons Attribution (CC BY) licence is applied to any author accepted manuscript version arising from this submission.Peer reviewe

    Promoting the achievement in schools of children and young people in care

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    As of March 2017, there were 72,670 children and young people in care in England. The number of looked after children has continued to increase steadily over the last eight years. Sixty per cent of these children are in care because of abuse or neglect and three-quarters are placed in foster care arrangements. Children and young people who are in or have experienced care remain one of the lowest performing groups in terms of educational outcomes. The average Attainment 8 score for children in care is 19.3 compared to 44.5 for non-looked after children and 19.3 for children in need. In 2017 there was an increase in the percentage of children in care achieving a pass in English and Mathematics from 17.4% to 17.5% and also in entering EBacc. Care leavers can experience poorer employment and health outcomes after leaving school compared to their peers. They are over-represented amongst the offender population and those who experience homelessness. However, research is emerging to show that children and young people in care can have very positive experiences of school if they are supported effectively to reach their full potential academically and socially. The purpose of this report is to share practice in local authorities (LA) from across England and Wales that is contributing to improved outcomes and school experiences for children and young people in care. The case studies were all undertaken as part of the Promoting the Achievement of Looked after Children (PALAC) programme between 2014 and 2017. This report presents an account of the programme, including the activities undertaken by the participants and the outcomes of the programme to date for pupils in care and staff in the participating virtual schools (VS) and local authorities

    Regulation of voltage-gated sodium channel expression in cancer : hormones, growth factors and auto-regulation

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    Although ion channels are increasingly being discovered in cancer cells in vitro and in vivo, and shown to contribute to different aspects and stages of the cancer process, much less is known about the mechanisms controlling their expression. Here, we focus on voltage-gated Na(+) channels (VGSCs) which are upregulated in many types of carcinomas where their activity potentiates cell behaviours integral to the metastatic cascade. Regulation of VGSCs occurs at a hierarchy of levels from transcription to post-translation. Importantly, mainstream cancer mechanisms, especially hormones and growth factors, play a significant role in the regulation. On the whole, in major hormone-sensitive cancers, such as breast and prostate cancer, there is a negative association between genomic steroid hormone sensitivity and functional VGSC expression. Activity-dependent regulation by positive feedback has been demonstrated in strongly metastatic cells whereby the VGSC is self-sustaining, with its activity promoting further functional channel expression. Such auto-regulation is unlike normal cells in which activity-dependent regulation occurs mostly via negative feedback. Throughout, we highlight the possible clinical implications of functional VGSC expression and regulation in cancer

    Alternative Splicing of the Cardiac Sodium Channel Creates Multiple Variants of Mutant T1620K Channels

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    Alternative splicing creates several Nav1.5 transcripts in the mammalian myocardium and in various other tissues including brain, dorsal root ganglia, breast cancer cells as well as neuronal stem cell lines. In total nine Nav1.5 splice variants have been discovered. Four of them, namely Nav1.5a, Nav1.5c, Nav1.5d, and Nav1.5e, generate functional channels in heterologous expression systems. The significance of alternatively spliced transcripts for cardiac excitation, in particular their role in SCN5A channelopathies, is less well understood. In the present study, we systematically investigated electrophysiological properties of mutant T1620K channels in the background of all known functional Nav1.5 splice variants in HEK293 cells. This mutation has been previously associated with two distinct cardiac excitation disorders: with long QT syndrome type 3 (LQT3) and isolated cardiac conduction disease (CCD). When investigating the effect of the T1620K mutation, we noticed similar channel defects in the background of hNav1.5, hNav1.5a, and hNav1.5c. In contrast, the hNav1.5d background produced differential effects: In the mutant channel, some gain-of-function features did not emerge, whereas loss-of-function became more pronounced. In case of hNav1.5e, the neonatal variant of hNav1.5, both the splice variant itself as well as the corresponding mutant channel showed electrophysiological properties that were distinct from the wild-type and mutant reference channels, hNav1.5 and T1620K, respectively. In conclusion, our data show that alternative splicing is a mechanism capable of generating a variety of functionally distinct wild-type and mutant hNav1.5 channels. Thus, the cellular splicing machinery is a potential player affecting genotype-phenotype correlations in SCN5A channelopathies

    Language experience impacts brain activation for spoken and signed language in infancy: Insights from unimodal and bimodal bilinguals

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    Recent neuroimaging studies suggest that monolingual infants activate a left lateralised fronto-temporal brain network in response to spoken language, which is similar to the network involved in processing spoken and signed language in adulthood. However, it is unclear how brain activation to language is influenced by early experience in infancy. To address this question, we present functional near infrared spectroscopy (fNIRS) data from 60 hearing infants (4-to-8 months): 19 monolingual infants exposed to English, 20 unimodal bilingual infants exposed to two spoken languages, and 21 bimodal bilingual infants exposed to English and British Sign Language (BSL). Across all infants, spoken language elicited activation in a bilateral brain network including the inferior frontal and posterior temporal areas, while sign language elicited activation in the right temporo-parietal area. A significant difference in brain lateralisation was observed between groups. Activation in the posterior temporal region was not lateralised in monolinguals and bimodal bilinguals, but right lateralised in response to both language modalities in unimodal bilinguals. This suggests that experience of two spoken languages influences brain activation for sign language when experienced for the first time. Multivariate pattern analyses (MVPA) could classify distributed patterns of activation within the left hemisphere for spoken and signed language in monolinguals (proportion correct = 0.68; p = 0.039) but not in unimodal or bimodal bilinguals. These results suggest that bilingual experience in infancy influences brain activation for language, and that unimodal bilingual experience has greater impact on early brain lateralisation than bimodal bilingual experience
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