179 research outputs found

    A Chemocentric Approach to the Identification of Cancer Targets

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    A novel chemocentric approach to identifying cancer-relevant targets is introduced. Starting with a large chemical collection, the strategy uses the list of small molecule hits arising from a differential cytotoxicity screening on tumor HCT116 and normal MRC-5 cell lines to identify proteins associated with cancer emerging from a differential virtual target profiling of the most selective compounds detected in both cell lines. It is shown that this smart combination of differential in vitro and in silico screenings (DIVISS) is capable of detecting a list of proteins that are already well accepted cancer drug targets, while complementing it with additional proteins that, targeted selectively or in combination with others, could lead to synergistic benefits for cancer therapeutics. The complete list of 115 proteins identified as being hit uniquely by compounds showing selective antiproliferative effects for tumor cell lines is provided

    Functional Polymorphism of the CK2Îą Intronless Gene Plays Oncogenic Roles in Lung Cancer

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    Protein kinase CK2 is frequently up-regulated in human cancers, although the mechanism of CK2 activation in cancer remains unknown. In this study, we investigated the role of the CK2α intronless gene (CSNK2A1P, a presumed CK2α pseudogene) in the pathogenesis of human cancers. We found evidence of amplification and over-expression of the CSNK2A1P gene in non- small cell lung cancer and leukemia cell lines and 25% of the lung cancer tissues studied. The mRNA expression levels correlated with the copy numbers of the CSNK2A1P gene. We also identified a novel polymorphic variant (398T/C, I133T) of the CSNK2A1P gene and showed that the 398T allele is selectively amplified over the 398C allele in 101 non-small cell lung cancer tissue samples compared to those in 48 normal controls (p = 0.013<0.05). We show for the first time CSNK2A1P protein expression in transfected human embryonic kidney 293T and mouse embryonic fibroblast NIH-3T3 cell lines. Both alleles are transforming in these cell lines, and the 398T allele appears to be more transforming than the 398C allele. Moreover, the 398T allele degrades PML tumor suppressor protein more efficiently than the 398C allele and shows a relatively stronger binding to PML. Knockdown of the CSNK2A1P gene expression with specific siRNA increased the PML protein level in lung cancer cells. We report, for the first time, that the CSNK2A1P gene is a functional proto-oncogene in human cancers and its functional polymorphism appears to degrade PML differentially in cancer cells. These results are consistent with an important role for the 398T allele of the CSNK2A1P in human lung cancer susceptibility

    A comparison of machine learning algorithms for chemical toxicity classification using a simulated multi-scale data model

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    <p>Abstract</p> <p>Background</p> <p>Bioactivity profiling using high-throughput <it>in vitro </it>assays can reduce the cost and time required for toxicological screening of environmental chemicals and can also reduce the need for animal testing. Several public efforts are aimed at discovering patterns or classifiers in high-dimensional bioactivity space that predict tissue, organ or whole animal toxicological endpoints. Supervised machine learning is a powerful approach to discover combinatorial relationships in complex <it>in vitro/in vivo </it>datasets. We present a novel model to simulate complex chemical-toxicology data sets and use this model to evaluate the relative performance of different machine learning (ML) methods.</p> <p>Results</p> <p>The classification performance of Artificial Neural Networks (ANN), K-Nearest Neighbors (KNN), Linear Discriminant Analysis (LDA), NaĂŻve Bayes (NB), Recursive Partitioning and Regression Trees (RPART), and Support Vector Machines (SVM) in the presence and absence of filter-based feature selection was analyzed using K-way cross-validation testing and independent validation on simulated <it>in vitro </it>assay data sets with varying levels of model complexity, number of irrelevant features and measurement noise. While the prediction accuracy of all ML methods decreased as non-causal (irrelevant) features were added, some ML methods performed better than others. In the limit of using a large number of features, ANN and SVM were always in the top performing set of methods while RPART and KNN (k = 5) were always in the poorest performing set. The addition of measurement noise and irrelevant features decreased the classification accuracy of all ML methods, with LDA suffering the greatest performance degradation. LDA performance is especially sensitive to the use of feature selection. Filter-based feature selection generally improved performance, most strikingly for LDA.</p> <p>Conclusion</p> <p>We have developed a novel simulation model to evaluate machine learning methods for the analysis of data sets in which in vitro bioassay data is being used to predict in vivo chemical toxicology. From our analysis, we can recommend that several ML methods, most notably SVM and ANN, are good candidates for use in real world applications in this area.</p

    The odds of duplicate gene persistence after polyploidization

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    Background: Gene duplication is an important biological phenomenon associated with genomic redundancy,degeneration, specialization, innovation, and speciation. After duplication, both copies continue functioning when natural selection favors duplicated protein function or expression, or when mutations make them functionally distinct before one copy is silenced. Results: Here we quantify the degree to which genetic parameters related to gene expression, molecular evolution, and gene structure in a diploid frog - Silurana tropicalis - influence the odds of functional persistence of orthologous duplicate genes in a closely related tetraploid species - Xenopus laevis. Using public databases and 454 pyrosequencing, we obtained genetic and expression data from S. tropicalis orthologs of 3,387 X. laevis paralogs and 4,746 X. laevis singletons - the most comprehensive dataset for African clawed frogs yet analyzed. Using logistic regression, we demonstrate that the most important predictors of the odds of duplicate gene persistence in the tetraploid species are the total gene expression level and evenness of expression across tissues and development in the diploid species. Slow protein evolution and information density (fewer exons, shorter introns) in the diploid are also positively correlated with duplicate gene persistence in the tetraploid. Conclusions: Our findings suggest that a combination of factors contribute to duplicate gene persistence following whole genome duplication, but that the total expression level and evenness of expression across tissues and through development before duplication are most important. We speculate that these parameters are useful predictors of duplicate gene longevity after whole genome duplication in other taxa

    A path forward in the debate over health impacts of endocrine disrupting chemicals

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    Several recent publications reflect debate on the issue of “endocrine disrupting chemicals” (EDCs), indicating that two seemingly mutually exclusive perspectives are being articulated separately and independently. Considering this, a group of scientists with expertise in basic science, medicine and risk assessment reviewed the various aspects of the debate to identify the most significant areas of dispute and to propose a path forward. We identified four areas of debate. The first is about the definitions for terms such as “endocrine disrupting chemical”, “adverse effects”, and “endocrine system”. The second is focused on elements of hormone action including “potency”, “endpoints”, “timing”, “dose” and “thresholds”. The third addresses the information needed to establish sufficient evidence of harm. Finally, the fourth focuses on the need to develop and the characteristics of transparent, systematic methods to review the EDC literature. Herein we identify areas of general consensus and propose resolutions for these four areas that would allow the field to move beyond the current and, in our opinion, ineffective debate

    Athlete brand construction: A perspective based on fans’ perceptions

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    Abstract The purpose of this study was to develop a framework for understanding the antecedents and components of athlete brand. Based on a set of 21 interviews conducted in three different countries, a detailed framework is proposed including five antecedents and two components of athlete brand. The antecedents are media (social media, mass media, video games and major sport events), oral communications (word of mouth, and rumors and narratives), impression management, social agents (parents, family members, friends and community), and teams and sport (sport interest, team interest and team geographical location). In turn, the components of athlete brand are related with on-field attributes (behavior, team, achievements, style of play and skills) and off-field attributes (physical attraction, lifestyle, personal appeal, ethnicity and entertainment). Complementarily, these components of athlete brand are proposed to have an impact on fans' loyalty towards the athlete. Implications of these findings for building and managing athlete brand are discussed, and directions for future studies are provided
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