25 research outputs found

    Morphologic characterization of osteosarcoma growth on the chick chorioallantoic membrane

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    <p>Abstract</p> <p>Background</p> <p>The chick chorio-allantoic membrane (CAM) assay is a commonly used method for studying angiogenic or anti-angiogenic activities <it>in vivo</it>. The ease of access allows direct monitoring of tumour growth by biomicroscopy and the possibility to screen many samples in an inexpensive way. The CAM model provides a powerful tool to study effects of molecules, which interfere with physiological angiogenesis, or experimental tumours derived from cancer cell lines. We therefore screened eight osteosarcoma cell lines for their ability to form vascularized tumours on the CAM.</p> <p>Findings</p> <p>We implanted 3-5 million cells of human osteosarcoma lines (HOS, MG63, MNNG-HOS, OST, SAOS, SJSA1, U2OS, ZK58) on the CAM at day 10 of embryonic development. Tumour growth was monitored by <it>in vivo </it>biomicroscopy at different time points and tumours were fixed in paraformaldehyde seven days after cell grafting. The tissue was observed, photographed and selected cases were further analyzed using standard histology.</p> <p>From the eight cell lines the MNNG-HOS, U2OS and SAOS were able to form solid tumours when grafted on the CAM. The MNNG-HOS tumours showed the most reliable and consistent growth and were able to penetrate the chorionic epithelium, grow in the CAM stroma and induce a strong angiogenic response.</p> <p>Conclusions</p> <p>Our results show that the CAM assay is a useful tool for studying osteosarcoma growth. The model provides an excellent alternative to current rodent models and could serve as a preclinical screening assay for anticancer molecules. It might increase the speed and efficacy of the development of new drugs for the treatment of osteosarcoma.</p

    Molecular chaperones and proteostasis regulation during redox imbalance

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    Free radicals originate from both exogenous environmental sources and as by-products of the respiratory chain and cellular oxygen metabolism. Sustained accumulation of free radicals, beyond a physiological level, induces oxidative stress that is harmful for the cellular homeodynamics as it promotes the oxidative damage and stochastic modification of all cellular biomolecules including proteins. In relation to proteome stability and maintenance, the increased concentration of oxidants disrupts the functionality of cellular protein machines resulting eventually in proteotoxic stress and the deregulation of the proteostasis (homeostasis of the proteome) network (PN). PN curates the proteome in the various cellular compartments and the extracellular milieu by modulating protein synthesis and protein machines assembly, protein recycling and stress responses, as well as refolding or degradation of damaged proteins. Molecular chaperones are key players of the PN since they facilitate folding of nascent polypeptides, as well as holding, folding, and/or degradation of unfolded, misfolded, or non-native proteins. Therefore, the expression and the activity of the molecular chaperones are tightly regulated at both the transcriptional and post-translational level at organismal states of increased oxidative and, consequently, proteotoxic stress, including ageing and various age-related diseases (e.g. degenerative diseases and cancer). In the current review we present a synopsis of the various classes of intra- and extracellular chaperones, the effects of oxidants on cellular homeodynamics and diseases and the redox regulation of chaperones. © 2014 The Authors

    Introduction

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    Book synopsis: Greece’s economy and society have undergone important structural changes in recent years as a result of the financial crisis and consequent austerity policies that have been implemented. The Greek labour market and employment relations system have been subject to immense pressures, leading to fundamental changes both in the structure of institutions and in the behaviour of the main employment relations actors. The present volume constitutes a first attempt to appreciate the consequences of a decade of austerity politics on the Greek labour market. Offering a multidisciplinary perspective and building on original research by leading Greek scholars in the fields of labour economics, employment relations and the sociology of work, it will discuss the impact of the crisis and the resulting policies on the Greek labour market and employment relations. This volume will be of interest to policy makers, researchers and students interested in the past, present and future of Greek employment relations and the impact of austerity on Greece

    From employment relations to consumption relations : balancing labor governance in global supply chains

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    Global supply chains are part of the corporate strategy of many multinational companies, often with adverse effects on labor conditions. While employment relations scholars focus on a production-oriented paradigm, revolving around interactions among employers, workers, and government, much of the activism motivating the development of private labor standards is based around companies' relations with their consumers. This article proposes an analytical framework conceptualizing the interface of employment relations and consumption relations within global supply chains, identifying four regimes of labor governance: governance gaps, collective bargaining, standards markets, and complementary regimes. Finally, we suggest a research agenda for examining the role of consumption relations in the changing nature of global labor governance

    The quantitative proteome of a human cell line

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    The generation of mathematical models of biological processes, the simulation of these processes under different conditions, and the comparison and integration of multiple data sets are explicit goals of systems biology that require the knowledge of the absolute quantity of the system's components. To date, systematic estimates of cellular protein concentrations have been exceptionally scarce. Here, we provide a quantitative description of the proteome of a commonly used human cell line in two functional states, interphase and mitosis. We show that these human cultured cells express at least ?10 000 proteins and that the quantified proteins span a concentration range of seven orders of magnitude up to 20 000 000 copies per cell. We discuss how protein abundance is linked to function and evolution
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