119 research outputs found

    Growth delay of human bladder cancer cells by Prostate Stem Cell Antigen downregulation is associated with activation of immune signaling pathways

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    <p>Abstract</p> <p>Background</p> <p>Prostate stem cell antigen (PSCA) is a glycosylphosphatidylinositol (GPI) anchored protein expressed not only in prostate but also in pancreas and bladder cancer as shown by immunohistochemistry and mRNA analysis. It has been targeted by monoclonal antibodies in preclinical animal models and more recently in a clinical trial in prostate cancer patients. The biological role played in tumor growth is presently unknown. In this report we have characterized the contribution of PSCA expression to tumor growth.</p> <p>Methods</p> <p>A bladder cell line was engineered to express a doxycycline (dox) regulated shRNA against PSCA. To shed light on the PSCA biological role in tumor growth, microarray analysis was carried out as a function of PSCA expression. Expression of gene set of interest was further analyzed by qPCR</p> <p>Results</p> <p>Down regulation of the PSCA expression was associated with reduced cell proliferation <it>in vitro </it>and <it>in vivo</it>. Mice bearing subcutaneous tumors showed a reduced tumor growth upon treatment with dox, which effectively induced shRNA against PSCA as revealed by GFP expression. Pathway analysis of deregulated genes suggests a statistical significant association between PSCA downregulation and activation of genes downstream of the IFNα/β receptor.</p> <p>Conclusions</p> <p>These experiments established for the first time a correlation between the level of PSCA expression and tumor growth and suggest a role of PSCA in counteracting the natural immune response.</p

    Search for Specific Biomarkers of IFNβ Bioactivity in Patients with Multiple Sclerosis

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    Myxovirus A (MxA), a protein encoded by the MX1 gene with antiviral activity, has proven to be a sensitive measure of IFNβ bioactivity in multiple sclerosis (MS). However, the use of MxA as a biomarker of IFNβ bioactivity has been criticized for the lack of evidence of its role on disease pathogenesis and the clinical response to IFNβ. Here, we aimed to identify specific biomarkers of IFNβ bioactivity in order to compare their gene expression induction by type I IFNs with the MxA, and to investigate their potential role in MS pathogenesis. Gene expression microarrays were performed in PBMC from MS patients who developed neutralizing antibodies (NAB) to IFNβ at 12 and/or 24 months of treatment and patients who remained NAB negative. Nine genes followed patterns in gene expression over time similar to the MX1, which was considered the gold standard gene, and were selected for further experiments: IFI6, IFI27, IFI44L, IFIT1, HERC5, LY6E, RSAD2, SIGLEC1, and USP18. In vitro experiments in PBMC from healthy controls revealed specific induction of selected biomarkers by IFNβ but not IFNγ, and several markers, in particular USP18 and HERC5, were shown to be significantly induced at lower IFNβ concentrations and more selective than the MX1 as biomarkers of IFNβ bioactivity. In addition, USP18 expression was deficient in MS patients compared with healthy controls (p = 0.0004). We propose specific biomarkers that may be considered in addition to the MxA to evaluate IFNβ bioactivity, and to further explore their implication in MS pathogenesis

    An OMICs-based meta-analysis to support infection state stratification

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    Motivation: A fundamental problem for disease treatment is that while antibiotics are a powerful counter to bacteria, they are ineffective against viruses. Often, bacterial and viral infections are confused due to their similar symptoms and lack of rapid diagnostics. With many clinicians relying primarily on symptoms for diagnosis, overuse and misuse of modern antibiotics are rife, contributing to the growing pool of antibiotic resistance. To ensure an individual receives optimal treatment given their disease state and to reduce over-prescription of antibiotics, the host response can in theory be measured quickly to distinguish between the two states. To establish a predictive biomarker panel of disease state (viral/bacterial/no-infection), we conducted a meta-analysis of human blood infection studies using machine learning. Results: We focused on publicly available gene expression data from two widely used platforms, Affymetrix and Illumina microarrays as they represented a significant proportion of the available data. We were able to develop multi-class models with high accuracies with our best model predicting 93% of bacterial and 89% viral samples correctly. To compare the selected features in each of the different technologies, we reverse-engineered the underlying molecular regulatory network and explored the neighbourhood of the selected features. The networks highlighted that although on the gene-level the models differed, they contained genes from the same areas of the network. Specifically, this convergence was to pathways including the Type I interferon Signalling Pathway, Chemotaxis, Apoptotic Processes and Inflammatory/Innate Response

    Novel developments in the pathogenesis and diagnosis of extranodal marginal zone lymphoma

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    Mitochondrial Localization and Pro-apoptotic Effects of the Interferon-inducible Protein ISG12a

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    ISG12a is one of the most highly induced genes following treatment of cells with type I interferons (IFNs). The encoded protein belongs to a family of poorly characterized, low molecular weight IFN-inducible proteins that includes 6–16 (G1P3), 1–8U (IFITM3), and 1–8D (IFITM2). Our studies demonstrate that the ISG12a protein associates with or inserts into the mitochondrial membrane. Transient expression of ISG12a led to decreased viable cell numbers and enhanced sensitivity to DNA-damage induced apoptosis, effects that were blocked by Bcl-2 co-expression or treatment with a pan-caspase inhibitor. ISG12a enhanced etoposide induced cytochrome c release, Bax activation and loss of mitochondrial membrane potential. siRNA-mediated inhibition of ectopic ISG12a protein expression prevented the sensitization to etoposide-induced apoptosis and also decreased the ability of IFN-β pretreatment to sensitize cells to etoposide, thereby demonstrating a role for ISG12a in this process. These data suggest that ISG12a contributes to IFN-dependent perturbation of normal mitochondrial function, thus adding ISG12a to a growing list of IFN-induced proteins that impact cellular apoptosis

    Biological and Clinical Properties of the Type 1 Interferons

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    Interferons (IFNs) are class 2 cytokines that carry out important physiological functions in higher vertebrates, particularly in the regulation of host adaptive and innate immune responses. The complex type 1 IFN family, which includes IFN-α and IFN-β, will be the focus of this chapter. Virus and other innate immune stimuli induce expression of type 1 IFNs, which then act on responsive cells to establish an antiviral state. Type 1 IFN effects are mediated by the protein products of IFN-responsive genes, the identities and functions of which are only now starting to emerge fully. In a clinical setting, type 1 IFNs, IFN-α in particular, have shown effectiveness against a variety of malignancies. Current efforts aimed at improving pharmacokinetic and pharmacodynamic profiles of IFNs, identifying subtypes with novel biological activities and/or establishment of combined treatment modalities involving type 1 IFNs should lead to future improvements in therapeutic effectiveness
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