119 research outputs found

    A point mutation in the MyoD basic domain imparts c-Myc-like properties.

    Full text link

    Varied effect of fortification of kale sprouts with novel organic selenium compounds on the synthesis of sulphur and phenolic compounds in relation to cytotoxic, antioxidant and anti-inflammatory activity

    Get PDF
    Selenium deficiency in daily diet is a common problem in many countries, thus searching for new dietary sources of this trace element is an important scientific challenge. Selenium biofortified sprouts from Brassicaceae family are good candidates for new dietary selenium source, as they reveal one of the highest capability to synthesize and accumulate this element. As a part of this extensive search, the influence of novel selenium organic compounds on fortification of kale sprouts biological activity was investigated. The present study is focused on the evaluation of the influence of these compounds on the synthesis of glucosinolates, isothiocyanates, indoles and phenolic acids in kale sprouts, together with the determination of their impact on antioxidant, anti-inflammatory and cytotoxic activity on gastrointestinal, prostate, and thyroid normal and cancer cells. The present study yields the conclusion that fortification of kale sprouts with selenium organic compounds bearing benzoselenoate scaffold influences the production of isothiocyanates, phenolic acids, and enhances the antioxidant properties of fortified sprouts. Notably, fortification with compounds based on benzoselenoate scaffold display chemoprotective properties in various cancer types (gastric, thyroid, and prostate cancer). The present study can facilitate the design of future agrochemicals. Compounds bearing benzoselenoate scaffold or selenyl phenylpiperazine motif seem to be particularly promising for these purposes.This study was partly supported by Polish grants N42/DBS/000231 and N42/DBS/000167. The publication was created with the use of equipment’s (Biotek Synergy microplate reader and Dionex HPLC system) co-financed by the qLIFE Priority Research Area under the program “Excellence Initiative—Research University” (No. 06/IDUB/2019/94) at Jagiellonian University

    Mitochondrial Structure, Function and Dynamics Are Temporally Controlled by c-Myc

    Get PDF
    Although the c-Myc (Myc) oncoprotein controls mitochondrial biogenesis and multiple enzymes involved in oxidative phosphorylation (OXPHOS), the coordination of these events and the mechanistic underpinnings of their regulation remain largely unexplored. We show here that re-expression of Myc in myc−/− fibroblasts is accompanied by a gradual accumulation of mitochondrial biomass and by increases in membrane polarization and mitochondrial fusion. A correction of OXPHOS deficiency is also seen, although structural abnormalities in electron transport chain complexes (ETC) are not entirely normalized. Conversely, the down-regulation of Myc leads to a gradual decrease in mitochondrial mass and a more rapid loss of fusion and membrane potential. Increases in the levels of proteins specifically involved in mitochondrial fission and fusion support the idea that Myc affects mitochondrial mass by influencing both of these processes, albeit favoring the latter. The ETC defects that persist following Myc restoration may represent metabolic adaptations, as mitochondrial function is re-directed away from producing ATP to providing a source of metabolic precursors demanded by the transformed cell

    Multiple Wnt/ß-Catenin Responsive Enhancers Align with the MYC Promoter through Long-Range Chromatin Loops

    Get PDF
    Inappropriate activation of c-Myc (MYC) gene expression by the Wnt/ß-catenin signaling pathway is required for colorectal carcinogenesis. The elevated MYC levels in colon cancer cells are attributed in part to ß-catenin/TCF4 transcription complexes that are assembled at proximal Wnt/ß-catenin responsive enhancers (WREs). Recent studies suggest that additional WREs that control MYC expression reside far upstream of the MYC transcription start site. Here, I report the characterization of five novel WREs that localize to a region over 400 kb upstream from MYC. These WREs harbor nucleosomes with post-translational histone modifications that demarcate enhancer and gene promoter regions. Using quantitative chromatin conformation capture, I show that the distal WREs are aligned with the MYC promoter through large chromatin loops. The chromatin loops are not restricted to colon cancer cells, but are also found in kidney epithelial and lung fibroblast cell lines that lack de-regulated Wnt signaling and nuclear ß-catenin/TCF4 complexes. While each chromatin loop is detected in quiescent cells, the positioning of three of the five distal enhancers with the MYC promoter is induced by serum mitogens. These findings suggest that the architecture of the MYC promoter is comprised of distal elements that are juxtaposed through large chromatin loops and that ß-catenin/TCF4 complexes utilize this conformation to activate MYC expression in colon cancer cells

    In Vivo Evolution of Tumor-Derived Endothelial Cells

    Get PDF
    The growth of a malignant tumor beyond a certain, limited size requires that it first develop an independent blood supply. In addition to providing metabolic support, this neovasculature also allows tumor cells to access the systemic circulation, thus facilitating metastatic dissemination. The neovasculature may originate either from normal blood vessels in close physical proximity to the tumor and/or from the recruitment of bone marrow-derived endothelial cell (EC) precursors. Recent studies have shown that human tumor vasculature ECs may also arise directly from tumor cells themselves and that the two populations have highly similar or identical karyotypes. We now show that, during the course of serial in vivo passage, these tumor-derived ECs (TDECs) progressively acquire more pronounced EC-like properties. These include higher-level expression of EC-specific genes and proteins, a greater capacity for EC-like behavior in vitro, and a markedly enhanced propensity to incorporate into the tumor vasculature. In addition, both vessel density and size are significantly increased in neoplasms derived from mixtures of tumor cells and serially passaged TDECs. A comparison of early- and late-passage TDECs using whole-genome single nucleotide polymorphism profiling showed the latter cells to have apparently evolved by a process of clonal expansion of a population with a distinct pattern of interstitial chromosomal gains and losses affecting a relatively small number of genes. The majority of these have established roles in vascular development, tumor suppression or epithelial-mesenchymal transition. These studies provide direct evidence that TDECs have a strong evolutionary capacity as a result of their inherent genomic instability. Consequently such cells might be capable of escaping anti-angiogenic cancer therapies by generating resistant populations

    Genomics and proteomics approaches to the study of cancer-stroma interactions

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The development and progression of cancer depend on its genetic characteristics as well as on the interactions with its microenvironment. Understanding these interactions may contribute to diagnostic and prognostic evaluations and to the development of new cancer therapies. Aiming to investigate potential mechanisms by which the tumor microenvironment might contribute to a cancer phenotype, we evaluated soluble paracrine factors produced by stromal and neoplastic cells which may influence proliferation and gene and protein expression.</p> <p>Methods</p> <p>The study was carried out on the epithelial cancer cell line (Hep-2) and fibroblasts isolated from a primary oral cancer. We combined a conditioned-medium technique with subtraction hybridization approach, quantitative PCR and proteomics, in order to evaluate gene and protein expression influenced by soluble paracrine factors produced by stromal and neoplastic cells.</p> <p>Results</p> <p>We observed that conditioned medium from fibroblast cultures (FCM) inhibited proliferation and induced apoptosis in Hep-2 cells. In neoplastic cells, 41 genes and 5 proteins exhibited changes in expression levels in response to FCM and, in fibroblasts, 17 genes and 2 proteins showed down-regulation in response to conditioned medium from Hep-2 cells (HCM). Nine genes were selected and the expression results of 6 down-regulated genes (<it>ARID4A</it>, <it>CALR</it>, <it>GNB2L1</it>, <it>RNF10</it>, <it>SQSTM1</it>, <it>USP9X</it>) were validated by real time PCR.</p> <p>Conclusions</p> <p>A significant and common denominator in the results was the potential induction of signaling changes associated with immune or inflammatory response in the absence of a specific protein.</p

    Effectiveness of prepregnancy care for women with pregestational diabetes mellitus: protocol for a systematic review of the literature and identification of a core outcomes set using a Delphi survey

    Full text link
    BACKGROUND: Women with pregnancy complicated by pregestational diabetes experience increased rates of adverse pregnancy outcomes. Prepregnancy care is the targeted support and additional care offered to those women who are planning pregnancy and is associated with improved outcomes. However, there is significant heterogeneity in the outcomes measured and reported in studies evaluating the effects of prepregnancy care, which makes meaningful comparison difficult. The aim of this article is to present a protocol for a study to develop a Core Outcome Set (COS) for trials and other studies evaluating the effectiveness of prepregnancy care for women with pregestational diabetes mellitus. METHODS/DESIGN: This study will include a systematic review of the literature to identify outcomes that have previously been reported in studies evaluating prepregnancy care for women with pregestational diabetes. We will then prioritise these outcomes from the perspective of key stakeholders, including women with pregestational diabetes as well as clinicians, using a Delphi survey. A final consensus meeting will be held with stakeholders to review and finalise the outcomes. DISCUSSION: The expectation is that the COS will always be collected and reported in all clinical trials, audits of practice and other forms of research that involve prepregnancy care programs for women with pregestational diabetes. This will facilitate comparing and contrasting of studies and allow for combining of appropriate studies with the ultimate goal of improved patient care. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13063-015-0894-8) contains supplementary material, which is available to authorized users

    Mitochondrial respiratory states and rate

    Get PDF
    As the knowledge base and importance of mitochondrial physiology to human health expands, the necessity for harmonizing the terminologyconcerning mitochondrial respiratory states and rates has become increasingly apparent. Thechemiosmotic theoryestablishes the mechanism of energy transformationandcoupling in oxidative phosphorylation. Theunifying concept of the protonmotive force providestheframeworkfordeveloping a consistent theoretical foundation ofmitochondrial physiology and bioenergetics.We followguidelines of the International Union of Pure and Applied Chemistry(IUPAC)onterminology inphysical chemistry, extended by considerationsofopen systems and thermodynamicsof irreversible processes.Theconcept-driven constructive terminology incorporates the meaning of each quantity and alignsconcepts and symbols withthe nomenclature of classicalbioenergetics. We endeavour to provide a balanced view ofmitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes.Uniform standards for evaluation of respiratory states and rates will ultimatelycontribute to reproducibility between laboratories and thussupport the development of databases of mitochondrial respiratory function in species, tissues, and cells.Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

    Mitochondrial physiology

    Get PDF
    As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery
    corecore