1,721,000 research outputs found
Protein–polyamine conjugates by transglutaminase 2 as potential markers for antineoplastic screening of natural compounds
No full textThe role of post-translational modification of cell proteins with polyamines, a reaction catalyzed by a tissue tranglutaminase (TG, EC 2.3.2.13), in the induction of cell differentiation, represents an intriguing strategy to control cell proliferation and metastatic ability of different tumor cell lines. In this review, we focus our attention on the metabolic aspects of some natural compounds (methylxantines, retinoids and flavonoids) responsible of their antitumor effects exerted through the induction of TG activity in cancer cells
Phytochemicals and protein-polyamine conjugates by transglutaminase as chemopreventive and chemotherapeutic tools in cancer.
No full textTransglutaminases: key regulators of cancer metastasis
No full textThe ability to metastasize represents the most important characteristic of malignant tumors. The biological details of the metastatic process remain somewhat unknown, due to difficulties in studying tumor cell behaviour with high spatial and temporal resolution in vivo. Several lines of evidence involve transglutaminases (TGs) in the key stages of tumor progression cascade, even though the molecular mechanisms remain controversial. TG expression and activity display a different role in the primary tumor or in metastatic cells. In fact, TG expression is low in the primary tumor mass, but augmented when cells acquire the metastatic phenotype. Nevertheless, in other cases, the use of inducers of TG transamidating activity seems to contrast tumor cell plasticity, migration and invasion. In the following review, the function of TGs in cancer cell migration into the extracellular matrix, adhesion to the capillary endothelium and its basement membrane, invasion and angiogenesis is discussed
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Antitumor properties of aloe-emodin and induction of transglutaminase 2 activity in B16-F10 melanoma cells.
No full textReply: Chili Pepper Intake and Mortality: Clarification on Management of Confounding and Mediating Pathways
No full textPost-translational modification of glutamine and lysine residues of HIV-1 aspartyl protease by transglutaminase increases its catalytic activity
No full textThe human immunodeficiency virus type 1 aspartyl protease (HIV-1 PR) is a homodimeric aspartyl endopeptidase that is required for virus replication. HIV-1 PR was shown to act invitro as acyl-donor and -acceptor for both guinea pig liver transglutaminase (TG, EC 2.3.2.13) and human Factor XIIIa. These preliminary evidences suggested that the HIV-1 PR contains at least three TG-reactive glutaminyl and one lysyl residues. We report here that the incubation of HIV-1 PR with TG increases its catalytic activity. This increase is dependent upon the time of incubation, the concentration of TG and the presence of Ca2+. Identification of epsilon-(gamma-glutamyl)lysine in the proteolytic digest of the TG-modified HIV-1 PR suggested intramolecular covalent cross-linking of this protease which may promote a non-covalent dimerization and subsequent activation of this enzyme via a conformational change. This hypothesis is supported by the observation that the TG-catalyzed activation of HIV-1 PR was completely abolished by spermidine (SPD) which acts as a competitive inhibitor of epsilon-(gamma-glutamyl)lysine formation. Indeed, in the presence of 1mM SPD the formation of the isopeptide was decreased of about 80%. The main products of the TG-catalyzed modification of HIV-1 PR in the presence of SPD were N(1)-mono(gamma-glutamyl)SPD and N(8)-mono(gamma-glutamyl)SPD. Negligible amount of N(1),N(8)-bis(gamma-glutamyl)SPD were found. The significance of these results is discussed with respect to the activation of the protease by post-translational modification and design of potential inhibitors
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Flavonoids: a myth or a reality for cancer therapy?
Full text linkNutraceuticals are biologically active molecules present in foods; they can have beneficial
effects on health, but they are not available in large enough quantities to perform this function.
Plant metabolites, such as polyphenols, are widely diffused in the plant kingdom, where they play
fundamental roles in plant development and interactions with the environment. Among these,
flavonoids are of particular interest as they have significant effects on human health. In vitro
and/or in vivo studies described flavonoids as essential nutrients for preventing several diseases.
They display broad and promising bioactivities to fight cancer, inflammation, bacterial infections,
as well as to reduce the severity of neurodegenerative and cardiovascular diseases or diabetes.
Therefore, it is not surprising that interest in flavonoids has sharply increased in recent years. More
than 23,000 scientific publications on flavonoids have described the potential anticancer activity of
these natural molecules in the last decade. Studies, in vitro and in vivo, show that flavonoids exhibit
anticancer properties, and many epidemiological studies confirm that dietary intake of flavonoids
leads to a reduced risk of cancer. This review provides a glimpse of the mechanisms of action of
flavonoids on cancer cells
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