1,721,037 research outputs found
Roles of enhancer of zeste homolog 2: From skeletal muscle differentiation to rhadbomyosarcoma carcinogenesis.
On the role of Retinoblastoma family proteins in the establishment and maintenance of the epigenetic landscape.
RB family members are negative regulators of the cell cycle, involved in numerous biological processes such as cellular senescence, development and differentiation. Disruption of RB family pathways are linked to loss of cell cycle control, cellular immortalization and cancer. RB family, and in particular the most studied member RB/p105, has been considered a tumor suppressor gene by more than three decades, and numerous efforts have been done to understand his molecular activity. However, the epigenetic mechanisms behind Rb-mediated tumor suppression have been uncovered only in recent years. In this review, the role of RB family members in cancer epigenetics will be discussed. We start with an introduction to epigenomes, chromatin modifications and cancer epigenetics. In order to provide a clear picture of the involvement of RB family in the epigenetic field, we describe the RB family role in the epigenetic landscape dynamics based on the heterochromatin variety involved, facultative or constitutive. We want to stress that, despite dissimilar modulations, RB family is involved in both mammalian varieties of heterochromatin establishment and maintenance and that disruption of RB family pathways drives to alterations of both heterochromatin structures, thus to the global epigenetic landscape
PRC2: an epigenetic multiprotein complex with a key role in the development of rhabdomyosarcoma carcinogenesis
Skeletal muscle formation represents a complex of highly organized and specialized systems that are still not fully understood. Epigenetic systems underline embryonic development, maintenance of stemness, and progression of differentiation. Polycomb group proteins play the role of gene silencing of stemness markers that regulate muscle differentiation. Enhancer of Zeste EZH2 is the catalytic subunit of the complex that is able to trimethylate lysine 27 of histone H3 and induce silencing of the involved genes. In embryonal Rhabdomyosarcoma and several other tumors, EZH2 is often deregulated and, in some cases, is associated with tumor malignancy. This review explores the molecular processes underlying the failure of muscle differentiation with a focus on the PRC2 complex. These considerations could open new studies aimed at the development of new cutting-edge therapeutic strategies in the onset of Rhabdomyosarcoma
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
Variations on the Author
“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
Appropriate Similarity Measures for Author Cocitation Analysis
We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
The role of enhancer of zeste homolog 2: From viral epigenetics to the carcinogenesis of hepatocellular carcinoma.
Nowadays, epigenetics covers a crucial role in different fields of science. The enhancer of zeste homolog 2 (EZH2), the catalytic subunit of the Polycomb Repressive Complex 2 (PRC2), is a big proponent of how epigenetic changes can affect the initiation and progression of several diseases. Through its catalytic activity, responsible for the tri-methylation of lysine 27 of the histone H3 (H3K27me3), EZH2 is a good target for both diagnosis and therapy of different pathologies. A large number of studies have demonstrated its crucial role in cancer initiation and progression. Nevertheless, only recently its function in virus diseases has been uncovered; therefore, EZH2 can be an important promoter of viral carcinogenesis. This review explores the role of EZH2 in viral epigenetics based on recent progress that demonstrated the role of this protein in virus environment. In particular, the review focuses on EZH2 behavior in Hepatitis B Virus, analyzing its role in the rise of Hepatocellular Carcinoma
Interazione tra selenio ed altri elementi in traccia nelle uova di gallina: confronto tra prodotti biofortificati e commerciali.
Selenio in uova biofortificate: confronto con uova commerciali
Obiettivi. Il selenio, micronutriente essenziale per l’uomo, sembra svolgere un ruolo protettivo nei confronti dell’insorgenza di malattie cronico-degenerative, in particolare del cancro, grazie alla sua attività antiossidante. La sorgente naturale di selenio è rappresentata dalla dieta e la sua concentrazione nei cibi dipende dalle caratteristiche geobotaniche dell’area di provenienza degli alimenti. Nell’ambito di uno studio sull’arricchimento delle uova con acidi grassi w3 e microelementi essenziali (Se e I), il nostro obiettivo era quello di verificare se la supplementazione con Se potesse realmente arricchire l’uovo con questo elemento contribuendo ad un miglioramento della qualità nutrizionale dell’uovo. Per confronto sono state esaminate uova presenti normalmente sul mercato.
Metodi. La prova è stata condotta su sette gruppi di galline ovaiole, alimentate con un mangime di base solo o addizionato con I o Se o con entrambi i sali. Le uova commerciali sono state acquistate tenendo conto dei diversi sistemi di allevamento delle ovaiole.
Risultati. Il Se si accumula prevalentemente nel tuorlo delle uova sia commerciali (1,04±0,28 mg/g) che trattate (da 1,60±0,21 a 1,98±0,16 mg/g, secondo il trattamento). La supplementazione con Se e ancora di più quella con Se + I si associava ad una riduzione del contenuto di Cd , in misura inferiore di Pb, e favoriva l’accumulo di acidi grassi w3. Tuttavia si è osservato una tendenza al calo di Zn nei prodotti supplementati
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