1,721,172 research outputs found
The Metabolic Landscape of Prostate Cancer
No full textNeoplastic cells are characterized by metabolic alterations that sustain tumor growth. Interventions aimed at modifying metabolic rewiring of cancer cells are currently being investigated in several tumor types, including prostate cancer (PC)
USP2a alters chemotherapeutic response by modulating redox
No full textCancer cells are characterized by altered ubiquitination of many proteins. The ubiquitin-specific protease 2a (USP2a) is a deubiquitinating enzyme overexpressed in prostate adenocarcinomas, where it exhibits oncogenic behavior in a variety of ways including targeting c-Myc via the miR-34b/c cluster. Here we demonstrate that USP2a induces drug resistance in both immortalized and transformed prostate cells. Specifically, it confers resistance to typically pro-oxidant agents, such as cisplatin (CDDP) and doxorubicin (Doxo), and to taxanes. USP2a overexpression protects from drug-induced oxidative stress by reducing reactive oxygen species (ROS) production and stabilizing the mitochondrial membrane potential (ΔΨ), thus impairing downstream p38 activation and triggering of apoptosis. The molecular mediator of the USP2a protective function is the glutathione (GSH). Through miR-34b/c-driven c-Myc regulation, USP2a increases intracellular GSH content, thus interfering with the oxidative cascade triggered by chemotherapeutic agents. In light of these findings, targeting Myc and/or miR-34b/c might revert chemo-resistance
De novo fatty acid synthesis at the mitotic exit is required to complete cellular division
Full text linkAlthough the regulation of the cell cycle has been extensively studied, much less is known about its coordination with the cellular metabolism. Using mass spectrometry we found that lysophospholipid levels decreased drastically from G2/M to G1 phase, while de novo phosphatidylcholine synthesis, the main phospholipid in mammalian cells, increased, suggesting that enhanced membrane production was concomitant to a decrease in its turnover. In addition, fatty acid synthesis and incorporation into membranes was increased upon cell division. the rate-limiting reaction for de novo fatty acid synthesis is catalyzed by acetyl-CoA carboxylase. As expected, its inhibiting phosphorylation decreased prior to cytokinesis initiation. Importantly, the inhibition of fatty acid synthesis arrested the cells at G2/M despite the presence of abundant fatty acids in the media. our results suggest that de novo lipogenesis is essential for cell cycle completion. this “lipogenic checkpoint” at G2/M may be therapeutically exploited for hyperproliferative diseases such as cancer.Fil: Scaglia, Natalia. Harvard Medical School; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tyekucheva, Svitlana. Harvard University. Harvard School of Public Health; Estados UnidosFil: Zadra, Giorgia. Harvard Medical School; Estados UnidosFil: Photopoulos, Cornelia. Harvard Medical School; Estados UnidosFil: Loda, Massimo. Harvard Medical School; Estados Unido
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
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe 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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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