1,720,963 research outputs found
An early-stage 3D fibroblast-featured tumor model mimics the gene expression of the naïve tumor microenvironment, including genes involved in cancer progression and drug resistance
No full textIntroduction: The tumor microenvironment (TME) plays a crucial role in cancer progression, yet the interactions between tumor cells and stromal components, such as fibroblasts, remain poorly understood. Traditional two-dimensional (2D) culture models fail to accurately replicate the complexities of the TME, hindering progress in cancer research and drug development. Methods: This study presents a novel 3D spheroid model, generated using the hanging drop system, that incorporates both tumor cells (B16F10 mouse melanoma) and fibroblasts (NIH/3T3), and aimed at simulating the early-stage TME. Results: We demonstrate that fibroblasts are essential for ECM deposition, which is absent in spheroids composed only of tumor cells. Co-cultured spheroids exhibited a more organized structure, enhanced ECM deposition (type-VI collagen), and more closely resembled the morphology of native tumors compared to monocultures. RNA sequencing analysis revealed that the gene expression profile of B16F10–NIH/3T3 spheroids closely matched that of in vivo tumors, with 693 genes involved in critical pathways such as “pathways in cancer” and those linked to drug resistance. Discussion: These findings highlight the importance of fibroblast inclusion in 3D models to replicate the genetic and structural features of the TME. Our spheroid system provides a more accurate representation of early tumor stages and offers a promising platform for drug screening, reducing the need for in vivo models by allowing the selection of the most effective compounds for further testing. This work underscores the potential of 3D culture systems in advancing our understanding of tumor biology and improving the precision of cancer therapeutics
The dark side of tumor-associated endothelial cells
Full text linkAngiogenesis is a hallmark of cancer and a requisite that tumors must achieve to fulfill their metabolic needs of nutrients and oxygen. As a critical step in cancer progression, the 'angiogenic switch' allows tumor cells to survive and grow, and provides them access to vasculature resulting in metastatic progression and dissemination. Tumor-dependent triggering of the angiogenic switch has critical consequences on tumor progression which extends from an increased nutrient supply and relies instead on the ability of the tumor to hijack the host immune response for the generation of a local immunoprivileged microenvironment. Tumor angiogenic-mediated establishment of endothelial anergy is responsible for this process. However, tumor endothelium can also promote immune tolerance by unbalanced expression of co-stimulatory and co-inhibitory molecules and by releasing soluble factors that restrain T cell function and induce apoptosis. In this review, we discuss the molecular properties of the tumor endothelial barrier and endothelial anergy and discuss the main immunosuppressive mechanisms triggered by the tumor endothelium. Lastly, we describe the current anti-angiogenic therapeutic landscape and how targeting tumor angiogenesis can contribute to improve clinical benefits for patients
DNA and adenoviral vectors encoding carcinoembryonic antigen fused to immunoenhancing sequences augment antigen-specific immune response and confer tumor protection
No full textVectors encoding carcinoembryonic antigen fused to the B subunit of heat-labile enterotoxin elicit antigen-specific immune responses and antitumor effects
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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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