1,720,975 research outputs found
The targeting of eEF1A1-actin complex by GT75 DNA-aptamer fight androgen-independent human prostate adenocarcinoma cells.
Full text linkIntroduction: In prostate cancer, the second most common form of solid cancer in men worldwide, castration-resistant prostate cancer (CRPC) forms are responsible for high cancer-related death. Treatments are limited and often the resistance towards the second and third lines of treatment occurs. Thus, efforts for the identification of novel therapeutic strategies/targets remain an urgent need. The eukaryotic elongation factor 1A1 (eEF1A1) can play a role in sustaining the growth of different tumors as we found that it is overexpressed in high Gleason score (7-8) tumor tissues. DNA-aptamers can recognize targets with high specificity and they have been proposed as anti-tumor-specific agents. Our group has demonstrated that a DNA-aptamer, named GT75, can target eEF1A1 in hepatocarcinoma and chronic lymphocytic leukemia cells.
Materials and methods: PC-3 cell line (resembling the CRCP phenotype) and PZHPV-7 cells (control non-tumorigenic prostate cells), were transfected with GT75 or control CT75 (Eurofins MWG) by lipofectamine 3000 (Invitrogen); cell growth was measured by MTT or MTS (Promega) at different days after transfection. Autophagy was assessed by a consecutive cell staining with neutral red (NR), and crystal violet (CV), and by an independent MTS assay (Sigma Aldrich). In Cell Western assay (ICW) was used to measure eEF1A1 protein level (mouse monoclonal EF-Tu, sc-21758, Santa Cruz Biotechnologies) and autophagy LC3B marker; cell adhesion/spreading was measured by methylene blue assay. Confocal immunofluorescence microscopy was performed with FITC-conjugated GT75 or CT75 or with fluorescent-labeled IgG anti-eEF1A1 antibody (Invitrogen).
Results and discussion: In a panel of cancer cells (LNCaP, 22RV-1, DU-145, and PC-3), a single dose of 125 nM of GT75 was able to reduce the cell growth compared to CT75 control, but the highest effect was measured in the PC-3 cells (-59%). Notably, in the non-tumorigenic PZHPV-7 cells, GT75 did not alter cell growth, demonstrating the tumor-specific effect of GT75. Besides, in PC-3 cells the GT75 reduced eEF1A1 protein levels (p<0.05). The confocal microscopy analysis in PC3 showed that GT75 targeted the eEF1A1-actin complexes bound to the cytoskeleton. On the contrary, nonspecific co-localization of eEF1A1/actin was found in non-tumorigenic PZHPV-7 cells (p<0.05). Finally, in GT75-treated PC-3 cells, a higher rate of autophagy, a lower rate of cell adhesion and spreading compared to CT75 control were observed.
Conclusion: Our data indicate the targeting of GT75 to the eEF1A1-actin complex bound to the cytoskeleton in androgen-independent prostate cancer cells. This was paralleled by the reduction of cell viability, the activation of cell autophagy, the impairment of cell adhesion and spreading. Together our observations open new perspectives for the development of targeted therapies for CRPC
A pivotal study in human prostate cancer tissues and cell lines to measure the expression levels of eukaryotic Elongation Factor 1A proteins and the effect of a nucleic acid-based GT75 aptamer
No full textBackground: Two major isoforms of the eukaryotic Elongation Factor 1A are recognised: the eEF1A1, ubiquitously expressed, and the eEF1A2 presents in adult heart and skeletal muscle, in the nervous system, and in some other specialized cells. Both proteins are implicated in the development and progression of human cancers with a different role. In prostate cancer, overexpression of eEF1A2 has been proposed to be involved in the onset of the tumour and it was related to a worse outcome. However, the expression level of both proteins in prostate cancer tissue is not well known. We explore the expression level of the two proteins and mRNAs in formalin-fixed paraffin-embedded tissues derived from prostate cancer patients. Moreover, we investigated the effect of the nucleic acid-based GT75 aptamer, targeting eEF1A protein, in human prostate cancer cell lines.
Materials and methods: Formalin-fixed, paraffin-embedded samples of hyperplasia (n = 10), of Gleason 4–6 (n = 10) and of Gleason 7–8 (n = 10) were analysed. Protein level of eEF1A1 and eEF1A2 was determined by an
IHC method previously described; the mRNA levels were quantified by ddPCR with probes. The tumorigenic PC-3 and the non-tumorigenic PZHPV-7 cell lines were transfected with the GT75 aptamer or CT75 control, the cell
growth was evaluated by MTS assay; the expression level of the proteins in cell culture was determined by an immunofluorescent assay. The results were statistically examined by Anova, Mann-Withney and Fisher tests.
Results: The expression level of the proteins in tissues was a score 0, 1, 2, 3. With respect to Gleason 4–6, eEF1A1 protein was found to increase in samples with Gleason 7–8 (p = 0.001); whereas a decrease in eEF1A2
levels were found in cancer samples with respect to hyperplasia (Gleason 4–6, p < 0.001; Gleason 7–8 p = 0.005). No significant difference among the groups was found in mRNA levels for both proteins. In cancer PC-3 cells, the
transfection of the GT75 aptamer led to 40% of cell growth inhibition with respect to CT75 oligonucleotide control. In agreement, a 60% decrease in eEF1A1 protein level was measured, but only a 20% reduction in eEF1A2.
Interestingly, no effects were found in the non-tumorigenic PZHPV-7 cells.
Conclusion: eEF1A1 protein could be an interesting molecular target for the control of cell proliferation in more aggressive prostate cancer forms
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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