1,720,981 research outputs found
Abstract 903: CXCR4 and CXCR7 play distinct and overlapping roles in prostate cancer dissemination to bone
No full textAbstract
Approximately 28,000 men die of prostate cancer (PCa) each year in the US, and 90-100% of them will be due to bone metastasis. It has been demonstrated that PCa cells detach from the primary tumor and “home” to bone. Osteoblasts (bone-forming cells) secrete the chemoattractant stromal-derived factor 1 (SDF-1, also known as CXCL12), and PCa cells express the receptors for SDF-1, C-X-C chemokine receptors 4 and 7 (CXCR4 and CXCR7). PCa cells use these receptors to enter the chemoprotective bone microenvironment, specifically, the hematopoietic stem cell (HSC) niche in the endosteum. While small molecule inhibition of CXCR4 can mobilize PCa cells from the bone marrow microenvironment, it is unknown whether CXCR7 plays a compensatory role when CXCR4 is antagonized. SDF-1 is known to bind with greater affinity to CXCR7 compared to CXCR4 indicating a possible role of CXCR7 in tumor migration to the endosteal niche. Therefore, it is crucial to determine the individual and combined roles of CXCR4 and CXCR7 in the formation and treatment of PCa bone metastases. To answer these questions, first we assessed CXCR4 and CXCR7 expression across a panel of prostate cancer cell lines. We then transiently overexpressed and knocked down CXCR4 and CXCR7 in PCa cells and found CXCR4 and CXCR7 expression in vitro to directly correlate to cell viability and migration in PC3 PCa cells. To further test dissemination and metastasis in bone, we are making stable overexpression and knockout cells and will perform in vivo metastasis experiments. We have developed a novel immunofluorescence protocol for detecting and quantifying tumor cells in murine blood and bone marrow and will use this technique to determine the ability of PCa cells to disseminate to bone in the presence or absence of CXCR4 and/or CXCR7. This will be quickly translatable because we are currently running a first-in-prostate cancer clinical trial to determine whether small molecule inhibition of CXCR4 to mobilize PCa tumor cells from the bone marrow, combined with docetaxel, will benefit metastatic PCa patients. If we determine that CXCR7 plays a compensatory role in dissemination and/or metastasis, we will need to add CXCR7 inhibition to our treatment strategy to obtain the most efficient benefit for patients.
Citation Format: Sounak Roy, Kenneth C. Valkenburg, Kenneth J. Pienta. CXCR4 and CXCR7 play distinct and overlapping roles in prostate cancer dissemination to bone [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 903. doi:10.1158/1538-7445.AM2017-903</jats:p
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
Abstract 4945: Axl-hi DTCs in the bone marrow of a genetically engineered mouse model of prostate cancer exhibit decreased proliferation
No full textAbstract
The majority of prostate cancer (PCa) deaths are attributed to bone metastases, which may not arise until years after the primary tumor has been removed. Disseminated tumor cells (DTCs) have been shown to already be present in the bone marrow of patients at the time of prostatectomy, and it is thought that they undergo a period of dormancy, allowing them to remain undetected for years before manifesting into clinically detectable metastases. It is not known what allows PCa DTCs to undergo and persist in this dormant state, but it is likely that factors in the bone marrow niche play an essential role. Previously our group has shown that one of these niche factors, Gas6, can regulate growth of PCa cells. The growth restraining effects of Gas6 on PCa cells is likely mediated through the tyrosine kinase receptor Axl, whose expression was found to be increased on dormant DTCs compared to proliferating metastases in a xenograft mouse model. Here, we utilized the TRAMP model, a genetically engineered mouse model of spontaneous PCa progression, to compare the frequency of Axl-hi and Axl-low bone marrow DTCs that are proliferating versus non-proliferating. Further, we also compared Axl expression and proliferation in matched primary tumors. To investigate the functional significance of Gas6/Axl signaling in mediating PCa dormancy, we have generated Axl knockout PCa cells to test the requirement of Axl in maintaining dormancy, and Axl overexpressing PCa cells to test the sufficiency of Axl in mediating dormancy. Determining the role of Axl and any other regulatory mechanisms of PCa DTC dormancy will be crucial in efforts to prevent lethal and incurable metastasis.
Citation Format: Haley D. Axelrod, Kenneth C. Valkenburg, Brian W. Simons, Kenneth J. Pienta. Axl-hi DTCs in the bone marrow of a genetically engineered mouse model of prostate cancer exhibit decreased proliferation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4945. doi:10.1158/1538-7445.AM2017-4945</jats:p
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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