1,720,997 research outputs found
Serologic detection of diffuse large B-cell lymphoma-associated antigens
No full textDiffuse large B-cell lymphoma (DLBCL) accounts for 30-40% of all adult non-Hodgkin's lymphomas, yet the understanding of its underlying genetic abnormalities remains poor. Our present study used the serological analysis of recombinant cDNA expression libraries (SEREX) technique to identify DLBCL-associated antigens. SEREX screening of testis libraries has previously identified cancer-testis antigens (CTAs) that may act as disease-specific targets for immunotherapy. Screening a testis cDNA expression library with serum from a DLBCL patient identified a total of 94 positive clones, representing 28 distinct antigens. Two of these antigens were novel, 8 were previously uncharacterised, and the remainder were proteins of known function. Screening of the antigens with sera from DLBCL (n = 10), acute myeloid leukaemia (AML, n = 10) and chronic myeloid leukaemia (CML, n = 10) patients, alongside normal healthy donor controls (n = 20), revealed that 7 of the antigens were recognised by DLBCL sera but not normal donor sera, whilst 2 of these antigens were also recognised by leukaemic sera. Some of the genes identified here were already known to be transcribed in DLBCL. The mRNA expression of the majority of the remaining antigens was confirmed in DLBCL cell lines using reverse-transcriptase PCR (RT-PCR). Our study identified a number of DLBCL associated antigens that may be suitable as prognostic/diagnostic markers and/or for the immunotherapy of haematologic malignancie
A novel zinc finger gene, ZNF465, is inappropriately expressed in acute myeloid leukaemia cells
No full textTo increase our knowledge of leukaemia-associated antigens, especially in acute myeloid leukaemia (AML) M4, we prepared a phage display cDNA library using mRNA from the bone marrow cells of a patient with AML M4 at diagnosis. We immunoscreened 10 pfu with autologous sera and identified an antigen which we named GKT-AML8. The cDNA showed more than 99% similarity to a sequence on 2q21.2 and 95% sequence similarity to a sequence on 19q13.3. These genes were named ZNF465 and ZNF466, respectively, following HUGO Gene Nomenclature Committee (HGNC) guidelines. Expressed sequence tag data suggests that both genes are transcriptionally active. ZNF465 and ZNF466 encode a 5′ krüppel associated box domain typical of negative regulators of gene transcription. We have confirmed the translational start site in the +1 frame in a near-Kozak sequence that produces a 102 amino acid polypeptide from ZNF465. The high level of sequence similarity between ZNF465 and ZNF466 makes their transcripts almost indistinguishable by real-time polymerase chain reaction (RT-PCR). However, GKT-AML8 showed most sequence similarity to ZNF465 and no transcript matching the 3′ ZNF466 sequence could be detected in patient samples or healthy volunteers. ZNF465/466 expression was detectable in 12/13 AML and 10/14 chronic myeloid leukaemia patients' samples but not in normal donor peripheral blood (0/8) or 0/3 bone marrow samples which had been separated into CD34 and CD34 samples. The altered expression of ZNF465/466 in patients' samples and its absence in healthy donor haematopoietic samples indicate that ZNF465 is overexpressed in early myeloid disease and as such may represent a promising target for immunotherapy
The biology of ELTD1/ADGRL4: a novel regulator of tumour angiogenesis
Get PDFBackground: Our laboratory identified ELTD1, an orphan GPCR belonging to the adhesion GPCR family (aGPCR), as a novel regulator of angiogenesis and a potential anti-cancer therapeutic target. ELTD1 is normally expressed in both endothelial cells and vascular smooth muscle cells and expression is significantly increased in the tumour vasculature. The aim of this project was to analyse ELTD1âs function in endothelial cells and its role in breast cancer.
Method: 62 sequenced vertebrate genomes were interrogated for ELTD1 conservation and domain alterations. A phylogenetic timetree was assembled to establish time estimates for ELTD1âs evolution. After ELTD1 silencing, mRNA array profiling was performed on primary human umbilical vein endothelial cells (HUVECs) and validated with qPCR and confocal microscopy. ELTD1âs signalling was investigated by applying the aGPCR âStinger/tethered-agonist Hypothesisâ. For this, truncated forms of ELTD1 and peptides analogous to the proposed tethered agonist region were designed. FRET-based 2nd messenger (Cisbio IP-1;cAMP) and luciferase-reporter assays (NFAT; NFκB; SRE; SRF-RE; CREB) were performed to establish canonical GPCR activation. To further investigate ELTD1âs role in endothelial cells, ELTD1 was stably overexpressed in HUVECS. Functional angiogenesis assays and mRNA array profiling were then performed. To investigate ELTD1 in breast cancer, a panel of cell lines representative of all molecular subtypes were screened using qPCR. Furthermore, an exploratory pilot study was performed on matched primary and regional nodal secondary breast cancers (n=43) which were stained for ELTD1 expression. Staining intensity was then scored and compared with relapse free survival and overall survival.
Results: ELTD1 arose 435 million years ago (mya) in bony fish and is present in all subsequent vertebrates. ELTD1 has 3 evolutionary variants of which 2 are most common: one variant with 3 EGFs and a variant with 2 EGFs. Additionally, ELTD1 may be ancestral to members of aGPCR family 2. HUVEC mRNA expression profiling after ELTD1 silencing showed upregulation of the mitochondrial citrate transporter SLC25A1, and ACLY which converts cytoplasmic citrate to Acetyl CoA, feeding fatty acid and cholesterol synthesis, and acetylation. A review of lipid droplet (fatty acid and cholesterol) accumulation by confocal microscopy and flow cytometry (FACS) revealed no changes with ELTD1 silencing. Silencing was also shown to affect the Notch pathway (downregulating the Notch ligand JAG1 and target gene HES2; upregulating the Notch ligand DLL4) and inducing KIT, a mediator of haematopoietic (HSC) and endothelial stem cell (ESC) maintenance. Signalling experiments revealed that unlike other aGPCRs, ELTD1 does not couple to any canonical GPCR pathways (Gαi, Gαs, Gαq, Gα12/13). ELTD1 overexpression in HUVECS revealed that ELTD1 induces an endothelial tip cell phenotype by promoting sprouting and capillary formation, inhibiting lumen anastomoses in mature vessels and lowering proliferation rate. There was no effect on wound healing or adhesion to angiogenesis associated matrix components. Gene expression changes following ELTD1 overexpression included upregulation of angiogenesis associated ANTRX1 as well as JAG1 and downregulation of migration associated CCL15 as well as KIT and DLL4. In breast cancer, none of the representative breast cancer cell lines screened expressed ELTD1. ELTD1 breast cancer immunohistochemistry revealed higher levels of vascular ELTD1 staining intensity within the tumour stroma contrasted to normal stroma and expression within tumour epithelial cells. Additionally, ELTD1 expression in tumour vessels was differentially expressed between the primary breast cancer microenvironment and that of the matched regional node. Due to the small size of the pilot study population, survival comparisons between the various subgroups did not yield significant results.
Conclusion: ELTD1 is a novel regulator of endothelial metabolism through its suppression of ACLY and the related citrate transporter SLC25A1. ELTD1 also represses KIT, which is known to mediate haematopoietic and endothelial progenitors stem cell maintenance, a possible mechanism through which endothelial cells maintain terminal endothelial differentiation. ELTD1 does not signal like other adhesion GPCRS with CTF and FL forms of ELTD1 not signalling canonically. Additionally, ELTD1 regulates various functions of endothelial cell behaviour and function, inducing an endothelial tip cell phenotype and is highly evolutionarily conserved. Lastly, ELTD1 is differentially expressed in tumour vessels between primary breast cancer and regional nodal metastases and is also expressed in a small subset of breast cancer cells in vivo despite no cancer cell lines expressing ELTD1. The pilot study investigating ELTD1 in the primary breast cancer and regional involved nodes will be followed up with a larger study including the investigation of ELTD1 in distant metastases.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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