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Bert Binas - One of the best experts on this subject based on the ideXlab platform.
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isolation of oct4 expressing extraembryonic endoderm precursor Cell Lines
PLOS ONE, 2009Co-Authors: Bisrat G Debeb, Vasiliy Galat, Jessica Epplefarmer, Steve Iannaccone, Wendy A Woodward, Michael Bader, Philip M Iannaccone, Bert BinasAbstract:Background: The extraembryonic endoderm (ExEn) defines the yolk sac, a set of membranes that provide essential support for mammalian embryos. Recent findings suggest that the committed ExEn precursor is present already in the embryonic Inner Cell Mass (ICM) as a group of Cells that intermingles with the closely related epiblast precursor. All ICM Cells contain Oct4, a key transcription factor that is first expressed at the morula stage. In vitro, the epiblast precursor is most closely represented by the well-characterized embryonic stem (ES) Cell Lines that maintain the expression of Oct4, but analogous ExEn precursor Cell Lines are not known and it is unclear if they would express Oct4. Methodology/Principal Findings: Here we report the isolation and characterization of permanently proliferating Oct4expressing rat Cell Lines (‘‘XEN-P Cell Lines’’), which closely resemble the ExEn precursor. We isolated the XEN-P Cell Lines from blastocysts and characterized them by plating and gene expression assays as well as by injection into embryos. Like ES Cells, the XEN-P Cells express Oct4 and SSEA1 at high levels and their growth is stimulated by leukemia inhibitory factor, but instead of the epiblast determinant Nanog, they express the ExEn determinants Gata6 and Gata4. Further, they lack markers characteristic of the more differentiated primitive/visceral and parietal ExEn stages, but exclusively differentiate into these stages in vitro and contribute to them in vivo. Conclusions/Significance: Our findings (i) suggest strongly that the ExEn precursor is a self-renewable entity, (ii) indicate that active Oct4 gene expression (transcription plus translation) is part of its molecular identity, and (iii) provide an in vitro model of early ExEn differentiation.
Hans G Drexler - One of the best experts on this subject based on the ideXlab platform.
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the ll 100 panel 100 Cell Lines for blood cancer studies
Scientific Reports, 2019Co-Authors: Hilmar Quentmeier, Roderick A F Macleod, Claudia Pommerenke, Wilhelm G Dirks, Sonja Eberth, Max Koeppel, Stefan Nagel, Klaus Steube, Cord C Uphoff, Hans G DrexlerAbstract:For many years, immortalized Cell Lines have been used as model systems for cancer research. Cell line panels were established for basic research and drug development, but did not cover the full spectrum of leukemia and lymphoma. Therefore, we now developed a novel panel (LL-100), 100 Cell Lines covering 22 entities of human leukemia and lymphoma including T-Cell, B-Cell and myeloid malignancies. Importantly, all Cell Lines are unequivocally authenticated and assigned to the correct tissue. Cell line samples were proven to be free of mycoplasma and non-inherent virus contamination. Whole exome sequencing and RNA-sequencing of the 100 Cell Lines were conducted with a uniform methodology to complement existing data on these publicly available Cell Lines. We show that such comprehensive sequencing data can be used to find lymphoma-subtype-characteristic copy number aberrations, mRNA isoforms, transcription factor activities and expression patterns of NKL homeobox genes. These exemplary studies confirm that the novel LL-100 panel will be useful for understanding the function of oncogenes and tumor suppressor genes and to develop targeted therapies.
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check your cultures a list of cross contaminated or misidentified Cell Lines
International Journal of Cancer, 2010Co-Authors: Amanda Capesdavis, Roderick A F Macleod, Hans G Drexler, George Theodosopoulos, Isobel Atkin, Arihiro Kohara, J R W Masters, Yukio Nakamura, Yvonne Reid, Roger R ReddelAbstract:Continuous Cell Lines consist of cultured Cells derived from a specific donor and tissue of origin that have acquired the ability to proliferate indefinitely. These Cell Lines are well-recognized models for the study of health and disease, particularly for cancer. However, there are cautions to be aware of when using continuous Cell Lines, including the possibility of contamination, in which a foreign Cell line or microorganism is introduced without the handler's knowledge. Cross-contamination, in which the contaminant is another Cell line, was first recognized in the 1950s but, disturbingly, remains a serious issue today. Many Cell Lines become cross-contaminated early, so that subsequent experimental work has been performed only on the contaminant, masquerading under a different name. What can be done in response—how can a researcher know if their own Cell Lines are cross-contaminated? Two practical responses are suggested here. First, it is important to check the literature, looking for previous work on cross-contamination. Some reports may be difficult to find and to make these more accessible, we have compiled a list of known cross-contaminated Cell Lines. The list currently contains 360 Cell Lines, drawn from 68 references. Most contaminants arise within the same species, with HeLa still the most frequently encountered (29%, 106/360) among human Cell Lines, but interspecies contaminants account for a small but substantial minority of cases (9%, 33/360). Second, even if there are no previous publications on cross-contamination for that Cell line, it is essential to check the sample itself by performing authentication testing.
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cytogenetic harvesting of commonly used tumor Cell Lines
Nature Protocols, 2007Co-Authors: Roderick A F Macleod, Maren Kaufmann, Hans G DrexlerAbstract:Tumor Cell Lines are widely used both as disease models and, increasingly, as genomic resources for the ascertainment of new cancer genes. Cytogenetic analysis remains a major route to uncovering the cancer genome. However, cancer Cell Lines vary inexplicably in their harvesting preferences, which must, therefore, be determined by trial and error. This article describes harvesting protocols optimized empirically for 550 commonly used, mainly human, cancer Cell Lines together with evidence-based procedures to assist in determining conditions for unlisted Cell Lines and subsidiary protocols for cytogenetic analysis using G-banding and fluorescence in situ hybridization.
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malignant hematopoietic Cell Lines in vitro models for the study of erythroleukemia
Leukemia Research, 2004Co-Authors: Hans G Drexler, Yoshinobu Matsuo, Roderick A F MacleodAbstract:A panel of leukemia Cell Lines has been assembled over the last 30 years representing a spectrum of erythroid Cells arrested at various stages of differentiation. The oldest Cell line is K-562 which is one of the most prolific in use. Most Cell Lines have been established from acute myeloid leukemia M6 or chronic myeloid leukemia in blast crisis and generally express immunoprofiles typically seen in immature erythroid Cells. Several Cell Lines are constitutively growth factor-dependent, responding proliferatively to a variety of cytokines. The predominant cytogenetic abnormalities are the t(9;22)(q34;q11) found exclusively in CML-derived Cell Lines, and rearrangements of chromosomes 5 and 7 which occur in all disease subtypes. Ph+ve Cell Lines consistently displayed structural and numerical changes associated with disease evolution, including +8, -17/17p-/i(17q), and +19. It is striking that many Cell Lines though committed to either the erythroid or megakaryocytic lineage tend to co-express features of the other lineage, consistent with the concept of a common erythroid-megakaryocytic progenitor. Several Cell Lines may be induced to differentiate along the erythroid, megakaryocytic or monocytic pathway by treatment with pharmacological or physiological reagents. Notable functional features include expression of various globin chains or the complete hemoglobins as erythroid attributes. Taken together, this class of Cell Lines is relatively well characterized and affords useful model systems for immature erythroid Cells.
Mark Waltham - One of the best experts on this subject based on the ideXlab platform.
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epithelial mesenchymal transition traits in human breast cancer Cell Lines
Clinical & Experimental Metastasis, 2008Co-Authors: Tony Blick, Mark Waltham, Edwin Widodo, Honor J Hugo, Marc E Lenburg, R M Neve, Erik W ThompsonAbstract:Epithelial mesenchymal transition (EMT) has long been associated with breast cancer Cell invasiveness and evidence of EMT processes in clinical samples is growing rapidly. Genome-wide transcriptional profiling of increasingly larger numbers of human breast cancer (HBC) Cell Lines have confirmed the existence of a subgroup of Cell Lines (termed Basal B/Mesenchymal) with enhanced invasive properties and a predominantly mesenchymal gene expression signature, distinct from subgroups with predominantly luminal (termed Luminal) or mixed basal/luminal (termed Basal A) features (Neve et al Cancer Cell 2006). Studies providing molecular and Cellular analyses of EMT features in these Cell Lines are summarised, and the expression levels of EMT-associated factors in these Cell Lines are analysed. Recent clinical studies supporting the presence of EMT-like changes in vivo are summarised. Human breast cancer Cell Lines with mesenchymal properties continue to hold out the promise of directing us towards key mechanisms at play in the metastatic dissemination of breast cancer.
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systematic variation in gene expression patterns in human cancer Cell Lines
Nature Genetics, 2000Co-Authors: Douglas T Ross, Uwe Scherf, Michael B Eisen, Charles M Perou, Christian A Rees, Paul T Spellman, Vishwanath R Iyer, Stefanie S Jeffrey, Matt Van De Rijn, Mark WalthamAbstract:We used cDNA microarrays to explore the variation in expression of approximately 8,000 unique genes among the 60 Cell Lines used in the National Cancer Institute's screen for anti-cancer drugs. Classification of the Cell Lines based solely on the observed patterns of gene expression revealed a correspondence to the ostensible origins of the tumours from which the Cell Lines were derived. The consistent relationship between the gene expression patterns and the tissue of origin allowed us to recognize outliers whose previous classification appeared incorrect. Specific features of the gene expression patterns appeared to be related to physiological properties of the Cell Lines, such as their doubling time in culture, drug metabolism or the interferon response. Comparison of gene expression patterns in the Cell Lines to those observed in normal breast tissue or in breast tumour specimens revealed features of the expression patterns in the tumours that had recognizable counterparts in specific Cell Lines, reflecting the tumour, stromal and inflammatory components of the tumour tissue. These results provided a novel molecular characterization of this important group of human Cell Lines and their relationships to tumours in vivo.
Ernest A Gould - One of the best experts on this subject based on the ideXlab platform.
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tick Cell Lines tools for tick and tick borne disease research
Trends in Parasitology, 2007Co-Authors: Lesley Bellsakyi, Erich Zweygarth, Edmour F Blouin, Ernest A GouldAbstract:Over 40 Cell Lines are currently available from 13 ixodid and one argasid tick species. The successful isolation and propagation of several economically important tick-borne pathogens in tick Cell Lines has created a useful model to study interactions between tick Cells and these viral and bacterial disease agents. Tick Cell Lines have already proved to be a useful tool in helping to define the complex nature of the host–vector–pathogen relationship. With the availability of genomics tools, tick Cell Lines will become increasingly important as a complement to tick and tick-borne disease research in vivo once genetic transformation and gene silencing using RNA interference become routine.
Jinfeng Liu - One of the best experts on this subject based on the ideXlab platform.
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a comprehensive transcriptional portrait of human cancer Cell Lines
Nature Biotechnology, 2015Co-Authors: Christiaan Klijn, Steffen Durinck, Eric W Stawiski, Peter M Haverty, Zhaoshi Jiang, Hanbin Liu, Jeremiah D Degenhardt, Oleg Mayba, Florian Gnad, Jinfeng LiuAbstract:Tumor-derived Cell Lines have served as vital models to advance our understanding of oncogene function and therapeutic responses. Although substantial effort has been made to define the genomic constitution of cancer Cell line panels, the transcriptome remains understudied. Here we describe RNA sequencing and single-nucleotide polymorphism (SNP) array analysis of 675 human cancer Cell Lines. We report comprehensive analyses of transcriptome features including gene expression, mutations, gene fusions and expression of non-human sequences. Of the 2,200 gene fusions catalogued, 1,435 consist of genes not previously found in fusions, providing many leads for further investigation. We combine multiple genome and transcriptome features in a pathway-based approach to enhance prediction of response to targeted therapeutics. Our results provide a valuable resource for studies that use cancer Cell Lines.
