2,310 research outputs found

    The chemokine receptor CX3CR1 is directly involved in the arrest of breast cancer cells to the skeleton

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    Abstract Introduction Skeletal metastases from breast adenocarcinoma are responsible for most of the morbidity and mortality associated with this tumor and represent a significant and unmet need for therapy. The arrival of circulating cancer cells to the skeleton depends first on the adhesive interactions with the endothelial cells lining the bone marrow sinusoids, and then the extravasation toward chemoattractant molecules produced by the surrounding bone stroma. We have previously shown that the membrane-bound and cell-adhesive form of the chemokine fractalkine is exposed on the luminal side of human bone marrow endothelial cells and that bone stromal cells release the soluble and chemoattractant form of this chemokine. The goal of this study was to determine the role of fractalkine and its specific receptor CX3CR1 in the homing of circulating breast cancer cells to the skeleton. Methods We employed a powerful pre-clinical animal model of hematogenous metastasis, in which fluorescent cancer cells are identified immediately after their arrival to the bone. We engineered cells to over-express either wild-type or functional mutants of CX3CR1 as well as employed transgenic mice knockout for fractalkine. Results CX3CR1 protein is detected in human tissue microarrays of normal and malignant mammary glands. We also found that breast cancer cells expressing high levels of this receptor have a higher propensity to spread to the skeleton. Furthermore, studies with fractalkine-null transgenic mice indicate that the ablation of the adhesive and chemotactic ligand of CX3CR1 dramatically impairs the skeletal dissemination of circulating cancer cells. Finally, we conclusively confirmed the crucial role of CX3CR1 on breast cancer cells for both adhesion to bone marrow endothelium and extravasation into the bone stroma. Conclusions We provide compelling evidence that the functional interactions between fractalkine produced by both the endothelial and stromal cells of bone marrow and the CX3CR1 receptor on breast cancer cells are determinant in the arrest and initial lodging needed for skeletal dissemination

    The Whole is Greater than the Sum of the Parts: Optimizing the Joint Science Return from LSST, Euclid and WFIRST

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    The focus of this report is on the opportunities enabled by the combination of LSST, Euclid and WFIRST, the optical surveys that will be an essential part of the next decade's astronomy. The sum of these surveys has the potential to be significantly greater than the contributions of the individual parts. As is detailed in this report, the combination of these surveys should give us multi-wavelength high-resolution images of galaxies and broadband data covering much of the stellar energy spectrum. These stellar and galactic data have the potential of yielding new insights into topics ranging from the formation history of the Milky Way to the mass of the neutrino. However, enabling the astronomy community to fully exploit this multi-instrument data set is a challenging technical task: for much of the science, we will need to combine the photometry across multiple wavelengths with varying spectral and spatial resolution. We identify some of the key science enabled by the combined surveys and the key technical challenges in achieving the synergies.Comment: Whitepaper developed at June 2014 U. Penn Workshop; 28 pages, 3 figure

    Reducing Zero-point Systematics in Dark Energy Supernova Experiments

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    We study the effect of filter zero-point uncertainties on future supernova dark energy missions. Fitting for calibration parameters using simultaneous analysis of all Type Ia supernova standard candles achieves a significant improvement over more traditional fit methods. This conclusion is robust under diverse experimental configurations (number of observed supernovae, maximum survey redshift, inclusion of additional systematics). This approach to supernova fitting considerably eases otherwise stringent mission calibration requirements. As an example we simulate a space-based mission based on the proposed JDEM satellite; however the method and conclusions are general and valid for any future supernova dark energy mission, ground or space-based.Comment: 30 pages,8 figures, 5 table, one reference added, submitted to Astroparticle Physic

    The chemokine receptor CX3CR1 is directly involved in the arrest of breast cancer cells to the skeleton

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    Abstract Introduction Skeletal metastases from breast adenocarcinoma are responsible for most of the morbidity and mortality associated with this tumor and represent a significant and unmet need for therapy. The arrival of circulating cancer cells to the skeleton depends first on the adhesive interactions with the endothelial cells lining the bone marrow sinusoids, and then the extravasation toward chemoattractant molecules produced by the surrounding bone stroma. We have previously shown that the membrane-bound and cell-adhesive form of the chemokine fractalkine is exposed on the luminal side of human bone marrow endothelial cells and that bone stromal cells release the soluble and chemoattractant form of this chemokine. The goal of this study was to determine the role of fractalkine and its specific receptor CX3CR1 in the homing of circulating breast cancer cells to the skeleton. Methods We employed a powerful pre-clinical animal model of hematogenous metastasis, in which fluorescent cancer cells are identified immediately after their arrival to the bone. We engineered cells to over-express either wild-type or functional mutants of CX3CR1 as well as employed transgenic mice knockout for fractalkine. Results CX3CR1 protein is detected in human tissue microarrays of normal and malignant mammary glands. We also found that breast cancer cells expressing high levels of this receptor have a higher propensity to spread to the skeleton. Furthermore, studies with fractalkine-null transgenic mice indicate that the ablation of the adhesive and chemotactic ligand of CX3CR1 dramatically impairs the skeletal dissemination of circulating cancer cells. Finally, we conclusively confirmed the crucial role of CX3CR1 on breast cancer cells for both adhesion to bone marrow endothelium and extravasation into the bone stroma. Conclusions We provide compelling evidence that the functional interactions between fractalkine produced by both the endothelial and stromal cells of bone marrow and the CX3CR1 receptor on breast cancer cells are determinant in the arrest and initial lodging needed for skeletal dissemination

    CS1 CAR-T targeting the distal domain of CS1 (SLAMF7) shows efficacy in high tumor burden myeloma model despite fratricide of CD8+CS1 expressing CAR-T cells

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    Despite improvement in treatment options for myeloma patients, including targeted immunotherapies, multiple myeloma remains a mostly incurable malignancy. High CS1 (SLAMF7) expression on myeloma cells and limited expression on normal cells makes it a promising target for CAR-T therapy. The CS1 protein has two extracellular domains - the distal Variable (V) domain and the proximal Constant 2 (C2) domain. We generated and tested CS1-CAR-T targeting the V domain of CS1 (Luc90-CS1-CAR-T) and demonstrated anti-myeloma killing in vitro and in vivo using two mouse models. Since fratricide of CD8 + cells occurred during production, we generated fratricide resistant CS1 deficient Luc90- CS1- CAR-T (ΔCS1-Luc90- CS1- CAR-T). This led to protection of CD8 + cells in the CAR-T cultures, but had no impact on efficacy. Our data demonstrate targeting the distal V domain of CS1 could be an effective CAR-T treatment for myeloma patients and deletion of CS1 in clinical production did not provide an added benefit using in vivo immunodeficient NSG preclinical models

    Weak Lensing from Space I: Instrumentation and Survey Strategy

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    A wide field space-based imaging telescope is necessary to fully exploit the technique of observing dark matter via weak gravitational lensing. This first paper in a three part series outlines the survey strategies and relevant instrumental parameters for such a mission. As a concrete example of hardware design, we consider the proposed Supernova/Acceleration Probe (SNAP). Using SNAP engineering models, we quantify the major contributions to this telescope's Point Spread Function (PSF). These PSF contributions are relevant to any similar wide field space telescope. We further show that the PSF of SNAP or a similar telescope will be smaller than current ground-based PSFs, and more isotropic and stable over time than the PSF of the Hubble Space Telescope. We outline survey strategies for two different regimes - a ``wide'' 300 square degree survey and a ``deep'' 15 square degree survey that will accomplish various weak lensing goals including statistical studies and dark matter mapping.Comment: 25 pages, 8 figures, 1 table, replaced with Published Versio

    Supernova / Acceleration Probe: A Satellite Experiment to Study the Nature of the Dark Energy

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    The Supernova / Acceleration Probe (SNAP) is a proposed space-based experiment designed to study the dark energy and alternative explanations of the acceleration of the Universe's expansion by performing a series of complementary systematics-controlled measurements. We describe a self-consistent reference mission design for building a Type Ia supernova Hubble diagram and for performing a wide-area weak gravitational lensing study. A 2-m wide-field telescope feeds a focal plane consisting of a 0.7 square-degree imager tiled with equal areas of optical CCDs and near infrared sensors, and a high-efficiency low-resolution integral field spectrograph. The SNAP mission will obtain high-signal-to-noise calibrated light-curves and spectra for several thousand supernovae at redshifts between z=0.1 and 1.7. A wide-field survey covering one thousand square degrees resolves ~100 galaxies per square arcminute. If we assume we live in a cosmological-constant-dominated Universe, the matter density, dark energy density, and flatness of space can all be measured with SNAP supernova and weak-lensing measurements to a systematics-limited accuracy of 1%. For a flat universe, the density-to-pressure ratio of dark energy can be similarly measured to 5% for the present value w0 and ~0.1 for the time variation w'. The large survey area, depth, spatial resolution, time-sampling, and nine-band optical to NIR photometry will support additional independent and/or complementary dark-energy measurement approaches as well as a broad range of auxiliary science programs. (Abridged)Comment: 40 pages, 18 figures, submitted to PASP, http://snap.lbl.go

    Mercury and monomethylmercury in fluids from Sea Cliff submarine hydrothermal field, Gorda Ridge

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    Author Posting. © American Geophysical Union, 2006. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 33 (2006): L17606, doi:10.1029/2006GL026321.Submarine hydrothermal systems are hypothesized to be a potentially important source of monomethylmercury (MMHg) to the ocean, yet the amount of MMHg in vent fluids is unknown. Here, we report total Hg and MMHg concentrations in hydrothermal vent fluids sampled from the Sea Cliff site on the Gorda Ridge. MMHg is the dominant Hg species, and levels of total Hg are enhanced slightly compared to seawater. Hg is enriched in deposits surrounding the site, suggesting near-field deposition from fluid plumes, with rapid MMHg demethylation and scavenging of Hg(II) complexes. Assuming the flux of MMHg from Sea Cliff is representative of global submarine hydrothermal inputs, we estimate a flux of 0.1–0.4 Mmoles y−1, which may be attenuated by scavenging near the vents. However, deep waters are not typically known to be elevated in Hg, and thus we suggest that hydrothermal systems are not significant sources of MMHg to commercial fisheries.WHOI Academic Programs Office, the Penzance Endowed Discretionary Fund, NSF-OCE and EPA-STAR, NOAA-NUR

    Search for charged Higgs decays of the top quark using hadronic tau decays

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    We present the result of a search for charged Higgs decays of the top quark, produced in ppˉp\bar{p} collisions at s=\surd s = 1.8 TeV. When the charged Higgs is heavy and decays to a tau lepton, which subsequently decays hadronically, the resulting events have a unique signature: large missing transverse energy and the low-charged-multiplicity tau. Data collected in the period 1992-1993 at the Collider Detector at Fermilab, corresponding to 18.7±\pm0.7~pb1^{-1}, exclude new regions of combined top quark and charged Higgs mass, in extensions to the standard model with two Higgs doublets.Comment: uuencoded, gzipped tar file of LaTeX and 6 Postscript figures; 11 pp; submitted to Phys. Rev.

    Measurement of Dijet Angular Distributions at CDF

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    We have used 106 pb^-1 of data collected in proton-antiproton collisions at sqrt(s)=1.8 TeV by the Collider Detector at Fermilab to measure jet angular distributions in events with two jets in the final state. The angular distributions agree with next to leading order (NLO) predictions of Quantum Chromodynamics (QCD) in all dijet invariant mass regions. The data exclude at 95% confidence level (CL) a model of quark substructure in which only up and down quarks are composite and the contact interaction scale is Lambda_ud(+) < 1.6 TeV or Lambda_ud(-) < 1.4 TeV. For a model in which all quarks are composite the excluded regions are Lambda(+) < 1.8 TeV and Lambda(-) < 1. 6 TeV.Comment: 16 pages, 2 figures, 2 tables, LaTex, using epsf.sty. Submitted to Physical Review Letters on September 17, 1996. Postscript file of full paper available at http://www-cdf.fnal.gov/physics/pub96/cdf3773_dijet_angle_prl.p
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