374 research outputs found

    Do human transposable element small RNAs serve primarily as genome defenders or genome regulators?

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    It is currently thought that small RNA (sRNA) based repression mechanisms are primarily employed to mitigate the mutagenic threat posed by the activity of transposable elements (TEs). This can be achieved by the sRNA guided processing of TE transcripts via Dicer-dependent (e.g., siRNA) or Dicer-independent (e.g., piRNA) mechanisms. For example, potentially active human L1 elements are silenced by mRNA cleavage induced by element encoded siRNAs, leading to a negative correlation between element mRNA and siRNA levels. On the other hand, there is emerging evidence that TE derived sRNAs can also be used to regulate the host genome. Here, we evaluated these two hypotheses for human TEs by comparing the levels of TE derived mRNA and TE sRNA across six tissues. The genome defense hypothesis predicts a negative correlation between TE mRNA and TE sRNA levels, whereas the genome regulatory hypothesis predicts a positive correlation. On average, TE mRNA and TE sRNA levels are positively correlated across human tissues. These correlations are higher than seen for human genes or for randomly permuted control data sets. Overall, Alu subfamilies show the highest positive correlations of element mRNA and sRNA levels across tissues, although a few of the youngest, and potentially most active, Alu subfamilies do show negative correlations. Thus, Alu derived sRNAs may be related to both genome regulation and genome defense. These results are inconsistent with a simple model whereby TE derived sRNAs reduce levels of standing TE mRNA via transcript cleavage, and suggest that human cells efficiently process TE transcripts into sRNA based on the available message levels. This may point to a widespread role for processed TE transcripts in genome regulation or to alternative roles of TE-to-sRNA processing including the mitigation of TE transcript cytotoxicity

    Local and Remote Mean and Extreme Temperature Response to Regional Aerosol Emissions Reductions

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    The climatic implications of regional aerosol and precursor emissions reductions implemented to protect human health are poorly understood. We investigate the mean and extreme temperature response to regional changes in aerosol emissions using three coupled chemistryclimate models: NOAA GFDL CM3, NCAR CESM1, and NASA GISS-E2. Our approach contrasts a long present-day control simulation from each model (up to 400 years with perpetual year 2000 or 2005 emissions) with 14 individual aerosol emissions perturbation simulations (160240 years each). We perturb emissions of sulfur dioxide (SO2) and/or carbonaceous aerosol within six world regions and assess the statistical significance of mean and extreme temperature responses relative to internal variability determined by the control simulation and across the models. In all models, the global mean surface temperature response (perturbation minus control) to SO2 and/or carbonaceous aerosol is mostly positive (warming) and statistically significant and ranges from +0.17 K (Europe SO2) to -0.06 K (US BC). The warming response to SO2 reductions is strongest in the US and Europe perturbation simulations, both globally and regionally, with Arctic warming up to 1 K due to a removal of European anthropogenic SO2 emissions alone; however, even emissions from regions remote to the Arctic, such as SO2 from India, significantly warm the Arctic by up to 0.5 K. Arctic warming is the most robust response across each model and several aerosol emissions perturbations. The temperature response in the Northern Hemisphere midlatitudes is most sensitive to emissions perturbations within that region. In the tropics, however, the temperature response to emissions perturbations is roughly the same in magnitude as emissions perturbations either within or outside of the tropics. We find that climate sensitivity to regional aerosol perturbations ranges from 0.5 to 1.0 K (W m(exp -2))(exp -1) depending on the region and aerosol composition and is larger than the climate sensitivity to a doubling of CO2 in two of three models. We update previous estimates of regional temperature potential (RTP), a metric for estimating the regional temperature responses to a regional emissions perturbation that can facilitate assessment of climate impacts with integrated assessment models without requiring computationally demanding coupled climate model simulations. These calculations indicate a robust regional response to aerosol forcing within the Northern Hemisphere midlatitudes, regardless of where the aerosol forcing is located longitudinally. We show that regional aerosol perturbations can significantly increase extreme temperatures on the regional scale. Except in the Arctic in the summer, extreme temperature responses largely mirror mean temperature responses to regional aerosol perturbations through a shift of the temperature distributions and are mostly dominated by local rather than remote aerosol forcing

    Stratospheric ozone chemistry feedbacks are not critical for the determination of climate sensitivity in CESM1(WACCM)

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    The Community Earth System Model‐Whole Atmosphere Community Climate Model (CESM1‐WACCM) is used to assess the importance of including chemistry feedbacks in determining the equilibrium climate sensitivity (ECS). Two 4×CO2 model experiments were conducted: one with interactive chemistry and one with chemical constituents other than CO2 held fixed at their preindustrial values. The ECS determined from these two experiments agrees to within 0.01 K. Similarly, the net feedback parameter agrees to within 0.01 W m−2 K−1. This agreement occurs in spite of large changes in stratospheric ozone found in the simulation with interactive chemistry: a 30% decrease in the tropical lower stratosphere and a 40% increase in the upper stratosphere, broadly consistent with other published estimates. Off‐line radiative transfer calculations show that ozone changes alone account for the difference in radiative forcing. We conclude that at least for determining global climate sensitivity metrics, the exclusion of chemistry feedbacks is not a critical source of error in CESM

    Microwave hyperthermia represses human papillomavirus oncoprotein activity and induces cell death due to cell stress in 3D tissue models of anogenital precancers and cancers

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    Background: Hyperthermia is a well-accepted cancer therapy. Microwaves provide a very precise, targeted means of hyperthermia and are currently used to treat plantar warts caused by cutaneous-infective human papillomaviruses (HPVs). Other HPV genotypes infecting the anogenital mucosa cause genital warts or preneoplastic lesions or cervical cancer. Effective, non-ablative therapies for these morbid HPV-associated lesions are lacking. Methods: The molecular consequences of microwave treatment were investigated in in vitro cultured three-dimensional HPV-positive cervical tumour tissues, and tissues formed from HPV-infected normal immortalised keratinocytes. Microwave energy delivery to tissues was quantified. Quantitative reverse transcriptase PCR was used to quantify mRNA expression. Immunohistochemistry and fluorescence immunostaining was used to assess protein expression. Findings: Microwave energy deposition induced sustained, localised cell death at the treatment site. There was a downregulation in levels of HPV oncoproteins E6 and E7 alongside a reduction in cellular growth/proliferation and induction of apoptosis/autophagy. HSP70 expression confirmed hyperthermia, concomitant with induction of translational stress. Interpretation: The data suggest that microwave treatment inhibits tumour cell proliferation and allows the natural apoptosis of HPV-infected cells to resume. Precision microwave delivery presents a potential new treatment for treating HPV-positive anogenital precancerous lesions and cancers. Funding: Funding was through an Innovate UK Biomedical Catalyst grant (ID# 92138-556187), a Chief Scientist Office grant (TCS/19/11) and core support from Medical Research Council (MC_ UU_12014) core funding for the MRC-University of Glasgow Centre for Virus Research

    Prognostic Molecular Biomarkers in Chordomas: A Systematic Review and Identification of Clinically Usable Biomarker Panels

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    INTRODUCTION AND OBJECTIVE: Despite the improvements in management and treatment of chordomas over time, the risk of disease recurrence remains high. Consequently, there is a push to develop effective systemic therapeutics for newly diagnosed and recurrent disease. In order to tailor treatment for individual chordoma patients and develop effective surveillance strategies, suitable clinical biomarkers need to be identified. The objective of this study was to systematically review all prognostic biomarkers for chordomas reported to date in order to classify them according to localization, study design and statistical analysis. METHODS: Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we systematically reviewed published studies reporting biomarkers that correlated with clinical outcomes. We included time-to-event studies that evaluated biomarkers in skull base or spine chordomas. To be included in our review, the study must have analyzed the outcomes with univariate and/or multivariate methods (log-rank test or a Cox-regression model). RESULTS: We included 68 studies, of which only 5 were prospective studies. Overall, 103 biomarkers were analyzed in 3183 patients. According to FDA classification, 85 were molecular biomarkers (82.5%) mainly located in nucleus and cytoplasm (48% and 27%, respectively). Thirty-four studies analyzed biomarkers with Cox-regression model. Within these studies, 32 biomarkers (31%) and 22 biomarkers (21%) were independent prognostic factors for PFS and OS, respectively. CONCLUSION: Our analysis identified a list of 13 biomarkers correlating with tumor control rates and survival. The future point will be gathering all these results to guide the clinical validation for a chordoma biomarker panel. Our identified biomarkers have strengths and weaknesses according to FDA\u27s guidelines, some are affordable, have a low-invasive collection method and can be easily measured in any health care setting (RDW and D-dimer), but others molecular biomarkers need specialized assay techniques (microRNAs, PD-1 pathway markers, CDKs and somatic chromosome deletions were more chordoma-specific). A focused list of biomarkers that correlate with local recurrence, metastatic spread and survival might be a cornerstone to determine the need of adjuvant therapies

    The Grizzly, September 14, 2023

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    Good Samaritan Policy Changes: Good Ideas? • Changes Across Wismer • Student Handbook Changes • Letter From the Editor • Hello From the News Editor • ODA\u27s Peer Mentor Program • Meet SGA President: Ben Douglas • Opinions: Upper Wismer\u27s Wonderful New Eats • Editor Introductions • UC Soccer on Fire! • Bears\u27 Football Comes Out of Hibernation With a Head of Steamhttps://digitalcommons.ursinus.edu/grizzlynews/2014/thumbnail.jp

    High-Grade Pleomorphic Sarcomas Treated with Immune Checkpoint Blockade: The MD Anderson Cancer Center Experience

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    BACKGROUND: Undifferentiated pleomorphic sarcomas (UPSs) are amongst the most common subtypes of soft-tissue sarcomas. Few real-world data on the use of immune checkpoint blockade (ICB) in UPS patients and other high-grade pleomorphic STS patients are available. PURPOSE: The purpose of our study is to describe the efficacy and toxicity of ICB in patients with advanced UPSs and other high-grade pleomorphic sarcomas treated at our institution. METHODS: This is a retrospective, observational study of all patients with metastatic high-grade pleomorphic sarcomas treated with FDA-approved ICB at MD Anderson Cancer Center between 1 January 2015 and 1 January 2023. Patients included in trials for which results are not yet published were excluded. RESULTS: Thirty-six patients with advanced/metastatic pleomorphic sarcomas were included. The median age was 52 years. A total of 26 patients (72%) had UPSs and 10 patients (28%) had other high-grade pleomorphic sarcomas. The median follow-up time was 8.8 months. The median PFS was 2.9 months. The 3-month PFS and 6-month PFS were 46% and 32%, respectively. The median OS was 12.9 months. The 12-month OS and 24-month OS were 53% and 29%, respectively. The best response, previous RT, and type of ICB treatment were significantly and independently associated with shorter PFS ( CONCLUSIONS: Real-world retrospective data are consistent with the published literature, with a promising 6-month PFS of 32%. Partial or stable responders to ICB treatment have significantly improved PFS compared to progressors

    The Carnegie Supernova Project: First Near-Infrared Hubble Diagram to z~0.7

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    The Carnegie Supernova Project (CSP) is designed to measure the luminosity distance for Type Ia supernovae (SNe Ia) as a function of redshift, and to set observational constraints on the dark energy contribution to the total energy content of the Universe. The CSP differs from other projects to date in its goal of providing an I-band {rest-frame} Hubble diagram. Here we present the first results from near-infrared (NIR) observations obtained using the Magellan Baade telescope for SNe Ia with 0.1 < z < 0.7. We combine these results with those from the low-redshift CSP at z <0.1 (Folatelli et al. 2009). We present light curves and an I-band Hubble diagram for this first sample of 35 SNe Ia and we compare these data to 21 new SNe Ia at low redshift. These data support the conclusion that the expansion of the Universe is accelerating. When combined with independent results from baryon acoustic oscillations (Eisenstein et al. 2005), these data yield Omega_m = 0.27 +/- 0.0 (statistical), and Omega_DE = 0.76 +/- 0.13 (statistical) +/- 0.09 (systematic), for the matter and dark energy densities, respectively. If we parameterize the data in terms of an equation of state, w, assume a flat geometry, and combine with baryon acoustic oscillations, we find that w = -1.05 +/- 0.13 (statistical) +/- 0.09 (systematic). The largest source of systematic uncertainty on w arises from uncertainties in the photometric calibration, signaling the importance of securing more accurate photometric calibrations for future supernova cosmology programs. Finally, we conclude that either the dust affecting the luminosities of SNe Ia has a different extinction law (R_V = 1.8) than that in the Milky Way (where R_V = 3.1), or that there is an additional intrinsic color term with luminosity for SNe Ia independent of the decline rate.Comment: 44 pages, 23 figures, 9 tables; Accepted for publication in the Astrophysical Journa
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