147 research outputs found

    PRC2 loss induces chemoresistance by repressing apoptosis in T cell acute lymphoblastic leukemia

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    The tendency of mitochondria to undergo or resist BCL2-controlled apoptosis (so-called mitochondrial priming) is a powerful predictor of response to cytotoxic chemotherapy. Fully exploiting this finding will require unraveling the molecular genetics underlying phenotypic variability in mitochondrial priming. Here, we report that mitochondria) apoptosis resistance in T cell acute lymphoblastic leukemia (T-ALL) is mediated by inactivation of polycomb repressive complex 2 (PRC2). In T-ALL clinical specimens, loss-of-function mutations of PRC2 core components (EZH2, FED, or SUZ12) were associated with mitochondrial apoptosis resistance. In T-ALL cells, PRC2 depletion induced resistance to apoptosis induction by multiple chemotherapeutics with distinct mechanisms of action. PRC2 loss induced apoptosis resistance via transcriptional up-regulation of the LIM domain transcription factor CRIP2 and downstream up-regulation of the mitochondrial chaperone TRAP1. These findings demonstrate the importance of mitochondrial apoptotic priming as a prognostic factor in T-ALL and implicate mitochondrial chaperone function as a molecular determinant of chemotherapy response

    Phylogenetic and environmental context of a Tournaisian tetrapod fauna

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    The end-Devonian to mid-Mississippian time interval has long been known for its depauperate palaeontological record, especially for tetrapods. This interval encapsulates the time of increasing terrestriality among tetrapods, but only two Tournaisian localities previously produced tetrapod fossils. Here we describe five new Tournaisian tetrapods (Perittodus apsconditus\textit{Perittodus apsconditus}, Koilops herma\textit{Koilops herma}, Ossirarus kierani\textit{Ossirarus kierani}, Diploradus austiumensis\textit{Diploradus austiumensis} and Aytonerpeton microps\textit{Aytonerpeton microps}) from two localities in their environmental context. A phylogenetic analysis retrieved three taxa as stem tetrapods, interspersed among Devonian and Carboniferous forms, and two as stem amphibians, suggesting a deep split among crown tetrapods. We also illustrate new tetrapod specimens from these and additional localities in the Scottish Borders region. The new taxa and specimens suggest that tetrapod diversification was well established by the Tournaisian. Sedimentary evidence indicates that the tetrapod fossils are usually associated with sandy siltstones overlying wetland palaeosols. Tetrapods were probably living on vegetated surfaces that were subsequently flooded. We show that atmospheric oxygen levels were stable across the Devonian/Carboniferous boundary, and did not inhibit the evolution of terrestriality. This wealth of tetrapods from Tournaisian localities highlights the potential for discoveries elsewhere.NERC consortium grants NE/J022713/1 (Cambridge), NE/J020729/1 (Leicester), NE/J021067/1 (BGS), NE/J020621/1 (NMS) and NE/J021091/1 (Southampton

    A phase I dose-escalating study of DaunoXome, liposomal daunorubicin, in metastatic breast cancer

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    The aims of this phase I study were to establish the maximum tolerated dose, safety profile and activity of liposomal daunorubicin, DaunoXome (NeXstar Pharmaceuticals), in the treatment of metastatic breast cancer. DaunoXome was administered intravenously over 2 h in 21 day cycles and doses were increased from 80 to 100, 120 and 150 mg m2. Sixteen patients were enrolled. A total of 70 cycles of DaunoXome were administered. The maximum tolerated dose was 120 mg m2, the dose-limiting toxicity being prolonged grade 4 neutropenia or neutropenic pyrexia necessitating dose reductions at 120 and 150 mg m2. Asymptomatic cardiotoxicity was observed in three patients: grade 1 in one treated with a cumulative dose of 800 mg m2 and grade 2 in two, one who received a cumulative dose of 960 mg m2 and the other a cumulative dose of 600 mg m2 with a previous neoadjuvant doxorubicin chemotherapy of 300 mg m2. Tumour response was evaluable in 15 patients, of whom two had objective responses, six had stable disease and seven had progressive disease. In conclusion, DaunoXome is associated with mild, manageable toxicities and has anti-tumour activity in metastatic breast cancer. The findings support further phase II evaluation of DaunoXome alone and in combination with other standard non-anthracycline cytotoxic or novel targeted agents. Although the dose-limiting toxicity for DaunoXome was febrile neutropenia at 120 mg m2, we would recommend this dose for further evaluation, as the febrile neutropenia occurred after four or more cycles in three of the four episodes seen, was short lived and uncomplicated

    The spotted gar genome illuminates vertebrate evolution and facilitates human-teleost comparisons

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    To connect human biology to fish biomedical models, we sequenced the genome of spotted gar (Lepisosteus oculatus), whose lineage diverged from teleosts before teleost genome duplication (TGD). The slowly evolving gar genome has conserved in content and size many entire chromosomes from bony vertebrate ancestors. Gar bridges teleosts to tetrapods by illuminating the evolution of immunity, mineralization and development (mediated, for example, by Hox, ParaHox and microRNA genes). Numerous conserved noncoding elements (CNEs; often cis regulatory) undetectable in direct human-teleost comparisons become apparent using gar: functional studies uncovered conserved roles for such cryptic CNEs, facilitating annotation of sequences identified in human genome-wide association studies. Transcriptomic analyses showed that the sums of expression domains and expression levels for duplicated teleost genes often approximate the patterns and levels of expression for gar genes, consistent with subfunctionalization. The gar genome provides a resource for understanding evolution after genome duplication, the origin of vertebrate genomes and the function of human regulatory sequences

    Understanding the retinal basis of vision across species

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    The vertebrate retina first evolved some 500 million years ago in ancestral marine chordates. Since then, the eyes of different species have been tuned to best support their unique visuoecological lifestyles. Visual specializations in eye designs, large-scale inhomogeneities across the retinal surface and local circuit motifs mean that all species' retinas are unique. Computational theories, such as the efficient coding hypothesis, have come a long way towards an explanation of the basic features of retinal organization and function; however, they cannot explain the full extent of retinal diversity within and across species. To build a truly general understanding of vertebrate vision and the retina's computational purpose, it is therefore important to more quantitatively relate different species' retinal functions to their specific natural environments and behavioural requirements. Ultimately, the goal of such efforts should be to build up to a more general theory of vision

    The Public Repository of Xenografts enables discovery and randomized phase II-like trials in mice

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    More than 90% of drugs with preclinical activity fail in human trials, largely due to insufficient efficacy. We hypothesized that adequately powered trials of patient-derived xenografts (PDX) in mice could efficiently define therapeutic activity across heterogeneous tumors. To address this hypothesis, we established a large, publicly available repository of well-characterized leukemia and lymphoma PDXs that undergo orthotopic engraftment, called the Public Repository of Xenografts (PRoXe). PRoXe includes all de-identified information relevant to the primary specimens and the PDXs derived from them. Using this repository, we demonstrate that large studies of acute leukemia PDXs that mimic human randomized clinical trials can characterize drug efficacy and generate transcriptional, functional, and proteomic biomarkers in both treatment-naive and relapsed/refractory disease

    Mapping and linking supply- and demand-side measures in climate-smart agriculture. A review

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    Climate change and food security are two of humanity’s greatest challenges and are highly interlinked. On the one hand, climate change puts pressure on food security. On the other hand, farming significantly contributes to anthropogenic greenhouse gas emissions. This calls for climate-smart agriculture—agriculture that helps to mitigate and adapt to climate change. Climate-smart agriculture measures are diverse and include emission reductions, sink enhancements, and fossil fuel offsets for mitigation. Adaptation measures include technological advancements, adaptive farming practices, and financial management. Here, we review the potentials and trade-offs of climate-smart agricultural measures by producers and consumers. Our two main findings are as follows: (1) The benefits of measures are often site-dependent and differ according to agricultural practices (e.g., fertilizer use), environmental conditions (e.g., carbon sequestration potential), or the production and consumption of specific products (e.g., rice and meat). (2) Climate-smart agricultural measures on the supply side are likely to be insufficient or ineffective if not accompanied by changes in consumer behavior, as climate-smart agriculture will affect the supply of agricultural commodities and require changes on the demand side in response. Such linkages between demand and supply require simultaneous policy and market incentives. It, therefore, requires interdisciplinary cooperation to meet the twin challenge of climate change and food security. The link to consumer behavior is often neglected in research but regarded as an essential component of climate-smart agriculture. We argue for not solely focusing research and implementation on one-sided measures but designing good, site-specific combinations of both demand- and supply-side measures to use the potential of agriculture more effectively to mitigate and adapt to climate change
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