245 research outputs found

    Myelodysplasia-associated mutations in serine/arginine-rich splicing factor SRSF2 lead to alternative splicing of CDC25C

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    Additional file 2: Figure S1. HA-tagged SRSF2 protein expression in uninduced TF-1 cell lines

    Limiting the Persistence of a Chromosome Break Diminishes Its Mutagenic Potential

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    To characterize the repair pathways of chromosome double-strand breaks (DSBs), one approach involves monitoring the repair of site-specific DSBs generated by rare-cutting endonucleases, such as I-SceI. Using this method, we first describe the roles of Ercc1, Msh2, Nbs1, Xrcc4, and Brca1 in a set of distinct repair events. Subsequently, we considered that the outcome of such assays could be influenced by the persistent nature of I-SceI-induced DSBs, in that end-joining (EJ) products that restore the I-SceI site are prone to repeated cutting. To address this aspect of repair, we modified I-SceI-induced DSBs by co-expressing I-SceI with a non-processive 3′ exonuclease, Trex2, which we predicted would cause partial degradation of I-SceI 3′ overhangs. We find that Trex2 expression facilitates the formation of I-SceI-resistant EJ products, which reduces the potential for repeated cutting by I-SceI and, hence, limits the persistence of I-SceI-induced DSBs. Using this approach, we find that Trex2 expression causes a significant reduction in the frequency of repair pathways that result in substantial deletion mutations: EJ between distal ends of two tandem DSBs, single-strand annealing, and alternative-NHEJ. In contrast, Trex2 expression does not inhibit homology-directed repair. These results indicate that limiting the persistence of a DSB causes a reduction in the frequency of repair pathways that lead to significant genetic loss. Furthermore, we find that individual genetic factors play distinct roles during repair of non-cohesive DSB ends that are generated via co-expression of I-SceI with Trex2

    Longitudinal cohort study of the impact of specialist cancer services for teenagers and young adults on quality of life: outcomes from the BRIGHTLIGHT study.

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    OBJECTIVES: In England, healthcare policy advocates specialised age-appropriate services for teenagers and young adults (TYA), those aged 13 to 24 years at diagnosis. Specialist Principal Treatment Centres (PTC) provide enhanced TYA age-specific care, although many still receive care in adult or children's cancer services. We present the first prospective structured analysis of quality of life (QOL) associated with the amount of care received in a TYA-PTC DESIGN: Longitudinal cohort study. SETTING: Hospitals delivering inpatient cancer care in England. PARTICIPANTS: 1114 young people aged 13 to 24 years newly diagnosed with cancer. INTERVENTION: Exposure to the TYA-PTC defined as patients receiving NO-TYA-PTC care with those receiving ALL-TYA-PTC and SOME-TYA-PTC care. PRIMARY OUTCOME: Quality of life measured at five time points: 6, 12, 18, 24 and 36 months after diagnosis. RESULTS: Group mean total QOL improved over time for all patients, but for those receiving NO-TYA-PTC was an average of 5.63 points higher (95% CI 2.77 to 8.49) than in young people receiving SOME-TYA-PTC care, and 4·17 points higher (95% CI 1.07 to 7.28) compared with ALL-TYA-PTC care. Differences were greatest 6 months after diagnosis, reduced over time and did not meet the 8-point level that is proposed to be clinically significant. Young people receiving NO-TYA-PTC care were more likely to have been offered a choice of place of care, be older, from more deprived areas, in work and have less severe disease. However, analyses adjusting for confounding factors did not explain the differences between TYA groups. CONCLUSIONS: Receipt of some or all care in a TYA-PTC was associated with lower QOL shortly after cancer diagnosis. The NO-TYA-PTC group had higher QOL 3 years after diagnosis, however those receiving all or some care in a TYA-PTC experienced more rapid QOL improvements. Receipt of some care in a TYA-PTC requires further study.This paper presents independent research funded by the National Institute for Health Research (NIHR) under its Programme Grants for Applied Research Programme (Grant Reference Number RP-PG-1209-10013). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health. The BRIGHTLIGHT Team acknowledges the support of the NIHR, through the Cancer Research Network. LAF and LH are funded by Teenage Cancer Trust, DPS holds research grant funding from Teenage Cancer Trust, and RR was (in part) supported by the National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care (CLAHRC) North Thames at Bart’s Health NHS Trust. RMT is a National Institute for Health Research (NIHR) Senior Nurse Research Leader. The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care. None of the funding bodies have been involved with study concept, design or decision to submit the manuscript. JA-G was subsidised by the Ramon & Cajal programme operated by the Ministry of Economy and Business (RYC-2016-19353), and the European Social Fund

    Bridging Alone: Religious Conservatism, Marital Homogamy, and Voluntary Association Membership

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    This study characterizes social insularity of religiously conservative American married couples by examining patterns of voluntary associationmembership. Constructing a dataset of 3938 marital dyads from the second wave of the National Survey of Families and Households, the author investigates whether conservative religious homogamy encourages membership in religious voluntary groups and discourages membership in secular voluntary groups. Results indicate that couples’ shared affiliation with conservative denominations, paired with beliefs in biblical authority and inerrancy, increases the likelihood of religious group membership for husbands and wives and reduces the likelihood of secular group membership for wives, but not for husbands. The social insularity of conservative religious groups appears to be reinforced by homogamy—particularly by wives who share faith with husbands

    Alternative-NHEJ Is a Mechanistically Distinct Pathway of Mammalian Chromosome Break Repair

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    Characterizing the functional overlap and mutagenic potential of different pathways of chromosomal double-strand break (DSB) repair is important to understand how mutations arise during cancer development and treatment. To this end, we have compared the role of individual factors in three different pathways of mammalian DSB repair: alternative-nonhomologous end joining (alt-NHEJ), single-strand annealing (SSA), and homology directed repair (HDR/GC). Considering early steps of repair, we found that the DSB end-processing factors KU and CtIP affect all three pathways similarly, in that repair is suppressed by KU and promoted by CtIP. In contrast, both KU and CtIP appear dispensable for the absolute level of total-NHEJ between two tandem I-SceI–induced DSBs. During later steps of repair, we find that while the annealing and processing factors RAD52 and ERCC1 are important to promote SSA, both HDR/GC and alt-NHEJ are significantly less dependent upon these factors. As well, while disruption of RAD51 causes a decrease in HDR/GC and an increase in SSA, inhibition of this factor did not affect alt-NHEJ. These results suggest that the regulation of DSB end-processing via KU/CtIP is a common step during alt-NHEJ, SSA, and HDR/GC. However, at later steps of repair, alt-NHEJ is a mechanistically distinct pathway of DSB repair, and thus may play a unique role in mutagenesis during cancer development and therapy

    53BP1 Enforces Distinct Pre- and Post-resection Blocks on Homologous Recombination.

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    53BP1 activity drives genome instability and lethality in BRCA1-deficient mice by inhibiting homologous recombination (HR). The anti-recombinogenic functions of 53BP1 require phosphorylation-dependent interactions with PTIP and RIF1/shieldin effector complexes. While RIF1/shieldin blocks 5'-3' nucleolytic processing of DNA ends, it remains unclear how PTIP antagonizes HR. Here, we show that mutation of the PTIP interaction site in 53BP1 (S25A) allows sufficient DNA2-dependent end resection to rescue the lethality of BRCA1Δ11 mice, despite increasing RIF1 "end-blocking" at DNA damage sites. However, double-mutant cells fail to complete HR, as excessive shieldin activity also inhibits RNF168-mediated loading of PALB2/RAD51. As a result, BRCA1Δ1153BP1S25A mice exhibit hallmark features of HR insufficiency, including premature aging and hypersensitivity to PARPi. Disruption of shieldin or forced targeting of PALB2 to ssDNA in BRCA1D1153BP1S25A cells restores RNF168 recruitment, RAD51 nucleofilament formation, and PARPi resistance. Our study therefore reveals a critical function of shieldin post-resection that limits the loading of RAD51.We thank Anthony Tubbs for comments on the paper; Jennifer Mehalko and Dom Esposito (Protein Expression Laboratory, Frederick National Laboratory for Cancer Research) for transgenic constructs; Karim Baktiar, Diana Haines, and Elijah Edmonson (Pathology/Histotechnology Laboratory, Frederick National Laboratory for Cancer Research) for rodent necropsy, pathology analysis, and imaging; Joseph Kalen and Nimit Patel (Small Animal Imaging Program, Frederick National Laboratory for Cancer Research) for X-ray computed tomography (CT) scan imaging; Jennifer Wise and Kelly Smith for assistance with animal work; Davide Robbiani and Kai Ge for antibodies; Dan Durocher for shieldin constructs; David Goldstein and the CCR Genomics core for sequencing support; and Neil Johnson for discussions. Research in the J.M.S. laboratory is supported by NIH grant R01CA197506. Research in the N.M. laboratory is supported by NIH grant R01 227001. The A.N. laboratory is supported by the Intramural Research Program of the NIH, an Ellison Medical Foundation Senior Scholar in Aging Award (AG-SS-2633-11), the Department of Defense Idea Expansion (W81XWH-15-2-006) and Breakthrough (W81XWH-16-1-599) Awards, the Alex's Lemonade Stand Foundation Award, and an NIH Intramural FLEX Award.S

    The relative efficiency of homology-directed repair has distinct effects on proper anaphase chromosome separation

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    Homology-directed repair (HDR) is essential to limit mutagenesis, chromosomal instability (CIN) and tumorigenesis. We have characterized the consequences of HDR deficiency on anaphase, using markers for incomplete chromosome separation: DAPI-bridges and Ultra-fine bridges (UFBs). We show that multiple HDR factors (Rad51, Brca2 and Brca1) are critical for complete chromosome separation during anaphase, while another chromosome break repair pathway, non-homologous end joining, does not affect chromosome segregation. We then examined the consequences of mild versus severe HDR disruption, using two different dominant-negative alleles of the strand exchange factor, Rad51. We show that mild HDR disruption is viable, but causes incomplete chromosome separation, as detected by DAPI-bridges and UFBs, while severe HDR disruption additionally results in multipolar anaphases and loss of clonogenic survival. We suggest that mild HDR disruption favors the proliferation of cells that are prone to CIN due to defective chromosome separation during anaphase, whereas, severe HDR deficiency leads to multipolar divisions that are prohibitive for cell proliferation

    Processes of care and survival associated with treatment in specialist teenage and young adult cancer centres: results from the BRIGHTLIGHT cohort study.

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    OBJECTIVE: Survival gains in teenagers and young adults (TYA) are reported to be lower than children and adults for some cancers. Place of care is implicated, influencing access to specialist TYA professionals and research.Consequently, age-appropriate specialist cancer care is advocated for TYA although systematic investigation of associated outcomes is lacking. In England, age-appropriate care is delivered through 13 Principal Treatment Centres (TYA-PTC). BRIGHTLIGHT is the national evaluation of TYA cancer services to examine outcomes associated with differing places and levels of care. We aimed to examine the association between exposure to TYA-PTC care, survival and documentation of clinical processes of care. DESIGN: Prospective cohort study. SETTING: 109 National Health Service (NHS) hospitals across England. PARTICIPANTS: 1114 TYA, aged 13-24, newly diagnosed with cancer between 2012 and 2014. INTERVENTION: Participants were assigned a TYA-PTC category dependent on the proportion of care delivered in a TYA-PTC in the first year after diagnosis: all care in a TYA-PTC (ALL-TYA-PTC, n=270), no care in a TYA-PTC (NO-TYA-PTC, n=359), and some care in a TYA-PTC with additional care in a children's/adult unit (SOME-TYA-PTC, n=419). PRIMARY OUTCOME: Data were collected on documented processes indicative of age-appropriate care using clinical report forms, and survival through linkage to NHS databases. RESULTS: TYA receiving NO-TYA-PTC care were less likely to have documentation of molecular diagnosis, be reviewed by a children's or TYA multidisciplinary team, be assessed by supportive care services or have a fertility discussion. There was no significant difference in survival according to category of care. There was weak evidence that the association between care category and survival differed by age (p=0.08) with higher HRs for those over 19 receiving ALL or SOME-TYA-PTC compared with NO-TYA-PTC. CONCLUSION: TYA-PTC care was associated with better documentation of clinical processes associated with age-appropriate care but not improved survival

    Variability of Disk Emission in Pre-Main Sequence and Related Stars. II. Variability in the Gas and Dust Emission of the Herbig Fe Star SAO 206462

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    We present thirteen epochs of near-infrared (0.8-5 micron) spectroscopic observations of the pre-transitional, "gapped" disk system in SAO 206462 (=HD 135344B). In all, six gas emission lines (including Br gamma, Pa beta, and the 0.8446 micron line of O I) along with continuum measurements made near the standard J, H, K, and L photometric bands were measured. A mass accretion rate of approximately 2 x 10^-8 solar masses per year was derived from the Br gamma and Pa beta lines. However, the fluxes of these lines varied by a factor of over two during the course of a few months. The continuum also varied, but by only ~30%, and even decreased at a time when the gas emission was increasing. The H I line at 1.083 microns was also found to vary in a manner inconsistent with that of either the hydrogen lines or the dust. Both the gas and dust variabilities indicate significant changes in the region of the inner gas and the inner dust belt that may be common to many young disk systems. If planets are responsible for defining the inner edge of the gap, they could interact with the material on time scales commensurate with what is observed for the variations in the dust, while other disk instabilities (thermal, magnetorotational) would operate there on longer time scales than we observe for the inner dust belt. For SAO 206462, the orbital period would likely be 1-3 years. If the changes are being induced in the disk material closer to the star than the gap, a variety of mechanisms (disk instabilities, interactions via planets) might be responsible for the changes seen. The He I feature is most likely due to a wind whose orientation changes with respect to the observer on time scales of a day or less. To further constrain the origin of the gas and dust emission will require multiple spectroscopic and interferometric observations on both shorter and longer time scales that have been sampled so far.Comment: 42 pages, 10 figure

    The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment

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    The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since July 2014. This paper describes the second data release from this phase, and the fourteenth from SDSS overall (making this, Data Release Fourteen or DR14). This release makes public data taken by SDSS-IV in its first two years of operation (July 2014-2016). Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey (eBOSS); the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data driven machine learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS website (www.sdss.org) has been updated for this release, and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020, and will be followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14 happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov 2017 (this is the "post-print" and "post-proofs" version; minor corrections only from v1, and most of errors found in proofs corrected
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