FANCM limits ALT activity by restricting telomeric replication stress induced by deregulated BLM and R-loops

© The Author(s) 2019. Open Access: This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.Telomerase negative immortal cancer cells elongate telomeres through the Alternative Lengthening of Telomeres (ALT) pathway. While sustained telomeric replicative stress is required to maintain ALT, it might also lead to cell death when excessive. Here, we show that the ATPase/translocase activity of FANCM keeps telomeric replicative stress in check specifically in ALT cells. When FANCM is depleted in ALT cells, telomeres become dysfunctional, and cells stop proliferating and die. FANCM depletion also increases ALT-associated marks and de novo synthesis of telomeric DNA. Depletion of the BLM helicase reduces the telomeric replication stress and cell proliferation defects induced by FANCM inactivation. Finally, FANCM unwinds telomeric R-loops in vitro and suppresses their accumulation in cells. Overexpression of RNaseH1 completely abolishes the replication stress remaining in cells codepleted for FANCM and BLM. Thus, FANCM allows controlled ALT activity and ALT cell proliferation by limiting the toxicity of uncontrolled BLM and telomeric R-loops.Research in the Azzalin laboratory was supported by the Swiss National Science Foundation (31003A_160338), the European Molecular Biology Organization (IG3576) and the Fundação para a Ciência e a Tecnologia (IF/01269/2015; PTDC/MED-ONC/28282/2017; PTDC/BIA-MOL/29352/2017). R.P. was supported by a Swiss National Science Foundation Doc.Mobility fellowship (P1EZP3-168771). Research in the Deans laboratory was supported by the Cancer Council of Victoria, Australian National Health and Medical Research Council (APP1139099), Buxton trust and the Victorian Government’s OIS Program. A.J.D is a Victorian Cancer Agency fellow. Publication costs were supported by UID/BIM/50005/2019, project funded by the Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior (MCTES) through Fundos do Orçamento de Estado.info:eu-repo/semantics/publishedVersio

The Changing Landscape for Stroke\ua0Prevention in AF: Findings From the GLORIA-AF Registry Phase 2

Background GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) is a prospective, global registry program describing antithrombotic treatment patterns in patients with newly diagnosed nonvalvular atrial fibrillation at risk of stroke. Phase 2 began when dabigatran, the first non\u2013vitamin K antagonist oral anticoagulant (NOAC), became available. Objectives This study sought to describe phase 2 baseline data and compare these with the pre-NOAC era collected during phase 1. Methods During phase 2, 15,641 consenting patients were enrolled (November 2011 to December 2014); 15,092 were eligible. This pre-specified cross-sectional analysis describes eligible patients\u2019 baseline characteristics. Atrial fibrillation disease characteristics, medical outcomes, and concomitant diseases and medications were collected. Data were analyzed using descriptive statistics. Results Of the total patients, 45.5% were female; median age was 71 (interquartile range: 64, 78) years. Patients were from Europe (47.1%), North America (22.5%), Asia (20.3%), Latin America (6.0%), and the Middle East/Africa (4.0%). Most had high stroke risk (CHA2DS2-VASc [Congestive heart failure, Hypertension, Age  6575 years, Diabetes mellitus, previous Stroke, Vascular disease, Age 65 to 74 years, Sex category] score  652; 86.1%); 13.9% had moderate risk (CHA2DS2-VASc = 1). Overall, 79.9% received oral anticoagulants, of whom 47.6% received NOAC and 32.3% vitamin K antagonists (VKA); 12.1% received antiplatelet agents; 7.8% received no antithrombotic treatment. For comparison, the proportion of phase 1 patients (of N = 1,063 all eligible) prescribed VKA was 32.8%, acetylsalicylic acid 41.7%, and no therapy 20.2%. In Europe in phase 2, treatment with NOAC was more common than VKA (52.3% and 37.8%, respectively); 6.0% of patients received antiplatelet treatment; and 3.8% received no antithrombotic treatment. In North America, 52.1%, 26.2%, and 14.0% of patients received NOAC, VKA, and antiplatelet drugs, respectively; 7.5% received no antithrombotic treatment. NOAC use was less common in Asia (27.7%), where 27.5% of patients received VKA, 25.0% antiplatelet drugs, and 19.8% no antithrombotic treatment. Conclusions The baseline data from GLORIA-AF phase 2 demonstrate that in newly diagnosed nonvalvular atrial fibrillation patients, NOAC have been highly adopted into practice, becoming more frequently prescribed than VKA in Europe and North America. Worldwide, however, a large proportion of patients remain undertreated, particularly in Asia and North America. (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation [GLORIA-AF]; NCT01468701

FANCM Translocase Promotes Telomere Stability and Cell Viability in ALT (Alternative Lengthening of Telomeres) Cells

Alternative Lengthening of Telomeres (ALT) is a telomere maintenance mechanism employed by a subset of human tumours to enable unlimited proliferation. In ALT cells, telomeric DNA damage triggers recombination between telomeric tracts and de novo synthesis of telomeric DNA. While this mechanism supports the unlimited growth of ALT cancer cells, excessive accumulation of DNA damage and recombination intermediates is detrimental for cellular viability. Therefore, ALT cells rely on maintaining a balance on the extent of DNA damage induction and this represents a vulnerability of these cancer cells that might be exploited for ALT-directed cancer therapies. We report here that FANCM (Fanconi anaemia complementation group M) translocase is essential in ALT cells. FANCM functions in the FA (Fanconi anaemia) pathway for the repair of interstrand crosslink (ICL) lesions by recruiting the FA core complex to chromatin. Via its translocase activity FANCM also exerts migration of the branch point within branched nucleic acid structures, which contributes to its FA-independent functions including replication fork reversal and replication traverse. Depletion of FANCM by RNA interference (RNAi) in ALT cells strongly decreases cell viability and leads to an accumulation of cells in G2 phase of the cell cycle, while cancer cells that maintain their telomeres by telomerase activity are largely unaffected by FANCM depletion. FANCM depletion in ALT cells generates replication stress at telomeres, as evidenced by accumulation of the replication stress marker pSer33 (Replication protein A32 phosphorylated at serine 33) at telomeres and telomeric single-stranded DNA (ssDNA). In addition, FANCM-depleted ALT cells accumulate partially single-stranded C-rich telomeric circles (C-circles) and ALT-specific PML (Promyelocytic leukaemia protein) nuclear bodies (APBs), which are hallmarks of ALT activity. FANCM depletion in ALT cells also results in an increase of RNA:DNA hybrid structures (R-loops) at telomeres, which are formed between the telomeric long non-coding RNA TERRA (Telomeric repeat-containing RNA) and telomeric DNA (telR-loops). R-loops can stall replication forks and thus generate replication stress and DNA damage. Reduction of total cellular R-loop levels by overexpression of the endonuclease RNaseH1, which cleaves the RNA moiety in RNA:DNA hybrids independently of the nucleic acid sequence, does not rescue the defects caused by FANCM depletion. This suggests that accumulation of telR-loops might not be their underlying cause. FANCM has multiple functions in DNA replication and repair and interacts with a protein complex formed by BLM (Bloom syndrome RecQ like helicase), TOP3A (DNA topoisomerase III alpha), RMI1 and RMI2 (RecQ mediated genome instability 1 and 2) (BTR complex), which promotes the dissolution of recombination intermediates. FANCM is required for the formation of BLM foci in response to DNA damage induced by camptothecin, an inhibitor of TOP1 (DNA topoisomerase 1). Yet, we observed a strong accumulation of BLM at telomeres in ALT cells upon depletion of FANCM, indicating a FANCM-independent recruitment mechanism for BLM. Co-depletion of BLM partially restores viability in FANCM-depleted ALT cells, suggesting a possible synthetic viable interaction between the two proteins in ALT cells. This observation is at odds with a recent study that suggests a synthetic lethal interaction between FANCM and BLM, indicating a more complex interaction between the two proteins that requires further investigation. The severe and fast impairment of ALT cell viability upon depletion of FANCM make it an interesting candidate for further studies addressing its potential as a drug target for ALT cancer therapies

Developing a global standard to enable the recording reporting and consolidation of online usage statistics for individual journal articles hosted by institutional repositories publishers and other entities.(Final Report)

The aim of PIRUS (Publisher and Institutional Repository Usage Statistics) was to develop COUNTER-compliant standards and usage reports at the individual article level that can be implemented by any entity (publisher, aggregator, repository, etc.,) that hosts online journal articles and will enable the usage of research outputs to be recorded, reported and consolidated at a global level in a standard way

PIRUS – Publisher and Institutional Repository Usage Statistics - Final Report

Developing a global standard to enable the recording, reporting and consolidation of online usage statistics for individual journal articles hosted by institutional repositories, publishers and other entities (Publisher Metadata and Interoperability Projects 3

Addressing Core Challenges for the Next Generation of Type 2 Translation Research and Systems: The Translation Science to Population Impact (TSci Impact) Framework

Evidence-based preventive interventions developed over the past two decades represent great potential for enhancing public health and well-being. Research confirming the limited extent to which these interventions have been broadly and effectively implemented, however, indicates much progress is needed to achieve population-level impact. In part, progress requires Type 2 translation research that investigates the complex processes and systems through which evidence-based interventions are adopted, implemented, and sustained on a large scale, with a strong orientation toward devising empirically-driven strategies for increasing their population impact. In this article, we address two core challenges to the advancement of T2 translation research: (1) building infrastructure and capacity to support systems-oriented scaling up of evidence-based interventions, with well-integrated practice-oriented T2 research, and (2) developing an agenda and improving research methods for advancing T2 translation science. We also summarize a heuristic “Translation Science to Population Impact (TSci Impact) Framework.” It articulates key considerations in addressing the core challenges, with three components that represent: (1) four phases of translation functions to be investigated (pre-adoption, adoption, implementation, and sustainability); (2) the multiple contexts in which translation occurs, ranging from community to national levels; and (3) necessary practice and research infrastructure supports. Discussion of the framework addresses the critical roles of practitioner–scientist partnerships and networks, governmental agencies and policies at all levels, plus financing partnerships and structures, all required for both infrastructure development and advances in the science. The article concludes with two sets of recommended action steps that could provide impetus for advancing the next generation of T2 translation science and, in turn, potentially enhance the health and well-being of subsequent generations of youth and families

Identifying trajectories of adolescent smoking: An application of latent growth mixture modeling

The goal of the current study was to identify discrete longitudinal patterns of change in adolescent smoking using latent growth mixture modeling. Five distinct longitudinal patterns were identified. A group of early rapid escalators was characterized by early escalation (at age 13) that rapidly increased to heavy smoking. A pattern characterized by occasional puffing up until age 15, at which time smoking escalated to moderate levels was also identified (late moderate escalators). Another group included adolescents who, after age 15, began to escalate slowly in their smoking to light (0.5 cigarettes per month) levels (late slow escalators). Finally, a group of stable light smokers (those who smoked 1-2 cigarettes per month) and a group of stable puffers (those. who smoked only a few puffs per month) were also identified. The stable puffer group was the largest group and represented 25% of smokers

Tobacco product use and the risks of SARS-CoV-2 infection and COVID-19: current understanding and recommendations for future research.

Heterogeneity in the clinical presentation of SARS-CoV-2 infection and COVID-19 progression underscores the urgent need to identify individual-level susceptibility factors that affect infection vulnerability and disease severity. Tobacco product use is a potential susceptibility factor. In this Personal View, we provide an overview of the findings of peer-reviewed, published studies relating tobacco product use to SARS-CoV-2 infection and COVID-19 outcomes, with most studies focusing on cigarette smoking in adults. Findings pertaining to the effects of tobacco product use on the incidence of SARS-CoV-2 infection are inconsistent. However, evidence supports a role for cigarette smoking in increasing the risk of poor COVID-19 outcomes, including hospital admission, progression in disease severity, and COVID-19-related mortality. We discuss the potential effects of tobacco use behaviour on SARS-CoV-2 transmission and infection, and highlight the pathophysiological changes associated with cigarette smoking that could promote SARS-CoV-2 infection and increased disease severity. We consider the biological mechanisms by which nicotine and other tobacco product constituents might affect immune and inflammatory responses to SARS-CoV-2 infection. Finally, we identify current knowledge gaps and suggest priorities for research to address acute and post-acute health outcomes of COVID-19 during and after the pandemic