TDP2-Dependent Non-Homologous End-Joining Protects against Topoisomerase II-Induced DNA Breaks and Genome Instability in Cells and In Vivo

Anticancer topoisomerase >poisons> exploit the break-and-rejoining mechanism of topoisomerase II (TOP2) to generate TOP2-linked DNA double-strand breaks (DSBs). This characteristic underlies the clinical efficacy of TOP2 poisons, but is also implicated in chromosomal translocations and genome instability associated with secondary, treatment-related, haematological malignancy. Despite this relevance for cancer therapy, the mechanistic aspects governing repair of TOP2-induced DSBs and the physiological consequences that absent or aberrant repair can have are still poorly understood. To address these deficits, we employed cells and mice lacking tyrosyl DNA phosphodiesterase 2 (TDP2), an enzyme that hydrolyses 5′-phosphotyrosyl bonds at TOP2-associated DSBs, and studied their response to TOP2 poisons. Our results demonstrate that TDP2 functions in non-homologous end-joining (NHEJ) and liberates DSB termini that are competent for ligation. Moreover, we show that the absence of TDP2 in cells impairs not only the capacity to repair TOP2-induced DSBs but also the accuracy of the process, thus compromising genome integrity. Most importantly, we find this TDP2-dependent NHEJ mechanism to be physiologically relevant, as Tdp2-deleted mice are sensitive to TOP2-induced damage, displaying marked lymphoid toxicity, severe intestinal damage, and increased genome instability in the bone marrow. Collectively, our data reveal TDP2-mediated error-free NHEJ as an efficient and accurate mechanism to repair TOP2-induced DSBs. Given the widespread use of TOP2 poisons in cancer chemotherapy, this raises the possibility of TDP2 being an important etiological factor in the response of tumours to this type of agent and in the development of treatment-related malignancy.Gobierno Español SAF2010-21017, BFU2010-11042-EEuropean Union PERG07- 2010-268466Queen Elisabeth Medical Foundation GSKE 111

Correction : Chaparro et al. Incidence, Clinical Characteristics and Management of Inflammatory Bowel Disease in Spain: Large-Scale Epidemiological Study. J. Clin. Med. 2021, 10, 2885

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Incidence, Clinical Characteristics and Management of Inflammatory Bowel Disease in Spain : Large-Scale Epidemiological Study

(1) Aims: To assess the incidence of inflammatory bowel disease (IBD) in Spain, to describe the main epidemiological and clinical characteristics at diagnosis and the evolution of the disease, and to explore the use of drug treatments. (2) Methods: Prospective, population-based nationwide registry. Adult patients diagnosed with IBD-Crohn's disease (CD), ulcerative colitis (UC) or IBD unclassified (IBD-U)-during 2017 in Spain were included and were followed-up for 1 year. (3) Results: We identified 3611 incident cases of IBD diagnosed during 2017 in 108 hospitals covering over 22 million inhabitants. The overall incidence (cases/100,000 person-years) was 16 for IBD, 7.5 for CD, 8 for UC, and 0.5 for IBD-U; 53% of patients were male and median age was 43 years (interquartile range = 31-56 years). During a median 12-month follow-up, 34% of patients were treated with systemic steroids, 25% with immunomodulators, 15% with biologics and 5.6% underwent surgery. The percentage of patients under these treatments was significantly higher in CD than UC and IBD-U. Use of systemic steroids and biologics was significantly higher in hospitals with high resources. In total, 28% of patients were hospitalized (35% CD and 22% UC patients, p < 0.01). (4) Conclusion: The incidence of IBD in Spain is rather high and similar to that reported in Northern Europe. IBD patients require substantial therapeutic resources, which are greater in CD and in hospitals with high resources, and much higher than previously reported. One third of patients are hospitalized in the first year after diagnosis and a relevant proportion undergo surgery

TDP2-Dependent Non-Homologous End-Joining Protects against Topoisomerase II-Induced DNA Breaks and Genome Instability in Cells and In Vivo

Gómez-Herreros, Fernando et al.Anticancer topoisomerase >poisons> exploit the break-and-rejoining mechanism of topoisomerase II (TOP2) to generate TOP2-linked DNA double-strand breaks (DSBs). This characteristic underlies the clinical efficacy of TOP2 poisons, but is also implicated in chromosomal translocations and genome instability associated with secondary, treatment-related, haematological malignancy. Despite this relevance for cancer therapy, the mechanistic aspects governing repair of TOP2-induced DSBs and the physiological consequences that absent or aberrant repair can have are still poorly understood. To address these deficits, we employed cells and mice lacking tyrosyl DNA phosphodiesterase 2 (TDP2), an enzyme that hydrolyses 5′-phosphotyrosyl bonds at TOP2-associated DSBs, and studied their response to TOP2 poisons. Our results demonstrate that TDP2 functions in non-homologous end-joining (NHEJ) and liberates DSB termini that are competent for ligation. Moreover, we show that the absence of TDP2 in cells impairs not only the capacity to repair TOP2-induced DSBs but also the accuracy of the process, thus compromising genome integrity. Most importantly, we find this TDP2-dependent NHEJ mechanism to be physiologically relevant, as Tdp2-deleted mice are sensitive to TOP2-induced damage, displaying marked lymphoid toxicity, severe intestinal damage, and increased genome instability in the bone marrow. Collectively, our data reveal TDP2-mediated error-free NHEJ as an efficient and accurate mechanism to repair TOP2-induced DSBs. Given the widespread use of TOP2 poisons in cancer chemotherapy, this raises the possibility of TDP2 being an important etiological factor in the response of tumours to this type of agent and in the development of treatment-related malignancy. © 2013 Gómez-Herreros et al.Work in FC-L laboratory is funded with grants from the Spanish Government (SAF2010-21017 and BFU2010-11042-E) and the European Union (PERG07- 2010-268466) and with the following fellowships from the Spanish Government: Ramo´n y Cajal (RYC-2009-03928) for FC-L, JAE-Doc (2010-011) for RR-G, and FPI (BES-2011-047351) for A´A-Q. Work in the KWC laboratory is funded by MRC grants to KWC (G0901606, G0600776, MR/J006750/1) and supported FG-H, ZZ, and LJ. Generation of the Tdp2 floxed and conditional mice in the DH lab was supported by the EC FP6 Integrated Project EndoTrack, the Interuniversity Attraction Pole IUAP-P6/20 and P7/07 project, and the Queen Elisabeth Medical Foundation (GSKE 1113) and type 3 large-infrastructure support InfraMouse (Hercules Foundation ZW09-03, to DH).Peer Reviewe

TDP2 protects transcription from abortive topoisomerase activity and is required for normal neural function

Gómez-Herreros, Fernando et al.Topoisomerase II (TOP2) removes torsional stress from DNA and facilitates gene transcription by introducing transient DNA double-strand breaks (DSBs). Such DSBs are normally rejoined by TOP2 but on occasion can become abortive and remain unsealed. Here we identify homozygous mutations in the TDP2 gene encoding tyrosyl DNA phosphodiesterase-2, an enzyme that repairs 'abortive' TOP2-induced DSBs, in individuals with intellectual disability, seizures and ataxia. We show that cells from affected individuals are hypersensitive to TOP2-induced DSBs and that loss of TDP2 inhibits TOP2-dependent gene transcription in cultured human cells and in mouse post-mitotic neurons following abortive TOP2 activity. Notably, TDP2 is also required for normal levels of many gene transcripts in developing mouse brain, including numerous gene transcripts associated with neurological function and/or disease, and for normal interneuron density in mouse cerebellum. Collectively, these data implicate chromosome breakage by TOP2 as an endogenous threat to gene transcription and to normal neuronal development and maintenanceThis work was funded in the Caldecott laboratory by the Medical Research Council (MRC; MR/J006750/1 and G0901606/1) and Cancer Research UK (C6563/A16771), in the Cortes-Ledesma laboratory by the Spanish government (SAF2010-21017, RYC-2009-03928 and JAE-Doc 2010-011) and European Union (PERG07-2010-268466), in the El-Khamisy laboratory by the Wellcome Trust (fellowship 085284 and grant 091043) and the Lister Institute of Preventative Medicine (fellowship), and in part by the Netherlands Organization for Health Research and Development (ZonMW; VIDI grant 917-86-319 to B.B.A.d.V.), the GENCODYS project (EU-7th-2010-241995 to B.B.A.d.V. and A.P.M.d.B.), a Brainwave–Irish Epilepsy Association/Medical Research Charities Group of Ireland/Health Research Board award (2009/001) and a Health Research Board of Ireland Translational Research Scholars award. Control samples were funded by National Institute for Mental Health (NIMH) awards (RC2MH089915, K01MH098126, R01MH099216 and R01MH097971), the Epi4K Gene Discovery in Epilepsy study (National Institute for Neurological Disorders and Stroke (NINDS) U01NS077303), the Epilepsy Genome/Phenome Project (EPGP; NINDS U01NS053998), the Center for HIV/AIDS Vaccine Immunology (CHAVI) study (National Institute of Allergy and Infectious Diseases (NIAID) UO1AIO67854), the Ellison Medical Foundation New Scholar award (AG-NS-0441-08), SAIC-Frederick, Inc. (M11-074) and Biogen Idec, Inc.Peer Reviewe

Topoisomerase II-induced DNA breaks and genome instability

Trabajo presentado en el Barcelona Biomed Conference: The DNA Damage Response in Human Disease, celebrado en Barcelona del 28 al 30 de mayo de 2012.Peer Reviewe