ALBERT

Description: Rev3, the catalytic subunit of DNA polymerase , is essential for translesion synthesis of cytotoxic DNA photolesions, whereas the Rev1 protein plays a noncatalytic role in translesion synthesis. Here, we reveal that mammalian Rev3 –/– and Rev1 –/– cell lines additionally display a nucleotide excision repair (NER) defect, specifically during S phase. This defect is correlated with the normal recruitment but protracted persistence at DNA damage sites of factors involved in an early stage of NER, while repair synthesis is affected. Remarkably, the NER defect becomes apparent only at 2 h post-irradiation indicating that Rev3 affects repair synthesis only indirectly, rather than performing an enzymatic role in NER. We provide evidence that the NER defect is caused by scarceness of Replication protein A (Rpa) available to NER, resulting from its sequestration at stalled replication forks. Also the induction of replicative stress using hydroxyurea precludes the accumulation of Rpa at photolesion sites, both in Rev3 –/– and in wild-type cells. These data support a model in which the limited Rpa pool coordinates replicative stress and NER, resulting in increased cytotoxicity of ultraviolet light when replicative stress exceeds a threshold.

Description: T-cell acute lymphoblastic leukaemia (T-ALL) is a haematological malignancy with a dismal overall prognosis, including a relapse rate of up to 25%, mainly because of the lack of non-cytotoxic targeted therapy options. Drugs that target the function of key epigenetic factors have been approved in the context of haematopoietic disorders, and mutations that affect chromatin modulators in a variety of leukaemias have recently been identified; however, 'epigenetic' drugs are not currently used for T-ALL treatment. Recently, we described that the polycomb repressive complex 2 (PRC2) has a tumour-suppressor role in T-ALL. Here we delineated the role of the histone 3 lysine 27 (H3K27) demethylases JMJD3 and UTX in T-ALL. We show that JMJD3 is essential for the initiation and maintenance of T-ALL, as it controls important oncogenic gene targets by modulating H3K27 methylation. By contrast, we found that UTX functions as a tumour suppressor and is frequently genetically inactivated in T-ALL. Moreover, we demonstrated that the small molecule inhibitor GSKJ4 (ref. 5) affects T-ALL growth, by targeting JMJD3 activity. These findings show that two proteins with a similar enzymatic function can have opposing roles in the context of the same disease, paving the way for treating haematopoietic malignancies with a new category of epigenetic inhibitors.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4209203/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4209203/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ntziachristos, Panagiotis -- Tsirigos, Aristotelis -- Welstead, G Grant -- Trimarchi, Thomas -- Bakogianni, Sofia -- Xu, Luyao -- Loizou, Evangelia -- Holmfeldt, Linda -- Strikoudis, Alexandros -- King, Bryan -- Mullenders, Jasper -- Becksfort, Jared -- Nedjic, Jelena -- Paietta, Elisabeth -- Tallman, Martin S -- Rowe, Jacob M -- Tonon, Giovanni -- Satoh, Takashi -- Kruidenier, Laurens -- Prinjha, Rab -- Akira, Shizuo -- Van Vlierberghe, Pieter -- Ferrando, Adolfo A -- Jaenisch, Rudolf -- Mullighan, Charles G -- Aifantis, Iannis -- 1R01CA105129/CA/NCI NIH HHS/ -- 1R01CA133379/CA/NCI NIH HHS/ -- 1R01CA149655/CA/NCI NIH HHS/ -- 5 T32 CA009161-37/CA/NCI NIH HHS/ -- 5P30CA16087-31/CA/NCI NIH HHS/ -- 5R01CA169784/CA/NCI NIH HHS/ -- 5R01CA173636/CA/NCI NIH HHS/ -- K99 CA188293/CA/NCI NIH HHS/ -- K99CA188293/CA/NCI NIH HHS/ -- P30 CA014051/CA/NCI NIH HHS/ -- P30 CA016087/CA/NCI NIH HHS/ -- P30 CA016087-30/CA/NCI NIH HHS/ -- P30 CA021765/CA/NCI NIH HHS/ -- R01 CA105129/CA/NCI NIH HHS/ -- R01 CA133379/CA/NCI NIH HHS/ -- R01 CA149655/CA/NCI NIH HHS/ -- R01 CA173636/CA/NCI NIH HHS/ -- R01CA120196/CA/NCI NIH HHS/ -- R37 HD045022/HD/NICHD NIH HHS/ -- R37-HD04502/HD/NICHD NIH HHS/ -- U10 CA180820/CA/NCI NIH HHS/ -- U10 CA180827/CA/NCI NIH HHS/ -- U10 CA21115/CA/NCI NIH HHS/ -- U24 CA114737/CA/NCI NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2014 Oct 23;514(7523):513-7. doi: 10.1038/nature13605. Epub 2014 Aug 17.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Howard Hughes Medical Institute and Department of Pathology, NYU School of Medicine, New York, New York 10016, USA [2] NYU Cancer Institute and Helen L. and Martin S. Kimmel Center for Stem Cell Biology, NYU School of Medicine, New York, New York 10016, USA [3]. ; 1] Howard Hughes Medical Institute and Department of Pathology, NYU School of Medicine, New York, New York 10016, USA [2] Center for Health Informatics and Bioinformatics, NYU School of Medicine, New York, New York 10016, USA [3]. ; 1] Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142, USA [2] Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA [3]. ; 1] Howard Hughes Medical Institute and Department of Pathology, NYU School of Medicine, New York, New York 10016, USA [2] NYU Cancer Institute and Helen L. and Martin S. Kimmel Center for Stem Cell Biology, NYU School of Medicine, New York, New York 10016, USA. ; Institute for Cancer Genetics, Columbia University Medical Center, New York, New York 10032, USA. ; Department of Pathology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA. ; Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA. ; Montefiore Medical Center North, Bronx, New York, New York 10467, USA. ; Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA. ; 1] Technion, Israel Institute of Technology, Haifa 31096, Israel [2] Shaare Zedek Medical Center, Jerusalem 9103102, Israel. ; Functional Genomics of Cancer Unit, Division of Molecular Oncology, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific Institute, 20132 Milan, Italy. ; 1] Laboratory of Host Defense, WPI Immunology Frontier Research Center (WPI IFReC), Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan [2] Department of Host Defense, Research Institute for Microbial Diseases (RIMD), Osaka University, 3-1Yamada-oka, Suita, Osaka 565-0871, Japan. ; Epinova DPU, Immuno-Inflammation Therapy Area, GlaxoSmithKline R&D, Medicines Research Centre, GunnelsWood Road, Stevenage SG1 2NY, UK. ; 1] Institute for Cancer Genetics, Columbia University Medical Center, New York, New York 10032, USA [2] Center for Medical Genetics, Ghent University Hospital, 9000 Ghent, Belgium. ; 1] Institute for Cancer Genetics, Columbia University Medical Center, New York, New York 10032, USA [2] Department of Pathology, Columbia University Medical Center, New York, New York 10032, USA [3] Department of Pediatrics, Columbia University Medical Center, New York, New York 10032, USA. ; 1] Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142, USA [2] Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25132549" target="_blank"〉PubMed〈/a〉