1
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Yang SF, Nelson CB, Wells JK, Fernando M, Lu R, Allen JAM, Malloy L, Lamm N, Murphy VJ, Mackay JP, Deans AJ, Cesare AJ, Sobinoff AP, Pickett HA. ZNF827 is a single-stranded DNA binding protein that regulates the ATR-CHK1 DNA damage response pathway. Nat Commun 2024; 15:2210. [PMID: 38472229 PMCID: PMC10933417 DOI: 10.1038/s41467-024-46578-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 03/04/2024] [Indexed: 03/14/2024] Open
Abstract
The ATR-CHK1 DNA damage response pathway becomes activated by the exposure of RPA-coated single-stranded DNA (ssDNA) that forms as an intermediate during DNA damage and repair, and as a part of the replication stress response. Here, we identify ZNF827 as a component of the ATR-CHK1 kinase pathway. We demonstrate that ZNF827 is a ssDNA binding protein that associates with RPA through concurrent binding to ssDNA intermediates. These interactions are dependent on two clusters of C2H2 zinc finger motifs within ZNF827. We find that ZNF827 accumulates at stalled forks and DNA damage sites, where it activates ATR and promotes the engagement of homologous recombination-mediated DNA repair. Additionally, we demonstrate that ZNF827 depletion inhibits replication initiation and sensitizes cancer cells to the topoisomerase inhibitor topotecan, revealing ZNF827 as a therapeutic target within the DNA damage response pathway.
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Affiliation(s)
- Sile F Yang
- Telomere Length Regulation Unit, Children's Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, NSW, 2145, Australia
| | - Christopher B Nelson
- Telomere Length Regulation Unit, Children's Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, NSW, 2145, Australia
| | - Jadon K Wells
- Telomere Length Regulation Unit, Children's Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, NSW, 2145, Australia
| | - Madushan Fernando
- Telomere Length Regulation Unit, Children's Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, NSW, 2145, Australia
| | - Robert Lu
- Telomere Length Regulation Unit, Children's Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, NSW, 2145, Australia
| | - Joshua A M Allen
- Telomere Length Regulation Unit, Children's Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, NSW, 2145, Australia
| | - Lisa Malloy
- Telomere Length Regulation Unit, Children's Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, NSW, 2145, Australia
| | - Noa Lamm
- Nuclear Dynamics Group, Children's Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, NSW, 2145, Australia
| | - Vincent J Murphy
- Genome Stability Unit, St Vincent's Institute, Fitzroy, VIC, 3065, Australia
| | - Joel P Mackay
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, 2006, Australia
| | - Andrew J Deans
- Genome Stability Unit, St Vincent's Institute, Fitzroy, VIC, 3065, Australia
- Department of Medicine (St Vincent's), University of Melbourne, Fitzroy, VIC, 3065, Australia
| | - Anthony J Cesare
- Genome Integrity Unit, Children's Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, NSW, 2145, Australia
| | - Alexander P Sobinoff
- Telomere Length Regulation Unit, Children's Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, NSW, 2145, Australia
| | - Hilda A Pickett
- Telomere Length Regulation Unit, Children's Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, NSW, 2145, Australia.
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2
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Ngo LH, Bert AG, Dredge BK, Williams T, Murphy V, Li W, Hamilton WB, Carey KT, Toubia J, Pillman KA, Liu D, Desogus J, Chao JA, Deans AJ, Goodall GJ, Wickramasinghe VO. Nuclear export of circular RNA. Nature 2024; 627:212-220. [PMID: 38355801 DOI: 10.1038/s41586-024-07060-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 01/12/2024] [Indexed: 02/16/2024]
Abstract
Circular RNAs (circRNAs), which are increasingly being implicated in a variety of functions in normal and cancerous cells1-5, are formed by back-splicing of precursor mRNAs in the nucleus6-10. circRNAs are predominantly localized in the cytoplasm, indicating that they must be exported from the nucleus. Here we identify a pathway that is specific for the nuclear export of circular RNA. This pathway requires Ran-GTP, exportin-2 and IGF2BP1. Enhancing the nuclear Ran-GTP gradient by depletion or chemical inhibition of the major protein exporter CRM1 selectively increases the nuclear export of circRNAs, while reducing the nuclear Ran-GTP gradient selectively blocks circRNA export. Depletion or knockout of exportin-2 specifically inhibits nuclear export of circRNA. Analysis of nuclear circRNA-binding proteins reveals that interaction between IGF2BP1 and circRNA is enhanced by Ran-GTP. The formation of circRNA export complexes in the nucleus is promoted by Ran-GTP through its interactions with exportin-2, circRNA and IGF2BP1. Our findings demonstrate that adaptors such as IGF2BP1 that bind directly to circular RNAs recruit Ran-GTP and exportin-2 to export circRNAs in a mechanism that is analogous to protein export, rather than mRNA export.
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Affiliation(s)
- Linh H Ngo
- RNA Biology and Cancer Laboratory, Peter MacCallum Cancer Centre and Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Victoria, Australia
| | - Andrew G Bert
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, South Australia, Australia
| | - B Kate Dredge
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, South Australia, Australia
- Adelaide Centre for Epigenetics, School of Biomedicine, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia
- South Australian immunoGENomics Cancer Institute (SAiGENCI), Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Tobias Williams
- RNA Biology and Cancer Laboratory, Peter MacCallum Cancer Centre and Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Victoria, Australia
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Vincent Murphy
- Genome Stability Unit, St Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia
| | - Wanqiu Li
- RNA Biology and Cancer Laboratory, Peter MacCallum Cancer Centre and Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Victoria, Australia
- Department of Pharmacology, Joint Laboratory of Guangdong-Hong Kong Universities for Vascular Homeostasis and Diseases, School of Medicine and Institute for Biological Electron Microscopy, Southern University of Science and Technology, Shenzhen, China
| | - William B Hamilton
- RNA Biology and Cancer Laboratory, Peter MacCallum Cancer Centre and Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Victoria, Australia
| | - Kirstyn T Carey
- RNA Biology and Cancer Laboratory, Peter MacCallum Cancer Centre and Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Victoria, Australia
| | - John Toubia
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, South Australia, Australia
| | - Katherine A Pillman
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, South Australia, Australia
- Department of Molecular and Biomedical Science, University of Adelaide, Adelaide, South Australia, Australia
| | - Dawei Liu
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, South Australia, Australia
| | - Jessica Desogus
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Jeffrey A Chao
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Andrew J Deans
- Genome Stability Unit, St Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia
| | - Gregory J Goodall
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, South Australia, Australia.
- Department of Molecular and Biomedical Science, University of Adelaide, Adelaide, South Australia, Australia.
- Department of Medicine, University of Adelaide, Adelaide, South Australia, Australia.
| | - Vihandha O Wickramasinghe
- RNA Biology and Cancer Laboratory, Peter MacCallum Cancer Centre and Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Victoria, Australia.
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia.
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3
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Tsui V, Lyu R, Novakovic S, Stringer JM, Dunleavy JE, Granger E, Semple T, Leichter A, Martelotto LG, Merriner DJ, Liu R, McNeill L, Zerafa N, Hoffmann ER, O’Bryan MK, Hutt K, Deans AJ, Heierhorst J, McCarthy DJ, Crismani W. Fancm has dual roles in the limiting of meiotic crossovers and germ cell maintenance in mammals. Cell Genom 2023; 3:100349. [PMID: 37601968 PMCID: PMC10435384 DOI: 10.1016/j.xgen.2023.100349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 03/30/2023] [Accepted: 06/02/2023] [Indexed: 08/22/2023]
Abstract
Meiotic crossovers are required for accurate chromosome segregation and producing new allelic combinations. Meiotic crossover numbers are tightly regulated within a narrow range, despite an excess of initiating DNA double-strand breaks. Here, we reveal the tumor suppressor FANCM as a meiotic anti-crossover factor in mammals. We use unique large-scale crossover analyses with both single-gamete sequencing and pedigree-based bulk-sequencing datasets to identify a genome-wide increase in crossover frequencies in Fancm-deficient mice. Gametogenesis is heavily perturbed in Fancm loss-of-function mice, which is consistent with the reproductive defects reported in humans with biallelic FANCM mutations. A portion of the gametogenesis defects can be attributed to the cGAS-STING pathway after birth. Despite the gametogenesis phenotypes in Fancm mutants, both sexes are capable of producing offspring. We propose that the anti-crossover function and role in gametogenesis of Fancm are separable and will inform diagnostic pathways for human genomic instability disorders.
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Affiliation(s)
- Vanessa Tsui
- DNA Repair and Recombination Laboratory, St Vincent’s Institute of Medical Research, Fitzroy, VIC, Australia
- The Faculty of Medicine, Dentistry and Health Science, The University of Melbourne, Parkville, VIC, Australia
| | - Ruqian Lyu
- Bioinformatics and Cellular Genomics, St Vincent’s Institute of Medical Research, Fitzroy, VIC, Australia
- Melbourne Integrative Genomics, Faculty of Science, The University of Melbourne, Parkville, VIC, Australia
| | - Stevan Novakovic
- DNA Repair and Recombination Laboratory, St Vincent’s Institute of Medical Research, Fitzroy, VIC, Australia
| | - Jessica M. Stringer
- Ovarian Biology Laboratory, Biomedicine Discovery Institute, Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, Australia
| | - Jessica E.M. Dunleavy
- Male Infertility and Germ Cell Biology Group, School of BioSciences and the Bio21 Institute, Faculty of Science, The University of Melbourne, Parkville, VIC, Australia
| | - Elissah Granger
- DNA Repair and Recombination Laboratory, St Vincent’s Institute of Medical Research, Fitzroy, VIC, Australia
| | - Tim Semple
- Single Cell Innovation Laboratory, Centre for Cancer Research, University of Melbourne, Parkville, VIC, Australia
| | - Anna Leichter
- Single Cell Innovation Laboratory, Centre for Cancer Research, University of Melbourne, Parkville, VIC, Australia
| | - Luciano G. Martelotto
- Single Cell Innovation Laboratory, Centre for Cancer Research, University of Melbourne, Parkville, VIC, Australia
| | - D. Jo Merriner
- Male Infertility and Germ Cell Biology Group, School of BioSciences and the Bio21 Institute, Faculty of Science, The University of Melbourne, Parkville, VIC, Australia
| | - Ruijie Liu
- Bioinformatics and Cellular Genomics, St Vincent’s Institute of Medical Research, Fitzroy, VIC, Australia
- Melbourne Integrative Genomics, Faculty of Science, The University of Melbourne, Parkville, VIC, Australia
| | - Lucy McNeill
- DNA Repair and Recombination Laboratory, St Vincent’s Institute of Medical Research, Fitzroy, VIC, Australia
| | - Nadeen Zerafa
- Ovarian Biology Laboratory, Biomedicine Discovery Institute, Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, Australia
| | - Eva R. Hoffmann
- DNRF Center for Chromosome Stability, Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Moira K. O’Bryan
- Male Infertility and Germ Cell Biology Group, School of BioSciences and the Bio21 Institute, Faculty of Science, The University of Melbourne, Parkville, VIC, Australia
| | - Karla Hutt
- Ovarian Biology Laboratory, Biomedicine Discovery Institute, Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, Australia
| | - Andrew J. Deans
- The Faculty of Medicine, Dentistry and Health Science, The University of Melbourne, Parkville, VIC, Australia
- Genome Stability Unit, St Vincent’s Institute of Medical Research, Fitzroy, VIC, Australia
| | - Jörg Heierhorst
- The Faculty of Medicine, Dentistry and Health Science, The University of Melbourne, Parkville, VIC, Australia
- Molecular Genetics Unit, St Vincent’s Institute of Medical Research, Fitzroy, VIC, Australia
| | - Davis J. McCarthy
- Bioinformatics and Cellular Genomics, St Vincent’s Institute of Medical Research, Fitzroy, VIC, Australia
- Melbourne Integrative Genomics, Faculty of Science, The University of Melbourne, Parkville, VIC, Australia
| | - Wayne Crismani
- DNA Repair and Recombination Laboratory, St Vincent’s Institute of Medical Research, Fitzroy, VIC, Australia
- The Faculty of Medicine, Dentistry and Health Science, The University of Melbourne, Parkville, VIC, Australia
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4
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Hodson C, van Twest S, Dylewska M, O'Rourke JJ, Tan W, Murphy VJ, Walia M, Abbouche L, Nieminuszczy J, Dunn E, Bythell-Douglas R, Heierhorst J, Niedzwiedz W, Deans AJ. Branchpoint translocation by fork remodelers as a general mechanism of R-loop removal. Cell Rep 2022; 41:111749. [PMID: 36476850 DOI: 10.1016/j.celrep.2022.111749] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 10/05/2022] [Accepted: 11/09/2022] [Indexed: 12/12/2022] Open
Abstract
Co-transcriptional R loops arise from stalling of RNA polymerase, leading to the formation of stable DNA:RNA hybrids. Unresolved R loops promote genome instability but are counteracted by helicases and nucleases. Here, we show that branchpoint translocases are a third class of R-loop-displacing enzyme in vitro. In cells, deficiency in the Fanconi-anemia-associated branchpoint translocase FANCM causes R-loop accumulation, particularly after treatment with DNA:RNA-hybrid-stabilizing agents. This correlates with FANCM localization at R-loop-prone regions of the genome. Moreover, other branchpoint translocases associated with human disease, such as SMARCAL1 and ZRANB3, and those from lower organisms can also remove R loops in vitro. Branchpoint translocases are more potent than helicases in resolving R loops, indicating their evolutionary important role in R-loop suppression. In human cells, FANCM, SMARCAL1, and ZRANB3 depletion causes additive effects on R-loop accumulation and DNA damage. Our work reveals a mechanistic basis for R-loop displacement that is linked to genome stability.
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Affiliation(s)
- Charlotte Hodson
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Sylvie van Twest
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | | | - Julienne J O'Rourke
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Winnie Tan
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Vincent J Murphy
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Mannu Walia
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Lara Abbouche
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | | | - Elyse Dunn
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Rohan Bythell-Douglas
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Jörg Heierhorst
- Department of Medicine (St Vincent's Health), University of Melbourne, Fitzroy, VIC 3065, Australia; Molecular Genetics Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | | | - Andrew J Deans
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia; Department of Medicine (St Vincent's Health), University of Melbourne, Fitzroy, VIC 3065, Australia.
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5
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Hodson C, Low JKK, van Twest S, Jones SE, Swuec P, Murphy V, Tsukada K, Fawkes M, Bythell-Douglas R, Davies A, Holien JK, O'Rourke JJ, Parker BL, Glaser A, Parker MW, Mackay JP, Blackford AN, Costa A, Deans AJ. Mechanism of Bloom syndrome complex assembly required for double Holliday junction dissolution and genome stability. Proc Natl Acad Sci U S A 2022; 119:e2109093119. [PMID: 35115399 PMCID: PMC8832983 DOI: 10.1073/pnas.2109093119] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 12/17/2021] [Indexed: 12/29/2022] Open
Abstract
The RecQ-like helicase BLM cooperates with topoisomerase IIIα, RMI1, and RMI2 in a heterotetrameric complex (the "Bloom syndrome complex") for dissolution of double Holliday junctions, key intermediates in homologous recombination. Mutations in any component of the Bloom syndrome complex can cause genome instability and a highly cancer-prone disorder called Bloom syndrome. Some heterozygous carriers are also predisposed to breast cancer. To understand how the activities of BLM helicase and topoisomerase IIIα are coupled, we purified the active four-subunit complex. Chemical cross-linking and mass spectrometry revealed a unique architecture that links the helicase and topoisomerase domains. Using biochemical experiments, we demonstrated dimerization mediated by the N terminus of BLM with a 2:2:2:2 stoichiometry within the Bloom syndrome complex. We identified mutations that independently abrogate dimerization or association of BLM with RMI1, and we show that both are dysfunctional for dissolution using in vitro assays and cause genome instability and synthetic lethal interactions with GEN1/MUS81 in cells. Truncated BLM can also inhibit the activity of full-length BLM in mixed dimers, suggesting a putative mechanism of dominant-negative action in carriers of BLM truncation alleles. Our results identify critical molecular determinants of Bloom syndrome complex assembly required for double Holliday junction dissolution and maintenance of genome stability.
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Affiliation(s)
- Charlotte Hodson
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Jason K K Low
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW 2006, Australia
| | - Sylvie van Twest
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Samuel E Jones
- Department of Oncology, MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, United Kingdom
| | - Paolo Swuec
- Francis Crick Institute, London NW1 1AT, United Kingdom
| | - Vincent Murphy
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Kaima Tsukada
- Department of Oncology, MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, United Kingdom
- Laboratory for Zero-Carbon Energy, Institute of Innovative Research, Tokyo Institute of Technology, Tokyo 152-8550, Japan
| | - Matthew Fawkes
- Department of Oncology, MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, United Kingdom
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford OX3 7DQ, United Kingdom
| | - Rohan Bythell-Douglas
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
- Department of Medicine (St. Vincent's), University of Melbourne, Fitzroy, VIC 3065, Australia
| | | | - Jessica K Holien
- Department of Medicine (St. Vincent's), University of Melbourne, Fitzroy, VIC 3065, Australia
- School of Science, RMIT University, Melbourne, VIC 3001, Australia
- Structural Biology Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Julienne J O'Rourke
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Benjamin L Parker
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW 2006, Australia
| | - Astrid Glaser
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Michael W Parker
- Structural Biology Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
- Bio21 Institute, University of Melbourne, Parkville, VIC 3010, Australia
| | - Joel P Mackay
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW 2006, Australia
| | - Andrew N Blackford
- Department of Oncology, MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, United Kingdom
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford OX3 7DQ, United Kingdom
| | | | - Andrew J Deans
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia;
- Department of Medicine (St. Vincent's), University of Melbourne, Fitzroy, VIC 3065, Australia
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Gavrila AD, Deans AJ, Dhruva Rao PK. TP7.2.5 Surgeon measured radiological pelvic measurements as a patient selection tool for laparoscopic rectal resection – an aide in early learning curve. Br J Surg 2021. [DOI: 10.1093/bjs/znab362.053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
Introduction
Rectal resections are considered one of the most technically demanding laparoscopic procedures. This study reviews one unit’s rectal cancer resections to determine whether pelvic dimensions measured by the surgeon could aide patient selection for laparoscopic resections.
Methods
A prospectively maintained database was used to identify rectal cancer resections between April 2015 to March 2018 and patient demographics, BMI, height of tumour and operative details were in extracted. Anteroposterior (Coccygio-pubic) and transverse (interspinous) distance were measured retrospectively on linked Axial & Saggital views on staging CT scans. Tumour dimensions in the respective planes were recorded and relative proportions of tumour to pelvic dimensions calculated. These were correlated to operative approach.
Results
Our cohort comprised of 70 patients (42 men) with a median BMI of 27 and mean age of 71. While 6 operations were planned as open procedures, 64 were attempted laparoscopically. Of these, 55 were completed laparoscopically and 9 were converted (16%). There was no correlation between gender and operative approach (p = 0.2). Mean BMI for laparoscopic group 28.7 and converted group 30.0 which was not statistically significant (p = 0.32). Conversion was more likely for low tumours (89%). Median tumour to pelvic area proportion was 0.14 laparoscopic compared to 0.03 for open and 0.03 for converted suggesting that bulkier tumours are more likely to need conversion.
Discussion
None of previously identified factors such as gender and BMI predicted conversion in our cohort individually. Tumour size relative to pelvic dimensions is a simple measure a surgeon could use to guide patient selection.
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7
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Peterlongo P, Figlioli G, Deans AJ, Couch FJ. Protein truncating variants in FANCM and risk for ER-negative/triple negative breast cancer. NPJ Breast Cancer 2021; 7:130. [PMID: 34584094 PMCID: PMC8478958 DOI: 10.1038/s41523-021-00338-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 08/26/2021] [Indexed: 11/09/2022] Open
Abstract
FANCM protein truncating variants (PTVs) are emerging as risk factors for ER-negative and triple negative breast cancer. Here, we discuss evidence that greatest risk associates with PTVs, such as p.Arg658*, that extensively truncate the 2048 amino acid FANCM protein. Moreover, risks associated with other less-truncating FANCM PTVs such as p.Gln1701* and p.Gly1906Alafs12* may be amplified by additional gene variants acting as modifiers. Further studies need to be conducted taking into considerations these aspects.
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Affiliation(s)
- Paolo Peterlongo
- Genome Diagnostics Program, IFOM - The FIRC Institute for Molecular Oncology, Milan, Italy.
| | - Gisella Figlioli
- Genome Diagnostics Program, IFOM - The FIRC Institute for Molecular Oncology, Milan, Italy
| | - Andrew J Deans
- Genome Stability Unit, St Vincent's Institute, Fitzroy, Victoria, Australia
| | - Fergus J Couch
- Departments of Health Sciences Research, Laboratory Medicine and Pathology, and Oncology, Mayo Clinic, Rochester, USA
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8
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Sharp MF, Bythell-Douglas R, Deans AJ, Crismani W. The Fanconi anemia ubiquitin E3 ligase complex as an anti-cancer target. Mol Cell 2021; 81:2278-2289. [PMID: 33984284 DOI: 10.1016/j.molcel.2021.04.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 03/27/2021] [Accepted: 04/21/2021] [Indexed: 10/21/2022]
Abstract
Agents that induce DNA damage can cure some cancers. However, the side effects of chemotherapy are severe because of the indiscriminate action of DNA-damaging agents on both healthy and cancerous cells. DNA repair pathway inhibition provides a less toxic and targeted alternative to chemotherapy. A compelling DNA repair target is the Fanconi anemia (FA) E3 ligase core complex due to its critical-and likely singular-role in the efficient removal of specific DNA lesions. FA pathway inactivation has been demonstrated to specifically kill some types of cancer cells without the addition of exogenous DNA damage, including cells that lack BRCA1, BRCA2, ATM, or functionally related genes. In this perspective, we discuss the genetic and biochemical evidence in support of the FA core complex as a compelling drug target for cancer therapy. In particular, we discuss the genetic, biochemical, and structural data that could rapidly advance our capacity to identify and implement the use of FA core complex inhibitors in the clinic.
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Affiliation(s)
- Michael F Sharp
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC, Australia
| | - Rohan Bythell-Douglas
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC, Australia
| | - Andrew J Deans
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC, Australia; Department of Medicine (St. Vincent's), University of Melbourne, Fitzroy, VIC, Australia
| | - Wayne Crismani
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC, Australia; Department of Medicine (St. Vincent's), University of Melbourne, Fitzroy, VIC, Australia.
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9
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Abstract
Two new studies in this issue of Molecular Cell demonstrate that bone marrow failure, in mice and humans, can be induced by formaldehyde generated either from defective metabolism (Dingler et al., 2020) or during the process of transcriptional reprogramming (Shen et al., 2020).
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Affiliation(s)
- Winnie Tan
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC, 3056, Australia
| | - Andrew J Deans
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC, 3056, Australia; Department of Medicine (St. Vincent's), University of Melbourne, Fitzroy, VIC, 3056, Australia.
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10
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Bythell-Douglas R, Deans AJ. A Structural Guide to the Bloom Syndrome Complex. Structure 2020; 29:99-113. [PMID: 33357470 DOI: 10.1016/j.str.2020.11.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 09/03/2020] [Accepted: 11/25/2020] [Indexed: 01/19/2023]
Abstract
The Bloom syndrome complex is a DNA damage repair machine. It consists of several protein components which are functional in isolation, but interdependent in cells for the maintenance of accurate homologous recombination. Mutations to any of the genes encoding these proteins cause numerous physical and developmental markers as well as phenotypes of genome instability, infertility, and cancer predisposition. Here we review the published structural and biochemical data on each of the components of the complex: the helicase BLM, the type IA topoisomerase TOP3A, and the OB-fold-containing RMI and RPA subunits. We describe how each component contributes to function, interacts with each other, and the DNA that it manipulates/repairs.
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Affiliation(s)
- Rohan Bythell-Douglas
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC, 3056, Australia.
| | - Andrew J Deans
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC, 3056, Australia; Department of Medicine (St Vincent's), University of Melbourne, Fitzroy, VIC, 3056, Australia.
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11
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Tan W, Deans AJ. The ubiquitination machinery of the Fanconi Anemia DNA repair pathway. Prog Biophys Mol Biol 2020; 163:5-13. [PMID: 33058944 DOI: 10.1016/j.pbiomolbio.2020.09.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 09/25/2020] [Accepted: 09/29/2020] [Indexed: 10/23/2022]
Abstract
The Fanconi Anemia (FA) pathway maintains genome stability by preventing DNA damage from occurring when replication is blocked. Central to the FA pathway is the monoubiquitination of FANCI-FANCD2 mediated by a ubiquitin RING-E3 ligase complex called the FA core complex. Genetic mutation in any component of the FA core complex results in defective FANCI-FANCD2 monoubiquitination and phenotypes of DNA damage sensitivity, birth defects, early-onset bone marrow failure and cancer. Here, we discuss the mechanisms of the FA core complex and FANCI-FANCD2 monoubiquitination at sites of blocked replication and review our current understanding of the biological functions of these proteins in replication fork protection.
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Affiliation(s)
- Winnie Tan
- Genome Stability Unit, St. Vincent's Institute of Medical Research, 9 Princes St, Fitzroy, Victoria, 3065, Australia
| | - Andrew J Deans
- Genome Stability Unit, St. Vincent's Institute of Medical Research, 9 Princes St, Fitzroy, Victoria, 3065, Australia; Department of Medicine, St. Vincent's Health, The University of Melbourne, Australia. https://twitter.com/GenomeStability
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12
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Sanij E, Hannan KM, Xuan J, Yan S, Ahern JE, Trigos AS, Brajanovski N, Son J, Chan KT, Kondrashova O, Lieschke E, Wakefield MJ, Frank D, Ellis S, Cullinane C, Kang J, Poortinga G, Nag P, Deans AJ, Khanna KK, Mileshkin L, McArthur GA, Soong J, Berns EMJJ, Hannan RD, Scott CL, Sheppard KE, Pearson RB. CX-5461 activates the DNA damage response and demonstrates therapeutic efficacy in high-grade serous ovarian cancer. Nat Commun 2020; 11:2641. [PMID: 32457376 PMCID: PMC7251123 DOI: 10.1038/s41467-020-16393-4] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 04/30/2020] [Indexed: 02/06/2023] Open
Abstract
Acquired resistance to PARP inhibitors (PARPi) is a major challenge for the clinical management of high grade serous ovarian cancer (HGSOC). Here, we demonstrate CX-5461, the first-in-class inhibitor of RNA polymerase I transcription of ribosomal RNA genes (rDNA), induces replication stress and activates the DNA damage response. CX-5461 co-operates with PARPi in exacerbating replication stress and enhances therapeutic efficacy against homologous recombination (HR) DNA repair-deficient HGSOC-patient-derived xenograft (PDX) in vivo. We demonstrate CX-5461 has a different sensitivity spectrum to PARPi involving MRE11-dependent degradation of replication forks. Importantly, CX-5461 exhibits in vivo single agent efficacy in a HGSOC-PDX with reduced sensitivity to PARPi by overcoming replication fork protection. Further, we identify CX-5461-sensitivity gene expression signatures in primary and relapsed HGSOC. We propose CX-5461 is a promising therapy in combination with PARPi in HR-deficient HGSOC and also as a single agent for the treatment of relapsed disease.
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Affiliation(s)
- Elaine Sanij
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3000, Australia.
- Department of Clinical Pathology, University of Melbourne, Parkville, VIC, 3010, Australia.
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC, 3010, Australia.
| | - Katherine M Hannan
- ACRF Department of Cancer Biology and Therapeutics, The John Curtin School of Medical Research, Australian National University, Acton, 2601, Australia Capital Territory, Australia.
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia.
| | - Jiachen Xuan
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3000, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Shunfei Yan
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3000, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Jessica E Ahern
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3000, Australia
| | - Anna S Trigos
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3000, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Natalie Brajanovski
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3000, Australia
| | - Jinbae Son
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3000, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Keefe T Chan
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3000, Australia
| | - Olga Kondrashova
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
- Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Elizabeth Lieschke
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
| | - Matthew J Wakefield
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
- Melbourne Bioinformatics, University of Melbourne, Victoria, 3010, Australia
| | - Daniel Frank
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
- Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Sarah Ellis
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3000, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Carleen Cullinane
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3000, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Jian Kang
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3000, Australia
| | - Gretchen Poortinga
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3000, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC, 3010, Australia
- Department of Medicine, St. Vincent's Hospital, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Purba Nag
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
- School of Environment and Sciences, Griffith University, Nathan, Brisbane, QLD, 4111, Australia
| | - Andrew J Deans
- Department of Medicine, St. Vincent's Hospital, University of Melbourne, Parkville, VIC, 3010, Australia
- Genome Stability Unit, St Vincent's Institute, Fitzroy, VIC, 3065, Australia
| | - Kum Kum Khanna
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Linda Mileshkin
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3000, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Grant A McArthur
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3000, Australia
- Department of Clinical Pathology, University of Melbourne, Parkville, VIC, 3010, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC, 3010, Australia
- Department of Medicine, St. Vincent's Hospital, University of Melbourne, Parkville, VIC, 3010, Australia
| | - John Soong
- Senhwa Biosciences, Virginia Commonwealth University School of Medicine, San Diego, CA, USA
| | - Els M J J Berns
- Department of Medical Oncology, Erasmus MC Cancer Institute, Rotterdam, The Netherlands
| | - Ross D Hannan
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3000, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC, 3010, Australia
- ACRF Department of Cancer Biology and Therapeutics, The John Curtin School of Medical Research, Australian National University, Acton, 2601, Australia Capital Territory, Australia
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, 3800, Australia
- School of Biomedical Sciences, University of Queensland, Brisbane, QLD, 4072, Australia
| | - Clare L Scott
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3000, Australia
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
- Department of Medicine and Health Sciences, Monash University, Clayton, VIC, 3168, Australia
| | - Karen E Sheppard
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3000, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC, 3010, Australia
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Richard B Pearson
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3000, Australia.
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC, 3010, Australia.
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia.
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, 3800, Australia.
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13
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Sharp MF, Murphy VJ, Twest SV, Tan W, Lui J, Simpson KJ, Deans AJ, Crismani W. Methodology for the identification of small molecule inhibitors of the Fanconi Anaemia ubiquitin E3 ligase complex. Sci Rep 2020; 10:7959. [PMID: 32409752 PMCID: PMC7224301 DOI: 10.1038/s41598-020-64868-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 04/23/2020] [Indexed: 12/16/2022] Open
Abstract
DNA inter-strand crosslinks (ICLs) threaten genomic stability by creating a physical barrier to DNA replication and transcription. ICLs can be caused by endogenous reactive metabolites or from chemotherapeutics. ICL repair in humans depends heavily on the Fanconi Anaemia (FA) pathway. A key signalling step of the FA pathway is the mono-ubiquitination of Fanconi Anaemia Complementation Group D2 (FANCD2), which is achieved by the multi-subunit E3 ligase complex. FANCD2 mono-ubiquitination leads to the recruitment of DNA repair proteins to the site of the ICL. The loss of FANCD2 mono-ubiquitination is a common clinical feature of FA patient cells. Therefore, molecules that restore FANCD2 mono-ubiquitination could lead to a potential drug for the management of FA. On the other hand, in some cancers, FANCD2 mono-ubiquitination has been shown to be essential for cell survival. Therefore, inhibition of FANCD2 mono-ubiquitination represents a possible therapeutic strategy for cancer specific killing. We transferred an 11-protein FANCD2 mono-ubiquitination assay to a high-throughput format. We screened 9,067 compounds for both activation and inhibition of the E3 ligase complex. The use of orthogonal assays revealed that candidate compounds acted via non-specific mechanisms. However, our high-throughput biochemical assays demonstrate the feasibility of using sophisticated and robust biochemistry to screen for small molecules that modulate a key step in the FA pathway. The future identification of FA pathway modulators is anticipated to guide future medicinal chemistry projects with drug leads for human disease.
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Affiliation(s)
- Michael F Sharp
- St Vincent's Institute of Medical Research, Fitzroy, Victoria, 3065, Australia
| | - Vince J Murphy
- St Vincent's Institute of Medical Research, Fitzroy, Victoria, 3065, Australia
| | - Sylvie Van Twest
- St Vincent's Institute of Medical Research, Fitzroy, Victoria, 3065, Australia
| | - Winnie Tan
- St Vincent's Institute of Medical Research, Fitzroy, Victoria, 3065, Australia.,Department of Medicine (St. Vincent's Health), The University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Jennii Lui
- Victorian Centre for Functional Genomics, Peter MacCallum Cancer Centre, Melbourne, VIC, 3000, Australia
| | - Kaylene J Simpson
- Victorian Centre for Functional Genomics, Peter MacCallum Cancer Centre, Melbourne, VIC, 3000, Australia.,Sir Peter MacCallum Cancer Centre Department of Oncology, University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Andrew J Deans
- St Vincent's Institute of Medical Research, Fitzroy, Victoria, 3065, Australia.,Department of Medicine (St. Vincent's Health), The University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Wayne Crismani
- St Vincent's Institute of Medical Research, Fitzroy, Victoria, 3065, Australia. .,Department of Medicine (St. Vincent's Health), The University of Melbourne, Melbourne, VIC, 3010, Australia.
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14
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Abstract
Break-induced replication is a specific type of DNA repair that has a co-opted role in telomere extension by telomerase-negative cancer cells. This Alternative Lengthening of Telomeres (or ‘ALT’) is required for viability in approximately 10% of all carcinomas, but up to 50% of the soft-tissue derived sarcomas. In several recent studies, we and others demonstrate that expression and activity of FANCM, a DNA translocase protein, is essential for the viability of ALT-associated cancers. Here we provide a summary of how and why FANCM depletion leads to deletion of ALT-controlled cancers, predominantly through a hyper-activation of break-induced replication. We also discuss how FANCM can and has been targeted in cancer cell killing, including potential opportunities in ALT and other genetic backgrounds.
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Affiliation(s)
- Julienne J O'Rourke
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, Australia.,Department of Medicine, (St Vincent's) University of Melbourne, Fitzroy, Australia
| | - Rohan Bythell-Douglas
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, Australia
| | - Elyse A Dunn
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, Australia
| | - Andrew J Deans
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, Australia.,Department of Medicine, (St Vincent's) University of Melbourne, Fitzroy, Australia
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15
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Jung M, Ramanagoudr-Bhojappa R, van Twest S, Rosti RO, Murphy V, Tan W, Donovan FX, Lach FP, Kimble DC, Jiang CS, Vaughan R, Mehta PA, Pierri F, Dufour C, Auerbach AD, Deans AJ, Smogorzewska A, Chandrasekharappa SC. Association of clinical severity with FANCB variant type in Fanconi anemia. Blood 2020; 135:1588-1602. [PMID: 32106311 PMCID: PMC7193183 DOI: 10.1182/blood.2019003249] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 02/12/2020] [Indexed: 01/05/2023] Open
Abstract
Fanconi anemia (FA) is the most common genetic cause of bone marrow failure and is caused by inherited pathogenic variants in any of 22 genes. Of these, only FANCB is X-linked. We describe a cohort of 19 children with FANCB variants, from 16 families of the International Fanconi Anemia Registry. Those with FANCB deletion or truncation demonstrate earlier-than-average onset of bone marrow failure and more severe congenital abnormalities compared with a large series of FA individuals in published reports. This reflects the indispensable role of FANCB protein in the enzymatic activation of FANCD2 monoubiquitination, an essential step in the repair of DNA interstrand crosslinks. For FANCB missense variants, more variable severity is associated with the extent of residual FANCD2 monoubiquitination activity. We used transcript analysis, genetic complementation, and biochemical reconstitution of FANCD2 monoubiquitination to determine the pathogenicity of each variant. Aberrant splicing and transcript destabilization were associated with 2 missense variants. Individuals carrying missense variants with drastically reduced FANCD2 monoubiquitination in biochemical and/or cell-based assays tended to show earlier onset of hematologic disease and shorter survival. Conversely, variants with near-normal FANCD2 monoubiquitination were associated with more favorable outcome. Our study reveals a genotype-phenotype correlation within the FA-B complementation group of FA, where severity is associated with level of residual FANCD2 monoubiquitination.
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Affiliation(s)
- Moonjung Jung
- Laboratory of Genome Maintenance, The Rockefeller University, New York, NY
| | - Ramanagouda Ramanagoudr-Bhojappa
- Cancer Genomics Unit, Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD
| | - Sylvie van Twest
- Genome Stability Unit, St Vincent's Institute of Medical Research, Melbourne, VIC, Australia
| | - Rasim Ozgur Rosti
- Laboratory of Genome Maintenance, The Rockefeller University, New York, NY
| | - Vincent Murphy
- Genome Stability Unit, St Vincent's Institute of Medical Research, Melbourne, VIC, Australia
| | - Winnie Tan
- Genome Stability Unit, St Vincent's Institute of Medical Research, Melbourne, VIC, Australia
| | - Frank X Donovan
- Cancer Genomics Unit, Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD
| | - Francis P Lach
- Laboratory of Genome Maintenance, The Rockefeller University, New York, NY
| | - Danielle C Kimble
- Cancer Genomics Unit, Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD
| | - Caroline S Jiang
- Department of Biostatistics, The Rockefeller University Hospital, The Rockefeller University, New York, NY
| | - Roger Vaughan
- Department of Biostatistics, The Rockefeller University Hospital, The Rockefeller University, New York, NY
| | - Parinda A Mehta
- Division of Bone Marrow Transplantation and Immune Deficiency, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
- Department of Pediatrics, College of Medicine, University of Cincinnati, Cincinnati, OH
| | | | - Carlo Dufour
- Hematology Unit, IRCSS G. Gaslini, Genoa, Italy; and
| | - Arleen D Auerbach
- Human Genetics and Hematology Program, The Rockefeller University, New York, NY
| | - Andrew J Deans
- Genome Stability Unit, St Vincent's Institute of Medical Research, Melbourne, VIC, Australia
| | - Agata Smogorzewska
- Laboratory of Genome Maintenance, The Rockefeller University, New York, NY
| | - Settara C Chandrasekharappa
- Cancer Genomics Unit, Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD
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16
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Tan W, van Twest S, Leis A, Bythell-Douglas R, Murphy VJ, Sharp M, Parker MW, Crismani W, Deans AJ. Monoubiquitination by the human Fanconi anemia core complex clamps FANCI:FANCD2 on DNA in filamentous arrays. eLife 2020; 9:e54128. [PMID: 32167469 PMCID: PMC7156235 DOI: 10.7554/elife.54128] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 03/12/2020] [Indexed: 12/24/2022] Open
Abstract
FANCI:FANCD2 monoubiquitination is a critical event for replication fork stabilization by the Fanconi anemia (FA) DNA repair pathway. It has been proposed that at stalled replication forks, monoubiquitinated-FANCD2 serves to recruit DNA repair proteins that contain ubiquitin-binding motifs. Here, we have reconstituted the FA pathway in vitro to study functional consequences of FANCI:FANCD2 monoubiquitination. We report that monoubiquitination does not promote any specific exogenous protein:protein interactions, but instead stabilizes FANCI:FANCD2 heterodimers on dsDNA. This clamping requires monoubiquitination of only the FANCD2 subunit. We further show using electron microscopy that purified monoubiquitinated FANCI:FANCD2 forms filament-like arrays on long dsDNA. Our results reveal how monoubiquitinated FANCI:FANCD2, defective in many cancer types and all cases of FA, is activated upon DNA binding.
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Affiliation(s)
- Winnie Tan
- Genome Stability Unit, St. Vincent’s Institute of Medical ResearchFitzroyAustralia
- Department of Medicine (St. Vincent’s Health), The University of MelbourneMelbourneAustralia
| | - Sylvie van Twest
- Genome Stability Unit, St. Vincent’s Institute of Medical ResearchFitzroyAustralia
| | - Andrew Leis
- Bio21 Institute, University of MelbourneParkvilleAustralia
| | | | - Vincent J Murphy
- Genome Stability Unit, St. Vincent’s Institute of Medical ResearchFitzroyAustralia
| | - Michael Sharp
- Genome Stability Unit, St. Vincent’s Institute of Medical ResearchFitzroyAustralia
| | - Michael W Parker
- Bio21 Institute, University of MelbourneParkvilleAustralia
- Structural Biology Unit, St. Vincent’s Institute of Medical ResearchFitzroyAustralia
| | - Wayne Crismani
- Genome Stability Unit, St. Vincent’s Institute of Medical ResearchFitzroyAustralia
- Department of Medicine (St. Vincent’s Health), The University of MelbourneMelbourneAustralia
| | - Andrew J Deans
- Genome Stability Unit, St. Vincent’s Institute of Medical ResearchFitzroyAustralia
- Department of Medicine (St. Vincent’s Health), The University of MelbourneMelbourneAustralia
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17
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Tan W, Murphy VJ, Charron A, van Twest S, Sharp M, Constantinou A, Parker MW, Crismani W, Bythell-Douglas R, Deans AJ. Preparation and purification of mono-ubiquitinated proteins using Avi-tagged ubiquitin. PLoS One 2020; 15:e0229000. [PMID: 32092106 PMCID: PMC7039436 DOI: 10.1371/journal.pone.0229000] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 01/27/2020] [Indexed: 01/13/2023] Open
Abstract
Site-specific conjugation of ubiquitin onto a range of DNA repair proteins regulates their critical functions in the DNA damage response. Biochemical and structural characterization of these functions are limited by an absence of tools for the purification of DNA repair proteins in purely the ubiquitinated form. To overcome this barrier, we designed a ubiquitin fusion protein that is N-terminally biotinylated and can be conjugated by E3 RING ligases onto various substrates. Biotin affinity purification of modified proteins, followed by cleavage of the affinity tag leads to release of natively-mono-ubiquitinated substrates. As proof-of-principle, we applied this method to several substrates of mono-ubiquitination in the Fanconi anemia (FA)-BRCA pathway of DNA interstrand crosslink repair. These include the FANCI:FANCD2 complex, the PCNA trimer and BRCA1 modified nucleosomes. This method provides a simple approach to study the role of mono-ubiquitination in DNA repair or any other mono-ubiquitination signaling pathways.
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Affiliation(s)
- Winnie Tan
- Genome Stability Unit, St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
- Department of Medicine (St. Vincent’s Health), The University of Melbourne, Victoria, Australia
| | - Vincent J. Murphy
- Genome Stability Unit, St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
| | - Aude Charron
- Genome Stability Unit, St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
- National Graduate School of Chemistry of Montpellier (ENSCM), Montpellier, France
| | - Sylvie van Twest
- Genome Stability Unit, St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
| | - Michael Sharp
- Genome Stability Unit, St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
| | - Angelos Constantinou
- Institute of Human Genetics (IGH), Centre National de la Recherche Scientifique (CNRS), Université de Montpellier (UM), Montpellier, France
| | - Michael W. Parker
- Structural Biology Unit, St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
- Bio21 Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Wayne Crismani
- Genome Stability Unit, St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
- Department of Medicine (St. Vincent’s Health), The University of Melbourne, Victoria, Australia
| | - Rohan Bythell-Douglas
- Genome Stability Unit, St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
- Department of Medicine (St. Vincent’s Health), The University of Melbourne, Victoria, Australia
| | - Andrew J. Deans
- Genome Stability Unit, St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
- Department of Medicine (St. Vincent’s Health), The University of Melbourne, Victoria, Australia
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18
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Tan W, van Twest S, Murphy VJ, Deans AJ. ATR-Mediated FANCI Phosphorylation Regulates Both Ubiquitination and Deubiquitination of FANCD2. Front Cell Dev Biol 2020; 8:2. [PMID: 32117957 PMCID: PMC7010609 DOI: 10.3389/fcell.2020.00002] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 01/03/2020] [Indexed: 01/02/2023] Open
Abstract
DNA interstrand crosslinks (ICLs) are a physical barrier to replication and therefore toxic to cell viability. An important mechanism for the removal of ICLs is the Fanconi Anemia DNA repair pathway, which is initiated by mono-ubiquitination of FANCD2 and its partner protein FANCI. Here, we show that maintenance of FANCD2 and FANCI proteins in a monoubiquitinated form is regulated by the ATR-kinase. Using recombinant proteins in biochemical reconstitution experiments we show that ATR directly phosphorylates FANCI on serine 556, 559, and 565 to stabilize its association with DNA and FANCD2. This increased association with DNA stimulates the conjugation of ubiquitin to both FANCI and FANCD2, but also inhibits ubiquitin deconjugation. Using phosphomimetic and phosphodead mutants of FANCI we show that S559 and S565 are particularly important for protecting the complex from the activity of the deubiquitinating enzyme USP1:UAF1. Our results reveal a major mechanism by which ATR kinase maintains the activation of the FA pathway, by promoting the accumulation of FANCD2 in the ubiquitinated form active in DNA repair.
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Affiliation(s)
- Winnie Tan
- Genome Stability Unit, St Vincent’s Institute of Medical Research, Fitzroy, VIC, Australia
- Department of Medicine (St Vincent’s Hospital), The University of Melbourne, Melbourne, VIC, Australia
| | - Sylvie van Twest
- Genome Stability Unit, St Vincent’s Institute of Medical Research, Fitzroy, VIC, Australia
| | - Vincent J. Murphy
- Genome Stability Unit, St Vincent’s Institute of Medical Research, Fitzroy, VIC, Australia
| | - Andrew J. Deans
- Genome Stability Unit, St Vincent’s Institute of Medical Research, Fitzroy, VIC, Australia
- Department of Medicine (St Vincent’s Hospital), The University of Melbourne, Melbourne, VIC, Australia
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19
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Castillo-Tandazo W, Smeets MF, Murphy V, Liu R, Hodson C, Heierhorst J, Deans AJ, Walkley CR. ATP-dependent helicase activity is dispensable for the physiological functions of Recql4. PLoS Genet 2019; 15:e1008266. [PMID: 31276497 PMCID: PMC6636780 DOI: 10.1371/journal.pgen.1008266] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 07/17/2019] [Accepted: 06/21/2019] [Indexed: 11/18/2022] Open
Abstract
Rothmund-Thomson syndrome (RTS) is a rare autosomal recessive disorder characterized by skin rash (poikiloderma), skeletal dysplasia, small stature, juvenile cataracts, sparse or absent hair, and predisposition to specific malignancies such as osteosarcoma and hematological neoplasms. RTS is caused by germ-line mutations in RECQL4, a RecQ helicase family member. In vitro studies have identified functions for the ATP-dependent helicase of RECQL4. However, its specific role in vivo remains unclear. To determine the physiological requirement and the biological functions of Recql4 helicase activity, we generated mice with an ATP-binding-deficient knock-in mutation (Recql4K525A). Recql4K525A/K525A mice were strikingly normal in terms of embryonic development, body weight, hematopoiesis, B and T cell development, and physiological DNA damage repair. However, mice bearing two distinct truncating mutations Recql4G522Efs and Recql4R347*, that abolished not only the helicase but also the C-terminal domain, developed a profound bone marrow failure and decrease in survival similar to a Recql4 null allele. These results demonstrate that the ATP-dependent helicase activity of Recql4 is not essential for its physiological functions and that other domains might contribute to this phenotype. Future studies need to be performed to elucidate the complex interactions of RECQL4 domains and its contribution to the development of RTS. DNA helicases unwind double-stranded nucleic acids using energy from ATP to access genetic information during cell replication. In humans, several families of helicases have been described and one of particular importance is the RecQ family, where mutations in three of five members cause human disease. RECQL4 is a member of this family and its mutation results in Rothmund-Thomson syndrome (RTS). Prior studies have shown that defects in the helicase region of RECQL4 may contribute to the disease, but no studies have specifically assessed the biological effects of its absence in a whole animal model. In this study, we generated a mouse model with a specific point mutation resulting in a helicase-inactive Recql4 protein. We found that an absence of ATP-dependent helicase activity does not perturb the physiological functions of Recql4 with the homozygous mutants being normal. In contrast, when we assessed point mutations that generate protein truncations these were pathogenic. Our results suggest that the helicase function of Recql4 is not essential for its physiological functions and that other domains of this protein might account for its functions in diseases such as RTS.
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Affiliation(s)
- Wilson Castillo-Tandazo
- St. Vincent’s Institute of Medical Research, Fitzroy, VIC, Australia
- Department of Medicine, St. Vincent’s Hospital, The University of Melbourne, Fitzroy, VIC, Australia
| | - Monique F. Smeets
- St. Vincent’s Institute of Medical Research, Fitzroy, VIC, Australia
- Department of Medicine, St. Vincent’s Hospital, The University of Melbourne, Fitzroy, VIC, Australia
| | - Vincent Murphy
- St. Vincent’s Institute of Medical Research, Fitzroy, VIC, Australia
| | - Rui Liu
- St. Vincent’s Institute of Medical Research, Fitzroy, VIC, Australia
| | - Charlotte Hodson
- St. Vincent’s Institute of Medical Research, Fitzroy, VIC, Australia
| | - Jörg Heierhorst
- St. Vincent’s Institute of Medical Research, Fitzroy, VIC, Australia
- Department of Medicine, St. Vincent’s Hospital, The University of Melbourne, Fitzroy, VIC, Australia
| | - Andrew J. Deans
- St. Vincent’s Institute of Medical Research, Fitzroy, VIC, Australia
- Department of Medicine, St. Vincent’s Hospital, The University of Melbourne, Fitzroy, VIC, Australia
| | - Carl R. Walkley
- St. Vincent’s Institute of Medical Research, Fitzroy, VIC, Australia
- Department of Medicine, St. Vincent’s Hospital, The University of Melbourne, Fitzroy, VIC, Australia
- Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, Australia
- * E-mail:
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20
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Lu R, O'Rourke JJ, Sobinoff AP, Allen JAM, Nelson CB, Tomlinson CG, Lee M, Reddel RR, Deans AJ, Pickett HA. The FANCM-BLM-TOP3A-RMI complex suppresses alternative lengthening of telomeres (ALT). Nat Commun 2019; 10:2252. [PMID: 31138797 PMCID: PMC6538672 DOI: 10.1038/s41467-019-10180-6] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 04/23/2019] [Indexed: 12/21/2022] Open
Abstract
The collapse of stalled replication forks is a major driver of genomic instability. Several committed mechanisms exist to resolve replication stress. These pathways are particularly pertinent at telomeres. Cancer cells that use Alternative Lengthening of Telomeres (ALT) display heightened levels of telomere-specific replication stress, and co-opt stalled replication forks as substrates for break-induced telomere synthesis. FANCM is a DNA translocase that can form independent functional interactions with the BLM-TOP3A-RMI (BTR) complex and the Fanconi anemia (FA) core complex. Here, we demonstrate that FANCM depletion provokes ALT activity, evident by increased break-induced telomere synthesis, and the induction of ALT biomarkers. FANCM-mediated attenuation of ALT requires its inherent DNA translocase activity and interaction with the BTR complex, but does not require the FA core complex, indicative of FANCM functioning to restrain excessive ALT activity by ameliorating replication stress at telomeres. Synthetic inhibition of FANCM-BTR complex formation is selectively toxic to ALT cancer cells.
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Affiliation(s)
- Robert Lu
- Telomere Length Regulation Unit, Children's Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, 2145, NSW, Australia
| | - Julienne J O'Rourke
- Genome Stability Unit, St. Vincent's Institute, 9 Princes St, Fitzroy, 3065, VIC, Australia
- Department of Medicine (St. Vincent's), University of Melbourne, Parkville, 3052, VIC, Australia
| | - Alexander P Sobinoff
- Telomere Length Regulation Unit, Children's Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, 2145, NSW, Australia
| | - Joshua A M Allen
- Telomere Length Regulation Unit, Children's Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, 2145, NSW, Australia
| | - Christopher B Nelson
- Telomere Length Regulation Unit, Children's Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, 2145, NSW, Australia
| | - Christopher G Tomlinson
- Telomere Length Regulation Unit, Children's Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, 2145, NSW, Australia
| | - Michael Lee
- Telomere Length Regulation Unit, Children's Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, 2145, NSW, Australia
| | - Roger R Reddel
- Cancer Research Unit, Children's Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, 2145, NSW, Australia
| | - Andrew J Deans
- Genome Stability Unit, St. Vincent's Institute, 9 Princes St, Fitzroy, 3065, VIC, Australia.
- Department of Medicine (St. Vincent's), University of Melbourne, Parkville, 3052, VIC, Australia.
| | - Hilda A Pickett
- Telomere Length Regulation Unit, Children's Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, 2145, NSW, Australia.
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21
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Roesley SNA, La Marca JE, Deans AJ, Mckenzie L, Suryadinata R, Burke P, Portela M, Wang H, Bernard O, Sarcevic B, Richardson HE. Phosphorylation of Drosophila Brahma on CDK-phosphorylation sites is important for cell cycle regulation and differentiation. Cell Cycle 2018; 17:1559-1578. [PMID: 29963966 DOI: 10.1080/15384101.2018.1493414] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The SWI/SNF ATP-dependent chromatin-remodeling complex is an important evolutionarily conserved regulator of cell cycle progression. It associates with the Retinoblastoma (pRb)/HDAC/E2F/DP transcription complex to modulate cell cycle-dependent gene expression. The key catalytic component of the SWI/SNF complex in mammals is the ATPase subunit, Brahma (BRM) or BRG1. BRG1 was previously shown to be phosphorylated by the G1-S phase cell cycle regulatory kinase Cyclin E/CDK2 in vitro, which was associated with the bypass of G1 arrest conferred by BRG1 expression. However, it is unknown whether direct Cyclin E/CDK2-mediated phosphorylation of BRM/BRG1 is important for G1-S phase cell cycle progression and proliferation in vivo. Herein, we demonstrate for the first time the importance of CDK-mediated phosphorylation of Brm in cell proliferation and differentiation in vivo using the Drosophila melanogaster model organism. Expression of a CDK-site phospho-mimic mutant of Brm, brm-ASP (all the potential CDK sites are mutated from Ser/Thr to Asp), which acts genetically as a brm loss-of-function allele, dominantly accelerates progression into the S phase, and bypasses a Retinoblastoma-induced developmental G1 phase arrest in the wing epithelium. Conversely, expression of a CDK-site phospho-blocking mutation of Brm, brm-ALA, acts genetically as a brm gain-of-function mutation, and in a Brm complex compromised background reduces S phase cells. Expression of the brm phospho-mutants also affected differentiation and Decapentaplegic (BMP/TGFβ) signaling in the wing epithelium. Altogether our results show that CDK-mediated phosphorylation of Brm is important in G1-S phase regulation and differentiation in vivo. ABBREVIATIONS A-P: Anterior-Posterior; BAF: BRG1-associated factor; BMP: Bone Morphogenetic Protein; Brg1: Brahma-Related Gene 1; Brm: Brahma; BSA: Bovine Serum Albumin; CDK: Cyclin dependent kinase dpp: decapentaplegic; EdU: 5-Ethynyl 2'-DeoxyUridine; EGFR: Epidermal Growth Factor Receptor; en: engrailed; GFP: Green Fluorescent Protein; GST: Glutathione-S-Transferase; HDAC: Histone DeACetylase; JNK: c-Jun N-terminal Kinase; Mad: Mothers Against Dpp; MAPK: Mitogen Activated Protein Kinase; MB:: Myelin Basic Protein; nub: nubbin; pH3: phosphorylated Histone H3; PBS: Phosphate Buffered Saline; PBT: PBS Triton; PFA: ParaFormAldehydep; Rb: Retinoblastoma protein; PCV: Posterior Cross-Vein; Snr1: Snf5-Related 1; SWI/SNF: SWitch/Sucrose Non-Fermentable; TGFβ: Transforming Growth Factor β; TUNEL: TdT-mediated dUTP Nick End Labelling; Wg: Wingless; ZNC: Zone of Non-Proliferating Cells.
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Affiliation(s)
- Siti Nur Ain Roesley
- a Cell Cycle and Cancer Unit , St Vincent's Medical Institute , Melbourne , Australia.,b Department of Medicine , University of Melbourne , Melbourne , Australia.,c Cell Cycle & Development Laboratory , Peter MacCallum Cancer Centre , Melbourne , Australia
| | - John E La Marca
- d Department of Biochemistry & Genetics , La Trobe Institute for Molecular Science, La Trobe University , Melbourne , Australia
| | - Andrew J Deans
- b Department of Medicine , University of Melbourne , Melbourne , Australia.,e Genome Stability Unit , St Vincent's Medical Institute , Melbourne , Australia
| | - Lisa Mckenzie
- c Cell Cycle & Development Laboratory , Peter MacCallum Cancer Centre , Melbourne , Australia
| | - Randy Suryadinata
- a Cell Cycle and Cancer Unit , St Vincent's Medical Institute , Melbourne , Australia.,b Department of Medicine , University of Melbourne , Melbourne , Australia
| | - Peter Burke
- c Cell Cycle & Development Laboratory , Peter MacCallum Cancer Centre , Melbourne , Australia.,d Department of Biochemistry & Genetics , La Trobe Institute for Molecular Science, La Trobe University , Melbourne , Australia
| | - Marta Portela
- c Cell Cycle & Development Laboratory , Peter MacCallum Cancer Centre , Melbourne , Australia.,d Department of Biochemistry & Genetics , La Trobe Institute for Molecular Science, La Trobe University , Melbourne , Australia
| | - Hongyan Wang
- f Neuroscience and Behavioral Disorders Program , Duke-National University of Singapore Graduate Medical School , Singapore.,g National University of Singapore Graduate School for Integrative Sciences and Engineering , National University of Singapore , Singapore.,h Department of Physiology , Yong Loo Lin School of Medicine, National University of Singapore , Singapore
| | - Ora Bernard
- b Department of Medicine , University of Melbourne , Melbourne , Australia
| | - Boris Sarcevic
- a Cell Cycle and Cancer Unit , St Vincent's Medical Institute , Melbourne , Australia.,b Department of Medicine , University of Melbourne , Melbourne , Australia
| | - Helena E Richardson
- d Department of Biochemistry & Genetics , La Trobe Institute for Molecular Science, La Trobe University , Melbourne , Australia.,e Genome Stability Unit , St Vincent's Medical Institute , Melbourne , Australia.,i Peter MacCallum Department of Oncology, Department of Biochemistry & Molecular Biology, Department of Anatomy & Neuroscience , University of Melbourne , Melbourne , Australia
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22
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Mollah ZUA, Quah HS, Graham KL, Jhala G, Krishnamurthy B, Dharma JFM, Chee J, Trivedi PM, Pappas EG, Mackin L, Chu EPF, Akazawa S, Fynch S, Hodson C, Deans AJ, Trapani JA, Chong MMW, Bird PI, Brodnicki TC, Thomas HE, Kay TWH. Granzyme A Deficiency Breaks Immune Tolerance and Promotes Autoimmune Diabetes Through a Type I Interferon-Dependent Pathway. Diabetes 2017; 66:3041-3050. [PMID: 28733313 DOI: 10.2337/db17-0517] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 07/13/2017] [Indexed: 11/13/2022]
Abstract
Granzyme A is a protease implicated in the degradation of intracellular DNA. Nucleotide complexes are known triggers of systemic autoimmunity, but a role in organ-specific autoimmune disease has not been demonstrated. To investigate whether such a mechanism could be an endogenous trigger for autoimmunity, we examined the impact of granzyme A deficiency in the NOD mouse model of autoimmune diabetes. Granzyme A deficiency resulted in an increased incidence in diabetes associated with accumulation of ssDNA in immune cells and induction of an interferon response in pancreatic islets. Central tolerance to proinsulin in transgenic NOD mice was broken on a granzyme A-deficient background. We have identified a novel endogenous trigger for autoimmune diabetes and an in vivo role for granzyme A in maintaining immune tolerance.
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Affiliation(s)
| | - Hong Sheng Quah
- St. Vincent's Institute, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | - Kate L Graham
- St. Vincent's Institute, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | - Gaurang Jhala
- St. Vincent's Institute, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | - Balasubramanian Krishnamurthy
- St. Vincent's Institute, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | - Joanna Francisca M Dharma
- St. Vincent's Institute, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | - Jonathan Chee
- St. Vincent's Institute, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | - Prerak M Trivedi
- St. Vincent's Institute, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | - Evan G Pappas
- St. Vincent's Institute, Fitzroy, Victoria, Australia
| | - Leanne Mackin
- St. Vincent's Institute, Fitzroy, Victoria, Australia
| | - Edward P F Chu
- St. Vincent's Institute, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | | | - Stacey Fynch
- St. Vincent's Institute, Fitzroy, Victoria, Australia
| | | | - Andrew J Deans
- St. Vincent's Institute, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | - Joseph A Trapani
- Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - Mark M W Chong
- St. Vincent's Institute, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | - Phillip I Bird
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Thomas C Brodnicki
- St. Vincent's Institute, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | - Helen E Thomas
- St. Vincent's Institute, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | - Thomas W H Kay
- St. Vincent's Institute, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
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23
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Swuec P, Renault L, Borg A, Shah F, Murphy VJ, van Twest S, Snijders AP, Deans AJ, Costa A. The FA Core Complex Contains a Homo-dimeric Catalytic Module for the Symmetric Mono-ubiquitination of FANCI-FANCD2. Cell Rep 2016; 18:611-623. [PMID: 27986592 PMCID: PMC5266791 DOI: 10.1016/j.celrep.2016.11.013] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 09/22/2016] [Accepted: 10/31/2016] [Indexed: 12/20/2022] Open
Abstract
Activation of the main DNA interstrand crosslink repair pathway in higher eukaryotes requires mono-ubiquitination of FANCI and FANCD2 by FANCL, the E3 ligase subunit of the Fanconi anemia core complex. FANCI and FANCD2 form a stable complex; however, the molecular basis of their ubiquitination is ill defined. FANCD2 mono-ubiquitination by FANCL is stimulated by the presence of the FANCB and FAAP100 core complex components, through an unknown mechanism. How FANCI mono-ubiquitination is achieved remains unclear. Here, we use structural electron microscopy, combined with crosslink-coupled mass spectrometry, to find that FANCB, FANCL, and FAAP100 form a dimer of trimers, containing two FANCL molecules that are ideally poised to target both FANCI and FANCD2 for mono-ubiquitination. The FANCC-FANCE-FANCF subunits bridge between FANCB-FANCL-FAAP100 and the FANCI-FANCD2 substrate. A transient interaction with FANCC-FANCE-FANCF alters the FANCI-FANCD2 configuration, stabilizing the dimerization interface. Our data provide a model to explain how equivalent mono-ubiquitination of FANCI and FANCD2 occurs. FANCB, FANCL, and FAAP100 form a symmetric dimer of trimers FANCL is ideally poised for the symmetric mono-ubiquitination of FANCI-FANCD2 Two separate FANCC-FANCE-FANCF complexes bind to the opposing poles of FANCB-FANCL-FAAP100 FANCC-FANCE-FANCF stabilizes FANCI-FANCD2 for efficient mono-ubiquitination
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Affiliation(s)
- Paolo Swuec
- Macromolecular Machines Laboratory, Clare Hall Laboratory, The Francis Crick Institute, Blanche Lane, South Mimms, EN6 3LD, UK
| | - Ludovic Renault
- Macromolecular Machines Laboratory, Clare Hall Laboratory, The Francis Crick Institute, Blanche Lane, South Mimms, EN6 3LD, UK
| | - Aaron Borg
- Mass Spectrometry Proteomics and Metabolomics, Clare Hall Laboratory, The Francis Crick Institute, Blanche Lane, South Mimms, EN6 3LD, UK
| | - Fenil Shah
- Genome Stability Unit, St. Vincent's Institute of Medical Research, 9 Princes St Fitzroy, Victoria, VIC 3065, Australia
| | - Vincent J Murphy
- Genome Stability Unit, St. Vincent's Institute of Medical Research, 9 Princes St Fitzroy, Victoria, VIC 3065, Australia
| | - Sylvie van Twest
- Genome Stability Unit, St. Vincent's Institute of Medical Research, 9 Princes St Fitzroy, Victoria, VIC 3065, Australia
| | - Ambrosius P Snijders
- Mass Spectrometry Proteomics and Metabolomics, Clare Hall Laboratory, The Francis Crick Institute, Blanche Lane, South Mimms, EN6 3LD, UK
| | - Andrew J Deans
- Genome Stability Unit, St. Vincent's Institute of Medical Research, 9 Princes St Fitzroy, Victoria, VIC 3065, Australia
| | - Alessandro Costa
- Macromolecular Machines Laboratory, Clare Hall Laboratory, The Francis Crick Institute, Blanche Lane, South Mimms, EN6 3LD, UK.
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van Twest S, Murphy VJ, Hodson C, Tan W, Swuec P, O'Rourke JJ, Heierhorst J, Crismani W, Deans AJ. Mechanism of Ubiquitination and Deubiquitination in the Fanconi Anemia Pathway. Mol Cell 2016; 65:247-259. [PMID: 27986371 DOI: 10.1016/j.molcel.2016.11.005] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 10/25/2016] [Accepted: 10/31/2016] [Indexed: 11/26/2022]
Abstract
Monoubiquitination and deubiquitination of FANCD2:FANCI heterodimer is central to DNA repair in a pathway that is defective in the cancer predisposition syndrome Fanconi anemia (FA). The "FA core complex" contains the RING-E3 ligase FANCL and seven other essential proteins that are mutated in various FA subtypes. Here, we purified recombinant FA core complex to reveal the function of these other proteins. The complex contains two spatially separate FANCL molecules that are dimerized by FANCB and FAAP100. FANCC and FANCE act as substrate receptors and restrict monoubiquitination to the FANCD2:FANCI heterodimer in only a DNA-bound form. FANCA and FANCG are dispensable for maximal in vitro ubiquitination. Finally, we show that the reversal of this reaction by the USP1:UAF1 deubiquitinase only occurs when DNA is disengaged. Our work reveals the mechanistic basis for temporal and spatial control of FANCD2:FANCI monoubiquitination that is critical for chemotherapy responses and prevention of Fanconi anemia.
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Affiliation(s)
- Sylvie van Twest
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Vincent J Murphy
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Charlotte Hodson
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Winnie Tan
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia; Department of Medicine (St. Vincent's Health), The University of Melbourne, VIC 3010, Australia
| | - Paolo Swuec
- Architecture and Dynamics of Macromolecular Machines Laboratory, London Research Institute, South Mimms, Hertfordshire EN6 3LD, UK
| | - Julienne J O'Rourke
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia; Department of Medicine (St. Vincent's Health), The University of Melbourne, VIC 3010, Australia
| | - Jörg Heierhorst
- Molecular Genetics Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia; Department of Medicine (St. Vincent's Health), The University of Melbourne, VIC 3010, Australia
| | - Wayne Crismani
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Andrew J Deans
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia; Department of Medicine (St. Vincent's Health), The University of Melbourne, VIC 3010, Australia.
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25
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Vuono EA, Mukherjee A, Vierra DA, Adroved MM, Hodson C, Deans AJ, Howlett NG. The PTEN phosphatase functions cooperatively with the Fanconi anemia proteins in DNA crosslink repair. Sci Rep 2016; 6:36439. [PMID: 27819275 PMCID: PMC5098254 DOI: 10.1038/srep36439] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 10/17/2016] [Indexed: 11/13/2022] Open
Abstract
Fanconi anemia (FA) is a genetic disease characterized by bone marrow failure and increased cancer risk. The FA proteins function primarily in DNA interstrand crosslink (ICL) repair. Here, we have examined the role of the PTEN phosphatase in this process. We have established that PTEN-deficient cells, like FA cells, exhibit increased cytotoxicity, chromosome structural aberrations, and error-prone mutagenic DNA repair following exposure to ICL-inducing agents. The increased ICL sensitivity of PTEN-deficient cells is caused, in part, by elevated PLK1 kinase-mediated phosphorylation of FANCM, constitutive FANCM polyubiquitination and degradation, and the consequent inefficient assembly of the FA core complex, FANCD2, and FANCI into DNA repair foci. We also establish that PTEN function in ICL repair is dependent on its protein phosphatase activity and ability to be SUMOylated, yet is independent of its lipid phosphatase activity. Finally, via epistasis analysis, we demonstrate that PTEN and FANCD2 function cooperatively in ICL repair.
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Affiliation(s)
- Elizabeth A. Vuono
- Department of Cell and Molecular Biology, University of Rhode Island, Kingston, Rhode Island, USA
| | - Ananda Mukherjee
- Department of Obstetrics, Gynecology, and Reproductive Biology, Michigan State University, Grand Rapids, Michigan, USA
| | - David A. Vierra
- Department of Cell and Molecular Biology, University of Rhode Island, Kingston, Rhode Island, USA
| | - Morganne M. Adroved
- Department of Cell and Molecular Biology, University of Rhode Island, Kingston, Rhode Island, USA
| | - Charlotte Hodson
- Genome Stability Unit, St. Vincent’s Institute, Fitzroy, VIC 3065, Australia
| | - Andrew J. Deans
- Genome Stability Unit, St. Vincent’s Institute, Fitzroy, VIC 3065, Australia
- Department of Medicine, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Niall G. Howlett
- Department of Cell and Molecular Biology, University of Rhode Island, Kingston, Rhode Island, USA
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26
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Schwab RA, Nieminuszczy J, Shah F, Langton J, Lopez Martinez D, Liang CC, Cohn MA, Gibbons RJ, Deans AJ, Niedzwiedz W. The Fanconi Anemia Pathway Maintains Genome Stability by Coordinating Replication and Transcription. Mol Cell 2015; 60:351-61. [PMID: 26593718 PMCID: PMC4644232 DOI: 10.1016/j.molcel.2015.09.012] [Citation(s) in RCA: 249] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 06/20/2015] [Accepted: 09/16/2015] [Indexed: 01/27/2023]
Abstract
DNA replication stress can cause chromosomal instability and tumor progression. One key pathway that counteracts replication stress and promotes faithful DNA replication consists of the Fanconi anemia (FA) proteins. However, how these proteins limit replication stress remains largely elusive. Here we show that conflicts between replication and transcription activate the FA pathway. Inhibition of transcription or enzymatic degradation of transcription-associated R-loops (DNA:RNA hybrids) suppresses replication fork arrest and DNA damage occurring in the absence of a functional FA pathway. Furthermore, we show that simple aldehydes, known to cause leukemia in FA-deficient mice, induce DNA:RNA hybrids in FA-depleted cells. Finally, we demonstrate that the molecular mechanism by which the FA pathway limits R-loop accumulation requires FANCM translocase activity. Failure to activate a response to physiologically occurring DNA:RNA hybrids may critically contribute to the heightened cancer predisposition and bone marrow failure of individuals with mutated FA proteins. Replication and transcription collisions cause genome instability in FA A functional FA pathway protects cells from unscheduled accumulation of R-loops Transcription inhibition or R-loop removal restores normal replication in FA cells FANCM resolves R-loops via its translocase activity
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Affiliation(s)
- Rebekka A Schwab
- Department of Oncology, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
| | - Jadwiga Nieminuszczy
- Department of Oncology, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
| | - Fenil Shah
- Genome Stability Unit, St. Vincent's Institute, Fitzroy, VIC 3065, Australia
| | - Jamie Langton
- Department of Oncology, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
| | | | - Chih-Chao Liang
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Martin A Cohn
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Richard J Gibbons
- Medical Research Council Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
| | - Andrew J Deans
- Genome Stability Unit, St. Vincent's Institute, Fitzroy, VIC 3065, Australia
| | - Wojciech Niedzwiedz
- Department of Oncology, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK.
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27
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Garsed DW, Marshall OJ, Corbin VDA, Hsu A, Di Stefano L, Schröder J, Li J, Feng ZP, Kim BW, Kowarsky M, Lansdell B, Brookwell R, Myklebost O, Meza-Zepeda L, Holloway AJ, Pedeutour F, Choo KHA, Damore MA, Deans AJ, Papenfuss AT, Thomas DM. The architecture and evolution of cancer neochromosomes. Cancer Cell 2014; 26:653-67. [PMID: 25517748 DOI: 10.1016/j.ccell.2014.09.010] [Citation(s) in RCA: 135] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 05/15/2014] [Accepted: 09/19/2014] [Indexed: 01/21/2023]
Abstract
We isolated and analyzed, at single-nucleotide resolution, cancer-associated neochromosomes from well- and/or dedifferentiated liposarcomas. Neochromosomes, which can exceed 600 Mb in size, initially arise as circular structures following chromothripsis involving chromosome 12. The core of the neochromosome is amplified, rearranged, and corroded through hundreds of breakage-fusion-bridge cycles. Under selective pressure, amplified oncogenes are overexpressed, while coamplified passenger genes may be silenced epigenetically. New material may be captured during punctuated chromothriptic events. Centromeric corrosion leads to crisis, which is resolved through neocentromere formation or native centromere capture. Finally, amplification terminates, and the neochromosome core is stabilized in linear form by telomere capture. This study investigates the dynamic mutational processes underlying the life history of a special form of cancer mutation.
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Affiliation(s)
- Dale W Garsed
- Cancer Genomics, Peter MacCallum Cancer Centre, East Melbourne, VIC 3002, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, VIC 3010, Australia; Department of Pathology, University of Melbourne, VIC 3010, Australia
| | - Owen J Marshall
- Chromosome Research, Murdoch Childrens Research Institute, and Department of Paediatrics, Royal Children's Hospital, University of Melbourne, Parkville, VIC 3052, Australia
| | - Vincent D A Corbin
- Bioinformatics Division, The Walter & Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, VIC 3010, Australia; Bioinformatics and Cancer Genomics, Peter MacCallum Cancer Centre, East Melbourne, VIC, 3002, Australia
| | - Arthur Hsu
- Bioinformatics Division, The Walter & Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia
| | - Leon Di Stefano
- Bioinformatics Division, The Walter & Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia
| | - Jan Schröder
- Bioinformatics Division, The Walter & Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, VIC 3010, Australia
| | - Jason Li
- Cancer Genomics, Peter MacCallum Cancer Centre, East Melbourne, VIC 3002, Australia
| | - Zhi-Ping Feng
- Bioinformatics Division, The Walter & Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, VIC 3010, Australia
| | - Bo W Kim
- Chromosome Research, Murdoch Childrens Research Institute, and Department of Paediatrics, Royal Children's Hospital, University of Melbourne, Parkville, VIC 3052, Australia
| | - Mark Kowarsky
- Bioinformatics Division, The Walter & Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia
| | - Ben Lansdell
- Bioinformatics Division, The Walter & Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia
| | - Ross Brookwell
- Sullivan Nicolaides Pathology, Indooroopilly, QLD 4068, Australia
| | - Ola Myklebost
- Department of Tumor Biology, Oslo University Hospital, Norwegian Radium Hospital, Oslo 0424, Norway
| | - Leonardo Meza-Zepeda
- Department of Tumor Biology, Oslo University Hospital, Norwegian Radium Hospital, Oslo 0424, Norway
| | - Andrew J Holloway
- Cancer Genomics, Peter MacCallum Cancer Centre, East Melbourne, VIC 3002, Australia
| | - Florence Pedeutour
- Laboratory of Solid Tumors Genetics, Nice University Hospital, Nice 06107, France
| | - K H Andy Choo
- Chromosome Research, Murdoch Childrens Research Institute, and Department of Paediatrics, Royal Children's Hospital, University of Melbourne, Parkville, VIC 3052, Australia
| | | | | | - Anthony T Papenfuss
- Bioinformatics Division, The Walter & Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, VIC 3010, Australia; Department of Mathematics and Statistics, University of Melbourne, VIC, 3010, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, VIC 3010, Australia; Bioinformatics and Cancer Genomics, Peter MacCallum Cancer Centre, East Melbourne, VIC, 3002, Australia.
| | - David M Thomas
- Cancer Genomics, Peter MacCallum Cancer Centre, East Melbourne, VIC 3002, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, VIC 3010, Australia; The Kinghorn Cancer Centre, Garvan Institute of Medical Research, Sydney, NSW 2010, Australia.
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28
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Smeets MF, DeLuca E, Wall M, Quach JM, Chalk AM, Deans AJ, Heierhorst J, Purton LE, Izon DJ, Walkley CR. The Rothmund-Thomson syndrome helicase RECQL4 is essential for hematopoiesis. J Clin Invest 2014; 124:3551-65. [PMID: 24960165 DOI: 10.1172/jci75334] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 05/01/2014] [Indexed: 12/31/2022] Open
Abstract
Mutations within the gene encoding the DNA helicase RECQL4 underlie the autosomal recessive cancer-predisposition disorder Rothmund-Thomson syndrome, though it is unclear how these mutations lead to disease. Here, we demonstrated that somatic deletion of Recql4 causes a rapid bone marrow failure in mice that involves cells from across the myeloid, lymphoid, and, most profoundly, erythroid lineages. Apoptosis was markedly elevated in multipotent progenitors lacking RECQL4 compared with WT cells. While the stem cell compartment was relatively spared in RECQL4-deficent mice, HSCs from these animals were not transplantable and even selected against. The requirement for RECQL4 was intrinsic in hematopoietic cells, and loss of RECQL4 in these cells was associated with increased replicative DNA damage and failed cell-cycle progression. Concurrent deletion of p53, which rescues loss of function in animals lacking the related helicase BLM, did not rescue BM phenotypes in RECQL4-deficient animals. In contrast, hematopoietic defects in cells from Recql4Δ/Δ mice were fully rescued by a RECQL4 variant without RecQ helicase activity, demonstrating that RECQL4 maintains hematopoiesis independently of helicase activity. Together, our data indicate that RECQL4 participates in DNA replication rather than genome stability and identify RECQL4 as a regulator of hematopoiesis with a nonredundant role compared with other RecQ helicases.
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29
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Abstract
Mutations in any of at least sixteen FANC genes (FANCA-Q) cause Fanconi anemia, a disorder characterized by sensitivity to DNA interstrand crosslinking agents. The clinical features of cytopenia, developmental defects, and tumor predisposition are similar in each group, suggesting that the gene products participate in a common pathway. The Fanconi anemia DNA repair pathway consists of an anchor complex that recognizes damage caused by interstrand crosslinks, a multisubunit ubiquitin ligase that monoubiquitinates two substrates, and several downstream repair proteins including nucleases and homologous recombination enzymes. We review progress in the use of structural and biochemical approaches to understanding how each FANC protein functions in this pathway.
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Affiliation(s)
- Helen Walden
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences, University of Dundee, Dundee DD1 5EH, United Kingdom;
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30
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Caldon CE, Sergio CM, Burgess A, Deans AJ, Sutherland RL, Musgrove EA. Cyclin E2 induces genomic instability by mechanisms distinct from cyclin E1. Cell Cycle 2013; 12:606-17. [PMID: 23324395 DOI: 10.4161/cc.23512] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Cyclins E1 drives the initiation of DNA replication, and deregulation of its periodic expression leads to mitotic delay associated with genomic instability. Since it is not known whether the closely related protein cyclin E2 shares these properties, we overexpressed cyclin E2 in breast cancer cells. This did not affect the duration of mitosis, nor did it cause an increase in p107 association with CDK2. In contrast, cyclin E1 overexpression led to inhibition of the APC complex, prolonged metaphase and increased p107 association with CDK2. Despite these different effects on the cell cycle, elevated levels of either cyclin E1 or E2 led to hallmarks of genomic instability, i.e., an increased proportion of abnormal mitoses, micronuclei and chromosomal aberrations. Cyclin E2 induction of genomic instability by a mechanism distinct from cyclin E1 indicates that these two proteins have unique functions in a cancer setting.
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Affiliation(s)
- C Elizabeth Caldon
- The Kinghorn Cancer Centre and Cancer Research Program, Garvan Institute of Medical Research, Sydney, NSW, Australia
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31
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Deans AJ. Fanconi proteins get histones moving. EMBO J 2012; 31:3511-2. [DOI: 10.1038/emboj.2012.222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Andrew J Deans
- Genome Stability Unit, St. Vincent's Institute of Medical Research; Fitzroy Victoria Australia
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32
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Blackford AN, Schwab RA, Nieminuszczy J, Deans AJ, West SC, Niedzwiedz W. The DNA translocase activity of FANCM protects stalled replication forks. Hum Mol Genet 2012; 21:2005-16. [PMID: 22279085 DOI: 10.1093/hmg/dds013] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
FANCM is the most highly conserved protein within the Fanconi anaemia (FA) tumour suppressor pathway. However, although FANCM contains a helicase domain with translocase activity, this is not required for its role in activating the FA pathway. Instead, we show here that FANCM translocaseactivity is essential for promoting replication fork stability. We demonstrate that cells expressing translocase-defective FANCM show altered global replication dynamics due to increased accumulation of stalled forks that subsequently degenerate into DNA double-strand breaks, leading to ATM activation, CTBP-interacting protein (CTIP)-dependent end resection and homologous recombination repair. Accordingly, abrogation of ATM or CTIP function in FANCM-deficient cells results in decreased cell survival. We also found that FANCM translocase activity protects cells from accumulating 53BP1-OPT domains, which mark lesions resulting from problems arising during replication. Taken together, these data show that FANCM plays an essential role in maintaining chromosomal integrity by promoting the recovery of stalled replication forks and hence preventing tumourigenesis.
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Affiliation(s)
- Andrew N Blackford
- Department of Oncology, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
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Abstract
Interstrand crosslinks (ICLs) are highly toxic DNA lesions that prevent transcription and replication by inhibiting DNA strand separation. Agents that induce ICLs were one of the earliest, and are still the most widely used, forms of chemotherapeutic drug. Only recently, however, have we begun to understand how cells repair these lesions. Important insights have come from studies of individuals with Fanconi anaemia (FA), a rare genetic disorder that leads to ICL sensitivity. Understanding how the FA pathway links nucleases, helicases and other DNA-processing enzymes should lead to more targeted uses of ICL-inducing agents in cancer treatment and could provide novel insights into drug resistance.
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Affiliation(s)
- Andrew J Deans
- London Research Institute, Cancer Research UK, Clare Hall Laboratories, South Mimms EN63LD, UK
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34
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MacKay C, Déclais AC, Lundin C, Agostinho A, Deans AJ, MacArtney TJ, Hofmann K, Gartner A, West SC, Helleday T, Lilley DM, Rouse J. Identification of KIAA1018/FAN1, a DNA repair nuclease recruited to DNA damage by monoubiquitinated FANCD2. Cell 2010; 142:65-76. [PMID: 20603015 PMCID: PMC3710700 DOI: 10.1016/j.cell.2010.06.021] [Citation(s) in RCA: 249] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Revised: 05/27/2010] [Accepted: 06/15/2010] [Indexed: 11/24/2022]
Abstract
DNA interstrand crosslinks (ICLs) are highly toxic because they block the progression of replisomes. The Fanconi Anemia (FA) proteins, encoded by genes that are mutated in FA, are important for repair of ICLs. The FA core complex catalyzes the monoubiquitination of FANCD2, and this event is essential for several steps of ICL repair. However, how monoubiquitination of FANCD2 promotes ICL repair at the molecular level is unknown. Here, we describe a highly conserved protein, KIAA1018/MTMR15/FAN1, that interacts with, and is recruited to sites of DNA damage by, the monoubiquitinated form of FANCD2. FAN1 exhibits endonuclease activity toward 5' flaps and has 5' exonuclease activity, and these activities are mediated by an ancient VRR_nuc domain. Depletion of FAN1 from human cells causes hypersensitivity to ICLs, defects in ICL repair, and genome instability. These data at least partly explain how ubiquitination of FANCD2 promotes DNA repair.
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Affiliation(s)
| | | | - Cecilia Lundin
- Gray Institute for Radiation Oncology & Biology, University of Oxford, Oxford OX3 7DQ, UK
| | - Ana Agostinho
- Wellcome Trust Centre for Gene Regulation and Expression College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - Andrew J. Deans
- London Research Institute, Cancer Research UK, Clare Hall Laboratories, South Mimms EN6 3LD, UK
| | | | - Kay Hofmann
- Miltenyi Biotec GmbH, D-51429 Bergisch Gladbach, Germany
| | - Anton Gartner
- Wellcome Trust Centre for Gene Regulation and Expression College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - Stephen C. West
- London Research Institute, Cancer Research UK, Clare Hall Laboratories, South Mimms EN6 3LD, UK
| | - Thomas Helleday
- Gray Institute for Radiation Oncology & Biology, University of Oxford, Oxford OX3 7DQ, UK
- Department of Genetics Microbiology and Toxicology, Stockholm University, S-106 91 Stockholm, Sweden
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35
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Collis SJ, Ciccia A, Deans AJ, Horejsí Z, Martin JS, Maslen SL, Skehel JM, Elledge SJ, West SC, Boulton SJ. FANCM and FAAP24 function in ATR-mediated checkpoint signaling independently of the Fanconi anemia core complex. Mol Cell 2008; 32:313-24. [PMID: 18995830 DOI: 10.1016/j.molcel.2008.10.014] [Citation(s) in RCA: 140] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2008] [Revised: 07/19/2008] [Accepted: 10/20/2008] [Indexed: 10/21/2022]
Abstract
The Fanconi anemia (FA) pathway is implicated in DNA repair and cancer predisposition. Central to this pathway is the FA core complex, which is targeted to chromatin by FANCM and FAAP24 following replication stress. Here we show that FANCM and FAAP24 interact with the checkpoint protein HCLK2 independently of the FA core complex. In addition to defects in FA pathway activation, downregulation of FANCM or FAAP24 also compromises ATR/Chk1-mediated checkpoint signaling, leading to defective Chk1, p53, and FANCE phosphorylation; 53BP1 focus formation; and Cdc25A degradation. As a result, FANCM and FAAP24 deficiency results in increased endogenous DNA damage and a failure to efficiently invoke cell-cycle checkpoint responses. Moreover, we find that the DNA translocase activity of FANCM, which is dispensable for FA pathway activation, is required for its role in ATR/Chk1 signaling. Our data suggest that DNA damage recognition and remodeling activities of FANCM and FAAP24 cooperate with ATR/Chk1 to promote efficient activation of DNA damage checkpoints.
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Affiliation(s)
- Spencer J Collis
- DNA Damage Response Laboratory, Cancer Research UK, Clare Hall, EN6 3LD South Mimms, UK
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36
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Spurdle AB, Deans AJ, Duffy D, Goldgar DE, Chen X, Beesley J, Easton DF, Antoniou AC, Peock S, Cook M, Nathanson KL, Domchek SM, MacArthur GA, Chenevix-Trench G. No evidence that CDKN1B (p27) polymorphisms modify breast cancer risk in BRCA1 and BRCA2 mutation carriers. Breast Cancer Res Treat 2008; 115:307-13. [DOI: 10.1007/s10549-008-0083-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2008] [Accepted: 05/27/2008] [Indexed: 11/25/2022]
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37
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Deans AJ, Khanna KK, McNees CJ, Mercurio C, Heierhorst J, McArthur GA. Cyclin-dependent kinase 2 functions in normal DNA repair and is a therapeutic target in BRCA1-deficient cancers. Cancer Res 2007; 66:8219-26. [PMID: 16912201 DOI: 10.1158/0008-5472.can-05-3945] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abnormal regulation of progression from G(1) to S phase of the cell cycle by altered activity of cyclin-dependent kinases (CDKs) is a hallmark of cancer. However, inhibition of CDKs, particularly CDK2, has not shown selective activity against most cancer cells because the kinase seems to be redundant in control of cell cycle progression. Here, we show a novel role in the DNA damage response and application of CDK inhibitors in checkpoint-deficient cells. CDK2(-/-) mouse fibroblasts and small interfering RNA--mediated or small-molecule--mediated CDK2 inhibition in MCF7 or U2OS cells lead to delayed damage signaling through Chk1, p53, and Rad51. This coincided with reduced DNA repair using the single-cell comet assay and defects observed in both homologous recombination and nonhomologous end-joining in cell-based assays. Furthermore, tumor cells lacking cancer predisposition genes BRCA1 or ATM are 2- to 4-fold more sensitive to CDK inhibitors. These data suggest that inhibitors of CDK2 can be applied to selectively enhance responses of cancer cells to DNA-damaging agents, such as cytotoxic chemotherapy and radiotherapy. Moreover, inhibitors of CDKs may be useful therapeutics in cancers with defects in DNA repair, such as mutations in the familial breast cancer gene BRCA1.
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Affiliation(s)
- Andrew J Deans
- Trescowthick Research Laboratories, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
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38
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Simpson KJ, Wati MR, Deans AJ, Lindeman GJ, Brown MA. MMTV-trBrca1 mice display strain-dependent abnormalities in vaginal development. Int J Dev Biol 2005; 48:675-8. [PMID: 15470641 DOI: 10.1387/ijdb.041849ks] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The breast cancer susceptibility gene Brca1 encodes a large multi-functional protein which is implicated as a caretaker of the genome, through its role in regulation of DNA damage response pathways, including apoptosis. Here we show that in mice expressing a dominant-negative Brca1 transgene on a BALB/c background, vaginal entrance remodeling is inhibited, and that the incidence of this phenotype is increased on a p53 +/- genotype. Given that this developmental process is mediated primarily by apoptosis, we hypothesized that disruption of BRCA1 may confer a resistance to apoptosis in normal epithelial cells. Consistent with this, we show that expression of this transgene in vitro leads to resistance to ionizing radiation induced cell killing in mammary epithelial cells. This is the first time that BRCA1 has been implicated in an apoptosis-mediated normal developmental process.
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MESH Headings
- Animals
- Apoptosis
- Disease Models, Animal
- Dose-Response Relationship, Radiation
- Female
- Genes, BRCA1
- Genotype
- Mammary Glands, Animal/embryology
- Mammary Neoplasms, Animal/genetics
- Mammary Tumor Virus, Mouse/genetics
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Inbred CBA
- Models, Genetic
- Mutation
- Time Factors
- Transgenes
- Vagina/embryology
- Vagina/pathology
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Affiliation(s)
- Kaylene J Simpson
- Department of Biochemistry and Molecular Biology, University of Melbourne, Victoria, Australia
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39
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Deans AJ, Simpson KJ, Trivett MK, Brown MA, McArthur GA. Brca1 inactivation induces p27(Kip1)-dependent cell cycle arrest and delayed development in the mouse mammary gland. Oncogene 2005; 23:6136-45. [PMID: 15208652 DOI: 10.1038/sj.onc.1207805] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
One common characteristic of breast cancers arising in carriers of the predisposition gene BRCA1 is a loss of expression of the CDK inhibitor p27(Kip1) (p27), suggesting that p27 interacts epistatically with BRCA1. To investigate this relationship, we examined expression of p27 in mice expressing a dominant negative allele of Brca1 (MMTV-trBr) in the mammary gland. While these mice rarely develop tumors, they showed a 50% increase in p27 protein and a delay in mammary gland development associated with reduced proliferation. In contrast, on a p27 heterozygote background, MMTV-trBrca1 mice showed an increase in S phase cells, and normal mammary development. p27 was the only protein in the cyclin-cyclin-dependent kinase network to show altered expression, suggesting that it may be a central mediator of cell cycle arrest in response to loss of function of BRCA1. Furthermore, in human mammary epithelial MCF7 cells expressing BRCA1-specific RNAi and in the BRCA1-deficient human tumor cell line HCC1937, p27 is elevated at the mRNA level compared to cells expressing wild-type BRCA1. We hypothesize that disruption of BRCA1 induces an increase in p27 that inhibits proliferation. Accordingly, reduction in p27 expression leads to enhancement of cellular proliferation in the absence of BRCA1.
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Affiliation(s)
- Andrew J Deans
- Molecular Oncology Laboratory, Trescowthick Research Laboratories, Peter MacCallum Cancer Centre, St Andrew's Place, East Melbourne 3002, Australia
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40
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Fabbro M, Savage K, Hobson K, Deans AJ, Powell SN, McArthur GA, Khanna KK. BRCA1-BARD1 complexes are required for p53Ser-15 phosphorylation and a G1/S arrest following ionizing radiation-induced DNA damage. J Biol Chem 2004; 279:31251-8. [PMID: 15159397 DOI: 10.1074/jbc.m405372200] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
BRCA1 is a major player in the DNA damage response. This is evident from its loss, which causes cells to become sensitive to a wide variety of DNA damaging agents. The major BRCA1 binding partner, BARD1, is also implicated in the DNA damage response, and recent reports indicate that BRCA1 and BARD1 co-operate in this pathway. In this report, we utilized small interfering RNA to deplete BRCA1 and BARD1 to demonstrate that the BRCA1-BARD1 complex is required for ATM/ATR (ataxia-telangiectasia-mutated/ATM and Rad3-related)-mediated phosphorylation of p53(Ser-15) following IR- and UV radiation-induced DNA damage. In contrast, phosphorylation of a number of other ATM/ATR targets including H2AX, Chk2, Chk1, and c-jun does not depend on the presence of BRCA1-BARD1 complexes. Moreover, prior ATM/ATR-dependent phosphorylation of BRCA1 at Ser-1423 or Ser-1524 regulates the ability of ATM/ATR to phosphorylate p53(Ser-15) efficiently. Phosphorylation of p53(Ser-15) is necessary for an IR-induced G(1)/S arrest via transcriptional induction of the cyclin-dependent kinase inhibitor p21. Consistent with these data, repressing p53(Ser-15) phosphorylation by BRCA1-BARD1 depletion compromises p21 induction and the G(1)/S checkpoint arrest in response to IR but not UV radia-tion. These findings suggest that BRCA1-BARD1 complexes act as an adaptor to mediate ATM/ATR-directed phosphorylation of p53, influencing G(1)/S cell cycle progression after DNA damage.
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Affiliation(s)
- Megan Fabbro
- Queensland Institute of Medical Research, Post Office Royal Brisbane Hospital, Brisbane, Queensland 4029, Australia
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41
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McArthur GA, Foley KP, Fero ML, Walkley CR, Deans AJ, Roberts JM, Eisenman RN. MAD1 and p27(KIP1) cooperate to promote terminal differentiation of granulocytes and to inhibit Myc expression and cyclin E-CDK2 activity. Mol Cell Biol 2002; 22:3014-23. [PMID: 11940659 PMCID: PMC133749 DOI: 10.1128/mcb.22.9.3014-3023.2002] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
To understand how cellular differentiation is coupled to withdrawal from the cell cycle, we have focused on two negative regulators of the cell cycle, the MYC antagonist MAD1 and the cyclin-dependent kinase inhibitor p27(KIP1). Generation of Mad1/p27(KIP1) double-null mice revealed a number of synthetic effects between the null alleles of Mad1 and p27(KIP1), including embryonic lethality, increased proliferation, and impaired differentiation of granulocyte precursors. Furthermore, with granulocyte cell lines derived from the Mad1/p27(KIP1) double-null mice, we observed constitutive Myc expression and cyclin E-CDK2 kinase activity as well as impaired differentiation following treatment with an inducer of differentiation. By contrast, similar treatment of granulocytes from Mad1 or p27(KIP1) single-null mice resulted in differentiation accompanied by downregulation of both Myc expression and cyclin E-CDK2 kinase activity. In the double-null granulocytic cells, addition of a CDK2 inhibitor in the presence of differentiation inducer was sufficient to restore differentiation and reduce Myc levels. We conclude that Mad1 and p27(KIP1) operate, at least in part, by distinct mechanisms to downregulate CDK2 activity and Myc expression in order to promote cell cycle exit during differentiation.
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Affiliation(s)
- Grant A McArthur
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109-1024, USA
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42
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Connors L, Deans AJ, Hagelin JS. Supersymmetry mechanism for naturally small density perturbations and baryogenesis. Phys Rev Lett 1993; 71:4291-4294. [PMID: 10055209 DOI: 10.1103/physrevlett.71.4291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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