1
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Yueh WT, Glass DJ, Johnson N. Brca1 Mouse Models: Functional Insights and Therapeutic Opportunities. J Mol Biol 2024; 436:168372. [PMID: 37979908 PMCID: PMC10882579 DOI: 10.1016/j.jmb.2023.168372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 11/08/2023] [Accepted: 11/14/2023] [Indexed: 11/20/2023]
Abstract
Brca1 mouse models were first reported in the mid-1990's shortly after cloning the human gene. Since then, many mouse models with a range of mutations have been generated, some mimic patient mutations, others are designed to probe specific protein domains and functions. In this review, we discuss early and recent studies using engineered Brca1 mouse alleles, and their implications for understanding Brca1 protein function in the context of DNA repair, tumorigenesis, and anti-cancer therapeutics.
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Affiliation(s)
- Wei-Ting Yueh
- Nuclear Dynamics Program, Fox Chase Cancer Center, Philadelphia, PA 19111, USA
| | - David J Glass
- Nuclear Dynamics Program, Fox Chase Cancer Center, Philadelphia, PA 19111, USA
| | - Neil Johnson
- Nuclear Dynamics Program, Fox Chase Cancer Center, Philadelphia, PA 19111, USA.
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2
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Zelceski A, Francica P, Lingg L, Mutlu M, Stok C, Liptay M, Alexander J, Baxter JS, Brough R, Gulati A, Haider S, Raghunandan M, Song F, Sridhar S, Forment JV, O'Connor MJ, Davies BR, van Vugt MATM, Krastev DB, Pettitt SJ, Tutt ANJ, Rottenberg S, Lord CJ. MND1 and PSMC3IP control PARP inhibitor sensitivity in mitotic cells. Cell Rep 2023; 42:112484. [PMID: 37163373 DOI: 10.1016/j.celrep.2023.112484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 12/22/2022] [Accepted: 04/24/2023] [Indexed: 05/12/2023] Open
Abstract
The PSMC3IP-MND1 heterodimer promotes meiotic D loop formation before DNA strand exchange. In genome-scale CRISPR-Cas9 mutagenesis and interference screens in mitotic cells, depletion of PSMC3IP or MND1 causes sensitivity to poly (ADP-Ribose) polymerase inhibitors (PARPi) used in cancer treatment. PSMC3IP or MND1 depletion also causes ionizing radiation sensitivity. These effects are independent of PSMC3IP/MND1's role in mitotic alternative lengthening of telomeres. PSMC3IP- or MND1-depleted cells accumulate toxic RAD51 foci in response to DNA damage, show impaired homology-directed DNA repair, and become PARPi sensitive, even in cells lacking both BRCA1 and TP53BP1. Epistasis between PSMC3IP-MND1 and BRCA1/BRCA2 defects suggest that abrogated D loop formation is the cause of PARPi sensitivity. Wild-type PSMC3IP reverses PARPi sensitivity, whereas a PSMC3IP p.Glu201del mutant associated with D loop defects and ovarian dysgenesis does not. These observations suggest that meiotic proteins such as MND1 and PSMC3IP have a greater role in mitotic DNA repair.
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Affiliation(s)
- Anabel Zelceski
- The CRUK Gene Function Laboratory, The Institute of Cancer Research, London SW3 6JB, UK; Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London SW3 6JB, UK
| | - Paola Francica
- Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland; Departement of Biomedical Research (DBMR), Cancer Therapy Resistance Cluster, University of Bern, 3012 Bern, Switzerland
| | - Lea Lingg
- Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland; Departement of Biomedical Research (DBMR), Cancer Therapy Resistance Cluster, University of Bern, 3012 Bern, Switzerland
| | - Merve Mutlu
- Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland
| | - Colin Stok
- Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713GZ Groningen, the Netherlands
| | - Martin Liptay
- Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland
| | - John Alexander
- Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London SW3 6JB, UK
| | - Joseph S Baxter
- The CRUK Gene Function Laboratory, The Institute of Cancer Research, London SW3 6JB, UK; Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London SW3 6JB, UK
| | - Rachel Brough
- The CRUK Gene Function Laboratory, The Institute of Cancer Research, London SW3 6JB, UK; Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London SW3 6JB, UK
| | - Aditi Gulati
- Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London SW3 6JB, UK
| | - Syed Haider
- Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London SW3 6JB, UK
| | - Maya Raghunandan
- Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London SW3 6JB, UK
| | - Feifei Song
- The CRUK Gene Function Laboratory, The Institute of Cancer Research, London SW3 6JB, UK; Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London SW3 6JB, UK
| | - Sandhya Sridhar
- The CRUK Gene Function Laboratory, The Institute of Cancer Research, London SW3 6JB, UK; Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London SW3 6JB, UK
| | | | | | | | | | - Dragomir B Krastev
- The CRUK Gene Function Laboratory, The Institute of Cancer Research, London SW3 6JB, UK; Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London SW3 6JB, UK
| | - Stephen J Pettitt
- The CRUK Gene Function Laboratory, The Institute of Cancer Research, London SW3 6JB, UK; Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London SW3 6JB, UK.
| | - Andrew N J Tutt
- Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London SW3 6JB, UK.
| | - Sven Rottenberg
- Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland; Departement of Biomedical Research (DBMR), Cancer Therapy Resistance Cluster, University of Bern, 3012 Bern, Switzerland; Division of Molecular Pathology, The Netherlands Cancer Institute, 1066CX Amsterdam, the Netherlands; Bern Center for Precision Medicine, University of Bern, 3012 Bern, Switzerland.
| | - Christopher J Lord
- The CRUK Gene Function Laboratory, The Institute of Cancer Research, London SW3 6JB, UK; Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London SW3 6JB, UK.
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3
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Tsujino T, Takai T, Hinohara K, Gui F, Tsutsumi T, Bai X, Miao C, Feng C, Gui B, Sztupinszki Z, Simoneau A, Xie N, Fazli L, Dong X, Azuma H, Choudhury AD, Mouw KW, Szallasi Z, Zou L, Kibel AS, Jia L. CRISPR screens reveal genetic determinants of PARP inhibitor sensitivity and resistance in prostate cancer. Nat Commun 2023; 14:252. [PMID: 36650183 PMCID: PMC9845315 DOI: 10.1038/s41467-023-35880-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Accepted: 01/05/2023] [Indexed: 01/18/2023] Open
Abstract
Prostate cancer harboring BRCA1/2 mutations are often exceptionally sensitive to PARP inhibitors. However, genomic alterations in other DNA damage response genes have not been consistently predictive of clinical response to PARP inhibition. Here, we perform genome-wide CRISPR-Cas9 knockout screens in BRCA1/2-proficient prostate cancer cells and identify previously unknown genes whose loss has a profound impact on PARP inhibitor response. Specifically, MMS22L deletion, frequently observed (up to 14%) in prostate cancer, renders cells hypersensitive to PARP inhibitors by disrupting RAD51 loading required for homologous recombination repair, although this response is TP53-dependent. Unexpectedly, loss of CHEK2 confers resistance rather than sensitivity to PARP inhibition through increased expression of BRCA2, a target of CHEK2-TP53-E2F7-mediated transcriptional repression. Combined PARP and ATR inhibition overcomes PARP inhibitor resistance caused by CHEK2 loss. Our findings may inform the use of PARP inhibitors beyond BRCA1/2-deficient tumors and support reevaluation of current biomarkers for PARP inhibition in prostate cancer.
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Affiliation(s)
- Takuya Tsujino
- Division of Urology, Department of Surgery, Brigham and Women's Hospital & Harvard Medical School, Boston, MA, USA
- Department of Urology, Osaka Medical and Pharmaceutical University, Osaka, Japan
| | - Tomoaki Takai
- Division of Urology, Department of Surgery, Brigham and Women's Hospital & Harvard Medical School, Boston, MA, USA
- Department of Urology, Osaka Medical and Pharmaceutical University, Osaka, Japan
| | - Kunihiko Hinohara
- Department of Medical Oncology, Dana-Farber Cancer Institute & Harvard Medical School, Boston, MA, USA
- Department of Immunology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Fu Gui
- Division of Urology, Department of Surgery, Brigham and Women's Hospital & Harvard Medical School, Boston, MA, USA
| | - Takeshi Tsutsumi
- Division of Urology, Department of Surgery, Brigham and Women's Hospital & Harvard Medical School, Boston, MA, USA
- Department of Urology, Osaka Medical and Pharmaceutical University, Osaka, Japan
| | - Xiao Bai
- Division of Urology, Department of Surgery, Brigham and Women's Hospital & Harvard Medical School, Boston, MA, USA
| | - Chenkui Miao
- Division of Urology, Department of Surgery, Brigham and Women's Hospital & Harvard Medical School, Boston, MA, USA
| | - Chao Feng
- Division of Urology, Department of Surgery, Brigham and Women's Hospital & Harvard Medical School, Boston, MA, USA
| | - Bin Gui
- Division of Urology, Department of Surgery, Brigham and Women's Hospital & Harvard Medical School, Boston, MA, USA
| | - Zsofia Sztupinszki
- Computational Health Informatics Program, Boston Children's Hospital, Boston, MA, USA
- Danish Cancer Society Research Center, Copenhagen, Denmark
| | - Antoine Simoneau
- Department of Pathology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, USA
| | - Ning Xie
- Vancouver Prostate Centre, Vancouver General Hospital, Vancouver, British Columbia, Canada
| | - Ladan Fazli
- Vancouver Prostate Centre, Vancouver General Hospital, Vancouver, British Columbia, Canada
| | - Xuesen Dong
- Vancouver Prostate Centre, Vancouver General Hospital, Vancouver, British Columbia, Canada
- Department of Urologic Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Haruhito Azuma
- Department of Urology, Osaka Medical and Pharmaceutical University, Osaka, Japan
| | - Atish D Choudhury
- Department of Medical Oncology, Dana-Farber Cancer Institute & Harvard Medical School, Boston, MA, USA
| | - Kent W Mouw
- Department of Radiation Oncology, Dana-Farber Cancer Institute & Brigham and Women's Hospital & Harvard Medical School, Boston, MA, USA
| | - Zoltan Szallasi
- Computational Health Informatics Program, Boston Children's Hospital, Boston, MA, USA
- Danish Cancer Society Research Center, Copenhagen, Denmark
| | - Lee Zou
- Department of Pathology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, USA
| | - Adam S Kibel
- Division of Urology, Department of Surgery, Brigham and Women's Hospital & Harvard Medical School, Boston, MA, USA
| | - Li Jia
- Division of Urology, Department of Surgery, Brigham and Women's Hospital & Harvard Medical School, Boston, MA, USA.
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4
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Adam S, Rossi SE, Moatti N, De Marco Zompit M, Xue Y, Ng TF, Álvarez-Quilón A, Desjardins J, Bhaskaran V, Martino G, Setiaputra D, Noordermeer SM, Ohsumi TK, Hustedt N, Szilard RK, Chaudhary N, Munro M, Veloso A, Melo H, Yin SY, Papp R, Young JTF, Zinda M, Stucki M, Durocher D. The CIP2A-TOPBP1 axis safeguards chromosome stability and is a synthetic lethal target for BRCA-mutated cancer. NATURE CANCER 2021; 2:1357-1371. [PMID: 35121901 DOI: 10.1038/s43018-021-00266-w] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 09/10/2021] [Indexed: 05/26/2023]
Abstract
BRCA1/2-mutated cancer cells adapt to the genome instability caused by their deficiency in homologous recombination (HR). Identification of these adaptive mechanisms may provide therapeutic strategies to target tumors caused by the loss of these genes. In the present study, we report genome-scale CRISPR-Cas9 synthetic lethality screens in isogenic pairs of BRCA1- and BRCA2-deficient cells and identify CIP2A as an essential gene in BRCA1- and BRCA2-mutated cells. CIP2A is cytoplasmic in interphase but, in mitosis, accumulates at DNA lesions as part of a complex with TOPBP1, a multifunctional genome stability factor. Unlike PARP inhibition, CIP2A deficiency does not cause accumulation of replication-associated DNA lesions that require HR for their repair. In BRCA-deficient cells, the CIP2A-TOPBP1 complex prevents lethal mis-segregation of acentric chromosomes that arises from impaired DNA synthesis. Finally, physical disruption of the CIP2A-TOPBP1 complex is highly deleterious in BRCA-deficient tumors, indicating that CIP2A represents an attractive synthetic lethal therapeutic target for BRCA1- and BRCA2-mutated cancers.
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Affiliation(s)
- Salomé Adam
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Silvia Emma Rossi
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Nathalie Moatti
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Mara De Marco Zompit
- Department of Gynecology, University Hospital and University of Zurich, Schlieren, Switzerland
| | - Yibo Xue
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Timothy F Ng
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Alejandro Álvarez-Quilón
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
- Repare Therapeutics, St-Laurent, Quebec, Canada
| | | | | | | | - Dheva Setiaputra
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Sylvie M Noordermeer
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Nicole Hustedt
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
- Lonza AG, Visp, Switzerland
| | - Rachel K Szilard
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Natasha Chaudhary
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Meagan Munro
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | | | - Henrique Melo
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | | | - Robert Papp
- Repare Therapeutics, St-Laurent, Quebec, Canada
| | | | | | - Manuel Stucki
- Department of Gynecology, University Hospital and University of Zurich, Schlieren, Switzerland
| | - Daniel Durocher
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada.
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada.
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5
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Pulver EM, Mukherjee C, van de Kamp G, Roobol SJ, Rother MB, van der Gulden H, de Bruijn R, Lattanzio MV, van der Burg E, Drenth AP, Verkaik NS, Hahn K, Klarenbeek S, de Korte-Grimmerink R, van de Ven M, Pritchard CEJ, Huijbers IJ, Xia B, van Gent DC, Essers J, van Attikum H, Ray Chaudhuri A, Bouwman P, Jonkers J. A BRCA1 coiled-coil domain variant disrupting PALB2 interaction promotes the development of mammary tumors and confers a targetable defect in homologous recombination repair. Cancer Res 2021; 81:6171-6182. [PMID: 34548335 PMCID: PMC7612117 DOI: 10.1158/0008-5472.can-21-1415] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 08/21/2021] [Accepted: 09/20/2021] [Indexed: 11/16/2022]
Abstract
The BRCA1 tumor suppressor gene encodes a multi-domain protein for which several functions have been described. These include a key role in homologous recombination repair (HRR) of DNA double-strand breaks (DSB), which is shared with two other high-risk hereditary breast cancer suppressors, BRCA2 and PALB2. Although both BRCA1 and BRCA2 interact with PALB2, BRCA1 missense variants affecting its PALB2-interacting coiled-coil domain are considered variants of uncertain clinical significance (VUS). Using genetically engineered mice, we show here that a BRCA1 coiled-coil domain VUS, Brca1 p.L1363P, disrupts the interaction with PALB2 and leads to embryonic lethality. Brca1 p.L1363P led to a similar acceleration in the development of Trp53-deficient mammary tumors as Brca1 loss, but the tumors showed distinct histopathological features, with more stable DNA copy number profiles in Brca1 p.L1363P tumors. Nevertheless, Brca1 p.L1363P mammary tumors were HRR-incompetent and responsive to cisplatin and PARP inhibition. Overall, these results provide the first direct evidence that a BRCA1 missense variant outside of the RING and BRCT domains increases the risk of breast cancer.
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Affiliation(s)
- Emilia M Pulver
- Division of Molecular Pathology, Oncode Institute, The Netherlands Cancer Institute
| | | | | | - Stefan J Roobol
- Molecular Genetics, Radiology and Nuclear Medicine, Erasmus MC
| | | | - Hanneke van der Gulden
- Division of Molecular Pathology and Cancer Genomics Centre, The Netherlands Cancer Institute
| | - Roebi de Bruijn
- Division of Molecular Pathology, The Netherlands Cancer Institute
| | | | | | | | | | - Kerstin Hahn
- Molecular Pathology, Oncode Institute-Netherlands Cancer Institute
| | | | - Renske de Korte-Grimmerink
- Mouse Clinic for Cancer and Aging (MCCA) Preclinical Intervention Unit, The Netherlands Cancer Institute
| | - Marieke van de Ven
- Mouse Clinic for Cancer and Aging (MCCA) Preclinical Intervention Unit, The Netherlands Cancer Institute
| | | | - Ivo J Huijbers
- Transgenic core facility, Mouse Clinic for Cancer and Aging (MCCA), The Netherlands Cancer Institute
| | - Bing Xia
- Radiation Oncology, Rutgers Cancer Institute of New Jersey
| | - Dik C van Gent
- Molecular Genetics, Erasmus MC University Medical Center Rotterdam and Oncode Institute, The Netherlands
| | | | | | | | - Peter Bouwman
- Division of Drug Discovery and Safety, Leiden Academic Centre for Drug Research
| | - Jos Jonkers
- Division of Molecular Pathology, Oncode Institute, The Netherlands Cancer Institute
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6
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Shah RB, Kernan JL, van Hoogstraten A, Ando K, Li Y, Belcher AL, Mininger I, Bussenault AM, Raman R, Ramanagoudr-Bhojappa R, Huang TT, D'Andrea AD, Chandrasekharappa SC, Aggarwal AK, Thompson R, Sidi S. FANCI functions as a repair/apoptosis switch in response to DNA crosslinks. Dev Cell 2021; 56:2207-2222.e7. [PMID: 34256011 DOI: 10.1016/j.devcel.2021.06.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 05/12/2021] [Accepted: 06/10/2021] [Indexed: 12/16/2022]
Abstract
Cells counter DNA damage through repair or apoptosis, yet a direct mechanism for this choice has remained elusive. When facing interstrand crosslinks (ICLs), the ICL-repair protein FANCI heterodimerizes with FANCD2 to initiate ICL excision. We found that FANCI alternatively interacts with a pro-apoptotic factor, PIDD1, to enable PIDDosome (PIDD1-RAIDD-caspase-2) formation and apoptotic death. FANCI switches from FANCD2/repair to PIDD1/apoptosis signaling in the event of ICL-repair failure. Specifically, removing key endonucleases downstream of FANCI/FANCD2, increasing ICL levels, or allowing damaged cells into mitosis (when repair is suppressed) all suffice for switching. Reciprocally, apoptosis-committed FANCI reverts from PIDD1 to FANCD2 after a failed attempt to assemble the PIDDosome. Monoubiquitination and deubiquitination at FANCI K523 impact interactor selection. These data unveil a repair-or-apoptosis switch in eukaryotes. Beyond ensuring the removal of unrepaired genomes, the switch's bidirectionality reveals that damaged cells can offset apoptotic defects via de novo attempts at lesion repair.
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Affiliation(s)
- Richa B Shah
- Department of Medicine, Division of Hematology and Medical Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Cell, Developmental and Regenerative Biology, the Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Jennifer L Kernan
- Department of Medicine, Division of Hematology and Medical Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Cell, Developmental and Regenerative Biology, the Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Anya van Hoogstraten
- Department of Medicine, Division of Hematology and Medical Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Cell, Developmental and Regenerative Biology, the Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Kiyohiro Ando
- Department of Medicine, Division of Hematology and Medical Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Cell, Developmental and Regenerative Biology, the Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Yuanyuan Li
- Department of Medicine, Division of Hematology and Medical Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Cell, Developmental and Regenerative Biology, the Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Alicia L Belcher
- Department of Medicine, Division of Hematology and Medical Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Cell, Developmental and Regenerative Biology, the Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ivy Mininger
- Department of Medicine, Division of Hematology and Medical Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Cell, Developmental and Regenerative Biology, the Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Andrei M Bussenault
- Department of Medicine, Division of Hematology and Medical Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Cell, Developmental and Regenerative Biology, the Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Renuka Raman
- Department of Medicine, Division of Hematology and Medical Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Cell, Developmental and Regenerative Biology, the Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ramanagouda Ramanagoudr-Bhojappa
- Cancer Genomics Unit, Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Tony T Huang
- Department of Biochemistry & Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Alan D D'Andrea
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Settara C Chandrasekharappa
- Cancer Genomics Unit, Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Aneel K Aggarwal
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ruth Thompson
- Department of Medicine, Division of Hematology and Medical Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Cell, Developmental and Regenerative Biology, the Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Oncology & Metabolism, University of Sheffield Medical School, Sheffield, UK
| | - Samuel Sidi
- Department of Medicine, Division of Hematology and Medical Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Cell, Developmental and Regenerative Biology, the Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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7
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Wassing IE, Esashi F. RAD51: Beyond the break. Semin Cell Dev Biol 2020; 113:38-46. [PMID: 32938550 PMCID: PMC8082279 DOI: 10.1016/j.semcdb.2020.08.010] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 08/14/2020] [Accepted: 08/28/2020] [Indexed: 01/30/2023]
Abstract
As the primary catalyst of homologous recombination (HR) in vertebrates, RAD51 has been extensively studied in the context of repair of double-stranded DNA breaks (DSBs). With recent advances in the understanding of RAD51 function extending beyond DSBs, the importance of RAD51 throughout DNA metabolism has become increasingly clear. Here we review the suggested roles of RAD51 beyond HR, specifically focusing on their interplay with DNA replication and the maintenance of genomic stability, in which RAD51 function emerges as a double-edged sword.
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Affiliation(s)
- Isabel E Wassing
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Fumiko Esashi
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.
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8
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Krais JJ, Johnson N. BRCA1 Mutations in Cancer: Coordinating Deficiencies in Homologous Recombination with Tumorigenesis. Cancer Res 2020; 80:4601-4609. [PMID: 32747362 PMCID: PMC7641968 DOI: 10.1158/0008-5472.can-20-1830] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/15/2020] [Accepted: 07/29/2020] [Indexed: 01/08/2023]
Abstract
Cancers that arise from BRCA1 germline mutations are deficient for homologous recombination (HR) DNA repair and are sensitive to DNA-damaging agents such as platinum and PARP inhibitors. In vertebrate organisms, knockout of critical HR genes including BRCA1 and BRCA2 is lethal because HR is required for genome replication. Thus, cancers must develop strategies to cope with loss of HR activity. Furthermore, as established tumors respond to chemotherapy selection pressure, additional genetic adaptations transition cancers to an HR-proficient state. In this review, we discuss biological mechanisms that influence the ability of BRCA1-mutant cancers to perform HR. Furthermore, we consider how the HR status fluctuates throughout the cancer life course, from tumor initiation to the development of therapy refractory disease.
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Affiliation(s)
- John J Krais
- Molecular Therapeutics Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Neil Johnson
- Molecular Therapeutics Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania.
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9
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Liu Y, Lu LY. BRCA1 and homologous recombination: implications from mouse embryonic development. Cell Biosci 2020; 10:49. [PMID: 32257107 PMCID: PMC7106644 DOI: 10.1186/s13578-020-00412-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 03/18/2020] [Indexed: 01/30/2023] Open
Abstract
As an important player in DNA damage response, BRCA1 maintains genomic stability and suppresses tumorigenesis by promoting DNA double-strand break (DSB) repair through homologous recombination (HR). Since the cloning of BRCA1 gene, many Brca1 mutant alleles have been generated in mice. Mice carrying homozygous Brca1 mutant alleles are embryonic lethal, suggesting that BRCA1's functions are important for embryonic development. Studies of embryonic development in Brca1 mutant mice not only reveal the physiological significance of BRCA1's known function in HR, but also lead to the discovery of BRCA1's new function in HR: regulation of DSB repair pathway choice.
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Affiliation(s)
- Yidan Liu
- 1Key Laboratory of Reproductive Genetics (Ministry of Education) and Women's Reproductive Health Laboratory of Zhejiang Province, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Lin-Yu Lu
- 1Key Laboratory of Reproductive Genetics (Ministry of Education) and Women's Reproductive Health Laboratory of Zhejiang Province, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China.,2Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China
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10
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Raimundo L, Ramos H, Loureiro JB, Calheiros J, Saraiva L. BRCA1/P53: Two strengths in cancer chemoprevention. Biochim Biophys Acta Rev Cancer 2020; 1873:188339. [PMID: 31917206 DOI: 10.1016/j.bbcan.2020.188339] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/03/2020] [Accepted: 01/03/2020] [Indexed: 02/06/2023]
Abstract
Increasing emphasis has been given to prevention as a feasible approach to reduce the cancer burden. However, for its clinical success, further advances are required to identify effective chemopreventive agents. This review affords a critical and up-to-date discussion of issues related to cancer prevention, including an in-depth knowledge on BRCA1 and p53 tumor suppressor proteins as key molecular players. Indeed, it compiles the most recent advances on the topic, highlighting the unique potential of BRCA1 and p53 germline mutations as molecular biomarkers for risk assessment and targets for chemoprevention. Relevant evidences are herein provided supporting the effectiveness of distinct pharmacological agents in cancer prevention, by targeting BRCA1 and p53. Moreover, the rationale for using germline mutant BRCA1- or p53-related cancer syndromes as model systems to investigate effective chemopreventive agents is also addressed. Altogether, this work provides an innovative conception about the dependence on p53 and BRCA1 co-inactivation in tumor formation and development, emphasizing the relationship between these two proteins as an encouraging direction for future personalized pharmacological interventions in cancer prevention.
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Affiliation(s)
- Liliana Raimundo
- LAQV/REQUIMTE, Laboratory of Microbiology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Helena Ramos
- LAQV/REQUIMTE, Laboratory of Microbiology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Joana B Loureiro
- LAQV/REQUIMTE, Laboratory of Microbiology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Juliana Calheiros
- LAQV/REQUIMTE, Laboratory of Microbiology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Lucília Saraiva
- LAQV/REQUIMTE, Laboratory of Microbiology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Porto, Portugal.
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11
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BRCA1 Mutation-Specific Responses to 53BP1 Loss-Induced Homologous Recombination and PARP Inhibitor Resistance. Cell Rep 2019; 24:3513-3527.e7. [PMID: 30257212 DOI: 10.1016/j.celrep.2018.08.086] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 08/01/2018] [Accepted: 08/29/2018] [Indexed: 12/21/2022] Open
Abstract
BRCA1 functions in homologous recombination (HR) both up- and downstream of DNA end resection. However, in cells with 53BP1 gene knockout (KO), BRCA1 is dispensable for the initiation of resection, but whether BRCA1 activity is entirely redundant after end resection is unclear. Here, we found that 53bp1 KO rescued the embryonic viability of a Brca1ΔC/ΔC mouse model that harbors a stop codon in the coiled-coil domain. However, Brca1ΔC/ΔC;53bp1-/- mice were susceptible to tumor formation, lacked Rad51 foci, and were sensitive to PARP inhibitor (PARPi) treatment, indicative of suboptimal HR. Furthermore, BRCA1 mutant cancer cell lines were dependent on truncated BRCA1 proteins that retained the ability to interact with PALB2 for 53BP1 KO induced RAD51 foci and PARPi resistance. Our data suggest that the overall efficiency of 53BP1 loss of function induced HR may be BRCA1 mutation dependent. In the setting of 53BP1 KO, hypomorphic BRCA1 proteins are active downstream of end resection, promoting RAD51 loading and PARPi resistance.
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12
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Noordermeer SM, van Attikum H. PARP Inhibitor Resistance: A Tug-of-War in BRCA-Mutated Cells. Trends Cell Biol 2019; 29:820-834. [PMID: 31421928 DOI: 10.1016/j.tcb.2019.07.008] [Citation(s) in RCA: 255] [Impact Index Per Article: 51.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 07/22/2019] [Accepted: 07/23/2019] [Indexed: 02/07/2023]
Abstract
Poly-(ADP)-ribose polymerase (PARP) inhibition is synthetic lethal with deficiency for homologous recombination (HR), a pathway essential for DNA double-strand break repair. PARP inhibitors (PARPi) therefore hold great promise for the treatment of tumors with disruptive mutations in BRCA1/2 or other HR factors. Unfortunately, PARPi resistance has proved to be a major problem in the clinic. Knowledge about PARPi resistance is expanding quickly, revealing four main mechanisms that alter drug availability, affect (de)PARylation enzymes, restore HR, or restore replication fork stability. We discuss how studies on resistance mechanisms have yielded important insights into the regulation of DNA double-strand break (DSB) repair and replication fork protection, and how these studies could pave the way for novel treatment options to target resistance mechanisms or acquired vulnerabilities.
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Affiliation(s)
- Sylvie M Noordermeer
- Leiden University Medical Center, Department of Human Genetics, Einthovenweg 20, 2333 ZC Leiden, The Netherlands; Oncode Institute, Jaarbeursplein 6, 3521 AL Utrecht, The Netherlands.
| | - Haico van Attikum
- Leiden University Medical Center, Department of Human Genetics, Einthovenweg 20, 2333 ZC Leiden, The Netherlands.
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13
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BRCA2 deficiency instigates cGAS-mediated inflammatory signaling and confers sensitivity to tumor necrosis factor-alpha-mediated cytotoxicity. Nat Commun 2019; 10:100. [PMID: 30626869 PMCID: PMC6327059 DOI: 10.1038/s41467-018-07927-y] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 12/03/2018] [Indexed: 11/29/2022] Open
Abstract
Loss of BRCA2 affects genome stability and is deleterious for cellular survival. Using a genome-wide genetic screen in near-haploid KBM-7 cells, we show that tumor necrosis factor-alpha (TNFα) signaling is a determinant of cell survival upon BRCA2 inactivation. Specifically, inactivation of the TNF receptor (TNFR1) or its downstream effector SAM68 rescues cell death induced by BRCA2 inactivation. BRCA2 inactivation leads to pro-inflammatory cytokine production, including TNFα, and increases sensitivity to TNFα. Enhanced TNFα sensitivity is not restricted to BRCA2 inactivation, as BRCA1 or FANCD2 inactivation, or hydroxyurea treatment also sensitizes cells to TNFα. Mechanistically, BRCA2 inactivation leads to cGAS-positive micronuclei and results in a cell-intrinsic interferon response, as assessed by quantitative mass-spectrometry and gene expression profiling, and requires ASK1 and JNK signaling. Combined, our data reveals that micronuclei induced by loss of BRCA2 instigate a cGAS/STING-mediated interferon response, which encompasses re-wired TNFα signaling and enhances TNFα sensitivity. The loss of homologous recombination (HR) genes such as BRCA1 and BRCA2 is deleterious to the survival of normal cells, yet it is tolerated in cancer cells. Here the authors identify TNFα signaling as a determinant of viability in BRCA2- inactivated cancer cells.
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14
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Zhang X, Li R. BRCA1-Dependent Transcriptional Regulation: Implication in Tissue-Specific Tumor Suppression. Cancers (Basel) 2018; 10:cancers10120513. [PMID: 30558184 PMCID: PMC6316118 DOI: 10.3390/cancers10120513] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Revised: 11/24/2018] [Accepted: 12/11/2018] [Indexed: 12/11/2022] Open
Abstract
Germ-line mutations in breast cancer susceptibility gene 1 (BRCA1) predominantly predispose women to breast and ovarian cancers. BRCA1 is best known for its functions in maintenance of genomic integrity including repairing DNA double-strand breaks through homologous recombination and suppressing DNA replication stress. However, whether these universally important BRCA1 functions in maintenance of genomic stability are sufficient to account for its tissue-specific tumor-suppressing function remains unclear. Accumulating evidence indicates that there are previously underappreciated roles of BRCA1 in transcriptional regulation and chromatin remodeling. In this review, we discuss the functional significance of interactions between BRCA1 and various transcription factors, its role in epigenetic regulation and chromatin dynamics, and BRCA1-dependent crosstalk between the machineries of transcription and genome integrity. Furthermore, we propose a model of how transcriptional regulation could contribute to tissue-dependent tumor-suppressing function of BRCA1.
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Affiliation(s)
- Xiaowen Zhang
- Department of Biochemistry & Molecular Medicine, School of Medicine & Health Sciences, The George Washington University, Washington, DC 20037, USA.
| | - Rong Li
- Department of Biochemistry & Molecular Medicine, School of Medicine & Health Sciences, The George Washington University, Washington, DC 20037, USA.
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15
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Mahdi AH, Huo Y, Tan Y, Simhadri S, Vincelli G, Gao J, Ganesan S, Xia B. Evidence of Intertissue Differences in the DNA Damage Response and the Pro-oncogenic Role of NF-κB in Mice with Disengaged BRCA1-PALB2 Interaction. Cancer Res 2018; 78:3969-3981. [PMID: 29739757 DOI: 10.1158/0008-5472.can-18-0388] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2018] [Revised: 04/10/2018] [Accepted: 05/04/2018] [Indexed: 12/14/2022]
Abstract
The BRCA1-PALB2-BRCA2 axis plays an essential role in DNA homologous recombination repair, defect in which drives genome instability and cancer development. How cells with defects in this pathway respond to DNA damage in vivo and how tumors develop from these cells remain poorly defined. Here, we analyzed several aspects of the DNA damage response in multiple tissues of Palb2-mutant mice in which the interaction between PALB2 and BRCA1 is disengaged. Without any challenge, the mutant mice showed increased endogenous DNA damage. Following ionizing radiation, the mutant mice displayed higher levels of DNA breaks and stronger induction of p53 and p21, but continued DNA synthesis, reduced apoptosis, and accelerated tumor development. The differences in p21 induction, DNA synthesis, and apoptosis between wild-type and mutant mice were substantially more pronounced in the mammary gland than in the intestine, suggesting a potential contributing factor to the increased risk and the tissue specificity of BRCA/PALB2-associated tumor development. Moreover, the mutant mice showed higher levels of reactive oxygen species and constitutive activation of NF-κB, an antiapoptotic transcription factor inducible by both DNA damage and oxidative stress. Treatment of the mutant mice with an inhibitor of NF-κB reactivated apoptosis and delayed tumor development following radiation. Thus, our results also suggest a prosurvival and pro-oncogenic role of NF-κB in PALB2-mutant cells.Significance: This study explores novel tumor suppression mechanisms of the BRCA1-PALB2 DNA damage response pathway and implicates NF-κB activation as a protumorogenic event and possible therapeutic target. Cancer Res; 78(14); 3969-81. ©2018 AACR.
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Affiliation(s)
- Amar Hekmat Mahdi
- Rutgers Cancer Institute of New Jersey, New Brunswick, New Jersey.,Department of Radiation Oncology, Rutgers Robert Wood Johnson Medical School, New Brunswick, New Jersey
| | - Yanying Huo
- Rutgers Cancer Institute of New Jersey, New Brunswick, New Jersey.,Department of Radiation Oncology, Rutgers Robert Wood Johnson Medical School, New Brunswick, New Jersey
| | - Yongmei Tan
- Rutgers Cancer Institute of New Jersey, New Brunswick, New Jersey.,Department of Radiation Oncology, Rutgers Robert Wood Johnson Medical School, New Brunswick, New Jersey.,Stomatological Hospital of Guangzhou Medical University, Guangzhou, P.R. China
| | - Srilatha Simhadri
- Rutgers Cancer Institute of New Jersey, New Brunswick, New Jersey.,Department of Medicine, Rutgers Robert Wood Johnson Medical School, New Brunswick, New Jersey
| | - Gabriele Vincelli
- Rutgers Cancer Institute of New Jersey, New Brunswick, New Jersey.,Department of Radiation Oncology, Rutgers Robert Wood Johnson Medical School, New Brunswick, New Jersey
| | - Jie Gao
- Stomatological Hospital of Guangzhou Medical University, Guangzhou, P.R. China
| | - Shridar Ganesan
- Rutgers Cancer Institute of New Jersey, New Brunswick, New Jersey.,Department of Medicine, Rutgers Robert Wood Johnson Medical School, New Brunswick, New Jersey
| | - Bing Xia
- Rutgers Cancer Institute of New Jersey, New Brunswick, New Jersey. .,Department of Radiation Oncology, Rutgers Robert Wood Johnson Medical School, New Brunswick, New Jersey
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16
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BRE/BRCC45 regulates CDC25A stability by recruiting USP7 in response to DNA damage. Nat Commun 2018; 9:537. [PMID: 29416040 PMCID: PMC5803202 DOI: 10.1038/s41467-018-03020-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 01/12/2018] [Indexed: 01/07/2023] Open
Abstract
BRCA2 is essential for maintaining genomic integrity. BRCA2-deficient primary cells are either not viable or exhibit severe proliferation defects. Yet, BRCA2 deficiency contributes to tumorigenesis. It is believed that mutations in genes such as TRP53 allow BRCA2 heterozygous cells to overcome growth arrest when they undergo loss of heterozygosity. Here, we report the use of an insertional mutagenesis screen to identify a role for BRE (Brain and Reproductive organ Expressed, also known as BRCC45), known to be a part of the BRCA1-DNA damage sensing complex, in the survival of BRCA2-deficient mouse ES cells. Cell viability by BRE overexpression is mediated by deregulation of CDC25A phosphatase, a key cell cycle regulator and an oncogene. We show that BRE facilitates deubiquitylation of CDC25A by recruiting ubiquitin-specific-processing protease 7 (USP7) in the presence of DNA damage. Additionally, we uncovered the role of CDC25A in BRCA-mediated tumorigenesis, which can have implications in cancer treatment. Loss of BRCA2 leads to cancer formation. Here, the authors use an insertional mutagenesis approach and identify a multiprotein complex consisting of BRE, USP7 and CDC25A that can support the survival of BRCA2-deficient cells.
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17
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Horiuchi A, Wang C, Kikuchi N, Osada R, Nikaido T, Konishi I. BRCA1 Expression is an Important Biomarker for Chemosensitivity: Suppression of BRCA1 Increases the Apoptosis via Up-regulation of p53 and p21 during Cisplatin Treatment in Ovarian Cancer Cells. Biomark Insights 2017. [DOI: 10.1177/117727190600100007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
BRCA1 is a tumor suppressor which plays a crucial role in the repair of DNA double-strand breaks, and its abnormality is responsible for hereditary ovarian cancer syndrome. It has recently been reported that reduced expression of BRCA1 is also common in sporadic ovarian carcinoma via its promoter hypermethylation, and that ovarian carcinoma patients negative for BRCA1 expression showed favorable prognosis. To address if BRCA1 expression plays a role in the chemotherapeutic response, we analyzed the effect of BRCA1 suppression on the sensitivity to cisplatin and paclitaxel in ovarian cancer cells. Specific siRNA for BRCA1 gene was transfected into 3 ovarian cancer cell lines with various p53 status. Reduced expression of BRCA1 by transfection of BRCA1-siRNA resulted in a 5.3-fold increase in sensitivity to cisplatin in p53-wild A2780 cells, but not in p53-mutated A2780/CDDP and p53-deleted SKOV3 cells. Regarding the sensitivity to paclitaxel, BRCA1 suppression caused no significant changes in all the 3 cell lines. For ionizing radiation sensitivity, BRCA1 suppression also showed a significant higher sensitivity in A2780 cells. Growth curve and cell cycle analyses showed no significant differences between BRCA1-siRNA-transfected A2780 cells and control cells. However, cisplatin treatment under suppression of BRCA1 showed a significantly increased apoptosis along with up-regulation of p53 and p21 in A2780 cells. Accordingly, reduced expression of BRCA1 enhances the cisplatin sensitivity and apoptosis via up-regulation of p53 and p21, but does not affect the paclitaxel sensitivity. Expression of BRCA1 might be an important biomarker for cisplatin resistance in ovarian carcinoma.
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Affiliation(s)
- Akiko Horiuchi
- Department of Obstetrics and Gynecology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan
| | - Cuiju Wang
- Department of Obstetrics and Gynecology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan
| | - Norihiko Kikuchi
- Department of Obstetrics and Gynecology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan
| | - Ryosuke Osada
- Department of Obstetrics and Gynecology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan
| | - Toshio Nikaido
- Department of Regenerative Medicine, Toyama University Graduate School of Medicine and Pharmaceutical Sciences, 2630 Sugitani, Toyama 930-0194, Japan
| | - Ikuo Konishi
- Department of Obstetrics and Gynecology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan
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18
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Abstract
Background Dysregulated DNA repair and cell proliferation controls are essential driving forces in mammary tumorigenesis. BCCIP was originally identified as a BRCA2 and CDKN1A interacting protein that has been implicated in maintenance of genomic stability, cell cycle regulation, and microtubule dynamics. The aims of this study were to determine whether BCCIP deficiency contributes to mammary tumorigenesis, especially for a subset of breast cancers with 53BP1 abnormality, and to reveal the mechanistic implications of BCCIP in breast cancer interventions. Methods We analyzed the BCCIP protein level in 470 cases of human breast cancer to determine the associations between BCCIP and 53BP1, p53, and subtypes of breast cancer. We further constructed a unique BCCIP knockdown mouse model to determine whether a partial BCCIP deficiency leads to spontaneous breast cancer formation. Results We found that the BCCIP protein level is downregulated in 49% of triple-negative breast cancer and 25% of nontriple-negative breast cancer. The downregulation of BCCIP is mutually exclusive with p53 mutations but concurrent with 53BP1 loss in triple-negative breast cancer. In a K14-Cre-mediated conditional BCCIP knockdown mouse model, we found that BCCIP downregulation causes a formation of benign modules in the mammary glands, resembling the epidermal inclusion cyst of the breast. However, the majority of these benign lesions remain indolent, and only ~ 10% of them evolve into malignant tumors after a long latency. This tumor progression is associated with a loss of 53BP1 and p16 expression. BCCIP knockdown did not alter the latency of mammary tumor formation induced by conditional Trp53 deletion. Conclusions Our data suggest a confounding role of BCCIP deficiency in modulating breast cancer development by enhancing tumor initiation but hindering progression. Furthermore, secondary genetic alternations may overcome the progression suppression imposed by BCCIP deficiency through a synthetic viability mechanism. Electronic supplementary material The online version of this article (doi:10.1186/s13058-017-0907-5) contains supplementary material, which is available to authorized users.
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19
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Somasundaram V, Hemalatha SK, Pal K, Sinha S, Nair AS, Mukhopadhyay D, Srinivas P. Selective mode of action of plumbagin through BRCA1 deficient breast cancer stem cells. BMC Cancer 2016; 16:336. [PMID: 27229859 PMCID: PMC4882782 DOI: 10.1186/s12885-016-2372-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 05/19/2016] [Indexed: 12/16/2022] Open
Abstract
Background Studies over the past decade and half have identified cancer stem cells (CSCs) to be responsible for tumorigenesis, invasion, sustenance of metastatic disease, radio- and chemo-resistance and tumor relapse. Recent reports have described the plasticity of breast CSCs (BCSCs) to shift between the epithelial and mesenchymal phenotypes via Epithelial-Mesenchymal Transition (EMT) and Mesenchymal-Epithelial Transition (MET) states as the reason for their invasive capabilities. Additionally, BRCA1 has been found to be a mammary stem cell fate determinant. However, it is not clear what would be the best marker that can be used for identifying CSCs in BRCA1 mutated cancers. Also, anticancer agents that can reduce CSC population in a BRCA1 defective condition have not been addressed so far. Methods Putative BCSCs were identified based on Hoechst exclusion, CD44+/24–/low expression and Aldehyde Dehydrogenase 1 (ALDH1) positivity using flow cytometry. The ‘stemness’ of the isolated ALDH1+ cells were analysed by immunofluorescence, western blotting for stem cell and EMT markers as well as in vitro mammosphere assays. Induction of Reactive Oxygen Species (ROS) by Plumbagin (PB) in BCSCs was assayed by Dichloro-dihydro-fluorescein diacetate (DCF-DA) staining. Ovarian cancer xenografts treated with PB were subjected to immunohistochemical analysis to study the ability of PB to target CSCs. Results We have confirmed that ALDH1 positivity is the best marker for the identification of BCSCs in BRCA1-defective breast cancer cell lines when compared to the CD marker profile and Side Population (SP) analysis. BRCA1 status was observed to be a determinant of the abundance of epithelial-like (ALDH1+) or mesenchymal-like (CD44+/24–/low) BCSCs, and the reconstitution of a full length, wild type BRCA1 in HCC1937 breast cancer cells possessing a mutated BRCA1, transforms them from ‘stem-like’ to more ‘mesenchymal’. For the first time we have shown that Plumbagin (PB), a naturally occurring naphthoquinone which is predominantly a ROS inducer, could reduce BCSCs specifically in BRCA1-defective, basal-like cancer cells. Conclusions The best marker for identifying BCSCs in BRCA1 defective condition could be ALDH1 and that BRCA1 mutated BCSCs would be mostly ‘stem like’ than ‘mesenchymal’. Also ROS inducers like PB could reduce BCSCs in BRCA1 defective cancers. Electronic supplementary material The online version of this article (doi:10.1186/s12885-016-2372-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Veena Somasundaram
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, 695014, India.,Present address: Center for Cancer Research, National Cancer Institute, Building 567, Room 254, Frederick, MD, 21702-1201, USA
| | - Sreelatha K Hemalatha
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, 695014, India
| | - Krishnendu Pal
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA
| | - Sutapa Sinha
- Department of Hematology, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA
| | - Asha S Nair
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, 695014, India
| | - Debabrata Mukhopadhyay
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA
| | - Priya Srinivas
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, 695014, India.
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20
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Ronowicz A, Janaszak-Jasiecka A, Skokowski J, Madanecki P, Bartoszewski R, Bałut M, Seroczyńska B, Kochan K, Bogdan A, Butkus M, Pęksa R, Ratajska M, Kuźniacka A, Wasąg B, Gucwa M, Krzyżanowski M, Jaśkiewicz J, Jankowski Z, Forsberg L, Ochocka JR, Limon J, Crowley MR, Buckley PG, Messiaen L, Dumanski JP, Piotrowski A. Concurrent DNA Copy-Number Alterations and Mutations in Genes Related to Maintenance of Genome Stability in Uninvolved Mammary Glandular Tissue from Breast Cancer Patients. Hum Mutat 2015. [PMID: 26219265 DOI: 10.1002/humu.22845] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Somatic mosaicism for DNA copy-number alterations (SMC-CNAs) is defined as gain or loss of chromosomal segments in somatic cells within a single organism. As cells harboring SMC-CNAs can undergo clonal expansion, it has been proposed that SMC-CNAs may contribute to the predisposition of these cells to genetic disease including cancer. Herein, the gross genomic alterations (>500 kbp) were characterized in uninvolved mammary glandular tissue from 59 breast cancer patients and matched samples of primary tumors and lymph node metastases. Array-based comparative genomic hybridization showed 10% (6/59) of patients harbored one to 359 large SMC-CNAs (mean: 1,328 kbp; median: 961 kbp) in a substantial portion of glandular tissue cells, distal from the primary tumor site. SMC-CNAs were partially recurrent in tumors, albeit with considerable contribution of stochastic SMC-CNAs indicating genomic destabilization. Targeted resequencing of 301 known predisposition and somatic driver loci revealed mutations and rare variants in genes related to maintenance of genomic integrity: BRCA1 (p.Gln1756Profs*74, p.Arg504Cys), BRCA2 (p.Asn3124Ile), NCOR1 (p.Pro1570Glnfs*45), PALB2 (p.Ser500Pro), and TP53 (p.Arg306*). Co-occurrence of gross SMC-CNAs along with point mutations or rare variants in genes responsible for safeguarding genomic integrity highlights the temporal and spatial neoplastic potential of uninvolved glandular tissue in breast cancer patients.
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Affiliation(s)
- Anna Ronowicz
- Faculty of Pharmacy, Medical University of Gdansk, Gdansk, Poland
| | | | - Jarosław Skokowski
- The Central Bank of Tissues and Genetic Specimens, Medical University of Gdansk, Gdansk, Poland.,Department of Surgical Oncology, Medical University of Gdansk, Gdansk, Poland
| | - Piotr Madanecki
- Faculty of Pharmacy, Medical University of Gdansk, Gdansk, Poland
| | | | - Magdalena Bałut
- Faculty of Pharmacy, Medical University of Gdansk, Gdansk, Poland
| | - Barbara Seroczyńska
- The Central Bank of Tissues and Genetic Specimens, Medical University of Gdansk, Gdansk, Poland
| | - Kinga Kochan
- Faculty of Pharmacy, Medical University of Gdansk, Gdansk, Poland
| | - Adam Bogdan
- Faculty of Pharmacy, Medical University of Gdansk, Gdansk, Poland
| | | | - Rafał Pęksa
- Department of Pathomorphology, Medical University of Gdansk, Gdansk, Poland
| | - Magdalena Ratajska
- Department of Biology and Genetics, Medical University of Gdansk, Gdansk, Poland
| | - Alina Kuźniacka
- Department of Biology and Genetics, Medical University of Gdansk, Gdansk, Poland
| | - Bartosz Wasąg
- Department of Biology and Genetics, Medical University of Gdansk, Gdansk, Poland
| | - Magdalena Gucwa
- Faculty of Pharmacy, Medical University of Gdansk, Gdansk, Poland
| | - Maciej Krzyżanowski
- Department of Forensic Medicine, Medical University of Gdansk, Gdansk, Poland
| | - Janusz Jaśkiewicz
- Department of Surgical Oncology, Medical University of Gdansk, Gdansk, Poland
| | - Zbigniew Jankowski
- Department of Forensic Medicine, Medical University of Gdansk, Gdansk, Poland
| | - Lars Forsberg
- Department of Immunology, Genetics and Pathology and SciLifeLab, Uppsala University, Uppsala, Sweden
| | - J Renata Ochocka
- Faculty of Pharmacy, Medical University of Gdansk, Gdansk, Poland
| | - Janusz Limon
- Department of Biology and Genetics, Medical University of Gdansk, Gdansk, Poland
| | - Michael R Crowley
- Heflin Center for Genomic Sciences, University of Alabama at Birmingham, Birmingham, Alabama
| | | | - Ludwine Messiaen
- Medical Genomics Laboratory, Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama
| | - Jan P Dumanski
- Department of Immunology, Genetics and Pathology and SciLifeLab, Uppsala University, Uppsala, Sweden
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21
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Abstract
In 2007, three scientists, Drs. Mario R. Capecchi, Martin J. Evans, and Oliver Smithies, received the Nobel Prize in Physiology or Medicine for their contributions of introducing specific gene modifications into mice. This technology, commonly referred to as gene targeting or knockout, has proven to be a powerful means for precisely manipulating the mammalian genome and has generated great impacts on virtually all phases of mammalian biology and basic biomedical research. Of note, germline mutations of many genes, especially tumor suppressors, often result in lethality during embryonic development or at developmental stages before tumor formation. This obstacle has been effectively overcome by the use of conditional knockout technology in conjunction with Cre-LoxP- or Flp-Frt-mediated temporal and/or spatial systems to generate genetic switches for precise DNA recombination. Currently, numerous conditional knockout mouse models have been successfully generated and applied in studying tumor initiation, progression, and metastasis. This review summarizes some conditional mutant mouse models that are widely used in cancer research and our understanding of the possible mechanisms underlying tumorigenesis.
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Affiliation(s)
- Chu-Xia Deng
- Genetics of Development and Disease Branch, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892
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22
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Gleicher N, McAlpine JN, Gilks CB, Kushnir VA, Lee HJ, Wu YG, Lazzaroni-Tealdi E, Barad DH. Absence of BRCA/FMR1 correlations in women with ovarian cancers. PLoS One 2014; 9:e102370. [PMID: 25036526 PMCID: PMC4103842 DOI: 10.1371/journal.pone.0102370] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 06/17/2014] [Indexed: 11/18/2022] Open
Abstract
Previously reported findings in Austrian BRCA1/2 mutation carriers suggested a possible dependency of embryos with BRCA1/2 mutations on so-called low alleles of the fragile X mental retardation 1 (FMR1) gene, characterized by less than 26 CGG repeats (CGG(n<26)). The hypothesis arose from a study reporting highly statistically significant enrichment of low FMR1 alleles, significantly exceeding low allele prevalence in a general population, suggesting embryo lethality of BRCA1/2 mutations, "rescued" by presence of low FMR1 alleles. Such a dependency would also offer an explanation for the so-called "BRCA-paradox," characterized by BRCA1/2 deficient embryonic tissues being anti-proliferative (thereby potentially causing embryo-lethality) but proliferative in malignant tumors, including breast and ovarian cancers. Follow up investigations by other investigators, however, at most demonstrated trends towards enrichment but, mostly, no enrichment at all, raising questions about the original observation and hypothesis. We in this study, therefore, investigated CGGn of the FMR1 gene of 86 anonymized DNA samples from women with various forms of ovarian cancer, and were unable to demonstrate differences in prevalence of low FMR1 alleles either between positive and negative ovarian cancer patients for BRCA1/2 or between ovarian cancer patients and reported rates in non-cancer populations. This raises further questions about a suggested dependency between BRCA1/2 and FMR1, but also raises the possibility that investigated Austrian BRCA1/2 carrier populations differ from those in other countries. Either only selected BRCA1/2 mutations, therefore, interact with low FMR1 alleles or the Austrian data reflect only coincidental observations.
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Affiliation(s)
- Norbert Gleicher
- Center for Human Reproduction, New York, New York, United States of America
- Foundation for Reproductive Medicine, New York, New York, United States of America
- * E-mail:
| | - Jessica N. McAlpine
- Division of Gynecologic Oncology, Department of Gynecology and Obstetrics, University of British Columbia, Vancouver, British Columbia, Canada
- OvCaRe Gynecologic Tissue Bank, BC Cancer Agency, Vancouver, British Columbia, Canada
| | - C. Blake Gilks
- OvCaRe Gynecologic Tissue Bank, BC Cancer Agency, Vancouver, British Columbia, Canada
- Department of Pathology and Laboratory Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Vitaly A. Kushnir
- Center for Human Reproduction, New York, New York, United States of America
| | - Ho-Joon Lee
- Center for Human Reproduction, New York, New York, United States of America
| | - Yan-Guang Wu
- Center for Human Reproduction, New York, New York, United States of America
| | | | - David H. Barad
- Center for Human Reproduction, New York, New York, United States of America
- Foundation for Reproductive Medicine, New York, New York, United States of America
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Pao GM, Zhu Q, Perez-Garcia CG, Chou SJ, Suh H, Gage FH, O’Leary DDM, Verma IM. Role of BRCA1 in brain development. Proc Natl Acad Sci U S A 2014; 111:E1240-8. [PMID: 24639535 PMCID: PMC3977248 DOI: 10.1073/pnas.1400783111] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Breast cancer susceptibility gene 1 (BRCA1) is a breast and ovarian cancer tumor suppressor whose loss leads to DNA damage and defective centrosome functions. Despite its tumor suppression functions, BRCA1 is most highly expressed in the embryonic neuroepithelium when the neural progenitors are highly proliferative. To determine its functional significance, we deleted BRCA1 in the developing brain using a neural progenitor-specific driver. The phenotype is characterized by severe agenesis of multiple laminated cerebral structures affecting most notably the neocortex, hippocampus, cerebellum, and olfactory bulbs. Major phenotypes are caused by excess apoptosis, as these could be significantly suppressed by the concomitant deletion of p53. Certain phenotypes attributable to centrosomal and cell polarity functions could not be rescued by p53 deletion. A double KO with the DNA damage sensor kinase ATM was able to rescue BRCA1 loss to a greater extent than p53. Our results suggest distinct apoptotic and centrosomal functions of BRCA1 in neural progenitors, with important implications to understand the sensitivity of the embryonic brain to DNA damage, as well as the developmental regulation of brain size.
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Affiliation(s)
| | | | - Carlos G. Perez-Garcia
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037
| | - Shen-Ju Chou
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037
| | | | | | - Dennis D. M. O’Leary
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037
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Colombo M, Blok MJ, Whiley P, Santamariña M, Gutiérrez-Enríquez S, Romero A, Garre P, Becker A, Smith LD, De Vecchi G, Brandão RD, Tserpelis D, Brown M, Blanco A, Bonache S, Menéndez M, Houdayer C, Foglia C, Fackenthal JD, Baralle D, Wappenschmidt B, Díaz-Rubio E, Caldés T, Walker L, Díez O, Vega A, Spurdle AB, Radice P, De La Hoya M. Comprehensive annotation of splice junctions supports pervasive alternative splicing at the BRCA1 locus: a report from the ENIGMA consortium. Hum Mol Genet 2014; 23:3666-80. [DOI: 10.1093/hmg/ddu075] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Affiliation(s)
- Mara Colombo
- Department of Preventive
and Predictive Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milano, Italy,
| | - Marinus J. Blok
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands,
| | - Phillip Whiley
- Molecular Cancer Epidemiology Laboratory, Genetics and Computational Division, QIMR Berghofer Medical Research Institute, Brisbane, Australia,
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia,
| | - Marta Santamariña
- Grupo de Medicina Xenómica-USC, Universidad de Santiago de Compostela, CIBERER, IDIS, Santiago de Compostela, Spain,
| | | | - Atocha Romero
- Laboratorio de Oncología Molecular, Instituto de Investigación Sanitaria San Carlos (IdISSC), Hospital Clínico San Carlos, Madrid, Spain,
| | - Pilar Garre
- Laboratorio de Oncología Molecular, Instituto de Investigación Sanitaria San Carlos (IdISSC), Hospital Clínico San Carlos, Madrid, Spain,
| | - Alexandra Becker
- Center of Familial Breast and Ovarian Cancer, University Hospital Cologne, Cologne, Germany,
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany,
| | - Lindsay Denise Smith
- Human Development and Health Academic Unit, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, UK,
| | - Giovanna De Vecchi
- Department of Preventive
and Predictive Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milano, Italy,
| | - Rita D. Brandão
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands,
| | - Demis Tserpelis
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands,
| | - Melissa Brown
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia,
| | - Ana Blanco
- Fundación Pública Galega de Medicina Xenómica-SERGAS, Grupo de Medicina Xenómica-USC, CIBERER, IDIS, Santiago de Compostela, Spain,
| | - Sandra Bonache
- Oncogenetics Group, Vall d'Hebron Institute of Oncology (VHIO) and
- Oncogenetics Group, Vall d'Hebron Research Institute (VHIR), Universitat Autonoma de Barcelona, Barcelona, Spain,
| | - Mireia Menéndez
- Genetic Diagnosis Unit, Hereditary Cancer Program, Institut Català d'Oncologia, Barcelona, Spain,
| | - Claude Houdayer
- Service de Génétique and INSERM U830, Institut Curie and Université Paris Descartes, Sorbonne Paris Cité, Paris, France,
| | - Claudia Foglia
- Department of Preventive
and Predictive Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milano, Italy,
| | - James D. Fackenthal
- Department of Medicine, The University of Chicago Medical Center, Chicago, IL, USA,
| | - Diana Baralle
- Human Development and Health Academic Unit, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, UK,
| | - Barbara Wappenschmidt
- Center of Familial Breast and Ovarian Cancer, University Hospital Cologne, Cologne, Germany,
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany,
| | - Eduardo Díaz-Rubio
- Laboratorio de Oncología Molecular, Instituto de Investigación Sanitaria San Carlos (IdISSC), Hospital Clínico San Carlos, Madrid, Spain,
- Servicio de Oncología Médica, Hospital Clínico San Carlos, Madrid, Spain,
| | - Trinidad Caldés
- Laboratorio de Oncología Molecular, Instituto de Investigación Sanitaria San Carlos (IdISSC), Hospital Clínico San Carlos, Madrid, Spain,
| | - Logan Walker
- Department of Pathology, University of Otago, Christchurch, New Zealand
| | - Orland Díez
- Oncogenetics Group, Vall d'Hebron Institute of Oncology (VHIO) and
- Oncogenetics Group, Vall d'Hebron Research Institute (VHIR), Universitat Autonoma de Barcelona, Barcelona, Spain,
- Oncogenetics Group, University Hospital of Vall d'Hebron, Barcelona, Spain
| | - Ana Vega
- Fundación Pública Galega de Medicina Xenómica-SERGAS, Grupo de Medicina Xenómica-USC, CIBERER, IDIS, Santiago de Compostela, Spain,
| | - Amanda B. Spurdle
- Molecular Cancer Epidemiology Laboratory, Genetics and Computational Division, QIMR Berghofer Medical Research Institute, Brisbane, Australia,
| | - Paolo Radice
- Department of Preventive
and Predictive Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milano, Italy,
| | - Miguel De La Hoya
- Laboratorio de Oncología Molecular, Instituto de Investigación Sanitaria San Carlos (IdISSC), Hospital Clínico San Carlos, Madrid, Spain,
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25
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Weigelt B, Reis-Filho JS. Epistatic interactions and drug response. J Pathol 2014; 232:255-63. [PMID: 24105606 DOI: 10.1002/path.4265] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 09/10/2013] [Accepted: 09/11/2013] [Indexed: 02/06/2023]
Abstract
The advent of massively parallel sequencing has allowed for an unprecedented genetic characterization of cancers, which has revealed not only the complexity of cancer genomes, but also the fact that tumours from the same anatomical site or even of the same histological and/or molecular subtype display distinct constellations of somatic genetic aberrations. Epistatic interactions (ie the interplay between genetic aberrations) are likely to play pivotal roles not only in terms of tumourigenesis and disease progression, but also in response to therapeutic interventions. In this review, we discuss the challenges posed by the complexity of tumour genomes and epistatic interactions, and approaches for harnessing the wealth of genetic information on human cancers for the implementation of precision medicine.
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Affiliation(s)
- Britta Weigelt
- Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, NY, 10065, USA
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26
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Abstract
Germline mutations of human breast cancer-associated gene 1 (BRCA1) predispose women to breast and ovarian cancers. In mice, over 20 distinct mutations, including null, hypomorphic, isoform, conditional, and point mutations, have been created to study functions of Brca1 in mammary development and tumorigenesis. Analyses using these mutant mice have yielded an enormous amount of information that greatly facilitates our understanding of the gender- and tissue-specific tumor suppressor functions of BRCA1, as well as enriches our insights into applying these preclinical models of disease to breast cancer research. Here, we review features of these mutant mice and their applications to cancer prevention and therapeutic treatment.
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Magwood AC, Malysewich MJ, Cealic I, Mundia MM, Knapp J, Baker MD. Endogenous levels of Rad51 and Brca2 are required for homologous recombination and regulated by homeostatic re-balancing. DNA Repair (Amst) 2013; 12:1122-33. [PMID: 24210700 DOI: 10.1016/j.dnarep.2013.10.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 10/15/2013] [Indexed: 12/17/2022]
Abstract
Stable expression of Rad51 siRNA was used to generate mouse hybridoma cell lines in which endogenous Rad51 levels were depleted by as much as 60%. Stable Rad51 knockdowns feature reduced homologous recombination responses. The relative ease with which stable Rad51 knockdowns were recovered was surprising, given the embryonic lethality of Rad51 ablation. Interestingly, Rad51-depleted hybridoma cell lines are characterized by reduced levels of p53 protein. Completely unexpected, was the finding that Rad51-depleted hybridoma cell lines are also reduced for the breast cancer susceptibility 2 (Brca2) protein. Additionally, hybridoma cell lines that are siRNA depleted for mouse Brca2 show a corresponding reduction in Rad51 and p53 proteins. Furthermore, cellular levels of Rad51, Brca2 and p53 can be elevated in these cell lines by ectopic expression of wild-type human Rad51 and wild-type human BRCA2. In marked contrast, hybridoma cell lines that are siRNA depleted for mouse p53 feature relatively normal Rad51 and Brca2 levels. These results suggest that cellular levels of Brca2 and Rad51 are mutually dependent on each other, and that low levels of these proteins provide selective pressure for reduction of p53, which permits cell growth.
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Affiliation(s)
- Alissa C Magwood
- Department of Molecular and Cellular Biology, College of Biological Science, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
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28
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Shin MH, He Y, Huang J. Embryonic stem cells shed new light on the developmental roles of p53. Cell Biosci 2013; 3:42. [PMID: 24171803 PMCID: PMC3852614 DOI: 10.1186/2045-3701-3-42] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 08/28/2013] [Indexed: 11/17/2022] Open
Abstract
The viability and subtle developmental defects of p53 knockout mice suggest that p53 does not play major role in development. However, contradictory evidence also exists. This discrepancy mainly results from the lack of molecular and cellular mechanisms and the general fact that p53 activation requires stresses. Recent studies of p53 in mouse and human ES cells and induced pluripotent stem (iPS) cells shed new light on the mechanisms of the developmental roles of p53. This review summarizes these new studies that support the developmental roles of p53, highlights the possible underlying molecular mechanisms, and discusses the potential relationship between the developmental roles and the tumor suppressive function of p53. In summary, the molecular mechanisms underlying the developmental roles of p53 are emerging, and the developmental roles and tumor suppressive function of p53 may be closely related.
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29
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MEIOB targets single-strand DNA and is necessary for meiotic recombination. PLoS Genet 2013; 9:e1003784. [PMID: 24068956 PMCID: PMC3778009 DOI: 10.1371/journal.pgen.1003784] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 07/25/2013] [Indexed: 11/19/2022] Open
Abstract
Meiotic recombination is a mandatory process for sexual reproduction. We identified a protein specifically implicated in meiotic homologous recombination that we named: meiosis specific with OB domain (MEIOB). This protein is conserved among metazoan species and contains single-strand DNA binding sites similar to those of RPA1. Our studies in vitro revealed that both recombinant and endogenous MEIOB can be retained on single-strand DNA. Those in vivo demonstrated the specific expression of Meiob in early meiotic germ cells and the co-localization of MEIOB protein with RPA on chromosome axes. MEIOB localization in Dmc1 (-/-) spermatocytes indicated that it accumulates on resected DNA. Homologous Meiob deletion in mice caused infertility in both sexes, due to a meiotic arrest at a zygotene/pachytene-like stage. DNA double strand break repair and homologous chromosome synapsis were impaired in Meiob (-/-) meiocytes. Interestingly MEIOB appeared to be dispensable for the initial loading of recombinases but was required to maintain a proper number of RAD51 and DMC1 foci beyond the zygotene stage. In light of these findings, we propose that RPA and this new single-strand DNA binding protein MEIOB, are essential to ensure the proper stabilization of recombinases which is required for successful homology search and meiotic recombination.
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30
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Reczek CR, Szabolcs M, Stark JM, Ludwig T, Baer R. The interaction between CtIP and BRCA1 is not essential for resection-mediated DNA repair or tumor suppression. ACTA ACUST UNITED AC 2013; 201:693-707. [PMID: 23712259 PMCID: PMC3664708 DOI: 10.1083/jcb.201302145] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In mammalian cells, the phospho-dependent interaction between BRCA1 and CtIP is not required for homology-directed DNA repair or tumor suppression. The CtIP protein facilitates homology-directed repair (HDR) of double-strand DNA breaks (DSBs) by initiating DNA resection, a process in which DSB ends are converted into 3′-ssDNA overhangs. The BRCA1 tumor suppressor, which interacts with CtIP in a phospho-dependent manner, has also been implicated in DSB repair through the HDR pathway. It was recently reported that the BRCA1–CtIP interaction is essential for HDR in chicken DT40 cells. To examine the role of this interaction in mammalian cells, we generated cells and mice that express Ctip polypeptides (Ctip-S326A) that fail to bind BRCA1. Surprisingly, isogenic lines of Ctip-S326A mutant and wild-type cells displayed comparable levels of HDR function and chromosomal stability. Although Ctip-S326A mutant cells were modestly sensitive to topoisomerase inhibitors, mice expressing Ctip-S326A polypeptides developed normally and did not exhibit a predisposition to cancer. Thus, in mammals, the phospho-dependent BRCA1–CtIP interaction is not essential for HDR-mediated DSB repair or for tumor suppression.
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Affiliation(s)
- Colleen R Reczek
- Institute for Cancer Genetics, Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY 10032, USA
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31
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Gorrini C, Baniasadi PS, Harris IS, Silvester J, Inoue S, Snow B, Joshi PA, Wakeham A, Molyneux SD, Martin B, Bouwman P, Cescon DW, Elia AJ, Winterton-Perks Z, Cruickshank J, Brenner D, Tseng A, Musgrave M, Berman HK, Khokha R, Jonkers J, Mak TW, Gauthier ML. BRCA1 interacts with Nrf2 to regulate antioxidant signaling and cell survival. ACTA ACUST UNITED AC 2013; 210:1529-44. [PMID: 23857982 PMCID: PMC3727320 DOI: 10.1084/jem.20121337] [Citation(s) in RCA: 202] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BRCA1 deficiency results in impaired Nrf2-mediated antioxidant responses followed by cell death, with estradiol rescuing the effect by inducing Nrf2 stabilization. Oxidative stress plays an important role in cancer development and treatment. Recent data implicate the tumor suppressor BRCA1 in regulating oxidative stress, but the molecular mechanism and the impact in BRCA1-associated tumorigenesis remain unclear. Here, we show that BRCA1 regulates Nrf2-dependent antioxidant signaling by physically interacting with Nrf2 and promoting its stability and activation. BRCA1-deficient mouse primary mammary epithelial cells show low expression of Nrf2-regulated antioxidant enzymes and accumulate reactive oxygen species (ROS) that impair survival in vivo. Increased Nrf2 activation rescues survival and ROS levels in BRCA1-null cells. Interestingly, 53BP1 inactivation, which has been shown to alleviate several defects associated with BRCA1 loss, rescues survival of BRCA1-null cells without restoring ROS levels. We demonstrate that estrogen treatment partially restores Nrf2 levels in the absence of BRCA1. Our data suggest that Nrf2-regulated antioxidant response plays a crucial role in controlling survival downstream of BRCA1 loss. The ability of estrogen to induce Nrf2 posits an involvement of an estrogen-Nrf2 connection in BRCA1 tumor suppression. Lastly, BRCA1-mutated tumors retain a defective antioxidant response that increases the sensitivity to oxidative stress. In conclusion, the role of BRCA1 in regulating Nrf2 activity suggests important implications for both the etiology and treatment of BRCA1-related cancers.
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Affiliation(s)
- Chiara Gorrini
- The Campbell Family Institute for Breast Cancer Research, University Health Network, Toronto, Ontario M5G 2M9, Canada
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32
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Abstract
Mutations of the breast and ovarian cancer susceptibility gene 1 (BRCA1) account for about 40-45% of hereditary breast cancer cases. Moreover, a significant fraction of sporadic (non-hereditary) breast and ovarian cancers exhibit reduced or absent expression of the BRCA1 protein, suggesting an additional role for BRCA1 in sporadic cancers. BRCA1 follows the classic pattern of a highly penetrant Knudsen-type tumor suppressor gene in which one allele is inactivated through a germ-line mutation and the other is mutated or deleted within the tumor. BRCA1 is a multi-functional protein but it is not fully understood which function(s) is (are) most important for tumor suppression, nor is it clear why BRCA1-mutations confer a high risk for breast and ovarian cancers and not a broad spectrum of tumor types. Here, we will review BRCA1 functions in the DNA damage response (DDR), which are likely to contribute to tumor suppression. In the process, we will highlight some of the controversies and unresolved issues in the field. We will also describe a recently identified and under-investigated role for BRCA1 in the regulation of telomeres and the implications of this role in the DDR and cancer suppression.
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Affiliation(s)
- Eliot M Rosen
- Department of Oncology, Georgetown University School of Medicine Washington, DC, USA ; Department of Biochemistry, Molecular and Cellular Biology, Georgetown University School of Medicine Washington, DC, USA ; Department of Radiation Medicine, Georgetown University School of Medicine Washington, DC, USA
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Palb2 synergizes with Trp53 to suppress mammary tumor formation in a model of inherited breast cancer. Proc Natl Acad Sci U S A 2013; 110:8632-7. [PMID: 23657012 DOI: 10.1073/pnas.1305362110] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Germ-line mutations in PALB2 lead to a familial predisposition to breast and pancreatic cancer or to Fanconi Anemia subtype N. PALB2 performs its tumor suppressor role, at least in part, by supporting homologous recombination-type double strand break repair (HR-DSBR) through physical interactions with BRCA1, BRCA2, and RAD51. To further understand the mechanisms underlying PALB2-mediated DNA repair and tumor suppression functions, we targeted Palb2 in the mouse. Palb2-deficient murine ES cells recapitulated DNA damage defects caused by PALB2 depletion in human cells, and germ-line deletion of Palb2 led to early embryonic lethality. Somatic deletion of Palb2 driven by K14-Cre led to mammary tumor formation with long latency. Codeletion of both Palb2 and Tumor protein 53 (Trp53) accelerated mammary tumor formation. Like BRCA1 and BRCA2 mutant breast cancers, these tumors were defective in RAD51 focus formation, reflecting a defect in Palb2 HR-DSBR function, a strongly suspected contributor to Brca1, Brca2, and Palb2 mammary tumor development. However, unlike the case of Brca1-mutant cells, Trp53bp1 deletion failed to rescue the genomic instability of Palb2- or Brca2-mutant primary lymphocytes. Therefore, Palb2-driven DNA damage control is, in part, distinct from that executed by Brca1 and more similar to that of Brca2. The mechanisms underlying Palb2 mammary tumor suppression functions can now be explored genetically in vivo.
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34
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Zhang J. The role of BRCA1 in homologous recombination repair in response to replication stress: significance in tumorigenesis and cancer therapy. Cell Biosci 2013; 3:11. [PMID: 23388117 PMCID: PMC3599463 DOI: 10.1186/2045-3701-3-11] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Accepted: 12/20/2012] [Indexed: 12/16/2022] Open
Abstract
Germ line mutations in breast cancer gene 1 (BRCA1) predispose women to breast and ovarian cancers. Although BRCA1 is involved in many important biological processes, the function of BRCA1 in homologous recombination (HR) mediated repair is considered one of the major mechanisms contributing to its tumor suppression activity, and the cause of hypersensitivity to poly(ADP-ribose) polymerase (PARP) inhibitors when BRCA1 is defective. Mounting evidence suggests that the mechanism of repairing DNA double strand breaks (DSBs) by HR is different than the mechanism operating when DNA replication is blocked. Although BRCA1 has been recognized as a central component in HR, the precise role of BRCA1 in HR, particularly under replication stress, has remained largely unknown. Given the fact that DNA lesions caused by replication blockages are the primary substrates for HR in mitotic cells, functional analysis of BRCA1 in HR repair in the context of replication stress should benefit our understanding of the molecular mechanisms underlying tumorigenesis associated with BRCA1 deficiencies, as well as the development of therapeutic approaches for cancer patients carrying BRCA1 mutations or reduced BRCA1 expression. This review focuses on the current advances in this setting and also discusses the significance in tumorigenesis and cancer therapy.
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Affiliation(s)
- Junran Zhang
- Department of Radiation Oncology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, BRB 323, Cleveland, OH, 44106, USA.
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35
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Halaby MJ, Hakem A, Li L, El Ghamrasni S, Venkatesan S, Hande PM, Sanchez O, Hakem R. Synergistic interaction of Rnf8 and p53 in the protection against genomic instability and tumorigenesis. PLoS Genet 2013; 9:e1003259. [PMID: 23382699 PMCID: PMC3561120 DOI: 10.1371/journal.pgen.1003259] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Accepted: 12/04/2012] [Indexed: 11/18/2022] Open
Abstract
Rnf8 is an E3 ubiquitin ligase that plays a key role in the DNA damage response as well as in the maintenance of telomeres and chromatin remodeling. Rnf8−/− mice exhibit developmental defects and increased susceptibility to tumorigenesis. We observed that levels of p53, a central regulator of the cellular response to DNA damage, increased in Rnf8−/− mice in a tissue- and cell type–specific manner. To investigate the role of the p53-pathway inactivation on the phenotype observed in Rnf8−/− mice, we have generated Rnf8−/−p53−/− mice. Double-knockout mice showed similar growth retardation defects and impaired class switch recombination compared to Rnf8−/− mice. In contrast, loss of p53 fully rescued the increased apoptosis and reduced number of thymocytes and splenocytes in Rnf8−/− mice. Similarly, the senescence phenotype of Rnf8−/− mouse embryonic fibroblasts was rescued in p53 null background. Rnf8−/−p53−/− cells displayed defective cell cycle checkpoints and DNA double-strand break repair. In addition, Rnf8−/−p53−/− mice had increased levels of genomic instability and a remarkably elevated tumor incidence compared to either Rnf8−/− or p53−/− mice. Altogether, the data in this study highlight the importance of p53-pathway activation upon loss of Rnf8, suggesting that Rnf8 and p53 functionally interact to protect against genomic instability and tumorigenesis. DNA double-strand breaks are the most dangerous type of DNA lesions that can occur in cells. Failure to repair these breaks quickly and efficiently can result in either cell death or genomic instability and eventually malignant transformation. Rnf8 and p53 are key proteins in the DNA damage response. We have generated mice that are deficient in both Rnf8 and p53 proteins to determine how these two proteins interact. We found that, when p53 is absent, some of the developmental defects caused by Rnf8 deficiency are rescued. However, this is at the expense of increased chromosomal abnormalities caused by the inability of double-mutant cells to restrain DNA synthesis and cell proliferation and by their escape of cell death in the presence of damaged DNA. We showed that loss of both Rnf8 and p53 led to the accelerated development of both hematological and solid tumors. This study has important implications for human cancer, where mutations in the p53 gene are found in more than 50% of all cancers but where the other factors that facilitate cancer development are not well understood. This study suggests cooperation between Rnf8 and p53 in the prevention of cancer.
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Affiliation(s)
- Marie-Jo Halaby
- Department of Medical Biophysics, University of Toronto and Ontario Cancer Institute, University Health Network, Toronto, Ontario, Canada
| | - Anne Hakem
- Department of Medical Biophysics, University of Toronto and Ontario Cancer Institute, University Health Network, Toronto, Ontario, Canada
| | - Li Li
- Department of Medical Biophysics, University of Toronto and Ontario Cancer Institute, University Health Network, Toronto, Ontario, Canada
| | - Samah El Ghamrasni
- Department of Medical Biophysics, University of Toronto and Ontario Cancer Institute, University Health Network, Toronto, Ontario, Canada
| | - Shriram Venkatesan
- Department of Physiology, Yong Loo Lin School of Medicine and Tembusu College, National University of Singapore, Singapore, Singapore
| | - Prakash M. Hande
- Department of Physiology, Yong Loo Lin School of Medicine and Tembusu College, National University of Singapore, Singapore, Singapore
| | - Otto Sanchez
- University of Ontario Institute of Technology, Oshawa, Ontario, Canada
| | - Razqallah Hakem
- Department of Medical Biophysics, University of Toronto and Ontario Cancer Institute, University Health Network, Toronto, Ontario, Canada
- * E-mail:
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Li X, Xu H, Xu C, Lin M, Song X, Yi F, Feng Y, Coughlan KA, Cho WCS, Kim SS, Cao L. The yin-yang of DNA damage response: roles in tumorigenesis and cellular senescence. Int J Mol Sci 2013; 14:2431-48. [PMID: 23354477 PMCID: PMC3587995 DOI: 10.3390/ijms14022431] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 01/08/2013] [Accepted: 01/09/2013] [Indexed: 01/06/2023] Open
Abstract
Senescent cells are relatively stable, lacking proliferation capacity yet retaining metabolic activity. In contrast, cancer cells are rather invasive and devastating, with uncontrolled proliferative capacity and resistance to cell death signals. Although tumorigenesis and cellular senescence are seemingly opposite pathological events, they are actually driven by a unified mechanism: DNA damage. Integrity of the DNA damage response (DDR) network can impose a tumorigenesis barrier by navigating abnormal cells to cellular senescence. Compromise of DDR, possibly due to the inactivation of DDR components, may prevent cellular senescence but at the expense of tumor formation. Here we provide an overview of the fundamental role of DDR in tumorigenesis and cellular senescence, under the light of the Yin-Yang concept of Chinese philosophy. Emphasis is placed on discussing DDR outcome in the light of in vivo models. This information is critical as it can help make better decisions for clinical treatments of cancer patients.
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Affiliation(s)
- Xiaoman Li
- Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang 110001, China; E-Mails: (X.L.); (H.X.); (M.L.); (X.S.); (F.Y.); (Y.F.)
| | - Hongde Xu
- Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang 110001, China; E-Mails: (X.L.); (H.X.); (M.L.); (X.S.); (F.Y.); (Y.F.)
| | - Chongan Xu
- Department of Medical Oncology, The Fourth Affiliated Hospital, China Medical University, Shenyang 110032, China; E-Mail:
| | - Meina Lin
- Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang 110001, China; E-Mails: (X.L.); (H.X.); (M.L.); (X.S.); (F.Y.); (Y.F.)
| | - Xiaoyu Song
- Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang 110001, China; E-Mails: (X.L.); (H.X.); (M.L.); (X.S.); (F.Y.); (Y.F.)
| | - Fei Yi
- Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang 110001, China; E-Mails: (X.L.); (H.X.); (M.L.); (X.S.); (F.Y.); (Y.F.)
| | - Yanling Feng
- Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang 110001, China; E-Mails: (X.L.); (H.X.); (M.L.); (X.S.); (F.Y.); (Y.F.)
| | - Kathleen A. Coughlan
- Section of Molecular Medicine, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; E-Mail:
| | | | - Sang Soo Kim
- Radiation Medicine Branch, National Cancer Center, Goyang, Gyenggi 410-769, Korea
- Authors to whom correspondence should be addressed; E-Mails: (S.S.K.); (L.C.); Tel.: +82-31-920-2491 (S.S.K.); +86-24-23256666 (ext. 6014) (L.C.); Fax: +82-31-920-2494 (S.S.K.); +86-24-23264417 (L.C.)
| | - Liu Cao
- Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang 110001, China; E-Mails: (X.L.); (H.X.); (M.L.); (X.S.); (F.Y.); (Y.F.)
- Authors to whom correspondence should be addressed; E-Mails: (S.S.K.); (L.C.); Tel.: +82-31-920-2491 (S.S.K.); +86-24-23256666 (ext. 6014) (L.C.); Fax: +82-31-920-2494 (S.S.K.); +86-24-23264417 (L.C.)
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BRCA1--conductor of the breast stem cell orchestra: the role of BRCA1 in mammary gland development and identification of cell of origin of BRCA1 mutant breast cancer. Stem Cell Rev Rep 2012; 8:982-93. [PMID: 22426855 DOI: 10.1007/s12015-012-9354-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Breast cancer treatment has been increasingly successful over the last 20 years due in large part to targeted therapies directed against different subtypes. However, basal-like breast cancers still represent a considerable challenge to clinicians and scientists alike since the pathogenesis underlying the disease and the target cell for transformation of this subtype is still undetermined. The considerable similarities between basal-like and BRCA1 mutant breast cancers led to the hypothesis that these cancers arise from transformation of a basal cell within the normal breast epithelium through BRCA1 dysfunction. Recently, however, a number of studies have called this hypothesis into question. This review summarises the initial findings which implicated the basal cell as the cell of origin of BRCA1 related basal-like breast cancers, as well as the more recent data which identifies the luminal progenitor cells as the likely target of transformation. We compare a number of key studies in this area and identify the differences that could explain some of the contradictory findings. In addition, we highlight the role of BRCA1 in breast cell differentiation and lineage determination by reviewing recent findings in the field and our own observations suggesting a role for BRCA1 in stem cell regulation through activation of the p63 and Notch pathways. We hope that through an increased understanding of the BRCA1 role in breast differentiation and the identification of the cell(s) of origin we can improve treatment options for both BRCA1 mutant and basal-like breast cancer subgroups.
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Weghofer A, Tea MK, Barad DH, Kim A, Singer CF, Wagner K, Gleicher N. BRCA1/2 mutations appear embryo-lethal unless rescued by low (CGG n<26) FMR1 sub-genotypes: explanation for the "BRCA paradox"? PLoS One 2012; 7:e44753. [PMID: 22984553 PMCID: PMC3440327 DOI: 10.1371/journal.pone.0044753] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Accepted: 08/07/2012] [Indexed: 12/24/2022] Open
Abstract
BRCA1/2 mutations and recently described constitutional FMR1 genotypes have, independently, been associated with prematurely diminished ovarian reserve. Whether they interrelate in distribution, and whether observed effects of BRCA1/2 and FMR1 on ovaries are independent of each other, is unknown. In a prospective comparative cohort study, we, therefore, investigated the distribution of constitutional FMR1 genotypes, normal (norm), heterozygous (het) and homozygous (hom), and of their respective sub-genotypes (high/low), in 99 BRCA1/2 mutation-positive women and 410 female controls to determine whether distribution patterns differed between study and control patients. In contrast to controls, BRCA1/2 carriers demonstrated almost complete absence of all constitutional FMR1 genotypes except for sub-genotypes with low (CGG n<26) alleles. Cross tabulation between BRCA1/2-positive patients and controls confirmed significant group membership, related to FMR1 distribution (P<0.0001). These results offer as most likely explanation the conclusion that BRCA1/2 mutations are embryo-lethal, unless rescued by low (CGG n<26) FMR1 sub-genotypes, present in approximately one quarter of all women. Women with low FMR1 sub-genotypes, therefore, should reflect increased BRCA1/2-associated cancer risks, while the remaining approximately 75 percent should face almost no such risks. If confirmed, this observation offers opportunities for more efficient and less costly BRCA1/2 cancer screening. The study also suggests that previously reported risk towards prematurely diminished ovarian reserve in association with BRCA mutations is FMR1-mediated, and offers a possible explanation for the so-called “BRCA paradox” by raising the possibility that the widely perceived BRCA1/2-associated tumor risk is actually FMR1-mediated.
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Affiliation(s)
- Andrea Weghofer
- The Center for Human Reproduction, New York, New York, United States of America
- Department of Gynecological Endocrinology and Reproductive Medicine, Medical University Vienna, Vienna, Austria
| | - Muy-Kheng Tea
- Department of Obstetrics and Gynecology, Medical University Vienna, Vienna, Austria
| | - David H. Barad
- The Center for Human Reproduction, New York, New York, United States of America
- Foundation for Reproductive Medicine, New York, New York, United States of America
| | - Ann Kim
- The Center for Human Reproduction, New York, New York, United States of America
| | - Christian F. Singer
- Department of Obstetrics and Gynecology, Medical University Vienna, Vienna, Austria
| | - Klaus Wagner
- Department of Human Genetics, Medical University Graz, Graz, Austria
| | - Norbert Gleicher
- The Center for Human Reproduction, New York, New York, United States of America
- Foundation for Reproductive Medicine, New York, New York, United States of America
- * E-mail:
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Reijns MAM, Rabe B, Rigby RE, Mill P, Astell KR, Lettice LA, Boyle S, Leitch A, Keighren M, Kilanowski F, Devenney PS, Sexton D, Grimes G, Holt IJ, Hill RE, Taylor MS, Lawson KA, Dorin JR, Jackson AP. Enzymatic removal of ribonucleotides from DNA is essential for mammalian genome integrity and development. Cell 2012; 149:1008-22. [PMID: 22579044 PMCID: PMC3383994 DOI: 10.1016/j.cell.2012.04.011] [Citation(s) in RCA: 349] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Revised: 02/21/2012] [Accepted: 04/23/2012] [Indexed: 12/01/2022]
Abstract
The presence of ribonucleotides in genomic DNA is undesirable given their increased susceptibility to hydrolysis. Ribonuclease (RNase) H enzymes that recognize and process such embedded ribonucleotides are present in all domains of life. However, in unicellular organisms such as budding yeast, they are not required for viability or even efficient cellular proliferation, while in humans, RNase H2 hypomorphic mutations cause the neuroinflammatory disorder Aicardi-Goutières syndrome. Here, we report that RNase H2 is an essential enzyme in mice, required for embryonic growth from gastrulation onward. RNase H2 null embryos accumulate large numbers of single (or di-) ribonucleotides embedded in their genomic DNA (>1,000,000 per cell), resulting in genome instability and a p53-dependent DNA-damage response. Our findings establish RNase H2 as a key mammalian genome surveillance enzyme required for ribonucleotide removal and demonstrate that ribonucleotides are the most commonly occurring endogenous nucleotide base lesion in replicating cells.
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Affiliation(s)
- Martin A M Reijns
- Medical Research Council Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK
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Magwood AC, Mundia MM, Baker MD. High levels of wild-type BRCA2 suppress homologous recombination. J Mol Biol 2012; 421:38-53. [PMID: 22579622 DOI: 10.1016/j.jmb.2012.05.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 04/23/2012] [Accepted: 05/03/2012] [Indexed: 11/26/2022]
Abstract
Endogenous levels of the BRCA2 (breast cancer susceptibility 2) protein promote homologous recombination by regulating the essential strand exchange protein RAD51. To examine BRCA2 function in homologous recombination, we expressed human BRCA2 in control mouse hybridoma cells, as well as those that were depleted of endogenous Brca2 by small interfering RNA. With moderate human BRCA2 expression, homologous recombination was stimulated. Conversely, a higher level of BRCA2 reduced homologous recombination and DNA-damage-induced Rad51 foci formation. Cells expressing high levels of BRCA2 feature normal growth, increased sensitivity to mitomycin C, and increased illegitimate recombination. BRCA2-overexpressing cells are also characterized by suppression of p53 transcriptional regulation and a corresponding reduction in the expression of the p53-responsive genes Noxa and p21. Notably, in cells expressing high levels of BRCA2, small interfering RNA depletion of human BRCA2 or ectopic expression of Rad51 increases homologous recombination and decreases illegitimate recombination. Thus, high levels of wild-type BRCA2 perturb Rad51-mediated homologous recombination, and relatively normal recombination responses can be restored by rebalancing recombination factors.
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Affiliation(s)
- Alissa C Magwood
- Department of Molecular and Cellular Biology, College of Biological Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1
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Kang SN, Hong SS, Lee MK, Lim SJ. Dual function of tributyrin emulsion: Solubilization and enhancement of anticancer effect of celecoxib. Int J Pharm 2012; 428:76-81. [DOI: 10.1016/j.ijpharm.2012.02.037] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Revised: 01/31/2012] [Accepted: 02/23/2012] [Indexed: 10/28/2022]
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Ishimura A, Minehata KI, Terashima M, Kondoh G, Hara T, Suzuki T. Jmjd5, an H3K36me2 histone demethylase, modulates embryonic cell proliferation through the regulation of Cdkn1a expression. Development 2012; 139:749-59. [PMID: 22241836 DOI: 10.1242/dev.074138] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Covalent modifications of histones play an important role in chromatin architecture and dynamics. In particular, histone lysine methylation is important for transcriptional control during diverse biological processes. The nuclear protein Jmjd5 (also called Kdm8) is a histone lysine demethylase that contains a JmjC domain in the C-terminal region. In this study, we have generated Jmjd5-deficient mice (Jmjd5(Δ)(/)(Δ)) to investigate the in vivo function of Jmjd5. Jmjd5(Δ)(/)(Δ) embryos showed severe growth retardation, resulting in embryonic lethality at the mid-gestation stage. Mouse embryonic fibroblasts (MEFs) derived from Jmjd5 hypomorphic embryos (Jmjd5(neo/neo)) also showed the growth defect. Quantitative PCR analysis of various cell cycle regulators indicated that only Cdkn1a expression was upregulated in Jmjd5(neo/neo) MEFs and Jmjd5(Δ)(/)(Δ) embryos. A knockdown assay with Cdkn1a-specific small interfering RNAs revealed that the growth defect of Jmjd5(neo/neo) MEFs was significantly rescued. In addition, a genetic study using Jmjd5(Δ)(/)(Δ); Cdkn1a(Δ)(/)(Δ) double-knockout mice showed that the growth retardation of Jmjd5(Δ)(/)(Δ) embryos was partially rescued by Cdkn1a deficiency. Chromatin immunoprecipitation analysis showed that increased di-methylated lysine 36 of histone H3 (H3K36me2) and reduced recruitment of endogenous Jmjd5 were detected in the transcribed regions of Cdkn1a in Jmjd5(neo/neo) MEFs. Taken together, these results suggest that Jmjd5 physiologically moderates embryonic cell proliferation through the epigenetic control of Cdkn1a expression.
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Affiliation(s)
- Akihiko Ishimura
- Division of Functional Genomics, Cancer Research Institute, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
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Genetics of Meiosis and Recombination in Mice. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY VOLUME 298 2012; 298:179-227. [DOI: 10.1016/b978-0-12-394309-5.00005-5] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Abstract
The proteins encoded by the two major breast cancer susceptibility genes, BRCA1 and BRCA2, work in a common pathway of genome protection. However, the two proteins work at different stages in the DNA damage response (DDR) and in DNA repair. BRCA1 is a pleiotropic DDR protein that functions in both checkpoint activation and DNA repair, whereas BRCA2 is a mediator of the core mechanism of homologous recombination. The links between the two proteins are not well understood, but they must exist to explain the marked similarity of human cancer susceptibility that arises with germline mutations in these genes. As discussed here, the proteins work in concert to protect the genome from double-strand DNA damage during DNA replication.
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Affiliation(s)
- Rohini Roy
- Molecular Biology Program and Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, USA
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45
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BRCA1 is an essential regulator of heart function and survival following myocardial infarction. Nat Commun 2011; 2:593. [PMID: 22186889 PMCID: PMC3247816 DOI: 10.1038/ncomms1601] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Accepted: 11/16/2011] [Indexed: 12/30/2022] Open
Abstract
The tumour suppressor BRCA1 is mutated in familial breast and ovarian cancer but its role in protecting other tissues from DNA damage has not been explored. Here we show a new role for BRCA1 as a gatekeeper of cardiac function and survival. In mice, loss of BRCA1 in cardiomyocytes results in adverse cardiac remodelling, poor ventricular function and higher mortality in response to ischaemic or genotoxic stress. Mechanistically, loss of cardiomyocyte BRCA1 results in impaired DNA double-strand break repair and activated p53-mediated pro-apoptotic signalling culminating in increased cardiomyocyte apoptosis, whereas deletion of the p53 gene rescues BRCA1-deficient mice from cardiac failure. In human adult and fetal cardiac tissues, ischaemia induces double-strand breaks and upregulates BRCA1 expression. These data reveal BRCA1 as a novel and essential adaptive response molecule shielding cardiomyocytes from DNA damage, apoptosis and heart dysfunction. BRCA1 mutation carriers, in addition to risk of breast and ovarian cancer, may be at a previously unrecognized risk of cardiac failure. The tumour suppressor BRCA1 is mutated in familial breast and ovarian cancer. Now, Shukla et al. demonstrate that mice lacking BRCA1 in cardiomyocytes are more sensitive to ischaemia than control mice, and that BRCA1 is elevated in human tissues exposed to ischaemia, suggesting a cardioprotective role for BRCA1.
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Mutation of a single allele of the cancer susceptibility gene BRCA1 leads to genomic instability in human breast epithelial cells. Proc Natl Acad Sci U S A 2011; 108:17773-8. [PMID: 21987798 DOI: 10.1073/pnas.1110969108] [Citation(s) in RCA: 121] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Biallelic inactivation of cancer susceptibility gene BRCA1 leads to breast and ovarian carcinogenesis. Paradoxically, BRCA1 deficiency in mice results in early embryonic lethality, and similarly, lack of BRCA1 in human cells is thought to result in cellular lethality in view of BRCA1's essential function. To survive homozygous BRCA1 inactivation during tumorigenesis, precancerous cells must accumulate additional genetic alterations, such as p53 mutations, but this requirement for an extra genetic "hit" contradicts the two-hit theory for the accelerated carcinogenesis associated with familial cancer syndromes. Here, we show that heterozygous BRCA1 inactivation results in genomic instability in nontumorigenic human breast epithelial cells in vitro and in vivo. Using somatic cell gene targeting, we demonstrated that a heterozygous BRCA1 185delAG mutation confers impaired homology-mediated DNA repair and hypersensitivity to genotoxic stress. Heterozygous mutant BRCA1 cell clones also showed a higher degree of gene copy number loss and loss of heterozygosity in SNP array analyses. In BRCA1 heterozygous clones and nontumorigenic breast epithelial tissues from BRCA mutation carriers, FISH revealed elevated genomic instability when compared with their respective controls. Thus, BRCA1 haploinsufficiency may accelerate hereditary breast carcinogenesis by facilitating additional genetic alterations.
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Aly A, Ganesan S. BRCA1, PARP, and 53BP1: conditional synthetic lethality and synthetic viability. J Mol Cell Biol 2011; 3:66-74. [PMID: 21278454 DOI: 10.1093/jmcb/mjq055] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
BRCA1 plays a critical role in the regulation of homologous recombination (HR)-mediated DNA double-strand break repair. BRCA1-deficient cancers have evolved to tolerate loss of BRCA1 function. This renders them vulnerable to agents, such as PARP inhibitors, that are conditionally 'synthetic lethal' with their underlying repair defect. Recent studies demonstrate that BRCA1-deficient cells may acquire resistance to these agents by partially correcting their defect in HR-mediated repair, either through reversion mutations in BRCA1 or through 'synthetic viable' loss of 53BP1. These findings and their clinical implications will be reviewed in this article.
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Affiliation(s)
- Amal Aly
- Cancer Institute of New Jersey, Robert Wood Johnson Medical School-UMDNJ, 195 Little Albany Street, New Brunswick, NJ 08903, USA
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Michalak EM, Jonkers J. Studying therapy response and resistance in mouse models for BRCA1-deficient breast cancer. J Mammary Gland Biol Neoplasia 2011; 16:41-50. [PMID: 21331759 DOI: 10.1007/s10911-011-9199-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 02/08/2011] [Indexed: 01/09/2023] Open
Abstract
Worldwide, more than one million women are diagnosed with breast cancer every year, making it the most common malignancy of females in the developed world. Germline mutations in the breast cancer susceptibility genes BRCA1 and BRCA2 account for 4-6% of all breast cancer cases, and mutation carriers have a lifetime risk of 80% for developing breast cancer and 40% for developing ovarian cancer. Current treatment options are limited and often do not lead to cure. In the 17 years since the discovery of BRCA1, the generation of mouse models for BRCA1 deficiency has greatly aided our understanding of it's role in tumorigenesis. In contrast to human BRCA1 mutation carriers, mice carrying heterozygous mutations in Brca1 did not develop spontaneous tumors. This led to the generation of conditional mouse models in which tissue-specific Brca1 deletion induces formation of mammary tumors that closely resemble human BRCA1-mutated breast tumors. These models have proven useful for studying BRCA1-related tumor development, drug response and resistance. BRCA1-deficient cancer cells are defective in DNA repair mediated by homologous recombination (HR) and therefore highly sensitive to DNA-damaging agents such as platinum drugs and poly(ADP-ribose) polymerase (PARP) inhibitors. However, BRCA1-mutated tumors can develop resistance to these drugs; hence improved treatment strategies are critical. Existing mouse models have already proven useful for preclinical testing of (combinations of) therapeutic agents that may be beneficial for the treatment of patients with BRCA1-mutated tumors. In this review, we discuss the progress made towards modeling BRCA1-deficient breast cancer in mice and what we have learned from preclinical studies using these models.
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Bouwman P, Drost R, Klijn C, Pieterse M, van der Gulden H, Song JY, Szuhai K, Jonkers J. Loss of p53 partially rescues embryonic development of Palb2 knockout mice but does not foster haploinsufficiency of Palb2 in tumour suppression. J Pathol 2011; 224:10-21. [PMID: 21404276 DOI: 10.1002/path.2861] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 01/13/2011] [Accepted: 01/16/2011] [Indexed: 11/07/2022]
Abstract
PALB2 interacts with BRCA1 and BRCA2 in supercomplexes involved in DNA repair via homologous recombination. Heterozygous germline mutations in PALB2 confer a moderate risk of breast cancer, while biallelic PALB2 mutations are linked to a severe form of Fanconi anaemia characterized by early childhood solid tumours and severe chromosomal instability. In contrast to BRCA1- or BRCA2-associated cancers, breast tumours in heterozygous PALB2 mutation carriers do not show loss of the wild-type allele, suggesting PALB2 might be haploinsufficient for tumour suppression. To study the role of PALB2 in development and tumourigenesis, we have generated Palb2(GT) mouse mutants using a gene trap approach. Whereas Palb2(GT/GT) homozygous mutant embryos died at mid-gestation due to massive apoptosis, Palb2(GT/+) heterozygous mice were viable and did not show any obvious abnormalities. Deletion of p53 alleviated the phenotype of Palb2(GT/GT) embryos, but did not rescue embryonic lethality. In addition, loss of p53 did not significantly collaborate with Palb2 heterozygosity in tumourigenesis in heterozygous or homozygous p53 knockout mice. Tumours arising in Palb2(GT/+) ;p53(+/-) or Palb2(GT/+) ;p53(-/-) compound mutant mice retained the wild-type Palb2 allele and did not display increased genomic instability.
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Affiliation(s)
- Peter Bouwman
- Division of Molecular Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
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50
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Mangia A, Malfettone A, Simone G, Darvishian F. Old and new concepts in histopathological characterization of familial breast cancer. Ann Oncol 2011; 22 Suppl 1:i24-30. [DOI: 10.1093/annonc/mdq662] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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