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Keahi DL, Sanders MA, Paul MR, Webster ALH, Fang Y, Wiley TF, Shalaby S, Carroll TS, Chandrasekharappa SC, Sandoval-Garcia C, MacMillan ML, Wagner JE, Hatten ME, Smogorzewska A. G-quadruplexes are a source of vulnerability in BRCA2 deficient granule cell progenitors and medulloblastoma. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.20.604431. [PMID: 39091814 PMCID: PMC11291086 DOI: 10.1101/2024.07.20.604431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
Biallelic pathogenic variants in the essential DNA repair gene BRCA2 causes Fanconi anemia, complementation group FA-D1. Patients in this group are highly prone to develop embryonal tumors, most commonly medulloblastoma arising from the cerebellar granule cell progenitors (GCPs). GCPs undergo high proliferation in the postnatal cerebellum under SHH activation, but the type of DNA lesions that require the function of the BRCA2 to prevent tumorigenesis remains unknown. To identify such lesions, we assessed both GCP neurodevelopment and tumor formation using a mouse model with deletion of exons three and four of Brca2 in the central nervous system, coupled with global Trp53 loss. Brca2 Δex3-4 ;Trp53 -/- animals developed SHH subgroup medulloblastomas with complete penetrance. Whole-genome sequencing of the tumors identified structural variants with breakpoints enriched in areas overlapping G-quadruplexes (G4s). Brca2-deficient GCPs exhibited decreased replication speed in the presence of the G4-stabilizer pyridostatin. Pif1 helicase, which resolves G4s during replication, was highly upregulated in tumors, and Pif1 knockout in primary MB tumor cells resulted in increased genome instability upon pyridostatin treatment. These data suggest that G4s may represent sites prone to replication stalling in highly proliferative GCPs and without BRCA2, G4s become a source of genome instability. Tumor cells upregulate G4-resolving helicases to facilitate rapid proliferation through G4s highlighting PIF1 helicase as a potential therapeutic target for treatment of BRCA2-deficient medulloblastomas.
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Affiliation(s)
- Danielle L. Keahi
- Laboratory of Genome Maintenance, The Rockefeller University, New York, NY, USA
| | - Mathijs A. Sanders
- Cancer, Ageing and Somatic Mutation (CASM), Wellcome Sanger Institute, Hinxton, UK
- Department of Hematology, Erasmus MC Cancer Institute, Rotterdam, The Netherlands
| | - Matthew R. Paul
- Bioinformatics Resource Center, The Rockefeller University, New York, NY, USA
| | | | - Yin Fang
- Laboratory of Developmental Neurobiology, The Rockefeller University, New York, NY, USA
| | - Tom F. Wiley
- Comparative Bioscience Center, The Rockefeller University, New York, NY, USA
| | - Samer Shalaby
- Flow Cytometry Resource Center, The Rockefeller University, New York, NY, USA
| | - Thomas S. Carroll
- Bioinformatics Resource Center, The Rockefeller University, New York, NY, USA
| | - Settara C. Chandrasekharappa
- Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | | | | | - John E. Wagner
- Department of Pediatrics, University of Minnesota, Minneapolis, MN, USA
| | - Mary E. Hatten
- Laboratory of Developmental Neurobiology, The Rockefeller University, New York, NY, USA
| | - Agata Smogorzewska
- Laboratory of Genome Maintenance, The Rockefeller University, New York, NY, USA
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2
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Ma J, Ren D, Wang Z, Li W, Li L, Liu T, Ye Q, Lei Y, Jian Y, Ma B, Fan Y, Liu J, Gao Y, Jin X, Huang H, Li L. CK2-dependent degradation of CBX3 dictates replication fork stalling and PARP inhibitor sensitivity. SCIENCE ADVANCES 2024; 10:eadk8908. [PMID: 38781342 PMCID: PMC11114232 DOI: 10.1126/sciadv.adk8908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Accepted: 04/17/2024] [Indexed: 05/25/2024]
Abstract
DNA replication is a vulnerable cellular process, and its deregulation leads to genomic instability. Here, we demonstrate that chromobox protein homolog 3 (CBX3) binds replication protein A 32-kDa subunit (RPA2) and regulates RPA2 retention at stalled replication forks. CBX3 is recruited to stalled replication forks by RPA2 and inhibits ring finger and WD repeat domain 3 (RFWD3)-facilitated replication restart. Phosphorylation of CBX3 at serine-95 by casein kinase 2 (CK2) kinase augments cadherin 1 (CDH1)-mediated CBX3 degradation and RPA2 dynamics at stalled replication forks, which permits replication fork restart. Increased expression of CBX3 due to gene amplification or CK2 inhibitor treatment sensitizes prostate cancer cells to poly(ADP-ribose) polymerase (PARP) inhibitors while inducing replication stress and DNA damage. Our work reveals CBX3 as a key regulator of RPA2 function and DNA replication, suggesting that CBX3 could serve as an indicator for targeted therapy of cancer using PARP inhibitors.
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Affiliation(s)
- Jian Ma
- Department of Urology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China
| | - Dianyun Ren
- Department of Pancreatic Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Zixi Wang
- Department of Urology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China
| | - Wei Li
- Department of Urology, The Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Lei Li
- Department of Urology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China
| | - Tianjie Liu
- Department of Urology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China
| | - Qi Ye
- Department of Urology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China
| | - Yuzeshi Lei
- Department of Urology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China
| | - Yanlin Jian
- Department of Urology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China
| | - Bohan Ma
- Department of Urology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China
| | - Yizeng Fan
- Department of Urology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China
| | - Jing Liu
- Department of Urology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China
| | - Yang Gao
- Department of Urology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China
| | - Xin Jin
- Department of Urology, The Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Haojie Huang
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine and Science, Rochester, MN 55905, USA
- Institute of Urologic Science and Technology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 311100, China
- Department of Urology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 311100, China
| | - Lei Li
- Department of Urology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China
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3
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Georgieva D, Wang N, Taglialatela A, Jerabek S, Reczek CR, Lim PX, Sung J, Du Q, Horiguchi M, Jasin M, Ciccia A, Baer R, Egli D. BRCA1 and 53BP1 regulate reprogramming efficiency by mediating DNA repair pathway choice at replication-associated double-strand breaks. Cell Rep 2024; 43:114006. [PMID: 38554279 PMCID: PMC11272184 DOI: 10.1016/j.celrep.2024.114006] [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: 02/26/2023] [Revised: 11/26/2023] [Accepted: 03/11/2024] [Indexed: 04/01/2024] Open
Abstract
Reprogramming to pluripotency is associated with DNA damage and requires the functions of the BRCA1 tumor suppressor. Here, we leverage separation-of-function mutations in BRCA1/2 as well as the physical and/or genetic interactions between BRCA1 and its associated repair proteins to ascertain the relevance of homology-directed repair (HDR), stalled fork protection (SFP), and replication gap suppression (RGS) in somatic cell reprogramming. Surprisingly, loss of SFP and RGS is inconsequential for the transition to pluripotency. In contrast, cells deficient in HDR, but proficient in SFP and RGS, reprogram with reduced efficiency. Conversely, the restoration of HDR function through inactivation of 53bp1 rescues reprogramming in Brca1-deficient cells, and 53bp1 loss leads to elevated HDR and enhanced reprogramming in mouse and human cells. These results demonstrate that somatic cell reprogramming is especially dependent on repair of replication-associated double-strand breaks (DSBs) by the HDR activity of BRCA1 and BRCA2 and can be improved in the absence of 53BP1.
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Affiliation(s)
- Daniela Georgieva
- Department of Pediatrics and Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, NY 10032, USA; Columbia University Stem Cell Initiative, New York, NY 10032, USA
| | - Ning Wang
- Department of Pediatrics and Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, NY 10032, USA; Columbia University Stem Cell Initiative, New York, NY 10032, USA
| | - Angelo Taglialatela
- Columbia University Stem Cell Initiative, New York, NY 10032, USA; Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Stepan Jerabek
- Department of Pediatrics and Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, NY 10032, USA; Columbia University Stem Cell Initiative, New York, NY 10032, USA; Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 542/2, 160 00 Praha 6, Czech Republic
| | - Colleen R Reczek
- Department of Pathology & Cell Biology, Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Pei Xin Lim
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Julie Sung
- Department of Pediatrics and Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Qian Du
- Department of Pediatrics and Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Michiko Horiguchi
- Department of Pathology & Cell Biology, Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Maria Jasin
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Alberto Ciccia
- Columbia University Stem Cell Initiative, New York, NY 10032, USA; Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Richard Baer
- Department of Pathology & Cell Biology, Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Dieter Egli
- Department of Pediatrics and Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, NY 10032, USA; Columbia University Stem Cell Initiative, New York, NY 10032, USA; Department of Obstetrics and Gynecology, Columbia University Irving Medical Center, New York, NY 10032, USA.
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Tuppurainen H, Laurila N, Nätynki M, Eshraghi L, Tervasmäki A, Erichsen L, Sørensen CS, Pylkäs K, Winqvist R, Peltoketo H. PALB2-mutated human mammary cells display a broad spectrum of morphological and functional abnormalities induced by increased TGFβ signaling. Cell Mol Life Sci 2024; 81:173. [PMID: 38597967 PMCID: PMC11006627 DOI: 10.1007/s00018-024-05183-6] [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: 06/02/2023] [Revised: 02/16/2024] [Accepted: 02/19/2024] [Indexed: 04/11/2024]
Abstract
Heterozygous mutations in any of three major genes, BRCA1, BRCA2 and PALB2, are associated with high-risk hereditary breast cancer susceptibility frequently seen as familial disease clustering. PALB2 is a key interaction partner and regulator of several vital cellular activities of BRCA1 and BRCA2, and is thus required for DNA damage repair and alleviation of replicative and oxidative stress. Little is however known about how PALB2-deficiency affects cell function beyond that, especially in the three-dimensional setting, and also about its role during early steps of malignancy development. To answer these questions, we have generated biologically relevant MCF10A mammary epithelial cell lines with mutations that are comparable to certain clinically important PALB2 defects. We show in a non-cancerous background how both mono- and biallelically PALB2-mutated cells exhibit gross spontaneous DNA damage and mitotic aberrations. Furthermore, PALB2-deficiency disturbs three-dimensional spheroid morphology, increases the migrational capacity and invasiveness of the cells, and broadly alters their transcriptome profiles. TGFβ signaling and KRT14 expression are enhanced in PALB2-mutated cells and their inhibition and knock down, respectively, lead to partial restoration of cell functions. KRT14-positive cells are also more abundant with DNA damage than KRT14-negative cells. The obtained results indicate comprehensive cellular changes upon PALB2 mutations, even in the presence of half dosage of wild type PALB2 and demonstrate how PALB2 mutations may predispose their carriers to malignancy.
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Affiliation(s)
- Hanna Tuppurainen
- Laboratory of Cancer Genetics and Tumor Biology, Translational Medicine Research Unit, Biocenter Oulu and Faculty of Medicine, Medical Research Center Oulu, University of Oulu, Oulu, Finland
| | - Niina Laurila
- Laboratory of Cancer Genetics and Tumor Biology, Translational Medicine Research Unit, Biocenter Oulu and Faculty of Medicine, Medical Research Center Oulu, University of Oulu, Oulu, Finland
| | - Marjut Nätynki
- Laboratory of Cancer Genetics and Tumor Biology, Translational Medicine Research Unit, Biocenter Oulu and Faculty of Medicine, Medical Research Center Oulu, University of Oulu, Oulu, Finland
| | - Leila Eshraghi
- Laboratory of Cancer Genetics and Tumor Biology, Translational Medicine Research Unit, Biocenter Oulu and Faculty of Medicine, Medical Research Center Oulu, University of Oulu, Oulu, Finland
- Garvan Institute of Medical Research, Sydney, Australia
| | - Anna Tervasmäki
- Laboratory of Cancer Genetics and Tumor Biology, Translational Medicine Research Unit, Biocenter Oulu and Faculty of Medicine, Medical Research Center Oulu, University of Oulu, Oulu, Finland
| | - Louisa Erichsen
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | | | - Katri Pylkäs
- Laboratory of Cancer Genetics and Tumor Biology, Translational Medicine Research Unit, Biocenter Oulu and Faculty of Medicine, Medical Research Center Oulu, University of Oulu, Oulu, Finland
- Northern Finland Laboratory Centre, Oulu, Finland
| | - Robert Winqvist
- Laboratory of Cancer Genetics and Tumor Biology, Translational Medicine Research Unit, Biocenter Oulu and Faculty of Medicine, Medical Research Center Oulu, University of Oulu, Oulu, Finland.
| | - Hellevi Peltoketo
- Laboratory of Cancer Genetics and Tumor Biology, Translational Medicine Research Unit, Biocenter Oulu and Faculty of Medicine, Medical Research Center Oulu, University of Oulu, Oulu, Finland.
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5
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Palihati M, Iwasaki H, Tsubouchi H. Analysis of the indispensable RAD51 cofactor BRCA2 in Naganishia liquefaciens, a Basidiomycota yeast. Life Sci Alliance 2024; 7:e202302342. [PMID: 38016757 PMCID: PMC10684384 DOI: 10.26508/lsa.202302342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Revised: 11/16/2023] [Accepted: 11/20/2023] [Indexed: 11/30/2023] Open
Abstract
The BRCA2 tumor suppressor plays a critical role in homologous recombination by regulating RAD51, the eukaryotic homologous recombinase. We identified the BRCA2 homolog in a Basidiomycota yeast, Naganishia liquefaciens BRCA2 homologs are found in many Basidiomycota species but not in Ascomycota species. Naganishia BRCA2 (Brh2, for BRCA2 homolog) is about one-third the size of human BRCA2. Brh2 carries three potential BRC repeats with two oligonucleotide/oligosaccharide-binding domains. The homolog of DSS1, a small acidic protein serving as an essential partner of BRCA2 was also identified. The yeast two-hybrid assay shows the interaction of Brh2 with both Rad51 and Dss1. Unlike human BRCA2, Brh2 is not required for normal cell growth, whereas loss of Dss1 results in slow growth. The loss of Brh2 caused pronounced sensitivity to UV and ionizing radiation, and their HR ability, as assayed by gene-targeting efficiency, is compromised. These phenotypes are indistinguishable from those of the rad51 mutant, and the rad51 brh2 double mutant. Naganishia Brh2 is likely the BRCA2 ortholog that functions as an indispensable auxiliary factor for Rad51.
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Affiliation(s)
- Maierdan Palihati
- https://ror.org/0112mx960 Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Hiroshi Iwasaki
- https://ror.org/0112mx960 Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Hideo Tsubouchi
- https://ror.org/0112mx960 Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
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6
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Fousek-Schuller VJ, Borgstahl GEO. The Intriguing Mystery of RPA Phosphorylation in DNA Double-Strand Break Repair. Genes (Basel) 2024; 15:167. [PMID: 38397158 PMCID: PMC10888239 DOI: 10.3390/genes15020167] [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: 12/20/2023] [Revised: 01/23/2024] [Accepted: 01/25/2024] [Indexed: 02/25/2024] Open
Abstract
Human Replication Protein A (RPA) was historically discovered as one of the six components needed to reconstitute simian virus 40 DNA replication from purified components. RPA is now known to be involved in all DNA metabolism pathways that involve single-stranded DNA (ssDNA). Heterotrimeric RPA comprises several domains connected by flexible linkers and is heavily regulated by post-translational modifications (PTMs). The structure of RPA has been challenging to obtain. Various structural methods have been applied, but a complete understanding of RPA's flexible structure, its function, and how it is regulated by PTMs has yet to be obtained. This review will summarize recent literature concerning how RPA is phosphorylated in the cell cycle, the structural analysis of RPA, DNA and protein interactions involving RPA, and how PTMs regulate RPA activity and complex formation in double-strand break repair. There are many holes in our understanding of this research area. We will conclude with perspectives for future research on how RPA PTMs control double-strand break repair in the cell cycle.
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Affiliation(s)
| | - Gloria E. O. Borgstahl
- Eppley Institute for Research in Cancer & Allied Diseases, UNMC, Omaha, NE 68198-6805, USA
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7
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Vanderlinden A, Jones CG, Myers KN, Rominiyi O, Collis SJ. DNA damage response inhibitors enhance tumour treating fields (TTFields) potency in glioma stem-like cells. Br J Cancer 2023; 129:1829-1840. [PMID: 37777579 PMCID: PMC10667536 DOI: 10.1038/s41416-023-02454-0] [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: 06/03/2023] [Revised: 09/19/2023] [Accepted: 09/22/2023] [Indexed: 10/02/2023] Open
Abstract
BACKGROUND High-grade gliomas are primary brain cancers with unacceptably low and persistent survival rates of 10-16 months for WHO grade 4 gliomas over the last 40 years, despite surgical resection and DNA-damaging chemo-radiotherapy. More recently, tumour-treating fields therapy (TTFields) has demonstrated modest survival benefit and been clinically approved in several countries. TTFields is thought to mediate anti-cancer activity by primarily disrupting mitosis. However, recent data suggest that TTFields may also attenuate DNA damage repair and replication fork dynamics, providing a potential platform for therapeutic combinations incorporating standard-of-care treatments and targeted DNA damage response inhibitors (DDRi). METHODS We have used patient-derived, typically resistant, glioma stem-like cells (GSCs) in combination with the previously validated preclinical Inovitro™ TTFields system together with a number of therapeutic DDRi. RESULTS We show that TTFields robustly activates PARP- and ATR-mediated DNA repair (including PARylation and CHK1 phosphorylation, respectively), whilst combining TTFields with PARP1 or ATR inhibitor treatment leads to significantly reduced clonogenic survival. The potency of each of these strategies is further enhanced by radiation treatment, leading to increased amounts of DNA damage with profound delay in DNA damage resolution. CONCLUSION To our knowledge, our findings represent the first report of TTFields applied with clinically approved or in-trial DDRi in GSC models and provides a basis for translational studies toward multimodal DDRi/TTFields-based therapeutic strategies for patients with these currently incurable tumours.
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Affiliation(s)
- Aurelie Vanderlinden
- Division of Clinical Medicine, The University of Sheffield, School of Medicine and Population Health, Sheffield, S10 2RX, UK
| | - Callum G Jones
- Division of Clinical Medicine, The University of Sheffield, School of Medicine and Population Health, Sheffield, S10 2RX, UK
| | - Katie N Myers
- Division of Clinical Medicine, The University of Sheffield, School of Medicine and Population Health, Sheffield, S10 2RX, UK
| | - Ola Rominiyi
- Division of Clinical Medicine, The University of Sheffield, School of Medicine and Population Health, Sheffield, S10 2RX, UK.
- Division of Neuroscience, The University of Sheffield, School of Medicine and Population Health, Sheffield, S10 2RX, UK.
- Department of Neurosurgery, Royal Hallamshire Hospital, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, S10 2JF, UK.
| | - Spencer J Collis
- Division of Clinical Medicine, The University of Sheffield, School of Medicine and Population Health, Sheffield, S10 2RX, UK.
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8
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Abstract
High-risk human papillomaviruses (HPVs) are associated with several human cancers. HPVs are small, DNA viruses that rely on host cell machinery for viral replication. The HPV life cycle takes place in the stratified epithelium, which is composed of different cell states, including terminally differentiating cells that are no longer active in the cell cycle. HPVs have evolved mechanisms to persist and replicate in the stratified epithelium by hijacking and modulating cellular pathways, including the DNA damage response (DDR). HPVs activate and exploit DDR pathways to promote viral replication, which in turn increases the susceptibility of the host cell to genomic instability and carcinogenesis. Here, we review recent advances in our understanding of the regulation of the host cell DDR by high-risk HPVs during the viral life cycle and discuss the potential cellular consequences of modulating DDR pathways.
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Affiliation(s)
- Caleb J Studstill
- Department of Microbiology and Immunology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA;
| | - Cary A Moody
- Department of Microbiology and Immunology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA;
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Kang Y, Han YG, Khim KW, Choi WG, Ju MK, Park K, Shin KJ, Chae YC, Choi JH, Kim H, Lee JY. Alteration of replication protein A binding mode on single-stranded DNA by NSMF potentiates RPA phosphorylation by ATR kinase. Nucleic Acids Res 2023; 51:7936-7950. [PMID: 37378431 PMCID: PMC10450186 DOI: 10.1093/nar/gkad543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 06/07/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023] Open
Abstract
Replication protein A (RPA), a eukaryotic single-stranded DNA (ssDNA) binding protein, dynamically interacts with ssDNA in different binding modes and plays essential roles in DNA metabolism such as replication, repair, and recombination. RPA accumulation on ssDNA due to replication stress triggers the DNA damage response (DDR) by activating the ataxia telangiectasia and RAD3-related (ATR) kinase, which phosphorylates itself and downstream DDR factors, including RPA. We recently reported that the N-methyl-D-aspartate receptor synaptonuclear signaling and neuronal migration factor (NSMF), a neuronal protein associated with Kallmann syndrome, promotes RPA32 phosphorylation via ATR upon replication stress. However, how NSMF enhances ATR-mediated RPA32 phosphorylation remains elusive. Here, we demonstrate that NSMF colocalizes and physically interacts with RPA at DNA damage sites in vivo and in vitro. Using purified RPA and NSMF in biochemical and single-molecule assays, we find that NSMF selectively displaces RPA in the more weakly bound 8- and 20-nucleotide binding modes from ssDNA, allowing the retention of more stable RPA molecules in the 30-nt binding mode. The 30-nt binding mode of RPA enhances RPA32 phosphorylation by ATR, and phosphorylated RPA becomes stabilized on ssDNA. Our findings provide new mechanistic insight into how NSMF facilitates the role of RPA in the ATR pathway.
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Affiliation(s)
- Yujin Kang
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Ye Gi Han
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Keon Woo Khim
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Woo Gyun Choi
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Min Kyung Ju
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Kibeom Park
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Kyeong Jin Shin
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Young Chan Chae
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Jang Hyun Choi
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
- Institute of Basic Science Center for Genomic Integrity, Ulsan 44919, Republic of Korea
| | - Hongtae Kim
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
- Institute of Basic Science Center for Genomic Integrity, Ulsan 44919, Republic of Korea
| | - Ja Yil Lee
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
- Institute of Basic Science Center for Genomic Integrity, Ulsan 44919, Republic of Korea
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10
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Uchida C, Niida H, Sakai S, Iijima K, Kitagawa K, Ohhata T, Shiotani B, Kitagawa M. p130RB2 positively contributes to ATR activation in response to replication stress via the RPA32-ETAA1 axis. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2023; 1870:119484. [PMID: 37201767 DOI: 10.1016/j.bbamcr.2023.119484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 03/17/2023] [Accepted: 04/23/2023] [Indexed: 05/20/2023]
Abstract
Ataxia-telangiectasia mutated and Rad3-related (ATR) kinase is a crucial regulator of the cell cycle checkpoint and activated in response to DNA replication stress by two independent pathways via RPA32-ETAA1 and TopBP1. However, the precise activation mechanism of ATR by the RPA32-ETAA1 pathway remains unclear. Here, we show that p130RB2, a member of the retinoblastoma protein family, participates in the pathway under hydroxyurea-induced DNA replication stress. p130RB2 binds to ETAA1, but not TopBP1, and depletion of p130RB2 inhibits the RPA32-ETAA1 interaction under replication stress. Moreover, p130RB2 depletion reduces ATR activation accompanied by phosphorylation of its targets RPA32, Chk1, and ATR itself. It also causes improper re-progression of S phase with retaining single-stranded DNA after cancelation of the stress, which leads to an increase in the anaphase bridge phenotype and a decrease in cell survival. Importantly, restoration of p130RB2 rescued the disrupted phenotypes of p130RB2 knockdown cells. These results suggest positive involvement of p130RB2 in the RPA32-ETAA1-ATR axis and proper re-progression of the cell cycle to maintain genome integrity.
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Affiliation(s)
- Chiharu Uchida
- Advanced Research Facilities & Services, Preeminent Medical Photonics Education & Research Center, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 431-3192, Japan.
| | - Hiroyuki Niida
- Department of Molecular Biology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 431-3192, Japan
| | - Satoshi Sakai
- Department of Molecular Biology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 431-3192, Japan
| | - Kenta Iijima
- Laboratory Animal Facilities & Services, Preeminent Medical Photonics Education & Research Center, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 431-3192, Japan
| | - Kyoko Kitagawa
- Department of Environmental Health, University of Occupational and Environmental Health, Kitakyushu, Fukuoka 807-8555, Japan
| | - Tatsuya Ohhata
- Department of Molecular Biology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 431-3192, Japan
| | - Bunsyo Shiotani
- Laboratory of Genome Stress Signaling, National Cancer Center Research Institute, Chuo-ku, Tokyo 104-0045, Japan
| | - Masatoshi Kitagawa
- Department of Molecular Biology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 431-3192, Japan
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11
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Yano K, Shiotani B. Emerging strategies for cancer therapy by ATR inhibitors. Cancer Sci 2023. [PMID: 37189251 DOI: 10.1111/cas.15845] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 04/19/2023] [Accepted: 04/29/2023] [Indexed: 05/17/2023] Open
Abstract
DNA replication stress (RS) causes genomic instability and vulnerability in cancer cells. To counteract RS, cells have evolved various mechanisms involving the ATR kinase signaling pathway, which regulates origin firing, cell cycle checkpoints, and fork stabilization to secure the fidelity of replication. However, ATR signaling also alleviates RS to support cell survival by driving RS tolerance, thereby contributing to therapeutic resistance. Cancer cells harboring genetic mutations and other changes that disrupt normal DNA replication increase the risk of DNA damage and the levels of RS, conferring addiction to ATR activity for sustainable replication and susceptibility to therapeutic approaches using ATR inhibitors (ATRis). Therefore, clinical trials are currently being conducted to evaluate the efficacy of ATRis as monotherapies or in combination with other drugs and biomarkers. In this review, we discuss recent advances in the elucidation of the mechanisms by which ATR functions in the RS response and its therapeutic relevance when utilizing ATRis.
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Affiliation(s)
- Kimiyoshi Yano
- Laboratory of Genome Stress Signaling, National Cancer Center Research Institute, Tokyo, Japan
| | - Bunsyo Shiotani
- Laboratory of Genome Stress Signaling, National Cancer Center Research Institute, Tokyo, Japan
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12
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Jackson LM, Moldovan GL. Mechanisms of PARP1 inhibitor resistance and their implications for cancer treatment. NAR Cancer 2022; 4:zcac042. [PMID: 36568963 PMCID: PMC9773381 DOI: 10.1093/narcan/zcac042] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 11/28/2022] [Accepted: 12/06/2022] [Indexed: 12/24/2022] Open
Abstract
The discovery of synthetic lethality as a result of the combined loss of PARP1 and BRCA has revolutionized the treatment of DNA repair-deficient cancers. With the development of PARP inhibitors, patients displaying germline or somatic mutations in BRCA1 or BRCA2 were presented with a novel therapeutic strategy. However, a large subset of patients do not respond to PARP inhibitors. Furthermore, many of those who do respond eventually acquire resistance. As such, combating de novo and acquired resistance to PARP inhibitors remains an obstacle in achieving durable responses in patients. In this review, we touch on some of the key mechanisms of PARP inhibitor resistance, including restoration of homologous recombination, replication fork stabilization and suppression of single-stranded DNA gap accumulation, as well as address novel approaches for overcoming PARP inhibitor resistance.
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Affiliation(s)
- Lindsey M Jackson
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - George-Lucian Moldovan
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
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13
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Foo TK, Xia B. BRCA1-Dependent and Independent Recruitment of PALB2-BRCA2-RAD51 in the DNA Damage Response and Cancer. Cancer Res 2022; 82:3191-3197. [PMID: 35819255 PMCID: PMC9481714 DOI: 10.1158/0008-5472.can-22-1535] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 06/22/2022] [Accepted: 07/08/2022] [Indexed: 11/16/2022]
Abstract
The BRCA1-PALB2-BRCA2 axis plays essential roles in the cellular response to DNA double-strand breaks (DSB), maintenance of genome integrity, and suppression of cancer development. Upon DNA damage, BRCA1 is recruited to DSBs, where it facilitates end resection and recruits PALB2 and its associated BRCA2 to load the central recombination enzyme RAD51 to initiate homologous recombination (HR) repair. In recent years, several BRCA1-independent mechanisms of PALB2 recruitment have also been reported. Collectively, these available data illustrate a series of hierarchical, context-dependent, and cooperating mechanisms of PALB2 recruitment that is critical for HR and therapy response either in the presence or absence of BRCA1. Here, we review these BRCA1-dependent and independent mechanisms and their importance in DSB repair, cancer development, and therapy. As BRCA1-mutant cancer cells regain HR function, for which PALB2 is generally required, and become resistant to targeted therapies, such as PARP inhibitors, targeting BRCA1-independent mechanisms of PALB2 recruitment represents a potential new avenue to improve treatment of BRCA1-mutant tumors.
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Affiliation(s)
- Tzeh Keong Foo
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey and Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, New Jersey
| | - Bing Xia
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey and Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, New Jersey
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14
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Functional assessment of missense variants of uncertain significance in the cancer susceptibility gene PALB2. NPJ Breast Cancer 2022; 8:86. [PMID: 35853885 PMCID: PMC9296472 DOI: 10.1038/s41523-022-00454-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Accepted: 07/05/2022] [Indexed: 11/10/2022] Open
Abstract
Germline PALB2 pathogenic variants are associated with an increased lifetime risk for breast, pancreatic, and ovarian cancer. However, the interpretation of the pathogenicity of numerous PALB2 missense variants of uncertain significance (VUSs) identified in germline genetic testing remains a challenge. Here we selected ten potentially pathogenic PALB2 VUSs identified in 2279 Chinese patients with breast cancer and evaluated their impacts on PALB2 function by systematic functional assays. We showed that three PALB2 VUSs p.K16M [c.47 A > T], p.L24F [c.72 G > C], and p.L35F [c.103 C > T] in the coiled-coil domain impaired PALB2-mediated homologous recombination. The p.L24F and p.L35F variants partially disrupted BRCA1-PALB2 interactions, reduced RAD51 foci formation in response to DNA damage, abrogated ionizing radiation-induced G2/M checkpoint maintenance, and conferred increased sensitivity to olaparib and cisplatin. The p.K16M variant presented mild effects on BRCA1-PALB2 interactions and RAD51 foci formation. Altogether, we identify two novel PALB2 VUSs, p.L24F and p.L35F, that compromise PALB2 function and may increase cancer risk. These two variants display marked olaparib and cisplatin sensitivity and may help predict response to targeted therapy in the clinical treatment of patients with these variants.
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15
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Saxena S, Zou L. Hallmarks of DNA replication stress. Mol Cell 2022; 82:2298-2314. [PMID: 35714587 DOI: 10.1016/j.molcel.2022.05.004] [Citation(s) in RCA: 114] [Impact Index Per Article: 57.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 04/15/2022] [Accepted: 05/04/2022] [Indexed: 12/12/2022]
Abstract
Faithful DNA replication is critical for the maintenance of genomic integrity. Although DNA replication machinery is highly accurate, the process of DNA replication is constantly challenged by DNA damage and other intrinsic and extrinsic stresses throughout the genome. A variety of cellular stresses interfering with DNA replication, which are collectively termed replication stress, pose a threat to genomic stability in both normal and cancer cells. To cope with replication stress and maintain genomic stability, cells have evolved a complex network of cellular responses to alleviate and tolerate replication problems. This review will focus on the major sources of replication stress, the impacts of replication stress in cells, and the assays to detect replication stress, offering an overview of the hallmarks of DNA replication stress.
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Affiliation(s)
- Sneha Saxena
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Lee Zou
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA; Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
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16
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Insights into the Possible Molecular Mechanisms of Resistance to PARP Inhibitors. Cancers (Basel) 2022; 14:cancers14112804. [PMID: 35681784 PMCID: PMC9179506 DOI: 10.3390/cancers14112804] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 06/02/2022] [Accepted: 06/03/2022] [Indexed: 12/12/2022] Open
Abstract
Simple Summary The increasingly wide use of PARP inhibitors in breast, ovarian, pancreatic, and prostate cancers harbouring a pathogenic variant in BRCA1 or BRCA2 has highlighted the problem of resistance to therapy. This review summarises the complex interactions between PARP1, cell cycle regulation, response to stress replication, homologous recombination, and other DNA damage repair pathways in the setting of BRCA1/2 mutated cancers that could explain the development of primary or secondary resistance to PARP inhibitors. Abstract PARP1 enzyme plays an important role in DNA damage recognition and signalling. PARP inhibitors are approved in breast, ovarian, pancreatic, and prostate cancers harbouring a pathogenic variant in BRCA1 or BRCA2, where PARP1 inhibition results mainly in synthetic lethality in cells with impaired homologous recombination. However, the increasingly wide use of PARP inhibitors in clinical practice has highlighted the problem of resistance to therapy. Several different mechanisms of resistance have been proposed, although only the acquisition of secondary mutations in BRCA1/2 has been clinically proved. The aim of this review is to outline the key molecular findings that could explain the development of primary or secondary resistance to PARP inhibitors, analysing the complex interactions between PARP1, cell cycle regulation, PI3K/AKT signalling, response to stress replication, homologous recombination, and other DNA damage repair pathways in the setting of BRCA1/2 mutated cancers.
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17
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PP2A-B55: substrates and regulators in the control of cellular functions. Oncogene 2022; 41:1-14. [PMID: 34686773 DOI: 10.1038/s41388-021-02068-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 09/29/2021] [Accepted: 10/06/2021] [Indexed: 12/17/2022]
Abstract
PP2A is a major serine/threonine phosphatase class involved in the regulation of cell signaling through the removal of protein phosphorylation. This class of phosphatases is comprised of different heterotrimeric complexes displaying distinct substrate specificities. The present review will focus on one specific heterocomplex, the phosphatase PP2A-B55. Herein, we will report the direct substrates of this phosphatase identified to date, and its impact on different cell signaling cascades. We will additionally describe its negative regulation by its inhibitors Arpp19 and ENSA and their upstream kinase Greatwall. Finally, we will describe the essential molecular features defining PP2A-B55 substrate specificity that confer the correct temporal pattern of substrate dephosphorylation. The main objective of this review is to provide the reader with a unique source compiling all the knowledge of this particular holoenzyme that has evolved as a key enzyme for cell homeostasis and cancer development.
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18
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RPA phosphorylation facilitates RAD52 dependent homologous recombination in BRCA-deficient cells. Mol Cell Biol 2021; 42:e0052421. [PMID: 34928169 DOI: 10.1128/mcb.00524-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Loss of RAD52 is synthetically lethal in BRCA-deficient cells, owing to its role in backup homologous recombination (HR) repair of DNA double-strand breaks (DSBs). In HR in mammalian cells, DSBs are processed to single-stranded DNA (ssDNA) overhangs, which are then bound by Replication Protein A(RPA). RPA is exchanged for RAD51 by mediator proteins: in mammals BRCA2 is the primary mediator, however, RAD52 provides an alternative mediator pathway in BRCA-deficient cells. RAD51 stimulates strand exchange between homologous DNA duplexes, a critical step in HR. RPA phosphorylation and de-phosphorylation are important for HR, but its effect on RAD52 mediator function is unknown. Here, we show that RPA phosphorylation is required for RAD52 to salvage HR in BRCA-deficient cells. Using BRCA2-depleted human cells, in which the only available mediator pathway is RAD52-dependent, the expression of phosphorylation-deficient RPA mutant reduced HR. Furthermore, RPA-phospho-mutant cells showed reduced association of RAD52 with RAD51. Interestingly, there was no effect of RPA phosphorylation on RAD52 recruitment to repair foci. Finally, we show that RPA phosphorylation does not affect RAD52-dependent ssDNA annealing. Thus, although RAD52 can be recruited independently of RPA's phosphorylation status, RPA phosphorylation is required for RAD52's association with RAD51, and its subsequent promotion of RAD52-mediated HR.
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19
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Graziano S, Coll-Bonfill N, Teodoro-Castro B, Kuppa S, Jackson J, Shashkova E, Mahajan U, Vindigni A, Antony E, Gonzalo S. Lamin A/C recruits ssDNA protective proteins RPA and RAD51 to stalled replication forks to maintain fork stability. J Biol Chem 2021; 297:101301. [PMID: 34648766 PMCID: PMC8571089 DOI: 10.1016/j.jbc.2021.101301] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 09/15/2021] [Accepted: 10/08/2021] [Indexed: 12/11/2022] Open
Abstract
Lamin A/C provides a nuclear scaffold for compartmentalization of genome function that is important for genome integrity. Lamin A/C dysfunction is associated with cancer, aging, and degenerative diseases. The mechanisms whereby lamin A/C regulates genome stability remain poorly understood. We demonstrate a crucial role for lamin A/C in DNA replication. Lamin A/C binds to nascent DNA, especially during replication stress (RS), ensuring the recruitment of replication fork protective factors RPA and RAD51. These ssDNA-binding proteins, considered the first and second responders to RS respectively, function in the stabilization, remodeling, and repair of the stalled fork to ensure proper restart and genome stability. Reduced recruitment of RPA and RAD51 upon lamin A/C depletion elicits replication fork instability (RFI) characterized by MRE11 nuclease–mediated degradation of nascent DNA, RS-induced DNA damage, and sensitivity to replication inhibitors. Importantly, unlike homologous recombination–deficient cells, RFI in lamin A/C-depleted cells is not linked to replication fork reversal. Thus, the point of entry of nucleases is not the reversed fork but regions of ssDNA generated during RS that are not protected by RPA and RAD51. Consistently, RFI in lamin A/C-depleted cells is rescued by exogenous overexpression of RPA or RAD51. These data unveil involvement of structural nuclear proteins in the protection of ssDNA from nucleases during RS by promoting recruitment of RPA and RAD51 to stalled forks. Supporting this model, we show physical interaction between RPA and lamin A/C. We suggest that RS is a major source of genomic instability in laminopathies and lamin A/C-deficient tumors.
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Affiliation(s)
- Simona Graziano
- Edward A. Doisy Department of Biochemistry and Molecular Biology, St Louis University School of Medicine, St Louis, Missouri, USA
| | - Nuria Coll-Bonfill
- Edward A. Doisy Department of Biochemistry and Molecular Biology, St Louis University School of Medicine, St Louis, Missouri, USA
| | - Barbara Teodoro-Castro
- Edward A. Doisy Department of Biochemistry and Molecular Biology, St Louis University School of Medicine, St Louis, Missouri, USA
| | - Sahiti Kuppa
- Edward A. Doisy Department of Biochemistry and Molecular Biology, St Louis University School of Medicine, St Louis, Missouri, USA
| | - Jessica Jackson
- Edward A. Doisy Department of Biochemistry and Molecular Biology, St Louis University School of Medicine, St Louis, Missouri, USA
| | - Elena Shashkova
- Edward A. Doisy Department of Biochemistry and Molecular Biology, St Louis University School of Medicine, St Louis, Missouri, USA
| | - Urvashi Mahajan
- Edward A. Doisy Department of Biochemistry and Molecular Biology, St Louis University School of Medicine, St Louis, Missouri, USA
| | - Alessandro Vindigni
- Edward A. Doisy Department of Biochemistry and Molecular Biology, St Louis University School of Medicine, St Louis, Missouri, USA
| | - Edwin Antony
- Edward A. Doisy Department of Biochemistry and Molecular Biology, St Louis University School of Medicine, St Louis, Missouri, USA
| | - Susana Gonzalo
- Edward A. Doisy Department of Biochemistry and Molecular Biology, St Louis University School of Medicine, St Louis, Missouri, USA.
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20
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Le HP, Heyer WD, Liu J. Guardians of the Genome: BRCA2 and Its Partners. Genes (Basel) 2021; 12:genes12081229. [PMID: 34440403 PMCID: PMC8394001 DOI: 10.3390/genes12081229] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 08/04/2021] [Accepted: 08/06/2021] [Indexed: 12/28/2022] Open
Abstract
The tumor suppressor BRCA2 functions as a central caretaker of genome stability, and individuals who carry BRCA2 mutations are predisposed to breast, ovarian, and other cancers. Recent research advanced our mechanistic understanding of BRCA2 and its various interaction partners in DNA repair, DNA replication support, and DNA double-strand break repair pathway choice. In this review, we discuss the biochemical and structural properties of BRCA2 and examine how these fundamental properties contribute to DNA repair and replication fork stabilization in living cells. We highlight selected BRCA2 binding partners and discuss their role in BRCA2-mediated homologous recombination and fork protection. Improved mechanistic understanding of how BRCA2 functions in genome stability maintenance can enable experimental evidence-based evaluation of pathogenic BRCA2 mutations and BRCA2 pseudo-revertants to support targeted therapy.
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Affiliation(s)
- Hang Phuong Le
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616, USA; (H.P.L.); (W.-D.H.)
| | - Wolf-Dietrich Heyer
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616, USA; (H.P.L.); (W.-D.H.)
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | - Jie Liu
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616, USA; (H.P.L.); (W.-D.H.)
- Correspondence: ; Tel.: +1-530-752-3016
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21
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Zhou Q, Howard ME, Tu X, Zhu Q, Denbeigh JM, Remmes NB, Herman MG, Beltran CJ, Yuan J, Greipp PT, Boughey JC, Wang L, Johnson N, Goetz MP, Sarkaria JN, Lou Z, Mutter RW. Inhibition of ATM Induces Hypersensitivity to Proton Irradiation by Upregulating Toxic End Joining. Cancer Res 2021; 81:3333-3346. [PMID: 33597272 PMCID: PMC8260463 DOI: 10.1158/0008-5472.can-20-2960] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 12/30/2020] [Accepted: 02/11/2021] [Indexed: 12/15/2022]
Abstract
Proton Bragg peak irradiation has a higher ionizing density than conventional photon irradiation or the entrance of the proton beam profile. Whether targeting the DNA damage response (DDR) could enhance vulnerability to the distinct pattern of damage induced by proton Bragg peak irradiation is currently unknown. Here, we performed genetic or pharmacologic manipulation of key DDR elements and evaluated DNA damage signaling, DNA repair, and tumor control in cell lines and xenografts treated with the same physical dose across a radiotherapy linear energy transfer spectrum. Radiotherapy consisted of 6 MV photons and the entrance beam or Bragg peak of a 76.8 MeV spot scanning proton beam. More complex DNA double-strand breaks (DSB) induced by Bragg peak proton irradiation preferentially underwent resection and engaged homologous recombination (HR) machinery. Unexpectedly, the ataxia-telangiectasia mutated (ATM) inhibitor, AZD0156, but not an inhibitor of ATM and Rad3-related, rendered cells hypersensitive to more densely ionizing proton Bragg peak irradiation. ATM inhibition blocked resection and shunted more DSBs to processing by toxic ligation through nonhomologous end-joining, whereas loss of DNA ligation via XRCC4 or Lig4 knockdown rescued resection and abolished the enhanced Bragg peak cell killing. Proton Bragg peak monotherapy selectively sensitized cell lines and tumor xenografts with inherent HR defects, and the repair defect induced by ATM inhibitor coadministration showed enhanced efficacy in HR-proficient models. In summary, inherent defects in HR or administration of an ATM inhibitor in HR-proficient tumors selectively enhances the relative biological effectiveness of proton Bragg peak irradiation. SIGNIFICANCE: Coadministration of an ATM inhibitor rewires DNA repair machinery to render cancer cells uniquely hypersensitive to DNA damage induced by the proton Bragg peak, which is characterized by higher density ionization.See related commentary by Nickoloff, p. 3156.
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Affiliation(s)
- Qin Zhou
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | | | - Xinyi Tu
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | - Qian Zhu
- Department of Oncology, Mayo Clinic, Rochester, Minnesota
| | - Janet M Denbeigh
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | | | - Michael G Herman
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | - Chris J Beltran
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | - Jian Yuan
- Department of Oncology, Mayo Clinic, Rochester, Minnesota
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota
| | - Patricia T Greipp
- Division of Laboratory Genetics and Genomics, Mayo Clinic, Rochester, Minnesota
| | - Judy C Boughey
- Department of Surgery, Mayo Clinic, Rochester, Minnesota
| | - Liewei Wang
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota
| | - Neil Johnson
- Molecular Therapeutics Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Matthew P Goetz
- Division of Medical Oncology, Mayo Clinic, Rochester, Minnesota
| | - Jann N Sarkaria
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | - Zhenkun Lou
- Department of Oncology, Mayo Clinic, Rochester, Minnesota.
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota
| | - Robert W Mutter
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota.
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22
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The epigenetic regulator LSH maintains fork protection and genomic stability via MacroH2A deposition and RAD51 filament formation. Nat Commun 2021; 12:3520. [PMID: 34112784 PMCID: PMC8192551 DOI: 10.1038/s41467-021-23809-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 05/12/2021] [Indexed: 12/18/2022] Open
Abstract
The Immunodeficiency Centromeric Instability Facial Anomalies (ICF) 4 syndrome is caused by mutations in LSH/HELLS, a chromatin remodeler promoting incorporation of histone variant macroH2A. Here, we demonstrate that LSH depletion results in degradation of nascent DNA at stalled replication forks and the generation of genomic instability. The protection of stalled forks is mediated by macroH2A, whose knockdown mimics LSH depletion and whose overexpression rescues nascent DNA degradation. LSH or macroH2A deficiency leads to an impairment of RAD51 loading, a factor that prevents MRE11 and EXO1 mediated nascent DNA degradation. The defect in RAD51 loading is linked to a disbalance of BRCA1 and 53BP1 accumulation at stalled forks. This is associated with perturbed histone modifications, including abnormal H4K20 methylation that is critical for BRCA1 enrichment and 53BP1 exclusion. Altogether, our results illuminate the mechanism underlying a human syndrome and reveal a critical role of LSH mediated chromatin remodeling in genomic stability. LSH/HELLS is a chromatin remodeler promoting incorporation of histone variant macroH2A. Here the authors reveal a role for LSH in genome stability, in protecting nascent DNA at stalled forks mediated by macroH2A deposition and RAD51 filament formation.
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23
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Garbarino J, Eckroate J, Sundaram RK, Jensen RB, Bindra RS. Loss of ATRX confers DNA repair defects and PARP inhibitor sensitivity. Transl Oncol 2021; 14:101147. [PMID: 34118569 PMCID: PMC8203843 DOI: 10.1016/j.tranon.2021.101147] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/24/2021] [Accepted: 05/31/2021] [Indexed: 02/01/2023] Open
Abstract
Drug screen shows that ATRX KO leads to PARP inhibitor sensitivity in glioma cells. PARPi leads to greater levels of replication stress in ATRX KO cells than WT. IDH1 R132H and ATRX KO have similar levels of PARP inhibitor sensitivity. ATRi and PARPi have greater synergy in ATRX KO cells.
Alpha Thalassemia/Mental Retardation Syndrome X-Linked (ATRX) is mutated frequently in gliomas and represents a potential target for cancer therapies. ATRX is known to function as a histone chaperone that helps incorporate histone variant, H3.3, into the genome. Studies have implicated ATRX in key DNA damage response (DDR) pathways but a distinct role in DNA repair has yet to be fully elucidated. To further investigate the function of ATRX in the DDR, we created isogenic wild-type (WT) and ATRX knockout (KO) model cell lines using CRISPR-based gene targeting. These studies revealed that loss of ATRX confers sensitivity to poly(ADP)-ribose polymerase (PARP) inhibitors, which was linked to an increase in replication stress, as detected by increased activation of the ataxia telangiectasia and Rad3-related (ATR) signaling axis. ATRX mutations frequently co-occur with mutations in isocitrate dehydrogenase-1 and -2 (IDH1/2), and the latter mutations also induce HR defects and PARP inhibitor sensitivity. We found that the magnitude of PARP inhibitor sensitivity was equal in the context of each mutation alone, although no further sensitization was observed in combination, suggesting an epistatic interaction. Finally, we observed enhanced synergistic tumor cell killing in ATRX KO cells with ATR and PARP inhibition, which is commonly seen in HR-defective cells. Taken together, these data reveal that ATRX may be used as a molecular marker for DDR defects and PARP inhibitor sensitivity, independent of IDH1/2 mutations. These data highlight the important role of common glioma-associated mutations in the regulation of DDR, and novel avenues for molecularly guided therapeutic intervention.
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Affiliation(s)
- Jennifer Garbarino
- Department of Molecular Biochemistry and Biophysics, Yale University, New Haven, CT 06511, USA
| | - Jillian Eckroate
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Ranjini K Sundaram
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Ryan B Jensen
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT 06511, USA.
| | - Ranjit S Bindra
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT 06511, USA.
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24
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Mhaskar AN, Koornneef L, Zelensky AN, Houtsmuller AB, Baarends WM. High Resolution View on the Regulation of Recombinase Accumulation in Mammalian Meiosis. Front Cell Dev Biol 2021; 9:672191. [PMID: 34109178 PMCID: PMC8181746 DOI: 10.3389/fcell.2021.672191] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 04/19/2021] [Indexed: 11/19/2022] Open
Abstract
A distinguishing feature of meiotic DNA double-strand breaks (DSBs), compared to DSBs in somatic cells, is the fact that they are induced in a programmed and specifically orchestrated manner, which includes chromatin remodeling prior to DSB induction. In addition, the meiotic homologous recombination (HR) repair process that follows, is different from HR repair of accidental DSBs in somatic cells. For instance, meiotic HR involves preferred use of the homolog instead of the sister chromatid as a repair template and subsequent formation of crossovers and non-crossovers in a tightly regulated manner. An important outcome of this distinct repair pathway is the pairing of homologous chromosomes. Central to the initial steps in homology recognition during meiotic HR is the cooperation between the strand exchange proteins (recombinases) RAD51 and its meiosis-specific paralog DMC1. Despite our understanding of their enzymatic activity, details on the regulation of their assembly and subsequent molecular organization at meiotic DSBs in mammals have remained largely enigmatic. In this review, we summarize recent mouse data on recombinase regulation via meiosis-specific factors. Also, we reflect on bulk “omics” studies of initial meiotic DSB processing, compare these with studies using super-resolution microscopy in single cells, at single DSB sites, and explore the implications of these findings for our understanding of the molecular mechanisms underlying meiotic HR regulation.
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Affiliation(s)
- Aditya N Mhaskar
- Department of Developmental Biology, Erasmus MC, Rotterdam, Netherlands
| | - Lieke Koornneef
- Department of Developmental Biology, Erasmus MC, Rotterdam, Netherlands.,Oncode Institute, Utrecht, Netherlands
| | - Alex N Zelensky
- Department of Molecular Genetics, Erasmus MC, Rotterdam, Netherlands
| | - Adriaan B Houtsmuller
- Erasmus Optical Imaging Centre, Department of Pathology, Erasmus MC, Rotterdam, Netherlands.,Department of Pathology, Erasmus MC, Rotterdam, Netherlands
| | - Willy M Baarends
- Department of Developmental Biology, Erasmus MC, Rotterdam, Netherlands
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25
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Qiu S, Jiang G, Cao L, Huang J. Replication Fork Reversal and Protection. Front Cell Dev Biol 2021; 9:670392. [PMID: 34041245 PMCID: PMC8141627 DOI: 10.3389/fcell.2021.670392] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 04/19/2021] [Indexed: 12/12/2022] Open
Abstract
During genome replication, replication forks often encounter obstacles that impede their progression. Arrested forks are unstable structures that can give rise to collapse and rearrange if they are not properly processed and restarted. Replication fork reversal is a critical protective mechanism in higher eukaryotic cells in response to replication stress, in which forks reverse their direction to form a Holliday junction-like structure. The reversed replication forks are protected from nuclease degradation by DNA damage repair proteins, such as BRCA1, BRCA2, and RAD51. Some of these molecules work cooperatively, while others have unique functions. Once the stress is resolved, the replication forks can restart with the help of enzymes, including human RECQ1 helicase, but restart will not be considered here. Here, we review research on the key factors and mechanisms required for the remodeling and protection of stalled replication forks in mammalian cells.
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Affiliation(s)
- Shan Qiu
- Department of General Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,The MOE Key Laboratory of Biosystems Homeostasis and Protection, Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou, China.,Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, Zhejiang University, Haining, China
| | - Guixing Jiang
- Department of General Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Liping Cao
- Department of General Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jun Huang
- Department of General Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,The MOE Key Laboratory of Biosystems Homeostasis and Protection, Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou, China
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26
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Tye S, Ronson GE, Morris JR. A fork in the road: Where homologous recombination and stalled replication fork protection part ways. Semin Cell Dev Biol 2021; 113:14-26. [PMID: 32653304 PMCID: PMC8082280 DOI: 10.1016/j.semcdb.2020.07.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 07/06/2020] [Accepted: 07/06/2020] [Indexed: 12/14/2022]
Abstract
In response to replication hindrances, DNA replication forks frequently stall and are remodelled into a four-way junction. In such a structure the annealed nascent strand is thought to resemble a DNA double-strand break and remodelled forks are vulnerable to nuclease attack by MRE11 and DNA2. Proteins that promote the recruitment, loading and stabilisation of RAD51 onto single-stranded DNA for homology search and strand exchange in homologous recombination (HR) repair and inter-strand cross-link repair also act to set up RAD51-mediated protection of nascent DNA at stalled replication forks. However, despite the similarities of these pathways, several lines of evidence indicate that fork protection is not simply analogous to the RAD51 loading step of HR. Protection of stalled forks not only requires separate functions of a number of recombination proteins, but also utilises nucleases important for the resection steps of HR in alternative ways. Here we discuss how fork protection arises and how its differences with HR give insights into the differing contexts of these two pathways.
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Affiliation(s)
- Stephanie Tye
- Section of Structural and Synthetic Biology, Department of Infectious Disease, Imperial College London, London, SW7 2AZ, UK
| | - George E Ronson
- University of Birmingham, College of Medical Dental Schools, Institute of Cancer and Genomics Sciences, Birmingham Centre for Genome Biology, Vincent Drive, Edgbaston, Birmingham, B15 2TT, UK
| | - Joanna R Morris
- University of Birmingham, College of Medical Dental Schools, Institute of Cancer and Genomics Sciences, Birmingham Centre for Genome Biology, Vincent Drive, Edgbaston, Birmingham, B15 2TT, UK.
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27
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Reed MR, Maddukuri L, Ketkar A, Byrum SD, Zafar MK, Bostian ACL, Tackett AJ, Eoff RL. Inhibition of tryptophan 2,3-dioxygenase impairs DNA damage tolerance and repair in glioma cells. NAR Cancer 2021; 3:zcab014. [PMID: 33870196 PMCID: PMC8034706 DOI: 10.1093/narcan/zcab014] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 03/15/2021] [Accepted: 03/23/2021] [Indexed: 01/21/2023] Open
Abstract
Expression of tryptophan 2,3-dioxygenase (TDO) is a determinant of malignancy in gliomas through kynurenine (KYN) signaling. We report that inhibition of TDO activity attenuated recovery from replication stress and increased the genotoxic effects of bis-chloroethylnitrosourea (BCNU). Activation of the Chk1 arm of the replication stress response (RSR) was reduced when TDO activity was blocked prior to BCNU treatment, whereas phosphorylation of serine 33 (pS33) on replication protein A (RPA) was enhanced—indicative of increased fork collapse. Analysis of quantitative proteomic results revealed that TDO inhibition reduced nuclear 53BP1 and sirtuin levels. We confirmed that cells lacking TDO activity exhibited elevated gamma-H2AX signal and defective recruitment of 53BP1 to chromatin following BCNU treatment, which corresponded with delayed repair of DNA breaks. Addition of exogenous KYN increased the rate of break repair. TDO inhibition diminished SIRT7 deacetylase recruitment to chromatin, which increased histone H3K18 acetylation—a key mark involved in preventing 53BP1 recruitment to sites of DNA damage. TDO inhibition also sensitized cells to ionizing radiation (IR)-induced damage, but this effect did not involve altered 53BP1 recruitment. These experiments support a model where TDO-mediated KYN signaling helps fuel a robust response to replication stress and DNA damage.
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Affiliation(s)
- Megan R Reed
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Leena Maddukuri
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Amit Ketkar
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Stephanie D Byrum
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Maroof K Zafar
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - April C L Bostian
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Alan J Tackett
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Robert L Eoff
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
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28
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Duan H, Mansour S, Reed R, Gillis MK, Parent B, Liu B, Sztupinszki Z, Birkbak N, Szallasi Z, Elia AEH, Garber JE, Pathania S. E3 ligase RFWD3 is a novel modulator of stalled fork stability in BRCA2-deficient cells. J Cell Biol 2021; 219:151752. [PMID: 32391871 PMCID: PMC7265328 DOI: 10.1083/jcb.201908192] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 01/15/2020] [Accepted: 03/03/2020] [Indexed: 02/07/2023] Open
Abstract
BRCA1/2 help maintain genomic integrity by stabilizing stalled forks. Here, we identify the E3 ligase RFWD3 as an essential modulator of stalled fork stability in BRCA2-deficient cells and show that codepletion of RFWD3 rescues fork degradation, collapse, and cell sensitivity upon replication stress. Stalled forks in BRCA2-deficient cells accumulate phosphorylated and ubiquitinated replication protein A (ubq-pRPA), the latter of which is mediated by RFWD3. Generation of this intermediate requires SMARCAL1, suggesting that it depends on stalled fork reversal. We show that in BRCA2-deficient cells, rescuing fork degradation might not be sufficient to ensure fork repair. Depleting MRE11 in BRCA2-deficient cells does block fork degradation, but it does not prevent fork collapse and cell sensitivity in the presence of replication stress. No such ubq-pRPA intermediate is formed in BRCA1-deficient cells, and our results suggest that BRCA1 may function upstream of BRCA2 in the stalled fork repair pathway. Collectively, our data uncover a novel mechanism by which RFWD3 destabilizes forks in BRCA2-deficient cells.
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Affiliation(s)
- Haohui Duan
- Center for Personalized Cancer Therapy, University of Massachusetts, Boston, MA.,Department of Biology, University of Massachusetts, Boston, MA
| | - Sarah Mansour
- Department of Biology, University of Massachusetts, Boston, MA
| | | | | | | | - Ben Liu
- Dana-Farber Cancer Institute, Boston, MA
| | | | - Nicolai Birkbak
- Department of Molecular Medicine, Aarhus University, Aarhus, Denmark.,Bioinformatics Research Centre, Aarhus University, Aarhus, Denmark
| | - Zoltan Szallasi
- Danish Cancer Society Research Center, Copenhagen, Denmark.,Boston Children's Hospital, Computational Health Informatics Program, Boston, MA
| | - Andrew E H Elia
- Massachusetts General Hospital, Department of Radiation Oncology, Center for Cancer Research, Boston, MA
| | | | - Shailja Pathania
- Center for Personalized Cancer Therapy, University of Massachusetts, Boston, MA.,Department of Biology, University of Massachusetts, Boston, MA
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29
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Chabot T, Cheraud Y, Fleury F. Relationships between DNA repair and RTK-mediated signaling pathways. Biochim Biophys Acta Rev Cancer 2020; 1875:188495. [PMID: 33346130 DOI: 10.1016/j.bbcan.2020.188495] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 12/06/2020] [Accepted: 12/13/2020] [Indexed: 10/22/2022]
Abstract
Receptor Tyrosine Kinases (RTK) are an important family involved in numerous signaling pathways essential for proliferation, cell survival, transcription or cell-cycle regulation. Their role and involvement in cancer cell survival have been widely described in the literature, and are generally associated with overexpression and/or excessive activity in the cancer pathology. Because of these characteristics, RTKs are relevant targets in the fight against cancer. In the last decade, increasingly numerous works describe the role of RTK signaling in the modulation of DNA repair, thus providing evidence of the relationship between RTKs and the protein actors in the repair pathways. In this review, we propose a summary of RTKs described as potential modulators of double-stranded DNA repair pathways in order to put forward new lines of research aimed at the implementation of new therapeutic strategies targeting both DNA repair pathways and RTK-mediated signaling pathways.
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Affiliation(s)
- Thomas Chabot
- Mechanism and regulation of DNA repair team, UFIP, CNRS UMR 6286, Université de Nantes, 2 rue de la Houssinière, 44322 Nantes, France
| | - Yvonnick Cheraud
- Mechanism and regulation of DNA repair team, UFIP, CNRS UMR 6286, Université de Nantes, 2 rue de la Houssinière, 44322 Nantes, France
| | - Fabrice Fleury
- Mechanism and regulation of DNA repair team, UFIP, CNRS UMR 6286, Université de Nantes, 2 rue de la Houssinière, 44322 Nantes, France.
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30
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Huang TT, Brill E, Nair JR, Zhang X, Wilson KM, Chen L, Thomas CJ, Lee JM. Targeting the PI3K/mTOR Pathway Augments CHK1 Inhibitor-Induced Replication Stress and Antitumor Activity in High-Grade Serous Ovarian Cancer. Cancer Res 2020; 80:5380-5392. [PMID: 32998994 DOI: 10.1158/0008-5472.can-20-1439] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 08/04/2020] [Accepted: 09/18/2020] [Indexed: 01/08/2023]
Abstract
High-grade serous ovarian carcinoma (HGSOC) is the most lethal gynecologic malignancy in industrialized countries and has limited treatment options. Targeting ataxia-telangiectasia and Rad3-related/cell-cycle checkpoint kinase 1 (CHK1)-mediated S-phase and G2-M-phase cell-cycle checkpoints has been a promising therapeutic strategy in HGSOC. To improve the efficacy of CHK1 inhibitor (CHK1i), we conducted a high-throughput drug combination screening in HGSOC cells. PI3K/mTOR pathway inhibitors (PI3K/mTORi) showed supra-additive cytotoxicity with CHK1i. Combined treatment with CHK1i and PI3K/mTORi significantly attenuated cell viability and increased DNA damage, chromosomal breaks, and mitotic catastrophe compared with monotherapy. PI3K/mTORi decelerated fork speed by promoting new origin firing via increased CDC45, thus potentiating CHK1i-induced replication stress. PI3K/mTORi also augmented CHK1i-induced DNA damage by attenuating DNA homologous recombination repair activity and RAD51 foci formation. High expression of replication stress markers was associated with poor prognosis in patients with HGSOC. Our findings indicate that combined PI3K/mTORi and CHK1i induces greater cell death in HGSOC cells and in vivo models by causing lethal replication stress and DNA damage. This insight can be translated therapeutically by further developing combinations of PI3K and cell-cycle pathway inhibitors in HGSOC. SIGNIFICANCE: Dual inhibition of CHK1 and PI3K/mTOR pathways yields potent synthetic lethality by causing lethal replication stress and DNA damage in HGSOC, warranting further clinical development.
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Affiliation(s)
- Tzu-Ting Huang
- Women's Malignancies Branch, Center for Cancer Research, NCI, Bethesda, Maryland.
| | - Ethan Brill
- Women's Malignancies Branch, Center for Cancer Research, NCI, Bethesda, Maryland
| | - Jayakumar R Nair
- Women's Malignancies Branch, Center for Cancer Research, NCI, Bethesda, Maryland
| | - Xiaohu Zhang
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, NIH, Bethesda, Maryland
| | - Kelli M Wilson
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, NIH, Bethesda, Maryland
| | - Lu Chen
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, NIH, Bethesda, Maryland
| | - Craig J Thomas
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, NIH, Bethesda, Maryland.,Lymphoid Malignancies Branch, Center for Cancer Research, NCI, Bethesda, Maryland
| | - Jung-Min Lee
- Women's Malignancies Branch, Center for Cancer Research, NCI, Bethesda, Maryland
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31
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Dueva R, Iliakis G. Replication protein A: a multifunctional protein with roles in DNA replication, repair and beyond. NAR Cancer 2020; 2:zcaa022. [PMID: 34316690 PMCID: PMC8210275 DOI: 10.1093/narcan/zcaa022] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/23/2020] [Accepted: 08/27/2020] [Indexed: 02/07/2023] Open
Abstract
Single-stranded DNA (ssDNA) forms continuously during DNA replication and is an important intermediate during recombination-mediated repair of damaged DNA. Replication protein A (RPA) is the major eukaryotic ssDNA-binding protein. As such, RPA protects the transiently formed ssDNA from nucleolytic degradation and serves as a physical platform for the recruitment of DNA damage response factors. Prominent and well-studied RPA-interacting partners are the tumor suppressor protein p53, the RAD51 recombinase and the ATR-interacting proteins ATRIP and ETAA1. RPA interactions are also documented with the helicases BLM, WRN and SMARCAL1/HARP, as well as the nucleotide excision repair proteins XPA, XPG and XPF–ERCC1. Besides its well-studied roles in DNA replication (restart) and repair, accumulating evidence shows that RPA is engaged in DNA activities in a broader biological context, including nucleosome assembly on nascent chromatin, regulation of gene expression, telomere maintenance and numerous other aspects of nucleic acid metabolism. In addition, novel RPA inhibitors show promising effects in cancer treatment, as single agents or in combination with chemotherapeutics. Since the biochemical properties of RPA and its roles in DNA repair have been extensively reviewed, here we focus on recent discoveries describing several non-canonical functions.
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Affiliation(s)
- Rositsa Dueva
- Institute of Medical Radiation Biology, University of Duisburg-Essen Medical School, 45122 Essen, Germany
| | - George Iliakis
- Institute of Medical Radiation Biology, University of Duisburg-Essen Medical School, 45122 Essen, Germany
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32
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Boonen RACM, Vreeswijk MPG, van Attikum H. Functional Characterization of PALB2 Variants of Uncertain Significance: Toward Cancer Risk and Therapy Response Prediction. Front Mol Biosci 2020; 7:169. [PMID: 33195396 PMCID: PMC7525363 DOI: 10.3389/fmolb.2020.00169] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 07/02/2020] [Indexed: 12/12/2022] Open
Abstract
In recent years it has become clear that pathogenic variants in PALB2 are associated with a high risk for breast, ovarian and pancreatic cancer. However, the clinical relevance of variants of uncertain significance (VUS) in PALB2, which are increasingly identified through clinical genetic testing, is unclear. Here we review recent advances in the functional characterization of VUS in PALB2. A combination of assays has been used to assess the impact of PALB2 VUS on its function in DNA repair by homologous recombination, cell cycle regulation and the control of cellular levels of reactive oxygen species (ROS). We discuss the outcome of this comprehensive analysis of PALB2 VUS, which showed that VUS in PALB2’s Coiled-Coil (CC) domain can impair the interaction with BRCA1, whereas VUS in its WD40 domain affect PALB2 protein stability. Accordingly, the CC and WD40 domains of PALB2 represent hotspots for variants that impair PALB2 protein function. We also provide a future perspective on the high-throughput analysis of VUS in PALB2, as well as the functional characterization of variants that affect PALB2 RNA splicing. Finally, we discuss how results from these functional assays can be valuable for predicting cancer risk and responsiveness to cancer therapy, such as treatment with PARP inhibitor- or platinum-based chemotherapy.
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Affiliation(s)
- Rick A C M Boonen
- Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
| | - Maaike P G Vreeswijk
- Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
| | - Haico van Attikum
- Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
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33
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Nguyen DD, Kim EY, Sang PB, Chai W. Roles of OB-Fold Proteins in Replication Stress. Front Cell Dev Biol 2020; 8:574466. [PMID: 33043007 PMCID: PMC7517361 DOI: 10.3389/fcell.2020.574466] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 08/25/2020] [Indexed: 12/20/2022] Open
Abstract
Accurate DNA replication is essential for maintaining genome stability. However, this stability becomes vulnerable when replication fork progression is stalled or slowed - a condition known as replication stress. Prolonged fork stalling can cause DNA damage, leading to genome instabilities. Thus, cells have developed several pathways and a complex set of proteins to overcome the challenge at stalled replication forks. Oligonucleotide/oligosaccharide binding (OB)-fold containing proteins are a group of proteins that play a crucial role in fork protection and fork restart. These proteins bind to single-stranded DNA with high affinity and prevent premature annealing and unwanted nuclease digestion. Among these OB-fold containing proteins, the best studied in eukaryotic cells are replication protein A (RPA) and breast cancer susceptibility protein 2 (BRCA2). Recently, another RPA-like protein complex CTC1-STN1-TEN1 (CST) complex has been found to counter replication perturbation. In this review, we discuss the latest findings on how these OB-fold containing proteins (RPA, BRCA2, CST) cooperate to safeguard DNA replication and maintain genome stability.
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Affiliation(s)
| | | | | | - Weihang Chai
- Department of Cancer Biology, Cardinal Bernardin Cancer Center, Loyola University Chicago Stritch School of Medicine, Maywood, IL, United States
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34
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Joseph SA, Taglialatela A, Leuzzi G, Huang JW, Cuella-Martin R, Ciccia A. Time for remodeling: SNF2-family DNA translocases in replication fork metabolism and human disease. DNA Repair (Amst) 2020; 95:102943. [PMID: 32971328 DOI: 10.1016/j.dnarep.2020.102943] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 07/24/2020] [Accepted: 07/26/2020] [Indexed: 02/07/2023]
Abstract
Over the course of DNA replication, DNA lesions, transcriptional intermediates and protein-DNA complexes can impair the progression of replication forks, thus resulting in replication stress. Failure to maintain replication fork integrity in response to replication stress leads to genomic instability and predisposes to the development of cancer and other genetic disorders. Multiple DNA damage and repair pathways have evolved to allow completion of DNA replication following replication stress, thus preserving genomic integrity. One of the processes commonly induced in response to replication stress is fork reversal, which consists in the remodeling of stalled replication forks into four-way DNA junctions. In normal conditions, fork reversal slows down replication fork progression to ensure accurate repair of DNA lesions and facilitates replication fork restart once the DNA lesions have been removed. However, in certain pathological situations, such as the deficiency of DNA repair factors that protect regressed forks from nuclease-mediated degradation, fork reversal can cause genomic instability. In this review, we describe the complex molecular mechanisms regulating fork reversal, with a focus on the role of the SNF2-family fork remodelers SMARCAL1, ZRANB3 and HLTF, and highlight the implications of fork reversal for tumorigenesis and cancer therapy.
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Affiliation(s)
- Sarah A Joseph
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY, USA
| | - Angelo Taglialatela
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY, USA
| | - Giuseppe Leuzzi
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY, USA
| | - Jen-Wei Huang
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY, USA
| | - Raquel Cuella-Martin
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY, USA
| | - Alberto Ciccia
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY, USA.
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35
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Wu S, Zhou J, Zhang K, Chen H, Luo M, Lu Y, Sun Y, Chen Y. Molecular Mechanisms of PALB2 Function and Its Role in Breast Cancer Management. Front Oncol 2020; 10:301. [PMID: 32185139 PMCID: PMC7059202 DOI: 10.3389/fonc.2020.00301] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 02/20/2020] [Indexed: 12/31/2022] Open
Abstract
Partner and localizer of BRCA2 (PALB2) is vital for homologous recombination (HR) repair in response to DNA double-strand breaks (DSBs). PALB2 functions as a tumor suppressor and participates in the maintenance of genome integrity. In this review, we summarize the current knowledge of the biological roles of the multifaceted PALB2 protein and of its regulation. Moreover, we describe the link between PALB2 pathogenic variants (PVs) and breast cancer predisposition, aggressive clinicopathological features, and adverse clinical prognosis. We also refer to both the opportunities and challenges that the identification of PALB2 PVs provides in breast cancer genetic counseling and precision medicine.
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Affiliation(s)
- Shijie Wu
- Department of Breast Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,The Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education, Zhejiang University School of Medicine, Hangzhou, China
| | - Jiaojiao Zhou
- Department of Breast Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,The Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education, Zhejiang University School of Medicine, Hangzhou, China
| | - Kun Zhang
- Department of Breast Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,The Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education, Zhejiang University School of Medicine, Hangzhou, China
| | - Huihui Chen
- Department of Breast Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,The Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education, Zhejiang University School of Medicine, Hangzhou, China
| | - Meng Luo
- Department of Breast Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,The Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education, Zhejiang University School of Medicine, Hangzhou, China
| | - Yuexin Lu
- Department of Breast Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,The Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education, Zhejiang University School of Medicine, Hangzhou, China
| | - Yuting Sun
- Department of Breast Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,The Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education, Zhejiang University School of Medicine, Hangzhou, China
| | - Yiding Chen
- Department of Breast Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,The Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education, Zhejiang University School of Medicine, Hangzhou, China
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36
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Gorecki L, Andrs M, Rezacova M, Korabecny J. Discovery of ATR kinase inhibitor berzosertib (VX-970, M6620): Clinical candidate for cancer therapy. Pharmacol Ther 2020; 210:107518. [PMID: 32109490 DOI: 10.1016/j.pharmthera.2020.107518] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 02/11/2020] [Indexed: 02/07/2023]
Abstract
Chemoresistance, radioresistance, and the challenge of achieving complete resection are major driving forces in the search for more robust and targeted anticancer therapies. Targeting the DNA damage response has recently attracted research interest, as these processes are enhanced in tumour cells. The major replication stress responder is ATM and Rad3-related (ATR) kinase, which is attracting attention worldwide with four drug candidates currently in phase I/II clinical trials. This review addresses a potent and selective small-molecule ATR inhibitor, which is known as VX-970 (also known as berzosertib or M6620), and summarizes the existing preclinical data to provide deep insight regarding its real potential. We also outline the transition from preclinical to clinical studies, as well as its relationships with other clinical candidates (AZD6738, VX-803 [M4344], and BAY1895344). The results suggest that VX-970 is indeed a promising anticancer drug that can be used both as monotherapy and in combination with either chemotherapy or radiotherapy strategies. Based on patient anamnesis and biomarker identification, VX-970 could become a valuable tool for oncologists in the fight against cancer.
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Affiliation(s)
- Lukas Gorecki
- Biomedical Research Center, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Martin Andrs
- Biomedical Research Center, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic; Laboratory of Cancer Cell Biology, Institute of Molecular Genetics of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic
| | - Martina Rezacova
- Department of Medical Biochemistry, Faculty of Medicine in Hradec Kralove, Charles University, Simkova 870, 500 38 Hradec Kralove, Czech Republic
| | - Jan Korabecny
- Biomedical Research Center, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic.
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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: 55] [Impact Index Per Article: 11.0] [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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Mutreja K, Krietsch J, Hess J, Ursich S, Berti M, Roessler FK, Zellweger R, Patra M, Gasser G, Lopes M. ATR-Mediated Global Fork Slowing and Reversal Assist Fork Traverse and Prevent Chromosomal Breakage at DNA Interstrand Cross-Links. Cell Rep 2019; 24:2629-2642.e5. [PMID: 30184498 PMCID: PMC6137818 DOI: 10.1016/j.celrep.2018.08.019] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 07/26/2018] [Accepted: 08/07/2018] [Indexed: 01/02/2023] Open
Abstract
Interstrand cross-links (ICLs) are toxic DNA lesions interfering with DNA metabolism that are induced by widely used anticancer drugs. They have long been considered absolute roadblocks for replication forks, implicating complex DNA repair processes at stalled or converging replication forks. Recent evidence challenged this view, proposing that single forks traverse ICLs by yet elusive mechanisms. Combining ICL immunolabeling and single-molecule approaches in human cells, we now show that ICL induction leads to global replication fork slowing, involving forks not directly challenged by ICLs. Active fork slowing is linked to rapid recruitment of RAD51 to replicating chromatin and to RAD51/ZRANB3-mediated fork reversal. This global modulation of fork speed and architecture requires ATR activation, promotes single-fork ICL traverse—here, directly visualized by electron microscopy—and prevents chromosomal breakage by untimely ICL processing. We propose that global fork slowing by remodeling provides more time for template repair and promotes bypass of residual lesions, limiting fork-associated processing. Fork slowing and reversal are also observed at forks not directly challenged by ICLs Fork reversal assists ICL traverse and limits DSBs associated with ICL unhooking ICL traverse can be directly visualized in human cells by electron microscopy ATR mediates global fork slowing and reversal upon different genotoxic treatments
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Affiliation(s)
- Karun Mutreja
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Jana Krietsch
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Jeannine Hess
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Sebastian Ursich
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Matteo Berti
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Fabienne K Roessler
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland; Center for Microscopy and Image Analysis, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Ralph Zellweger
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Malay Patra
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Gilles Gasser
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Massimo Lopes
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
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Graziano S, Kreienkamp R, Coll-Bonfill N, Gonzalo S. Causes and consequences of genomic instability in laminopathies: Replication stress and interferon response. Nucleus 2019; 9:258-275. [PMID: 29637811 PMCID: PMC5973265 DOI: 10.1080/19491034.2018.1454168] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Mammalian nuclei are equipped with a framework of intermediate filaments that function as a karyoskeleton. This nuclear scaffold, formed primarily by lamins (A-type and B-type), maintains the spatial and functional organization of the genome and of sub-nuclear compartments. Over the past decade, a body of evidence has highlighted the significance of these structural nuclear proteins in the maintenance of nuclear architecture and mechanical stability, as well as genome function and integrity. The importance of these structures is now unquestioned given the wide range of degenerative diseases that stem from LMNA gene mutations, including muscular dystrophy disorders, peripheral neuropathies, lipodystrophies, and premature aging syndromes. Here, we review our knowledge about how alterations in nuclear lamins, either by mutation or reduced expression, impact cellular mechanisms that maintain genome integrity. Despite the fact that DNA replication is the major source of DNA damage and genomic instability in dividing cells, how alterations in lamins function impact replication remains minimally explored. We summarize recent studies showing that lamins play a role in DNA replication, and that the DNA damage that accumulates upon lamins dysfunction is elicited in part by deprotection of replication forks. We also discuss the emerging model that DNA damage and replication stress are “sensed” at the cytoplasm by proteins that normally survey this space in search of foreign nucleic acids. In turn, these cytosolic sensors activate innate immune responses, which are materializing as important players in aging and cancer, as well as in the response to cancer immunotherapy.
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Affiliation(s)
- Simona Graziano
- a Edward A. Doisy Department of Biochemistry and Molecular Biology , Saint Louis University School of Medicine , St. Louis , MO , USA
| | - Ray Kreienkamp
- a Edward A. Doisy Department of Biochemistry and Molecular Biology , Saint Louis University School of Medicine , St. Louis , MO , USA
| | - Nuria Coll-Bonfill
- a Edward A. Doisy Department of Biochemistry and Molecular Biology , Saint Louis University School of Medicine , St. Louis , MO , USA
| | - Susana Gonzalo
- a Edward A. Doisy Department of Biochemistry and Molecular Biology , Saint Louis University School of Medicine , St. Louis , MO , USA
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40
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Lanz MC, Dibitetto D, Smolka MB. DNA damage kinase signaling: checkpoint and repair at 30 years. EMBO J 2019; 38:e101801. [PMID: 31393028 PMCID: PMC6745504 DOI: 10.15252/embj.2019101801] [Citation(s) in RCA: 158] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 07/03/2019] [Accepted: 07/24/2019] [Indexed: 12/27/2022] Open
Abstract
From bacteria to mammalian cells, damaged DNA is sensed and targeted by DNA repair pathways. In eukaryotes, kinases play a central role in coordinating the DNA damage response. DNA damage signaling kinases were identified over two decades ago and linked to the cell cycle checkpoint concept proposed by Weinert and Hartwell in 1988. Connections between the DNA damage signaling kinases and DNA repair were scant at first, and the initial perception was that the importance of these kinases for genome integrity was largely an indirect effect of their roles in checkpoints, DNA replication, and transcription. As more substrates of DNA damage signaling kinases were identified, it became clear that they directly regulate a wide range of DNA repair factors. Here, we review our current understanding of DNA damage signaling kinases, delineating the key substrates in budding yeast and humans. We trace the progress of the field in the last 30 years and discuss our current understanding of the major substrate regulatory mechanisms involved in checkpoint responses and DNA repair.
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Affiliation(s)
- Michael Charles Lanz
- Department of Molecular Biology and GeneticsWeill Institute for Cell and Molecular BiologyCornell UniversityIthacaNYUSA
| | - Diego Dibitetto
- Department of Molecular Biology and GeneticsWeill Institute for Cell and Molecular BiologyCornell UniversityIthacaNYUSA
| | - Marcus Bustamante Smolka
- Department of Molecular Biology and GeneticsWeill Institute for Cell and Molecular BiologyCornell UniversityIthacaNYUSA
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41
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Daza-Martin M, Densham RM, Morris JR. BRCA1-BARD1: the importance of being in shape. Mol Cell Oncol 2019; 6:e1656500. [PMID: 31692900 PMCID: PMC6816425 DOI: 10.1080/23723556.2019.1656500] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 08/12/2019] [Accepted: 08/13/2019] [Indexed: 11/24/2022]
Abstract
The breast cancer type-1 susceptibility protein (BRCA1) contributes to genome integrity through homologous recombinational DNA repair and by protecting stalled replication forks from nucleolytic degradation. We recently discovered that fork protection requires a conformational change of BRCA1 unimportant to homologous recombination repair, indicating separate roles for BRCA1 in these pathways.
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Affiliation(s)
- Manuel Daza-Martin
- Birmingham Centre for Genome Biology and Institute of Cancer and Genomics Sciences, University of Birmingham, Birmingham, UK
| | - Ruth M. Densham
- Birmingham Centre for Genome Biology and Institute of Cancer and Genomics Sciences, University of Birmingham, Birmingham, UK
| | - Joanna R. Morris
- Birmingham Centre for Genome Biology and Institute of Cancer and Genomics Sciences, University of Birmingham, Birmingham, UK
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42
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Ibler AEM, ElGhazaly M, Naylor KL, Bulgakova NA, F El-Khamisy S, Humphreys D. Typhoid toxin exhausts the RPA response to DNA replication stress driving senescence and Salmonella infection. Nat Commun 2019; 10:4040. [PMID: 31492859 PMCID: PMC6731267 DOI: 10.1038/s41467-019-12064-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 08/15/2019] [Indexed: 01/10/2023] Open
Abstract
Salmonella Typhi activates the host DNA damage response through the typhoid toxin, facilitating typhoid symptoms and chronic infections. Here we reveal a non-canonical DNA damage response, which we call RING (response induced by a genotoxin), characterized by accumulation of phosphorylated histone H2AX (γH2AX) at the nuclear periphery. RING is the result of persistent DNA damage mediated by toxin nuclease activity and is characterized by hyperphosphorylation of RPA, a sensor of single-stranded DNA (ssDNA) and DNA replication stress. The toxin overloads the RPA pathway with ssDNA substrate, causing RPA exhaustion and senescence. Senescence is also induced by canonical γΗ2ΑΧ foci revealing distinct mechanisms. Senescence is transmitted to non-intoxicated bystander cells by an unidentified senescence-associated secreted factor that enhances Salmonella infections. Thus, our work uncovers a mechanism by which genotoxic Salmonella exhausts the RPA response by inducing ssDNA formation, driving host cell senescence and facilitating infection.
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Affiliation(s)
- Angela E M Ibler
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
- Department of Pathology, Tennis Court Road, University of Cambridge, Cambridge, CB2 1QP, UK
| | - Mohamed ElGhazaly
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
| | - Kathryn L Naylor
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
| | - Natalia A Bulgakova
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
| | - Sherif F El-Khamisy
- The Healthy Life Span Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
- Center of Genomics, Zewail City of Science and Technology, Giza, Egypt
| | - Daniel Humphreys
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK.
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43
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Lin YF, Shih HY, Shang ZF, Kuo CT, Guo J, Du C, Lee H, Chen BPC. PIDD mediates the association of DNA-PKcs and ATR at stalled replication forks to facilitate the ATR signaling pathway. Nucleic Acids Res 2019; 46:1847-1859. [PMID: 29309644 PMCID: PMC5829747 DOI: 10.1093/nar/gkx1298] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 12/19/2017] [Indexed: 12/13/2022] Open
Abstract
The DNA-dependent protein kinase (DNA-PK), consisting of the DNA binding Ku70/80 heterodimer and the catalytic subunit DNA-PKcs, has been well characterized in the non-homologous end-joining mechanism for DNA double strand break (DSB) repair and radiation resistance. Besides playing a role in DSB repair, DNA-PKcs is required for the cellular response to replication stress and participates in the ATR-Chk1 signaling pathway. However, the mechanism through which DNA-PKcs is recruited to stalled replication forks is still unclear. Here, we report that the apoptosis mediator p53-induced protein with a death domain (PIDD) is required to promote DNA-PKcs activity in response to replication stress. PIDD is known to interact with PCNA upon UV-induced replication stress. Our results demonstrate that PIDD is required to recruit DNA-PKcs to stalled replication forks through direct binding to DNA-PKcs at the N’ terminal region. Disruption of the interaction between DNA-PKcs and PIDD not only compromises the ATR association and regulation of DNA-PKcs, but also the ATR signaling pathway, intra-S-phase checkpoint and cellular resistance to replication stress. Taken together, our results indicate that PIDD, but not the Ku heterodimer, mediates the DNA-PKcs activity at stalled replication forks and facilitates the ATR signaling pathway in the cellular response to replication stress.
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Affiliation(s)
- Yu-Fen Lin
- Division of Molecular Radiation Biology, Department of Radiation Oncology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA
| | - Hung-Ying Shih
- Division of Molecular Radiation Biology, Department of Radiation Oncology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA
| | - Zeng-Fu Shang
- Division of Molecular Radiation Biology, Department of Radiation Oncology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA
| | - Ching-Te Kuo
- Division of Molecular Radiation Biology, Department of Radiation Oncology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA.,Department of Life Science, National Taiwan University, Taipei 10617, Taiwan, Republic of China
| | - Jiaming Guo
- Division of Molecular Radiation Biology, Department of Radiation Oncology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA.,Department of Radiation Medicine, Faculty of Naval Medicine, Second Military Medical University, Shanghai 200433, People's Republic of China
| | - Chunying Du
- Department of Cancer and Cell Biology, College of Medicine, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Hsinyu Lee
- Department of Life Science, National Taiwan University, Taipei 10617, Taiwan, Republic of China
| | - Benjamin P C Chen
- Division of Molecular Radiation Biology, Department of Radiation Oncology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA
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44
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Oldreive CE, Byrd PJ, Stewart GS, Taylor AJ, Farhat S, Skowronska A, Smith E, Raghavan M, Janic D, Dokmanovic L, Clokie S, Davies N, Kwok M, Pratt G, Paneesha S, Moss P, Stankovic T, Taylor M. PALB2 variant status in hematological malignancies - a potential therapeutic target? Leuk Lymphoma 2019; 60:1823-1826. [PMID: 30614742 DOI: 10.1080/10428194.2018.1551539] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 11/09/2018] [Accepted: 11/18/2018] [Indexed: 01/05/2023]
Affiliation(s)
- Ceri E Oldreive
- a Institute of Cancer and Genomic Sciences, University of Birmingham , Birmingham , UK
| | - Philip J Byrd
- a Institute of Cancer and Genomic Sciences, University of Birmingham , Birmingham , UK
| | - Grant S Stewart
- a Institute of Cancer and Genomic Sciences, University of Birmingham , Birmingham , UK
| | - Alexander J Taylor
- a Institute of Cancer and Genomic Sciences, University of Birmingham , Birmingham , UK
| | - Sana Farhat
- a Institute of Cancer and Genomic Sciences, University of Birmingham , Birmingham , UK
| | - Anna Skowronska
- b West Midlands Regional Genetics Laboratory , Birmingham , UK
| | - Edward Smith
- a Institute of Cancer and Genomic Sciences, University of Birmingham , Birmingham , UK
| | - Manoj Raghavan
- a Institute of Cancer and Genomic Sciences, University of Birmingham , Birmingham , UK
| | - Dragana Janic
- c School of Medicine, University Children's Hospital , University of Belgrade , Belgrade , Serbia
| | - Lidija Dokmanovic
- c School of Medicine, University Children's Hospital , University of Belgrade , Belgrade , Serbia
| | - Sam Clokie
- b West Midlands Regional Genetics Laboratory , Birmingham , UK
| | - Nicholas Davies
- a Institute of Cancer and Genomic Sciences, University of Birmingham , Birmingham , UK
| | - Marwan Kwok
- a Institute of Cancer and Genomic Sciences, University of Birmingham , Birmingham , UK
| | - Guy Pratt
- a Institute of Cancer and Genomic Sciences, University of Birmingham , Birmingham , UK
| | | | - Paul Moss
- e Institute of Immunity and Infection, University of Birmingham , Birmingham , UK
| | - Tatjana Stankovic
- a Institute of Cancer and Genomic Sciences, University of Birmingham , Birmingham , UK
| | - Malcolm Taylor
- a Institute of Cancer and Genomic Sciences, University of Birmingham , Birmingham , UK
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45
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A Cell-Intrinsic Interferon-like Response Links Replication Stress to Cellular Aging Caused by Progerin. Cell Rep 2019; 22:2006-2015. [PMID: 29466729 PMCID: PMC5848491 DOI: 10.1016/j.celrep.2018.01.090] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 12/22/2017] [Accepted: 01/30/2018] [Indexed: 12/05/2022] Open
Abstract
Hutchinson-Gilford progeria syndrome (HGPS) is a premature aging disease caused by a truncated lamin A protein (progerin) that drives cellular and organismal decline. HGPS patient-derived fibroblasts accumulate genomic instability, but its underlying mechanisms and contribution to disease remain poorly understood. Here, we show that progerin-induced replication stress (RS) drives genomic instability by eliciting replication fork (RF) stalling and nuclease-mediated degradation. Rampant RS is accompanied by upregulation of the cGAS/STING cytosolic DNA sensing pathway and activation of a robust STAT1-regulated interferon (IFN)-like response. Reducing RS and the IFN-like response, especially with calcitriol, improves the fitness of progeria cells and increases the efficiency of cellular reprogramming. Importantly, other compounds that improve HGPS phenotypes reduce RS and the IFN-like response. Our study reveals mechanisms underlying progerin toxicity, including RS-induced genomic instability and activation of IFN-like responses, and their relevance for cellular decline in HGPS.
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46
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Turchick A, Liu Y, Zhao W, Cohen I, Glazer PM. Synthetic lethality of a cell-penetrating anti-RAD51 antibody in PTEN-deficient melanoma and glioma cells. Oncotarget 2019; 10:1272-1283. [PMID: 30863489 PMCID: PMC6407680 DOI: 10.18632/oncotarget.26654] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 01/09/2019] [Indexed: 12/14/2022] Open
Abstract
PTEN is a tumor suppressor that is highly mutated in a variety of human cancers. Recent studies have suggested a link between PTEN loss and deficiency in the non-homologous end-joining (NHEJ) pathway of DNA double strand break (DSB) repair. As a means to achieve synthetic lethality in this context, we tested the effect of 3E10, a cell-penetrating autoantibody that inhibits RAD51, a key factor in the alternative pathway of DSB repair, homology dependent repair (HDR). We report here that treatment of PTEN-deficient glioma cells with 3E10 leads to an accumulation of DNA damage causing decreased proliferation and increased cell death compared to isogenic PTEN proficient controls. Similarly, 3E10 was synthetically lethal to a series of PTEN-deficient, patient-derived primary melanoma cell populations. Further, 3E10 was found to synergize with a small molecule inhibitor of the ataxia telangiectasia and Rad3-related (ATR) protein, a DNA damage checkpoint kinase, in both PTEN-deficient glioma cells and primary melanoma cells. These results point to a targeted synthetic lethal strategy to treat PTEN-deficient cancers through a combination designed to disrupt both DNA repair and DNA damage checkpoint signaling.
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Affiliation(s)
- Audrey Turchick
- Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
| | - Yanfeng Liu
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT, USA
| | - Weixi Zhao
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT, USA
| | - Inessa Cohen
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT, USA
| | - Peter M. Glazer
- Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT, USA
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47
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Rickman K, Smogorzewska A. Advances in understanding DNA processing and protection at stalled replication forks. J Cell Biol 2019; 218:1096-1107. [PMID: 30670471 PMCID: PMC6446843 DOI: 10.1083/jcb.201809012] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 12/20/2018] [Accepted: 01/03/2019] [Indexed: 11/22/2022] Open
Abstract
The replisome, the molecular machine dedicated to copying DNA, encounters a variety of obstacles during S phase. Without a proper response to this replication stress, the genome becomes unstable, leading to disease, including cancer. The immediate response is localized to the stalled replisome and includes protection of the nascent DNA. A number of recent studies have provided insight into the factors recruited to and responsible for protecting stalled replication forks. In response to replication stress, the SNF2 family of DNA translocases has emerged as being responsible for remodeling replication forks in vivo. The protection of stalled replication forks requires the cooperation of RAD51, BRCA1, BRCA2, and many other DNA damage response proteins. In the absence of these fork protection factors, fork remodeling renders them vulnerable to degradation by nucleases and helicases, ultimately compromising genome integrity. In this review, we focus on the recent progress in understanding the protection, processing, and remodeling of stalled replication forks in mammalian cells.
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Affiliation(s)
- Kimberly Rickman
- Laboratory of Genome Maintenance, The Rockefeller University, New York, NY
| | - Agata Smogorzewska
- Laboratory of Genome Maintenance, The Rockefeller University, New York, NY
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48
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Song F, Li M, Liu G, Swapna G, Daigham NS, Xia B, Montelionep GT, Bunting SF. Antiparallel Coiled-Coil Interactions Mediate the Homodimerization of the DNA Damage-Repair Protein PALB2. Biochemistry 2018; 57:6581-6591. [PMID: 30289697 PMCID: PMC6652205 DOI: 10.1021/acs.biochem.8b00789] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Deficits in DNA damage-repair pathways are the root cause of several human cancers. In mammalian cells, DNA double-strand break repair is carried out by multiple mechanisms, including homologous recombination (HR). The partner and localizer of BRCA2 (PALB2), which is an essential factor for HR, binds to the breast cancer susceptibility 1 (BRCA1) protein at DNA double-strand breaks. At the break site, PALB2 also associates with the breast cancer susceptibility 2 (BRCA2) protein to form a multiprotein complex that facilitates HR. The BRCA1-PALB2 interaction is mediated by association of predicted helical coiled-coil regions in both proteins. PALB2 can also homodimerize through the formation of a coiled coil by the self-association of helical elements at the N-terminus of the PALB2 protein, and this homodimerization has been proposed to regulate the efficiency of HR. We have produced a segment of PALB2, designated PALB2cc (PALB2 coiled coil segment) that forms α-helical structures, which assemble into stable homodimers. PALB2cc also forms heterodimers with a helical segment of BRCA1, called BRCA1cc (BRCA1 coiled coil segment). The three-dimensional structure of the homodimer formed by PALB2cc was determined by solution NMR spectroscopy. This PALB2cc homodimer is a classical antiparallel coiled-coil leucine zipper. NMR chemical-shift perturbation studies were used to study dimer formation for both the PALB2cc homodimer and the PALB2cc/BRCA1cc heterodimer. The mutation of residue Leu24 of PALB2cc significantly reduces its homodimer stability, but has a more modest effect on the stability of the heterodimer formed between PALB2cc and BRCA1cc. We show that mutation of Leu24 leads to genomic instability and reduced cell viability after treatment with agents that induce DNA double-strand breaks. These studies may allow the identification of distinct mutations of PALB2cc that selectively disrupt homodimeric versus heterodimeric interactions, and reveal the specific role of PALB2cc homodimerization in HR.
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Affiliation(s)
- Fei Song
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, USA
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, USA
| | - Minxing Li
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, USA
| | - Gaohua Liu
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, USA
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, USA
| | - G.V.T. Swapna
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, USA
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, USA
| | - Nourhan S. Daigham
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, USA
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, USA
| | - Bing Xia
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08901, USA
| | - Gaetano T. Montelionep
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, USA
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, USA
| | - Samuel F. Bunting
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, USA
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Byrne BM, Oakley GG. Replication protein A, the laxative that keeps DNA regular: The importance of RPA phosphorylation in maintaining genome stability. Semin Cell Dev Biol 2018; 86:112-120. [PMID: 29665433 DOI: 10.1016/j.semcdb.2018.04.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 03/30/2018] [Accepted: 04/06/2018] [Indexed: 11/25/2022]
Abstract
The eukaryotic ssDNA-binding protein, Replication protein A (RPA), was first discovered almost three decades ago. Since then, much progress has been made to elucidate the critical roles for RPA in DNA metabolic pathways that help promote genomic stability. The canonical RPA heterotrimer (RPA1-3) is an essential coordinator of DNA metabolism that interacts with ssDNA and numerous protein partners to coordinate its roles in DNA replication, repair, recombination and telomere maintenance. An alternative form of RPA, termed aRPA, is formed by a complex of RPA4 with RPA1 and RPA3. aRPA is expressed differentially in cells compared to canonical RPA and has been shown to inhibit canonical RPA function while allowing for regular maintenance of cell viability. Interestingly, while aRPA is defective in DNA replication and cell cycle progression, it was shown to play a supporting role in nucleotide excision repair and recombination. The binding domains of canonical RPA interact with a growing number of partners involved in numerous genome maintenance processes. The protein interactions of the RPA-ssDNA complex are not only governed by competition between the binding proteins but also by post-translation modifications such as phosphorylation. Phosphorylation of RPA2 is an important post-translational modification of the RPA complex, and is essential for directing context-specific functions of the RPA complex in the DNA damage response. Due to the importance of RPA in cellular metabolism, it was identified as an appealing target for chemotherapeutic drug development that could be used in future cancer treatment regimens.
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Affiliation(s)
- Brendan M Byrne
- University of Nebraska Medical Center Department of Oral Biology, Lincoln NE, USA.
| | - Gregory G Oakley
- University of Nebraska Medical Center Department of Oral Biology, Lincoln NE, USA; Eppley Cancer Center, Omaha NE, USA.
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50
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Abstract
PALB2 (Partner and Localizer of BRCA2) was first identified as a BRCA2-interacting protein. Subsequently, PALB2 has been recognized as a cog in the cellular machinery for DNA repair by homologous recombination (HR). PALB2 also mediates S and G2 DNA damage checkpoints, and has an apparent function in protecting transcriptionally active genes from genotoxic stress. PALB2 also interacts with, is localized by, and functions downstream of BRCA1. Further, PALB2 interacts with other essential effectors of HR, including RAD51 and RAD51C, as well as BRCA2. Consistent with its function in HR and its interaction with key HR proteins, PALB2-deficient cells are hypersensitive to ionizing radiation and DNA interstrand crosslinking agents such as mitomycin C and cisplatin. Mechanistically, PALB2 is required for HR by mediating the recruitment of BRCA2 and the RAD51 recombinase to sites of DNA damage. Similar to bi-allelic loss-of-function mutations of BRCA1, BRCA2, RAD51 and RAD51C, bi-allelic mutations in PALB2 cause Fanconi anemia (FA), a rare childhood disorder which is associated with progressive bone marrow failure, congenital anomalies, and a predisposition to leukemia and solid tumors. Due to their close functional relationship, bi-allelic mutations of PALB2 and BRCA2 cause particularly severe forms of FA, called FANCN and FANCD1, both characterized by severe congenital abnormalities and very early onset of various cancers. This includes acute leukemias, Wilms tumor, medulloblastoma and neuroblastomas. Also, heterozygous germ-line mutations of PALB2, like mutations in several other essential HR genes listed above, yield an increased susceptibility to breast and pancreatic cancer.
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Affiliation(s)
- Helmut Hanenberg
- Department of Pediatrics III, University Children's Hospital Essen, University Duisburg-Essen, Essen Germany
| | - Paul R Andreassen
- Division of Experimental Hematology & Cancer Biology, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, Cincinnati OH, USA
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