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The SWI/SNF subunit SMARCD3 regulates cell cycle progression and predicts survival outcome in ER+ breast cancer. Breast Cancer Res Treat 2020; 185:601-614. [PMID: 33180234 DOI: 10.1007/s10549-020-05997-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 10/26/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE Chromatin remodeling plays an essential role in regulating transcriptional networks and timing of gene expression. Chromatin remodelers such as SWItch/Sucrose Non-Fermentable (SWI/SNF) harbor many protein components, with the catalytic subunit providing ATPase activity to displace histones along or from the DNA molecules, and associated subunits ensuring tissue specificity and transcriptional or co-transcriptional activities. Mutations in several of the SWI/SNF subunits have been linked to cancer. Here, we investigate between SMARCD3/Baf60c expression and hormone-positive (ER+) breast cancer. METHODS The level of SMARCD3 was detected by immunohistochemistry in breast cancer patient samples, and expression levels of SMARCD1, SMARCD2, and SMARCD3 were investigated using publicly available datasets from large cohorts of breast cancer patients. Using molecular biology and microscopy, we interrogated the cellular consequences of lower SMARCD3 expression. RESULTS Lower proliferation rates were observed in SMARCD3-depleted cells, which reflects a failure of the cell cycle progression and an increase in endoreplication. In the absence of SMARCD3, p21 accumulates in cells, but does not halt the cell cycle, and DNA damage accumulates and remains unrepaired. CONCLUSION Taken together, our data begin to explain why ER+ breast cancer patients with low-SMARCD3 expressing tumors exhibit reduced survival rates compared to patients expressing normal or higher levels of SMARCD3. SMARCD3 might act as a tumor suppressor through regulation of cell cycle checkpoints and could be a reliable and specific breast cancer prognostic biomarker.
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52
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Hays E, Nettleton E, Carter C, Morales M, Vo L, Passo M, Vélez-Cruz R. The SWI/SNF ATPase BRG1 stimulates DNA end resection and homologous recombination by reducing nucleosome density at DNA double strand breaks and by promoting the recruitment of the CtIP nuclease. Cell Cycle 2020; 19:3096-3114. [PMID: 33044911 PMCID: PMC7714457 DOI: 10.1080/15384101.2020.1831256] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
DNA double strand breaks (DSBs) are among the most toxic DNA lesions and can be repaired accurately through homologous recombination (HR). HR requires processing of the DNA ends by nucleases (DNA end resection) in order to generate the required single-stranded DNA (ssDNA) regions. The SWI/SNF chromatin remodelers are 10–15 subunit complexes that contain one ATPase (BRG1 or BRM). Multiple subunits of these complexes have recently been identified as a novel family of tumor suppressors. These complexes are capable of remodeling chromatin by pushing nucleosomes along the DNA. More recent studies have identified these chromatin remodelers as important factors in DNA repair. Using the DR-U2OS reporter system, we show that the down regulation of BRG1 significantly reduces HR efficiency, while BRM has a minor effect. Inactivation of BRG1 impairs DSB repair and results in a defect in DNA end resection, as measured by the amount of BrdU-containing ssDNA generated after DNA damage. Inactivation of BRG1 also impairs the activation of the ATR kinase, reduces the levels of chromatin-bound RPA, and reduces the number of RPA and RAD51 foci after DNA damage. This defect in DNA end resection is explained by the defective recruitment of GFP-CtIP to laser-induced DSBs in the absence of BRG1. Importantly, we show that BRG1 reduces nucleosome density at DSBs. Finally, inactivation of BRG1 renders cells sensitive to anti-cancer drugs that induce DSBs. This study identifies BRG1 as an important factor for HR, which suggests that BRG1-mutated cancers have a DNA repair vulnerability that can be exploited therapeutically.
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Affiliation(s)
- Emily Hays
- Department of Biochemistry and Molecular Genetics, Midwestern University , Downers Grove, IL, USA.,College of Graduate Studies, Midwestern University , Downers Grove, IL, USA
| | - Elizabeth Nettleton
- Chicago College of Osteopathic Medicine, Midwestern University , Downers Grove, IL, USA
| | - Caitlin Carter
- Chicago College of Osteopathic Medicine, Midwestern University , Downers Grove, IL, USA
| | - Mariangel Morales
- College of Graduate Studies, Midwestern University , Downers Grove, IL, USA.,Biomedical Sciences Program, Midwestern University , Downers Grove, IL, USA
| | - Lynn Vo
- Chicago College of Osteopathic Medicine, Midwestern University , Downers Grove, IL, USA
| | - Max Passo
- College of Graduate Studies, Midwestern University , Downers Grove, IL, USA.,Biomedical Sciences Program, Midwestern University , Downers Grove, IL, USA
| | - Renier Vélez-Cruz
- Department of Biochemistry and Molecular Genetics, Midwestern University , Downers Grove, IL, USA.,College of Graduate Studies, Midwestern University , Downers Grove, IL, USA.,Chicago College of Optometry, Midwestern University , Downers Grove, IL, USA
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53
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Retinoblastoma Tumor Suppressor Protein Roles in Epigenetic Regulation. Cancers (Basel) 2020; 12:cancers12102807. [PMID: 33003565 PMCID: PMC7600434 DOI: 10.3390/cancers12102807] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 09/19/2020] [Accepted: 09/27/2020] [Indexed: 12/14/2022] Open
Abstract
Simple Summary Loss of function of the retinoblastoma gene (RB1) is the rate-limiting step in the initiation of both the hereditary and sporadic forms of retinoblastoma tumor. Furthermore, loss of function of the retinoblastoma tumor suppressor protein (pRB) is frequently found in most human cancers. In retinoblastoma, tumor progression is driven by epigenetic changes following pRB loss. This review focuses on the diverse functions of pRB in epigenetic regulation. Abstract Mutations that result in the loss of function of pRB were first identified in retinoblastoma and since then have been associated with the propagation of various forms of cancer. pRB is best known for its key role as a transcriptional regulator during cell cycle exit. Beyond the ability of pRB to regulate transcription of cell cycle progression genes, pRB can remodel chromatin to exert several of its other biological roles. In this review, we discuss the diverse functions of pRB in epigenetic regulation including nucleosome mobilization, histone modifications, DNA methylation and non-coding RNAs.
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Pesch AM, Hirsh NH, Chandler BC, Michmerhuizen AR, Ritter CL, Androsiglio MP, Wilder-Romans K, Liu M, Gersch CL, Larios JM, Pierce LJ, Rae JM, Speers CW. Short-term CDK4/6 Inhibition Radiosensitizes Estrogen Receptor-Positive Breast Cancers. Clin Cancer Res 2020; 26:6568-6580. [PMID: 32967938 DOI: 10.1158/1078-0432.ccr-20-2269] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 08/09/2020] [Accepted: 09/18/2020] [Indexed: 12/15/2022]
Abstract
PURPOSE Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors have improved progression-free survival for metastatic, estrogen receptor-positive (ER+) breast cancers, but their role in the nonmetastatic setting remains unclear. We sought to understand the effects of CDK4/6 inhibition (CDK4/6i) and radiotherapy in multiple preclinical breast cancer models. EXPERIMENTAL DESIGN Transcriptomic and proteomic analyses were used to identify significantly altered pathways after CDK4/6i. Clonogenic assays were used to quantify the radiotherapy enhancement ratio (rER). DNA damage was quantified using γH2AX staining and the neutral comet assay. DNA repair was assessed using RAD51 foci formation and nonhomologous end joining (NHEJ) reporter assays. Orthotopic xenografts were used to assess the efficacy of combination therapy. RESULTS Palbociclib significantly radiosensitized multiple ER+ cell lines at low nanomolar, sub IC50 concentrations (rER: 1.21-1.52) and led to a decrease in the surviving fraction of cells at 2 Gy (P < 0.001). Similar results were observed in ribociclib-treated (rER: 1.08-1.68) and abemaciclib-treated (rER: 1.19-2.05) cells. Combination treatment decreased RAD51 foci formation (P < 0.001), leading to a suppression of homologous recombination activity, but did not affect NHEJ efficiency (P > 0.05). Immortalized breast epithelial cells and cells with acquired resistance to CDK4/6i did not demonstrate radiosensitization (rER: 0.94-1.11) or changes in RAD51 foci. In xenograft models, concurrent palbociclib and radiotherapy led to a significant decrease in tumor growth. CONCLUSIONS These studies provide preclinical rationale to test CDK4/6i and radiotherapy in women with locally advanced ER+ breast cancer at high risk for locoregional recurrence.
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Affiliation(s)
- Andrea M Pesch
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan.,Department of Pharmacology, University of Michigan, Ann Arbor, Michigan.,Rogel Cancer Center, University of Michigan, Ann Arbor, Michigan
| | - Nicole H Hirsh
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan.,Rogel Cancer Center, University of Michigan, Ann Arbor, Michigan
| | - Benjamin C Chandler
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan.,Rogel Cancer Center, University of Michigan, Ann Arbor, Michigan.,Cancer Biology Program, University of Michigan, Ann Arbor, Michigan
| | - Anna R Michmerhuizen
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan.,Rogel Cancer Center, University of Michigan, Ann Arbor, Michigan.,Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, Michigan
| | - Cassandra L Ritter
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan.,Rogel Cancer Center, University of Michigan, Ann Arbor, Michigan
| | | | - Kari Wilder-Romans
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan.,Rogel Cancer Center, University of Michigan, Ann Arbor, Michigan
| | - Meilan Liu
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan
| | - Christina L Gersch
- Rogel Cancer Center, University of Michigan, Ann Arbor, Michigan.,Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - José M Larios
- Rogel Cancer Center, University of Michigan, Ann Arbor, Michigan.,Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Lori J Pierce
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan
| | - James M Rae
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan.,Rogel Cancer Center, University of Michigan, Ann Arbor, Michigan.,Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Corey W Speers
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan. .,Rogel Cancer Center, University of Michigan, Ann Arbor, Michigan
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Harrod A, Lane KA, Downs JA. The role of the SWI/SNF chromatin remodelling complex in the response to DNA double strand breaks. DNA Repair (Amst) 2020; 93:102919. [PMID: 33087260 DOI: 10.1016/j.dnarep.2020.102919] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Mammalian cells possess multiple closely related SWI/SNF chromatin remodelling complexes. These complexes have been implicated in the cellular response to DNA double strand breaks (DSBs). Evidence suggests that SWI/SNF complexes contribute to successful repair via both the homologous recombination and non-homologous end joining pathways. In addition, repressing transcription near DSBs is dependent on SWI/SNF activity. Understanding these roles is important because SWI/SNF complexes are frequently dysregulated in cancer, and DNA DSB repair defects have the potential to be therapeutically exploited. In this graphical review, we summarise what is known about SWI/SNF contribution to DNA DSB responses in mammalian cells and provide an overview of the SWI/SNF-encoding gene alteration spectrum in human cancers.
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Affiliation(s)
- Alison Harrod
- Epigenetics and Genome Stability Team, The Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK
| | - Karen A Lane
- Epigenetics and Genome Stability Team, The Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK
| | - Jessica A Downs
- Epigenetics and Genome Stability Team, The Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK.
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Manickavinayaham S, Velez-Cruz R, Biswas AK, Chen J, Guo R, Johnson DG. The E2F1 transcription factor and RB tumor suppressor moonlight as DNA repair factors. Cell Cycle 2020; 19:2260-2269. [PMID: 32787501 PMCID: PMC7513849 DOI: 10.1080/15384101.2020.1801190] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 06/19/2020] [Accepted: 07/06/2020] [Indexed: 02/08/2023] Open
Abstract
The E2F1 transcription factor and RB tumor suppressor are best known for their roles in regulating the expression of genes important for cell cycle progression but, they also have transcription-independent functions that facilitate DNA repair at sites of damage. Depending on the type of DNA damage, E2F1 can recruit either the GCN5 or p300/CBP histone acetyltransferases to deposit different histone acetylation marks in flanking chromatin. At DNA double-strand breaks, E2F1 also recruits RB and the BRG1 ATPase to remodel chromatin and promote loading of the MRE11-RAD50-NBS1 complex. Knock-in mouse models demonstrate important roles for E2F1 post-translational modifications in regulating DNA repair and physiological responses to DNA damage. This review highlights how E2F1 moonlights in DNA repair, thus revealing E2F1 as a versatile protein that recruits many of the same chromatin-modifying enzymes to sites of DNA damage to promote repair that it recruits to gene promoters to regulate transcription.
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Affiliation(s)
- Swarnalatha Manickavinayaham
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Smithville, TX, USA
| | - Renier Velez-Cruz
- Department of Biochemistry and Molecular Genetics, College of Graduate Studies, Midwestern University, Downers Grove, IL, USA
| | - Anup K. Biswas
- Herbert Irving Comprehensive Cancer Center, Columbia University, New York, NY, USA
| | - Jie Chen
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Smithville, TX, USA
| | - Ruifeng Guo
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - David G. Johnson
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Smithville, TX, USA
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57
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Moulay Lakhdar I, Ferlazzo ML, Al Choboq J, Berthel E, Sonzogni L, Devic C, Granzotto A, Thariat J, Foray N. Fibroblasts from Retinoblastoma Patients Show Radiosensitivity Linked to Abnormal Localization of the ATM Protein. Curr Eye Res 2020; 46:546-557. [PMID: 32862699 DOI: 10.1080/02713683.2020.1808998] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
PURPOSE/AIM OF THE STUDY Retinoblastoma (Rb) is a rare form of pediatric cancer that develops from retina cells. Bilateral and some unilateral forms of Rb are associated with heterozygous germline mutations of the (retinoblastoma 1) RB1 gene. RB1 mutations are also associated with a significant risk of secondary malignancy like head and neck tumors. Hence, to date, even if Rb patients are less subjected to radiotherapy to treat their primary ocular tumors, their healthy tissues may be exposed to significant doses of ionizing radiation during the treatment against their secondary malignancies with a significant risk of adverse tissue reactions (radiosensitivity) and/or radiation-induced cancer (radiosusceptibility). However, the biological role of the Rb protein in response to radiation remains misunderstood. Since the ataxia telangiectasia mutated (ATM) protein is a key protein of radiation response and since untransformed skin fibroblasts are a current model to quantify cellular radiosensitivity, we investigated here for the first time the functionality of the ATM-dependent signaling and repair pathway of the radiation-induced DNA double-strand breaks (DSB) in irradiated skin fibroblasts derived from Rb patients. MATERIALS AND METHODS The major biomarkers of the DSB repair and signaling, namely clonogenic cell survival, micronuclei, nuclear foci of the phosphorylated forms of the X variant of the H2A histone (γH2AX), the phosphorylated forms of the ATM protein (pATM) and the meiotic recombination 11 nuclease (MRE11) were assessed in untransformed skin fibroblasts derived from three Rb patients. RESULTS Skin fibroblasts from Rb patients showed significant cellular radiosensitivity, incomplete DSB recognition, delay in the ATM nucleo-shuttling and exacerbated MRE11 nuclease activity. Treatment with statin and bisphosphonates led to significant complementation of these impairments. CONCLUSIONS Our findings strongly suggest the involvement of the ATM kinase in the radiosensitivity/radiosusceptibility phenotype observed in Rb cases.
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Affiliation(s)
- Ismahane Moulay Lakhdar
- Institut National De La Santé Et De La Recherche Médicale, UA8 Unit, Radiations, Defense, Health and Environment, Centre Léon-Bérard, Lyon, France
| | - Mélanie L Ferlazzo
- Institut National De La Santé Et De La Recherche Médicale, UA8 Unit, Radiations, Defense, Health and Environment, Centre Léon-Bérard, Lyon, France
| | - Joelle Al Choboq
- Institut National De La Santé Et De La Recherche Médicale, UA8 Unit, Radiations, Defense, Health and Environment, Centre Léon-Bérard, Lyon, France
| | - Elise Berthel
- Institut National De La Santé Et De La Recherche Médicale, UA8 Unit, Radiations, Defense, Health and Environment, Centre Léon-Bérard, Lyon, France
| | - Laurène Sonzogni
- Institut National De La Santé Et De La Recherche Médicale, UA8 Unit, Radiations, Defense, Health and Environment, Centre Léon-Bérard, Lyon, France
| | - Clément Devic
- Institut National De La Santé Et De La Recherche Médicale, UA8 Unit, Radiations, Defense, Health and Environment, Centre Léon-Bérard, Lyon, France.,Fibermetrix, 7 Allée De l'Europe, Entsheim, France
| | - Adeline Granzotto
- Institut National De La Santé Et De La Recherche Médicale, UA8 Unit, Radiations, Defense, Health and Environment, Centre Léon-Bérard, Lyon, France
| | | | - Nicolas Foray
- Institut National De La Santé Et De La Recherche Médicale, UA8 Unit, Radiations, Defense, Health and Environment, Centre Léon-Bérard, Lyon, France
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58
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Zluhan-Martínez E, Pérez-Koldenkova V, Ponce-Castañeda MV, Sánchez MDLP, García-Ponce B, Miguel-Hernández S, Álvarez-Buylla ER, Garay-Arroyo A. Beyond What Your Retina Can See: Similarities of Retinoblastoma Function between Plants and Animals, from Developmental Processes to Epigenetic Regulation. Int J Mol Sci 2020; 21:E4925. [PMID: 32664691 PMCID: PMC7404004 DOI: 10.3390/ijms21144925] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 06/29/2020] [Accepted: 07/07/2020] [Indexed: 12/15/2022] Open
Abstract
The Retinoblastoma protein (pRb) is a key cell cycle regulator conserved in a wide variety of organisms. Experimental analysis of pRb's functions in animals and plants has revealed that this protein participates in cell proliferation and differentiation processes. In addition, pRb in animals and its orthologs in plants (RBR), are part of highly conserved protein complexes which suggest the possibility that analogies exist not only between functions carried out by pRb orthologs themselves, but also in the structure and roles of the protein networks where these proteins are involved. Here, we present examples of pRb/RBR participation in cell cycle control, cell differentiation, and in the regulation of epigenetic changes and chromatin remodeling machinery, highlighting the similarities that exist between the composition of such networks in plants and animals.
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Affiliation(s)
- Estephania Zluhan-Martínez
- Laboratorio de Genética Molecular, Epigenética, Desarrollo y Evolución de Plantas, Instituto de Ecología, Universidad Nacional Autónoma de Mexico, 3er Circuito Ext. Junto a J. Botánico, Ciudad Universitaria, UNAM 04510, Mexico; (E.Z.-M.); (M.d.l.P.S.); (B.G.-P.)
- Posgrado en Ciencias Biomédicas, Universidad Nacional Autónoma de México, Av. Universidad 3000, Coyoacán 04510, Mexico
| | - Vadim Pérez-Koldenkova
- Laboratorio Nacional de Microscopía Avanzada, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Av. Cuauhtémoc, 330. Col. Doctores, Alc. Cuauhtémoc 06720, Mexico;
| | - Martha Verónica Ponce-Castañeda
- Unidad de Investigación Médica en Enfermedades Infecciosas, Centro Médico Nacional SXXI, Instituto Mexicano del Seguro Social, Mexico City 06720, Mexico;
| | - María de la Paz Sánchez
- Laboratorio de Genética Molecular, Epigenética, Desarrollo y Evolución de Plantas, Instituto de Ecología, Universidad Nacional Autónoma de Mexico, 3er Circuito Ext. Junto a J. Botánico, Ciudad Universitaria, UNAM 04510, Mexico; (E.Z.-M.); (M.d.l.P.S.); (B.G.-P.)
| | - Berenice García-Ponce
- Laboratorio de Genética Molecular, Epigenética, Desarrollo y Evolución de Plantas, Instituto de Ecología, Universidad Nacional Autónoma de Mexico, 3er Circuito Ext. Junto a J. Botánico, Ciudad Universitaria, UNAM 04510, Mexico; (E.Z.-M.); (M.d.l.P.S.); (B.G.-P.)
| | - Sergio Miguel-Hernández
- Laboratorio de Citopatología Ambiental, Departamento de Morfología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Campus Zacatenco, Calle Wilfrido Massieu Esquina Cda, Manuel Stampa 07738, Mexico;
| | - Elena R. Álvarez-Buylla
- Laboratorio de Genética Molecular, Epigenética, Desarrollo y Evolución de Plantas, Instituto de Ecología, Universidad Nacional Autónoma de Mexico, 3er Circuito Ext. Junto a J. Botánico, Ciudad Universitaria, UNAM 04510, Mexico; (E.Z.-M.); (M.d.l.P.S.); (B.G.-P.)
| | - Adriana Garay-Arroyo
- Laboratorio de Genética Molecular, Epigenética, Desarrollo y Evolución de Plantas, Instituto de Ecología, Universidad Nacional Autónoma de Mexico, 3er Circuito Ext. Junto a J. Botánico, Ciudad Universitaria, UNAM 04510, Mexico; (E.Z.-M.); (M.d.l.P.S.); (B.G.-P.)
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59
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Taiana E, Ronchetti D, Todoerti K, Nobili L, Tassone P, Amodio N, Neri A. LncRNA NEAT1 in Paraspeckles: A Structural Scaffold for Cellular DNA Damage Response Systems? Noncoding RNA 2020; 6:ncrna6030026. [PMID: 32630183 PMCID: PMC7549348 DOI: 10.3390/ncrna6030026] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 06/25/2020] [Accepted: 06/28/2020] [Indexed: 12/13/2022] Open
Abstract
Nuclear paraspeckle assembly transcript 1 (NEAT1) is a long non-coding RNA (lncRNA) reported to be frequently deregulated in various types of cancers and neurodegenerative processes. NEAT1 is an indispensable structural component of paraspeckles (PSs), which are dynamic and membraneless nuclear bodies that affect different cellular functions, including stress response. Furthermore, increasing evidence supports the crucial role of NEAT1 and essential structural proteins of PSs (PSPs) in the regulation of the DNA damage repair (DDR) system. This review aims to provide an overview of the current knowledge on the involvement of NEAT1 and PSPs in DDR, which might strengthen the rationale underlying future NEAT1-based therapeutic options in tumor and neurodegenerative diseases.
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Affiliation(s)
- Elisa Taiana
- Department of Oncology and Hemato-oncology, University of Milan, 20122 Milan, Italy; (D.R.); (L.N.)
- Hematology, Fondazione Cà Granda IRCCS Policlinico, 20122 Milan, Italy;
- Correspondence: (E.T.); (A.N.); Tel.: +39-02-5032-0420 (E.T. & A.N.)
| | - Domenica Ronchetti
- Department of Oncology and Hemato-oncology, University of Milan, 20122 Milan, Italy; (D.R.); (L.N.)
- Hematology, Fondazione Cà Granda IRCCS Policlinico, 20122 Milan, Italy;
| | - Katia Todoerti
- Hematology, Fondazione Cà Granda IRCCS Policlinico, 20122 Milan, Italy;
| | - Lucia Nobili
- Department of Oncology and Hemato-oncology, University of Milan, 20122 Milan, Italy; (D.R.); (L.N.)
| | - Pierfrancesco Tassone
- Department of Experimental and Clinical Medicine, Magna Graecia University of Catanzaro, 88100 Catanzaro, Italy; (P.T.); (N.A.)
| | - Nicola Amodio
- Department of Experimental and Clinical Medicine, Magna Graecia University of Catanzaro, 88100 Catanzaro, Italy; (P.T.); (N.A.)
| | - Antonino Neri
- Department of Oncology and Hemato-oncology, University of Milan, 20122 Milan, Italy; (D.R.); (L.N.)
- Hematology, Fondazione Cà Granda IRCCS Policlinico, 20122 Milan, Italy;
- Correspondence: (E.T.); (A.N.); Tel.: +39-02-5032-0420 (E.T. & A.N.)
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60
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Knarr M, Avelar RA, Sekhar SC, Kwiatkowski LJ, Dziubinski ML, McAnulty J, Skala S, Avril S, Drapkin R, DiFeo A. miR-181a initiates and perpetuates oncogenic transformation through the regulation of innate immune signaling. Nat Commun 2020; 11:3231. [PMID: 32591511 PMCID: PMC7320168 DOI: 10.1038/s41467-020-17030-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 06/08/2020] [Indexed: 01/17/2023] Open
Abstract
Genomic instability (GI) predisposes cells to malignant transformation, however the molecular mechanisms that allow for the propagation of cells with a high degree of genomic instability remain unclear. Here we report that miR-181a is able to transform fallopian tube secretory epithelial cells through the inhibition of RB1 and stimulator-of-interferon-genes (STING) to propagate cells with a high degree of GI. MiR-181a targeting of RB1 leads to profound nuclear defects and GI generating aberrant cytoplasmic DNA, however simultaneous miR-181a mediated inhibition of STING allows cells to bypass interferon mediated cell death. We also found that high miR-181a is associated with decreased IFNγ response and lymphocyte infiltration in patient tumors. DNA oncoviruses are the only known inhibitors of STING that allow for cellular transformation, thus, our findings are the first to identify a miRNA that can downregulate STING expression to suppress activation of intrinsic interferon signaling. This study introduces miR-181a as a putative biomarker and identifies the miR-181a-STING axis as a promising target for therapeutic exploitation.
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Affiliation(s)
- Matthew Knarr
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, 44106, USA.,Department of Obstetrics & Gynecology, The University of Michigan, Ann Arbor, MI, 48109, USA.,Department of Pathology, The University of Michigan, Ann Arbor, MI, 48109, USA
| | - Rita A Avelar
- Department of Obstetrics & Gynecology, The University of Michigan, Ann Arbor, MI, 48109, USA.,Department of Pathology, The University of Michigan, Ann Arbor, MI, 48109, USA.,The Rogel Cancer Center, The University of Michigan, Ann Arbor, MI, 48109, USA
| | - Sreeja C Sekhar
- Department of Obstetrics & Gynecology, The University of Michigan, Ann Arbor, MI, 48109, USA.,Department of Pathology, The University of Michigan, Ann Arbor, MI, 48109, USA.,The Rogel Cancer Center, The University of Michigan, Ann Arbor, MI, 48109, USA
| | - Lily J Kwiatkowski
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Michele L Dziubinski
- Department of Obstetrics & Gynecology, The University of Michigan, Ann Arbor, MI, 48109, USA.,Department of Pathology, The University of Michigan, Ann Arbor, MI, 48109, USA.,The Rogel Cancer Center, The University of Michigan, Ann Arbor, MI, 48109, USA
| | - Jessica McAnulty
- Department of Obstetrics & Gynecology, The University of Michigan, Ann Arbor, MI, 48109, USA.,Department of Pathology, The University of Michigan, Ann Arbor, MI, 48109, USA.,The Rogel Cancer Center, The University of Michigan, Ann Arbor, MI, 48109, USA
| | - Stephanie Skala
- Department of Pathology, The University of Michigan, Ann Arbor, MI, 48109, USA
| | - Stefanie Avril
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, 44106, USA.,Department of Pathology, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Ronny Drapkin
- Penn Ovarian Cancer Research Center, Department of Obstetrics and Gynecology, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, PA, USA
| | - Analisa DiFeo
- Department of Obstetrics & Gynecology, The University of Michigan, Ann Arbor, MI, 48109, USA. .,Department of Pathology, The University of Michigan, Ann Arbor, MI, 48109, USA. .,The Rogel Cancer Center, The University of Michigan, Ann Arbor, MI, 48109, USA.
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Functional genomics identifies new synergistic therapies for retinoblastoma. Oncogene 2020; 39:5338-5357. [PMID: 32572160 PMCID: PMC7391301 DOI: 10.1038/s41388-020-1372-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 06/03/2020] [Accepted: 06/12/2020] [Indexed: 12/19/2022]
Abstract
Local intravitreal or intra-arterial chemotherapy has improved therapeutic success for the pediatric cancer retinoblastoma (RB), but toxicity remains a major caveat. RB initiates primarily with RB1 loss or, rarely, MYCN amplification, but the critical downstream networks are incompletely understood. We set out to uncover perturbed molecular hubs, identify synergistic drug combinations to target these vulnerabilities, and expose and overcome drug resistance. We applied dynamic transcriptomic analysis to identify network hubs perturbed in RB versus normal fetal retina, and performed in vivo RNAi screens in RB1null and RB1wt;MYCNamp orthotopic xenografts to pinpoint essential hubs. We employed in vitro and in vivo studies to validate hits, define mechanism, develop new therapeutic modalities, and understand drug resistance. We identified BRCA1 and RAD51 as essential for RB cell survival. Their oncogenic activity was independent of BRCA1 functions in centrosome, heterochromatin, or ROS regulation, and instead linked to DNA repair. RAD51 depletion or inhibition with the small molecule inhibitor, B02, killed RB cells in a Chk1/Chk2/p53-dependent manner. B02 further synergized with clinically relevant topotecan (TPT) to engage this pathway, activating p53-BAX mediated killing of RB but not human retinal progenitor cells. Paradoxically, a B02/TPT-resistant tumor exhibited more DNA damage than sensitive RB cells. Resistance reflected dominance of the p53-p21 axis, which mediated cell cycle arrest instead of death. Deleting p21 or applying the BCL2/BCL2L1 inhibitor Navitoclax re-engaged the p53-BAX axis, and synergized with B02, TPT or both to override resistance. These data expose new synergistic therapies to trigger p53-induced killing in diverse RB subtypes.
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62
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Chen L, Liu S, Tao Y. Regulating tumor suppressor genes: post-translational modifications. Signal Transduct Target Ther 2020; 5:90. [PMID: 32532965 PMCID: PMC7293209 DOI: 10.1038/s41392-020-0196-9] [Citation(s) in RCA: 190] [Impact Index Per Article: 47.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 05/19/2020] [Accepted: 05/24/2020] [Indexed: 01/10/2023] Open
Abstract
Tumor suppressor genes cooperate with each other in tumors. Three important tumor suppressor proteins, retinoblastoma (Rb), p53, phosphatase, and tensin homolog deleted on chromosome ten (PTEN) are functionally associated and they regulated by post-translational modification (PTMs) as well. PTMs include phosphorylation, SUMOylation, acetylation, and other novel modifications becoming growing appreciated. Because most of PTMs are reversible, normal cells use them as a switch to control the state of cells being the resting or proliferating, and PTMs also involve in cell survival and cell cycle, which may lead to abnormal proliferation and tumorigenesis. Although a lot of studies focus on the importance of each kind of PTM, further discoveries shows that tumor suppressor genes (TSGs) form a complex "network" by the interaction of modification. Recently, there are several promising strategies for TSGs for they change more frequently than carcinogenic genes in cancers. We here review the necessity, characteristics, and mechanisms of each kind of post-translational modification on Rb, p53, PTEN, and its influence on the precise and selective function. We also discuss the current antitumoral therapies of Rb, p53 and PTEN as predictive, prognostic, and therapeutic target in cancer.
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Affiliation(s)
- Ling Chen
- Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Department of Pathology, Xiangya Hospital, School of Basic Medicine, Central South University, 410078, Changsha, Hunan, China
- NHC Key Laboratory of Carcinogenesis (Central South University), Cancer Research Institute, Central South University, 410078, Changsha, Hunan, China
| | - Shuang Liu
- Department of Oncology, Institute of Medical Sciences, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, 410008, Changsha, Hunan, China
| | - Yongguang Tao
- Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Department of Pathology, Xiangya Hospital, School of Basic Medicine, Central South University, 410078, Changsha, Hunan, China.
- NHC Key Laboratory of Carcinogenesis (Central South University), Cancer Research Institute, Central South University, 410078, Changsha, Hunan, China.
- Hunan Key Laboratory of Early Diagnosis and Precision Therapy, Department of Thoracic Surgery, Second Xiangya Hospital, Central South University, 410011, Changsha, China.
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63
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Protein expression profiling identifies differential modulation of homologous recombination by platinum-based antitumor agents. Cancer Chemother Pharmacol 2020; 85:1129-1140. [PMID: 32468080 DOI: 10.1007/s00280-020-04085-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 05/14/2020] [Indexed: 12/18/2022]
Abstract
PURPOSE Oxaliplatin and satraplatin demonstrate activity against cisplatin-resistant tumor cells. Although the two platinum analogs are structurally-related, oxaliplatin is more active. Therefore, studies focusing on protein expression profiling were undertaken to identify the molecular mechanism for the difference in antitumor activity. METHODS We included cisplatin as reference and DAP as a Pt(IV)-prodrug of oxaliplatin to offset Pt(IV) status of satraplatin, and utilized A2780, cisplatin-resistant 2780CP/Cl-16, U2OS, and HCT-116 tumor cells in the investigation. Protein expressions following drug exposures were examined by reverse-phase protein array and ingenuity pathway analysis. Cell cycle was assessed by flow cytometry, cytotoxicity by growth inhibition assay, and homologous recombination (HR) by a GFP reporter assay. RESULTS Clustering analysis paired oxaliplatin with DAP and, surprisingly, satraplatin with cisplatin. This correlated with differential upregulation of p53/p21 pathway, with S and G2/M arrests by cisplatin and satraplatin in contrast to G1 arrest by oxaliplatin and DAP. Moreover, Rad51 and BRCA1 were severely downregulated by oxaliplatin and DAP, but not cisplatin and satraplatin. As a result, HR was inhibited only by oxaliplatin and DAP and this also contributed to their greater drug activity over cisplatin and satraplatin. CONCLUSIONS Oxaliplatin and DAP robustly activate p53 and p21, which downregulate HR proteins to enhance drug activity. More significantly, since oxaliplatin induces a BRCAness state, it may have potential against BRCA-proficient cancers. Satraplatin, on the other hand, resembled cisplatin in its protein expression profile, which indicates that small changes in chemical structure can substantially alter signal transduction pathways to modulate drug activity.
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64
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Boopathi E, Thangavel C. CDK4/6 inhibition protects normal cells against cancer therapy-induced damage. Transl Cancer Res 2020; 9:405-408. [PMID: 32432028 PMCID: PMC7236812 DOI: 10.21037/tcr.2019.12.86] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Ettickan Boopathi
- Department of Medicine, Center for Translational Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Chellappagounder Thangavel
- Department of Radiation Oncology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
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Niedermaier B, Sak A, Zernickel E, Xu S, Groneberg M, Stuschke M. Targeting ARID1A-mutant colorectal cancer: depletion of ARID1B increases radiosensitivity and modulates DNA damage response. Sci Rep 2019; 9:18207. [PMID: 31796878 PMCID: PMC6890697 DOI: 10.1038/s41598-019-54757-z] [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: 08/15/2019] [Accepted: 11/13/2019] [Indexed: 12/13/2022] Open
Abstract
The SWI/SNF chromatin remodeling complex has been found mutated in a wide range of human cancers, causing alterations in gene expression patterns, proliferation and DNA damage response that have been linked to poor clinical prognosis. Here, we investigated weather knockdown of ARID1B, one of two mutually exclusive subunits within the SWI/SNF complex, can sensitize colorectal cancer cell lines mutated in the other subunit, ARID1A, to ionizing radiation (IR). ARID1A-mutated colorectal cancer (CRC) cell lines are selectively sensitized to IR after siRNA mediated ARID1B depletion, as measured by clonogenic survival. This is characterized by a decrease in the surviving cell fraction to 87.3% ± 2.1%, 86.0% ± 1.1% and 77.2% ± 1.5% per 1 Gy compared with control siRNA exposed cells in the dose range of 0–6 Gy for the LS180, RKO and SW48 lines, respectively (p < 0.0001, F-test). The magnitude of this dose modifying effect was significantly larger in ARID1A mutated than in non-mutated cell lines (Spearman rank correlation rs = 0.88, p = 0.02). Furthermore, initial formation of RAD51 foci at 4 h after IR, as a measure for homologous recombination repair, was significantly reduced in ARID1A-mutant CRC cell lines but not in the majority of wildtype lines nor in fibroblasts. These findings open up perspectives for targeting ARID1B in combination with radiotherapy to improve outcomes of patients with ARID1A-mutant CRC.
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Affiliation(s)
- B Niedermaier
- Department of Radiotherapy, University of Duisburg-Essen, University Hospital, Essen, Germany.
| | - A Sak
- Department of Radiotherapy, University of Duisburg-Essen, University Hospital, Essen, Germany
| | - E Zernickel
- Department of Radiotherapy, University of Duisburg-Essen, University Hospital, Essen, Germany
| | - Shan Xu
- Department of Radiotherapy, University of Duisburg-Essen, University Hospital, Essen, Germany
| | - M Groneberg
- Department of Radiotherapy, University of Duisburg-Essen, University Hospital, Essen, Germany
| | - M Stuschke
- Department of Radiotherapy, University of Duisburg-Essen, University Hospital, Essen, Germany
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E2F1 acetylation directs p300/CBP-mediated histone acetylation at DNA double-strand breaks to facilitate repair. Nat Commun 2019; 10:4951. [PMID: 31666529 PMCID: PMC6821830 DOI: 10.1038/s41467-019-12861-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 10/03/2019] [Indexed: 12/31/2022] Open
Abstract
E2F1 and retinoblastoma (RB) tumor-suppressor protein not only regulate the periodic expression of genes important for cell proliferation, but also localize to DNA double-strand breaks (DSBs) to promote repair. E2F1 is acetylated in response to DNA damage but the role this plays in DNA repair is unknown. Here we demonstrate that E2F1 acetylation creates a binding motif for the bromodomains of the p300/KAT3B and CBP/KAT3A acetyltransferases and that this interaction is required for the recruitment of p300 and CBP to DSBs and the induction of histone acetylation at sites of damage. A knock-in mutation that blocks E2F1 acetylation abolishes the recruitment of p300 and CBP to DSBs and also the accumulation of other chromatin modifying activities and repair factors, including Tip60, BRG1 and NBS1, and renders mice hypersensitive to ionizing radiation (IR). These findings reveal an important role for E2F1 acetylation in orchestrating the remodeling of chromatin structure at DSBs to facilitate repair. E2F1, which localises to DNA double-strand breaks (DSBs) to promote repair, is acetylated in response to DNA damage but the role this plays in DNA repair is unknown. Here the authors show that E2F1 acetylation creates a binding motif for the bromodomains of the p300/KAT3B and CBP/KAT3A acetyltransferases, which is required for recruitment of p300 and CBP to DSBs, to facilate repair.
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67
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RB1 Deletion in Retinoblastoma Protein Pathway-Disrupted Cells Results in DNA Damage and Cancer Progression. Mol Cell Biol 2019; 39:MCB.00105-19. [PMID: 31138663 DOI: 10.1128/mcb.00105-19] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 05/20/2019] [Indexed: 12/12/2022] Open
Abstract
Proliferative control in cancer cells is frequently disrupted by mutations in the retinoblastoma protein (RB) pathway. Intriguingly, RB1 mutations can arise late in tumorigenesis in cancer cells whose RB pathway is already compromised by another mutation. In this study, we present evidence for increased DNA damage and instability in cancer cells with RB pathway defects when RB1 mutations are induced. We generated isogenic RB1 mutant genotypes with CRISPR/Cas9 in a number of cell lines. Cells with even one mutant copy of RB1 have increased basal levels of DNA damage and increased mitotic errors. Elevated levels of reactive oxygen species as well as impaired homologous recombination repair underlie this DNA damage. When xenografted into immunocompromised mice, RB1 mutant cells exhibit an elevated propensity to seed new tumors in recipient lungs. This study offers evidence that late-arising RB1 mutations can facilitate genome instability and cancer progression that are beyond the preexisting proliferative control deficit.
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68
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Richter C, Marquardt S, Li F, Spitschak A, Murr N, Edelhäuser BAH, Iliakis G, Pützer BM, Logotheti S. Rewiring E2F1 with classical NHEJ via APLF suppression promotes bladder cancer invasiveness. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2019; 38:292. [PMID: 31287003 PMCID: PMC6615232 DOI: 10.1186/s13046-019-1286-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 06/20/2019] [Indexed: 12/29/2022]
Abstract
Background Bladder cancer progression has been associated with dysfunctional repair of double-strand breaks (DSB), a deleterious type of DNA lesions that fuel genomic instability. Accurate DSB repair relies on two distinct pathways, homologous recombination (HR) and classical non-homologous end-joining (c-NHEJ). The transcription factor E2F1 supports HR-mediated DSB repair and protects genomic stability. However, invasive bladder cancers (BC) display, in contrast to non-invasive stages, genomic instability despite their high E2F1 levels. Hence, E2F1 is either inefficient in controlling DSB repair in this setting, or rewires the repair apparatus towards alternative, error-prone DSB processing pathways. Methods RT-PCR and immunoblotting, in combination with bioinformatics tools were applied to monitor c-NHEJ factors status in high-E2F1-expressing, invasive BC versus low-E2F1-expressing, non-invasive BC. In vivo binding of E2F1 on target gene promoters was demonstrated by ChIP assays and E2F1 CRISPR-Cas9 knockdown. MIR888-dependent inhibition of APLF by E2F1 was demonstrated using overexpression and knockdown experiments, in combination with luciferase assays. Methylation status of MIR888 promoter was monitored by methylation-specific PCR. The changes in invasion potential and the DSB repair efficiency were estimated by Boyden chamber assays and pulse field electrophoresis, correspondingly. Results Herein, we show that E2F1 directly transactivates the c-NHEJ core factors Artemis, DNA-PKcs, ligase IV, NHEJ1, Ku70/Ku80 and XRCC4, but indirectly inhibits APLF, a chromatin modifier regulating c-NHEJ. Inhibition is achieved by miR-888-5p, a testis-specific, X-linked miRNA which, in normal tissues, is often silenced via promoter methylation. Upon hypomethylation in invasive BC cells, MIR888 is transactivated by E2F1 and represses APLF. Consequently, E2F1/miR-888/APLF rewiring is established, generating conditions of APLF scarcity that compromise proper c-NHEJ function. Perturbation of the E2F1/miR-888/APLF axis restores c-NHEJ and ameliorates cell invasiveness. Depletion of miR-888 can establish a ‘high E2F1/APLF/DCLRE1C’ signature, which was found to be particularly favorable for BC patient survival. Conclusion Suppression of the ‘out-of-context’ activity of miR-888 improves DSB repair and impedes invasiveness by restoring APLF. Electronic supplementary material The online version of this article (10.1186/s13046-019-1286-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Christin Richter
- Institute of Experimental Gene Therapy and Cancer Research, Rostock University Medical Center, Schillingallee 69, 18057, Rostock, Germany
| | - Stephan Marquardt
- Institute of Experimental Gene Therapy and Cancer Research, Rostock University Medical Center, Schillingallee 69, 18057, Rostock, Germany
| | - Fanghua Li
- Institute of Medical Radiation Biology, University of Duisburg-Essen Medical School, Essen, Germany
| | - Alf Spitschak
- Institute of Experimental Gene Therapy and Cancer Research, Rostock University Medical Center, Schillingallee 69, 18057, Rostock, Germany
| | - Nico Murr
- Institute of Experimental Gene Therapy and Cancer Research, Rostock University Medical Center, Schillingallee 69, 18057, Rostock, Germany
| | - Berdien A H Edelhäuser
- Institute of Experimental Gene Therapy and Cancer Research, Rostock University Medical Center, Schillingallee 69, 18057, Rostock, Germany
| | - George Iliakis
- Institute of Medical Radiation Biology, University of Duisburg-Essen Medical School, Essen, Germany
| | - Brigitte M Pützer
- Institute of Experimental Gene Therapy and Cancer Research, Rostock University Medical Center, Schillingallee 69, 18057, Rostock, Germany. .,Department Life, Light and Matter of the Interdisciplinary Faculty at Rostock University, Rostock, Germany.
| | - Stella Logotheti
- Institute of Experimental Gene Therapy and Cancer Research, Rostock University Medical Center, Schillingallee 69, 18057, Rostock, Germany
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Abstract
The cyclin-dependent kinase (CDK)-RB-E2F axis forms the core transcriptional machinery driving cell cycle progression, dictating the timing and fidelity of genome replication and ensuring genetic material is accurately passed through each cell division cycle. The ultimate effectors of this axis are members of a family of eight distinct E2F genes encoding transcriptional activators and repressors. E2F transcriptional activity is tightly regulated throughout the cell cycle via transcriptional and translational regulation, post-translational modifications, protein degradation, binding to cofactors and subcellular localization. Alterations in one or more key components of this axis (CDKs, cyclins, CDK inhibitors and the RB family of proteins) occur in virtually all cancers and result in heightened oncogenic E2F activity, leading to uncontrolled proliferation. In this Review, we discuss the activities of E2F proteins with an emphasis on the newest atypical E2F family members, the specific and redundant functions of E2F proteins, how misexpression of E2F transcriptional targets promotes cancer and both current and developing therapeutic strategies being used to target this oncogenic pathway.
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Affiliation(s)
- Lindsey N Kent
- Department of Biochemistry and Molecular Biology, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, USA
| | - Gustavo Leone
- Department of Biochemistry and Molecular Biology, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, USA.
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Ribeiro-Silva C, Vermeulen W, Lans H. SWI/SNF: Complex complexes in genome stability and cancer. DNA Repair (Amst) 2019; 77:87-95. [PMID: 30897376 DOI: 10.1016/j.dnarep.2019.03.007] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 03/12/2019] [Accepted: 03/14/2019] [Indexed: 01/25/2023]
Abstract
SWI/SNF complexes are among the most studied ATP-dependent chromatin remodeling complexes, mostly due to their critical role in coordinating chromatin architecture and gene expression. Mutations in genes encoding SWI/SNF subunits are frequently observed in a large variety of human cancers, suggesting that one or more of the multiple SWI/SNF functions protect against tumorigenesis. Chromatin remodeling is an integral component of the DNA damage response (DDR), which safeguards against DNA damage-induced genome instability and tumorigenesis by removing DNA damage through interconnected DNA repair and signaling pathways. SWI/SNF has been implicated in facilitating repair of double-strand breaks, by non-homologous end-joining as well as homologous recombination, and repair of helix-distorting DNA damage by nucleotide excision repair. Here, we review current knowledge on SWI/SNF activity in the DDR and discuss the potential of exploiting DDR-related vulnerabilities due to SWI/SNF dysfunction for precision cancer therapy.
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Affiliation(s)
- Cristina Ribeiro-Silva
- Department of Molecular Genetics, Oncode Institute, Erasmus MC, University Medical Center Rotterdam, Dr. Molewaterplein 40, 3015 GD, Rotterdam, the Netherlands
| | - Wim Vermeulen
- Department of Molecular Genetics, Oncode Institute, Erasmus MC, University Medical Center Rotterdam, Dr. Molewaterplein 40, 3015 GD, Rotterdam, the Netherlands.
| | - Hannes Lans
- Department of Molecular Genetics, Oncode Institute, Erasmus MC, University Medical Center Rotterdam, Dr. Molewaterplein 40, 3015 GD, Rotterdam, the Netherlands.
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71
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Sanidas I, Morris R, Fella KA, Rumde PH, Boukhali M, Tai EC, Ting DT, Lawrence MS, Haas W, Dyson NJ. A Code of Mono-phosphorylation Modulates the Function of RB. Mol Cell 2019; 73:985-1000.e6. [PMID: 30711375 DOI: 10.1016/j.molcel.2019.01.004] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 11/26/2018] [Accepted: 01/02/2019] [Indexed: 12/21/2022]
Abstract
Hyper-phosphorylation of RB controls its interaction with E2F and inhibits its tumor suppressor properties. However, during G1 active RB can be mono-phosphorylated on any one of 14 CDK phosphorylation sites. Here, we used quantitative proteomics to profile protein complexes formed by each mono-phosphorylated RB isoform (mP-RB) and identified the associated transcriptional outputs. The results show that the 14 sites of mono-phosphorylation co-ordinate RB's interactions and confer functional specificity. All 14 mP-RBs interact with E2F/DP proteins, but they provide different shades of E2F regulation. RB mono-phosphorylation at S811, for example, alters RB transcriptional activity by promoting its association with NuRD complexes. The greatest functional differences between mP-RBs are evident beyond the cell cycle machinery. RB mono-phosphorylation at S811 or T826 stimulates the expression of oxidative phosphorylation genes, increasing cellular oxygen consumption. These results indicate that RB activation signals are integrated in a phosphorylation code that determines the diversity of RB activity.
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Affiliation(s)
- Ioannis Sanidas
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Building 149 13th Street, Charlestown, MA 02129, USA
| | - Robert Morris
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Building 149 13th Street, Charlestown, MA 02129, USA
| | - Katerina A Fella
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Building 149 13th Street, Charlestown, MA 02129, USA
| | - Purva H Rumde
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Building 149 13th Street, Charlestown, MA 02129, USA
| | - Myriam Boukhali
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Building 149 13th Street, Charlestown, MA 02129, USA
| | - Eric C Tai
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Building 149 13th Street, Charlestown, MA 02129, USA
| | - David T Ting
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Building 149 13th Street, Charlestown, MA 02129, USA
| | - Michael S Lawrence
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Building 149 13th Street, Charlestown, MA 02129, USA; Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, MA 02142, USA
| | - Wilhelm Haas
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Building 149 13th Street, Charlestown, MA 02129, USA
| | - Nicholas J Dyson
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Building 149 13th Street, Charlestown, MA 02129, USA.
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Zernickel E, Sak A, Riaz A, Klein D, Groneberg M, Stuschke M. Targeting of BRM Sensitizes BRG1-Mutant Lung Cancer Cell Lines to Radiotherapy. Mol Cancer Ther 2018; 18:656-666. [PMID: 30478150 DOI: 10.1158/1535-7163.mct-18-0067] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 06/30/2018] [Accepted: 11/15/2018] [Indexed: 11/16/2022]
Abstract
Targeting of epigenetic regulators as the chromatin remodeler SWI/SNF is proving to be a promising therapeutic strategy for individualized treatment of cancer patients. Here, we tested whether targeting one of the two mutually exclusive subdomains of the SWI/SNF complex BRM/SMARCA2 can sensitize specifically non-small cell lung carcinoma (NSCLC) cells with mutations in the other subunit BRG1/SMARCA4 toward ionizing radiation (IR). Knockdown of BRM with siRNA or shRNA and its consequences for radiation sensitivity as measured by clonogenic survival and plaque-monolayer control was studied in different NSCLC lines with or without BRG1 mutations and in primary fibroblasts. Furthermore, the effect on double-strand break (DSB) repair markers measured by immunofluorescence staining of 53BP1-, γ-H2AX-, and Rad51-foci was investigated. BRG1-mutated cell lines showed an increased surviving fraction compared with BRG1 proficient cells. Depletion of BRM (i) leads to a decreased proliferation rate and plating efficiency specifically in BRG1-mutated cells, (ii) specifically sensitized BRG1-mutant NSCLC cells toward IR as characterized by a survival reducing factor of 0.63 [95% confidence interval (CI), 0.57-0.69] in the dose range between 2 and 6 Gy, and (iii) decreased the tumor control doses after daily fractionation at 4 Gy in BRG1-mutant NSCLC cell lines A549 and H1299 in minimonolayers by 9.9% ± 1.3% and 13.6% ± 1.8%, respectively. In addition, an increase of residual Rad51-foci at 24 hours after irradiation in BRG1-mutant cells was demonstrated. Therefore, targeting of BRM in combination with radiotherapy is supposed to improve the therapeutic outcome of lung cancer patients harboring BRG1 mutations.The present study shows that the moderate radioresponsiveness of NSCLC cells with BRG1 mutations can be increased upon BRM depletion that is associated with a prolonged Rad51-foci prevalence at DNA DSBs.
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Affiliation(s)
- Erika Zernickel
- Department of Radiotherapy, University of Duisburg-Essen, University Hospital, Essen, Germany.
| | - Ali Sak
- Department of Radiotherapy, University of Duisburg-Essen, University Hospital, Essen, Germany
| | - Assad Riaz
- Department of Radiotherapy, University of Duisburg-Essen, University Hospital, Essen, Germany
| | - Diana Klein
- Institute of Cell Biology (Cancer Research), University of Duisburg-Essen, University Hospital, Essen, Germany
| | - Michael Groneberg
- Department of Radiotherapy, University of Duisburg-Essen, University Hospital, Essen, Germany
| | - Martin Stuschke
- Department of Radiotherapy, University of Duisburg-Essen, University Hospital, Essen, Germany
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73
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Chen ES. Targeting epigenetics using synthetic lethality in precision medicine. Cell Mol Life Sci 2018; 75:3381-3392. [PMID: 30003270 PMCID: PMC11105276 DOI: 10.1007/s00018-018-2866-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 06/30/2018] [Accepted: 07/03/2018] [Indexed: 12/31/2022]
Abstract
Technological breakthroughs in genomics have had a significant impact on clinical therapy for human diseases, allowing us to use patient genetic differences to guide medical care. The "synthetic lethal approach" leverages on cancer-specific genetic rewiring to deliver a therapeutic regimen that preferentially targets malignant cells while sparing normal cells. The utility of this system is evident in several recent studies, particularly in poor prognosis cancers with loss-of-function mutations that become "treatable" when two otherwise discrete and unrelated genes are targeted simultaneously. This review focuses on the chemotherapeutic targeting of epigenetic alterations in cancer cells and consolidates a network that outlines the interplay between epigenetic and genetic regulators in DNA damage repair. This network consists of numerous synergistically acting relationships that are druggable, even in recalcitrant triple-negative breast cancer. This collective knowledge points to the dawn of a new era of personalized medicine.
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Affiliation(s)
- Ee Sin Chen
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore.
- National University Health System (NUHS), Singapore, 119228, Singapore.
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), Life Sciences Institute, National University of Singapore, Singapore, 117456, Singapore.
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore, 117456, Singapore.
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74
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Jiang Y, Chu WK. Potential Roles of the Retinoblastoma Protein in Regulating Genome Editing. Front Cell Dev Biol 2018; 6:81. [PMID: 30109230 PMCID: PMC6079259 DOI: 10.3389/fcell.2018.00081] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 07/13/2018] [Indexed: 01/15/2023] Open
Abstract
Genome editing is an important tool for modifying genomic DNA through introducing DNA insertion or deletion at specific locations of a genome. Recently CRISPR/Cas9 has been widely employed to improve the efficiency of genome editing. The Cas9 nuclease creates site-specific double strand breaks (DSBs) at targeted loci in the genome. Subsequently, the DSBs are repaired by two pathways: Homologous Recombination (HR) and Non-Homologous End-Joining (NHEJ). HR has been considered as "error-free" because it repairs DSBs by copying DNA sequences from a homologous DNA template, while NHEJ is "error-prone" as there are base deletions or insertions at the breakage site. Recently, RB1, a gene that is commonly mutated in retinoblastoma, has been reported to affect the repair efficiencies of HR and NHEJ. This review focuses on the roles of RB1 in repairing DNA DSBs, which have impacts on the precision and consequences of the genome editing, both at the targeted loci and the overall genome.
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Affiliation(s)
- Yuning Jiang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Sha Tin, Hong Kong
| | - Wai Kit Chu
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Sha Tin, Hong Kong
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75
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Abstract
The canonical model of RB-mediated tumour suppression developed over the past 30 years is based on the regulation of E2F transcription factors to restrict cell cycle progression. Several additional functions have been proposed for RB, on the basis of which a non-canonical RB pathway can be described. Mechanistically, the non-canonical RB pathway promotes histone modification and regulates chromosome structure in a manner distinct from cell cycle regulation. These functions have implications for chemotherapy response and resistance to targeted anticancer agents. This Opinion offers a framework to guide future studies of RB in basic and clinical research.
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Affiliation(s)
- Frederick A Dick
- London Regional Cancer Program, Children's Health Research Institute, Western University, London, Ontario, Canada.
- London Regional Cancer Program, Department of Biochemistry, Western University, London, Ontario, Canada.
| | - David W Goodrich
- Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, NY, USA
| | - Julien Sage
- Departments of Pediatrics and Genetics, Stanford University, Stanford, CA, USA
| | - Nicholas J Dyson
- Massachusetts General Hospital Cancer Center, Laboratory of Molecular Oncology, Harvard Medical School, Charlestown, MA, USA
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76
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Chiu LY, Gong F, Miller KM. Bromodomain proteins: repairing DNA damage within chromatin. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0286. [PMID: 28847823 DOI: 10.1098/rstb.2016.0286] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/17/2017] [Indexed: 12/21/2022] Open
Abstract
Genome surveillance and repair, termed the DNA damage response (DDR), functions within chromatin. Chromatin-based DDR mechanisms sustain genome and epigenome integrity, defects that can disrupt cellular homeostasis and contribute to human diseases. An important chromatin DDR pathway is acetylation signalling which is controlled by histone acetyltransferase (HAT) and histone deacetylase (HDAC) enzymes, which regulate acetylated lysines within proteins. Acetylated proteins, including histones, can modulate chromatin structure and provide molecular signals that are bound by acetyl-lysine binders, including bromodomain (BRD) proteins. Acetylation signalling regulates several DDR pathways, as exemplified by the preponderance of HATs, HDACs and BRD proteins that localize at DNA breaks to modify chromatin for lesion repair. Here, we explore the involvement of acetylation signalling in the DDR, focusing on the involvement of BRD proteins in promoting chromatin remodelling to repair DNA double-strand breaks. BRD proteins have widespread DDR functions including chromatin remodelling, chromatin modification and transcriptional regulation. We discuss mechanistically how BRD proteins read acetylation signals within chromatin to trigger DDR and chromatin activities to facilitate genome-epigenome maintenance. Thus, DDR pathways involving BRD proteins represent key participants in pathways that preserve genome-epigenome integrity to safeguard normal genome and cellular functions.This article is part of the themed issue 'Chromatin modifiers and remodellers in DNA repair and signalling'.
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Affiliation(s)
- Li-Ya Chiu
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, The University of Texas at Austin, 2506 Speedway, Austin, TX 78712, USA
| | - Fade Gong
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, The University of Texas at Austin, 2506 Speedway, Austin, TX 78712, USA
| | - Kyle M Miller
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, The University of Texas at Austin, 2506 Speedway, Austin, TX 78712, USA
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77
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Torrecilla I, Oehler J, Ramadan K. The role of ubiquitin-dependent segregase p97 (VCP or Cdc48) in chromatin dynamics after DNA double strand breaks. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0282. [PMID: 28847819 PMCID: PMC5577460 DOI: 10.1098/rstb.2016.0282] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/24/2017] [Indexed: 12/27/2022] Open
Abstract
DNA double strand breaks (DSBs) are the most cytotoxic DNA lesions and, if not repaired, lead to chromosomal rearrangement, genomic instability and cell death. Cells have evolved a complex network of DNA repair and signalling molecules which promptly detect and repair DSBs, commonly known as the DNA damage response (DDR). The DDR is orchestrated by various post-translational modifications such as phosphorylation, methylation, ubiquitination or SUMOylation. As DSBs are located in complex chromatin structures, the repair of DSBs is engineered at two levels: (i) at sites of broken DNA and (ii) at chromatin structures that surround DNA lesions. Thus, DNA repair and chromatin remodelling machineries must work together to efficiently repair DSBs. Here, we summarize the current knowledge of the ubiquitin-dependent molecular unfoldase/segregase p97 (VCP in vertebrates and Cdc48 in worms and lower eukaryotes) in DSB repair. We identify p97 as an essential factor that regulates DSB repair. p97-dependent extraction of ubiquitinated substrates mediates spatio-temporal protein turnover at and around the sites of DSBs, thus orchestrating chromatin remodelling and DSB repair. As p97 is a druggable target, p97 inhibition in the context of DDR has great potential for cancer therapy, as shown for other DDR components such as PARP, ATR and CHK1.This article is part of the themed issue 'Chromatin modifiers and remodellers in DNA repair and signalling'.
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Affiliation(s)
- Ignacio Torrecilla
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
| | - Judith Oehler
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
| | - Kristijan Ramadan
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
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78
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Lai J, Han D, Yang C. AtMMS21: Connecting DNA Repair and Root Development. TRENDS IN PLANT SCIENCE 2018; 23:89-91. [PMID: 29208353 DOI: 10.1016/j.tplants.2017.11.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 10/15/2017] [Accepted: 11/20/2017] [Indexed: 05/27/2023]
Abstract
Two recent reports show that SUMO ligase AtMMS21 controls the cell cycle through dissociating the E2Fa/DPa complex, and regulates chromatin remodeling by maintaining the stability of BRAHMA. We discuss these novel functions of AtMMS21 and its potential role in linking DNA repair and root development.
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Affiliation(s)
- Jianbin Lai
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Science, South China Normal University, Guangzhou 510631, China
| | - Danlu Han
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Science, South China Normal University, Guangzhou 510631, China
| | - Chengwei Yang
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Science, South China Normal University, Guangzhou 510631, China.
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79
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Wiest NE, Houghtaling S, Sanchez JC, Tomkinson AE, Osley MA. The SWI/SNF ATP-dependent nucleosome remodeler promotes resection initiation at a DNA double-strand break in yeast. Nucleic Acids Res 2017; 45:5887-5900. [PMID: 28398510 PMCID: PMC5449591 DOI: 10.1093/nar/gkx221] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 04/06/2017] [Indexed: 12/27/2022] Open
Abstract
DNA double-strand breaks (DSBs) are repaired by either the non-homologous end joining (NHEJ) or homologous recombination (HR) pathway. Pathway choice is determined by the generation of 3΄ single-strand DNA overhangs at the break that are initiated by the action of the Mre11-Rad50-Xrs2 (MRX) complex to direct repair toward HR. DSB repair occurs in the context of chromatin, and multiple chromatin regulators have been shown to play important roles in the repair process. We have investigated the role of the SWI/SNF ATP-dependent nucleosome-remodeling complex in the repair of a defined DNA DSB. SWI/SNF was previously shown to regulate presynaptic events in HR, but its function in these events is unknown. We find that in the absence of functional SWI/SNF, the initiation of DNA end resection is significantly delayed. The delay in resection initiation is accompanied by impaired recruitment of MRX to the DSB, and other functions of MRX in HR including the recruitment of long-range resection factors and activation of the DNA damage response are also diminished. These phenotypes are correlated with a delay in the eviction of nucleosomes surrounding the DSB. We propose that SWI/SNF orchestrates the recruitment of a pool of MRX that is specifically dedicated to HR.
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Affiliation(s)
- Nathaniel E Wiest
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA.,Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Scott Houghtaling
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Joseph C Sanchez
- Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA
| | - Alan E Tomkinson
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA.,Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Mary Ann Osley
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
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80
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Vélez-Cruz R, Johnson DG. The Retinoblastoma (RB) Tumor Suppressor: Pushing Back against Genome Instability on Multiple Fronts. Int J Mol Sci 2017; 18:ijms18081776. [PMID: 28812991 PMCID: PMC5578165 DOI: 10.3390/ijms18081776] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 08/13/2017] [Accepted: 08/13/2017] [Indexed: 12/13/2022] Open
Abstract
The retinoblastoma (RB) tumor suppressor is known as a master regulator of the cell cycle. RB is mutated or functionally inactivated in the majority of human cancers. This transcriptional regulator exerts its function in cell cycle control through its interaction with the E2F family of transcription factors and with chromatin remodelers and modifiers that contribute to the repression of genes important for cell cycle progression. Over the years, studies have shown that RB participates in multiple processes in addition to cell cycle control. Indeed, RB is known to interact with over 200 different proteins and likely exists in multiple complexes. RB, in some cases, acts through its interaction with E2F1, other members of the pocket protein family (p107 and p130), and/or chromatin remodelers and modifiers. RB is a tumor suppressor with important chromatin regulatory functions that affect genomic stability. These functions include the role of RB in DNA repair, telomere maintenance, chromosome condensation and cohesion, and silencing of repetitive regions. In this review we will discuss recent advances in RB biology related to RB, partner proteins, and their non-transcriptional functions fighting back against genomic instability.
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Affiliation(s)
- Renier Vélez-Cruz
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, 1808 Park Road 1C, P.O. Box 389, Smithville, TX 78957, USA.
- Department of Biochemistry, Midwestern University, Chicago College of Osteopathic Medicine, 555 31st Street, Downers Grove, IL 60515, USA.
| | - David G Johnson
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, 1808 Park Road 1C, P.O. Box 389, Smithville, TX 78957, USA.
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81
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Horvath BM, Kourova H, Nagy S, Nemeth E, Magyar Z, Papdi C, Ahmad Z, Sanchez-Perez GF, Perilli S, Blilou I, Pettkó-Szandtner A, Darula Z, Meszaros T, Binarova P, Bogre L, Scheres B. Arabidopsis RETINOBLASTOMA RELATED directly regulates DNA damage responses through functions beyond cell cycle control. EMBO J 2017; 36:1261-1278. [PMID: 28320736 PMCID: PMC5412863 DOI: 10.15252/embj.201694561] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 02/20/2017] [Accepted: 02/23/2017] [Indexed: 12/26/2022] Open
Abstract
The rapidly proliferating cells in plant meristems must be protected from genome damage. Here, we show that the regulatory role of the Arabidopsis RETINOBLASTOMA RELATED (RBR) in cell proliferation can be separated from a novel function in safeguarding genome integrity. Upon DNA damage, RBR and its binding partner E2FA are recruited to heterochromatic γH2AX-labelled DNA damage foci in an ATM- and ATR-dependent manner. These γH2AX-labelled DNA lesions are more dispersedly occupied by the conserved repair protein, AtBRCA1, which can also co-localise with RBR foci. RBR and AtBRCA1 physically interact in vitro and in planta Genetic interaction between the RBR-silenced amiRBR and Atbrca1 mutants suggests that RBR and AtBRCA1 may function together in maintaining genome integrity. Together with E2FA, RBR is directly involved in the transcriptional DNA damage response as well as in the cell death pathway that is independent of SOG1, the plant functional analogue of p53. Thus, plant homologs and analogues of major mammalian tumour suppressor proteins form a regulatory network that coordinates cell proliferation with cell and genome integrity.
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Affiliation(s)
- Beatrix M Horvath
- School of Biological Sciences, Centre for Systems and Synthetic Biology, Royal Holloway, University of London, Egham, UK
- Department of Molecular Genetics, Utrecht University, Utrecht, The Netherlands
| | - Hana Kourova
- Institute of Microbiology CAS, v.v.i., Laboratory of Cell Reproduction, Prague 4, Czech Republic
| | - Szilvia Nagy
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, Budapest, Hungary
| | - Edit Nemeth
- School of Biological Sciences, Centre for Systems and Synthetic Biology, Royal Holloway, University of London, Egham, UK
| | - Zoltan Magyar
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
| | - Csaba Papdi
- School of Biological Sciences, Centre for Systems and Synthetic Biology, Royal Holloway, University of London, Egham, UK
| | - Zaki Ahmad
- School of Biological Sciences, Centre for Systems and Synthetic Biology, Royal Holloway, University of London, Egham, UK
| | - Gabino F Sanchez-Perez
- Department of Plant Sciences, Wageningen University Research Centre, Wageningen, The Netherlands
| | - Serena Perilli
- Department of Plant Sciences, Wageningen University Research Centre, Wageningen, The Netherlands
| | - Ikram Blilou
- Department of Plant Sciences, Wageningen University Research Centre, Wageningen, The Netherlands
| | | | - Zsuzsanna Darula
- Laboratory of Proteomic Research, Biological Research Centre, Szeged, Hungary
| | - Tamas Meszaros
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, Budapest, Hungary
- Technical Analytical Research Group of HAS, Budapest, Hungary
| | - Pavla Binarova
- Institute of Microbiology CAS, v.v.i., Laboratory of Cell Reproduction, Prague 4, Czech Republic
| | - Laszlo Bogre
- School of Biological Sciences, Centre for Systems and Synthetic Biology, Royal Holloway, University of London, Egham, UK
| | - Ben Scheres
- Department of Molecular Genetics, Utrecht University, Utrecht, The Netherlands
- Department of Plant Sciences, Wageningen University Research Centre, Wageningen, The Netherlands
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