DOCSLIB.ORG

DNA Damage Tolerance Pathway Involving DNA Polymerase Ι and The

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
DNA Damage Tolerance Pathway Involving DNA Polymerase Ι and The DNA damage tolerance pathway involving DNA PNAS PLUS polymerase ι and the tumor suppressor p53 regulates DNA replication fork progression Stephanie Hamppa, Tina Kiesslinga, Kerstin Buechlea, Sabrina F. Mansillab, Jürgen Thomalec, Melanie Ralla, Jinwoo Ahnd,1, Helmut Pospieche,f, Vanesa Gottifredib, and Lisa Wiesmüllera,2 aDepartment of Obstetrics and Gynecology, Ulm University, D-89075 Ulm, Germany; bCell Cycle and Genomic Stability Laboratory, Fundación Instituto Leloir–Instituto de Investigaciones Bioquimicas de Buenos Aires, National Scientific and Technical Research Council, Buenos Aires C1405BWE, Argentina; cInstitute of Cell Biology (Cancer Research), University of Duisburg-Essen Medical School, D-45122 Essen, Germany; dDepartment of Biological Sciences, Columbia University, New York, NY 10027; eResearch Group Biochemistry, Leibniz Institute on Aging–Fritz Lipmann Institute, D-07745 Jena, Germany; and fFaculty of Biochemistry and Molecular Medicine, University of Oulu, FIN-90014, Oulu, Finland Edited by Carol Prives, Columbia University, New York, NY, and approved June 10, 2016 (received for review April 11, 2016) DNA damage tolerance facilitates the progression of replication spontaneous HR during S-phase to overcome replication fork stalling forks that have encountered obstacles on the template strands. It and to prevent fork collapse (10, 13, 14). By this mechanism, p53 is involves either translesion DNA synthesis initiated by proliferating believed to protect replicating DNA (14). However, the prorecom- cell nuclear antigen monoubiquitination or less well-characterized binogenic function of p53 during DNA synthesis has remained less fork reversal and template switch mechanisms. Herein, we char- well understood. p53 was found to associate with HR factors in acterize a novel tolerance pathway requiring the tumor suppressor S-phase cells after induced replication arrest (15–17) and was p53, the translesion polymerase ι (POLι), the ubiquitin ligase Rad5- shown to interact with the replication factor RPA (replication related helicase-like transcription factor (HLTF), and the SWI/SNF protein A) and with POLα-primase (18, 19). Therefore, p53 seems catalytic subunit (SNF2) translocase zinc finger ran-binding domain con- to escort the replisome, at least after replication stress. Despite taining 3 (ZRANB3). This novel p53 activity is lost in the exonuclease- these pieces of evidence, the exact role of p53 in DNA replication deficient but transcriptionally active p53(H115N) mutant. Wild-type remains unknown. p53, but not p53(H115N), associates with POLι in vivo. Strikingly, the Recombination is one possible mechanism to resolve stalled concertedactionofp53andPOLι decelerates nascent DNA elonga- and collapsed replication forks (20, 21). WT p53 exerts a prosur- tion and promotes HLTF/ZRANB3-dependent recombination dur- vival so-called healer effect on tumor cells in response to poly- ing unperturbed DNA replication. Particularly after cross-linker– (ADP ribose) polymerase (PARP) inhibition, which correlates with ι induced replication stress, p53 and POL also act together to promote a stimulation of replication-associated recombination (14, 22). Be- meiotic recombination enzyme 11 (MRE11)-dependent accumulation cause of the hypothesized role of p53 in HR and/or HR-driven of (phospho-)replication protein A (RPA)-coated ssDNA. These results replication events, we further examined the role of p53 in HR implicate a direct role of p53 in the processing of replication forks during unperturbed replication or after enforced replication fork encountering obstacles on the template strand. Our findings define an unprecedented function of p53 and POLι in the DNA damage Significance response to endogenous or exogenous replication stress. DNA damage bypass | DNA polymerase idling | nascent DNA elongation | DNA damage tolerance pathways like translesion synthesis and polymerase ι | p53 recombination facilitate the bypass of replication-blocking le- sions. Such events are crucial for the survival of rapidly pro- liferating cells, including cancer and stem cells undergoing CELL BIOLOGY he tumor suppressor protein p53 has been called the guardian- active duplication during tissue renewal. Herein, we charac- Tof-the-genome due to its ability to transactivate downstream terize an unprecedented damage tolerance pathway that re- targets transcriptionally, which prevents S-phase entrance before quires the combined function of a highly enigmatic translesion facilitating DNA repair or eliminating cells with severe DNA dam- DNA polymerase ι (POLι) and the so-called guardian-of-the- age via apoptosis (1). Interestingly, p53 also encodes an intrinsic genome, p53. We provide evidence demonstrating that p53 3′–5′ exonuclease activity located within its central DNA-binding do- complexed with POLι triggers idling events that decelerate main (2–4). The contribution of the exonuclease proficiency to p53’s nascent DNA elongation at replication barriers, facilitating the function has largely remained obscure. Exonucleases are involved in resolution of stalled forks by specialized structure-specific en- DNA replication, DNA repair, and recombination, increasing the zymes. Our findings implicate p53 in the protection of quickly fidelity or efficiency of these processes. The 3′–5′ exonuclease ac- growing cancer and stem cells from endogenous and exoge- tivity of DNA polymerases (POLs) catalyzes the correction of rep- nous sources of replication stress. lication errors, thereby preventing genomic instability and cancer (5– 7). The potential involvement of p53’s exonuclease in DNA repair Author contributions: S.H., H.P., V.G., and L.W. designed research; S.H., T.K., K.B., and S.F.M. has been ascribed to transcription-independent functions in nucle- performed research; J.T., M.R., J.A., V.G., and L.W. contributed new reagents/analytic tools; S.H., T.K., K.B., H.P., V.G., and L.W. analyzed data; and S.H., H.P., V.G., and L.W. otide excision repair and base excision repair, in homologous re- wrote the paper. – combination (HR), and in mitochondrial processes (8 10). Conflict of interest statement: L.W. is an inventor of a patent on a test system for de- Regarding HR, in particular, reports indicate a dual role for p53. termining genotoxicities, which is owned by L.W. On the one hand, it has been reported that p53 down-regulates This article is a PNAS Direct Submission. unscheduled and excessive HR in response to severe genotoxic Freely available online through the PNAS open access option. – stress, like formation of DNA double-strand breaks (DSBs) (8 10). 1Present address: Department of Structural Biology, University of Pittsburgh, Pittsburgh, This antirecombinogenic effect of p53 has been linked to the PA 15260. blockage of continued strand exchange by interactions with recom- 2To whom correspondence should be addressed. Email: [email protected]. binase RAD51, RAD54, and nascent HR intermediates carrying This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10. specific mismatches (11, 12). On the other hand, p53 stimulates 1073/pnas.1605828113/-/DCSupplemental. www.pnas.org/cgi/doi/10.1073/pnas.1605828113 PNAS | Published online | E4311–E4319 Downloaded by guest on September 26, 2021 stalling using DNA cross-linking, which is known to require HR for of chromosomally integrated EGFP recombination substrates its resolution (23, 24). The recently identified p53 mutant with after expression of either p53(WT) or p53(H115N) (Fig. 1). In separated functions in transcription/cell cycle regulation and exo- both p53-negative K562 leukemia cells and p53-mutated lympho- nucleolytic DNA degradation enabled us to explore the specific blastoid WTK1 cells, expression of p53(WT) led to a robust in- contribution of p53’s exonuclease activity to the hypothesized role crease of the recombination frequency (Fig. 1 B and C). Intriguingly, of p53 in HR-driven replication events, such as increasing the an increased recombination frequency was not evident in K562 or fidelity of these processes (2). Our study reveals that WT p53, in WTK1 cells expressing the p53(H115N) mutant, although this mutant concert with POLι, protects the integrity of replication forks by is transcriptionally active and modulates the cell cycle and apoptosis to mastering idling-like events, which either leads to successful DNA a similar extent as the WT (Fig. 1 B and C and Fig. S1A). The damage bypass or to pronounced meiotic recombination enzyme augmentation of the global DNA damaging response by means of 11 (MRE11)-dependent resection of DNA. An epistasis-like func- treatment with mitomycin C (MMC; 3 μM, 45 min) did not sub- tional and biochemical analysis unraveled the details of the DNA stantially increase the frequency of spontaneous recombination damage bypass mechanism, which involves a previously unknown compared with the untreated controls in p53(WT)-expressing cells complex between p53 and the specialized POLι, promoting fork (Fig. S1B). Therefore, we conclude that the major trigger for reactivation via helicase-like transcription factor (HLTF) and zinc spontaneous recombination by p53 is dependent on local signals at finger ran-binding domain containing 3 (ZRANB3). the replicating EGFP region. Interestingly, in H1299 cells expressing tetracycline-regulated Results p53 variants (27), p53(WT) caused a statistically significant in- WT p53, but Not Its H115N Mutant, Stimulates Replication-Associated crease (1.5-fold; P = 0.0169) in the IC50 value following MMC Recombination.
Load more

Recommended publications
  • Molecular Anatomy and Regulation of a Stable Replisome at a Paused Eukaryotic DNA Replication Fork
    Downloaded from genesdev.cshlp.org on September 29, 2021 - Published by Cold Spring Harbor Laboratory Press Molecular anatomy and regulation of a stable replisome at a paused eukaryotic DNA replication fork Arturo Calzada,1,2,3 Ben Hodgson,1,3 Masato Kanemaki,1 Avelino Bueno,2 and Karim Labib1,4 1Paterson Institute for Cancer Research, Christie Hospital NHS Trust, Manchester M20 4BX, United Kingdom; 2Cancer Research Institute, University of Salamanca/CSIC, 37007 Salamanca, Spain Eukaryotic cells regulate the progression and integrity of DNA replication forks to maintain genomic stability and couple DNA synthesis to other processes. The budding yeast proteins Mrc1 and Tof1 associate with the putative MCM–Cdc45 helicase and limit progression of the replisome when nucleotides are depleted, and the checkpoint kinases Mec1 and Rad53 stabilize such stalled forks and prevent disassembly of the replisome. Forks also pause transiently during unperturbed chromosome replication, at sites where nonnucleosomal proteins bind DNA tightly. We describe a method for inducing prolonged pausing of forks at protein barriers assembled at unique sites on a yeast chromosome, allowing us to examine for the first time the effects of pausing upon replisome integrity. We show that paused forks maintain an intact replisome that contains Mrc1, Tof1, MCM–Cdc45, GINS, and DNA polymerases ␣ and ␧ and that recruits the Rrm3 helicase. Surprisingly, pausing does not require Mrc1, although Tof1 and Csm3 are both important. In addition, the integrity of the paused forks does not require Mec1, Rad53, or recombination. We also show that paused forks at analogous barriers in the rDNA are regulated similarly. These data indicate that paused and stalled eukaryotic replisomes resemble each other but are regulated differently.
    [Show full text]
  • Incision of Damaged DNA in the Presence of an Impaired Smc5/6 Complex Imperils Genome Stability Jie Peng and Wenyi Feng*
    10216–10229 Nucleic Acids Research, 2016, Vol. 44, No. 21 Published online 17 August 2016 doi: 10.1093/nar/gkw720 Incision of damaged DNA in the presence of an impaired Smc5/6 complex imperils genome stability Jie Peng and Wenyi Feng* Department of Biochemistry and Molecular Biology, State University of New York Upstate Medical University, Syracuse, NY 13210, USA Received February 01, 2016; Revised August 05, 2016; Accepted August 08, 2016 ABSTRACT cleotide excision repair (RER) pathways, respectively (7). / Virtually all DNA repair pathways require recognition and The Smc5 6 complex is implicated in homologous subsequent excisions of the damaged nucleotide, giving rise recombination-mediated DNA repair during DNA to a single-stranded gap in the DNA polymer (7). The mech- damage or replication stress. Here, we analysed anisms ensuring such a structural alteration of the chro- genome-wide replication dynamics in a hypomorphic mosome is efficiently repaired and does not lead to further budding yeast mutant, smc6-P4. The overall replica- degradation are underexplored. Conceivably, these mecha- tion dynamics in the smc6 mutant is similar to that nisms would involve protein complexes directly interacting in the wild-type cells. However, we captured a dif- with the chromosomal DNA and implicated in DNA dam- ference in the replication profile of an early S phase age or replication stress response. sample in the mutant, prompting the hypothesis that One of the three evolutionarily conserved Structure the mutant incorporates ribonucleotides and/or ac- Maintenance of Chromosome (SMC) protein complexes, the Smc5/6 complex, plays a key role in DNA damage re- cumulates single-stranded DNA gaps during replica- pair.
    [Show full text]
  • Working on Genomic Stability: from the S-Phase to Mitosis
    G C A T T A C G G C A T genes Review Working on Genomic Stability: From the S-Phase to Mitosis Sara Ovejero 1,2,3,* , Avelino Bueno 1,4 and María P. Sacristán 1,4,* 1 Instituto de Biología Molecular y Celular del Cáncer (IBMCC), Universidad de Salamanca-CSIC, Campus Miguel de Unamuno, 37007 Salamanca, Spain; [email protected] 2 Institute of Human Genetics, CNRS, University of Montpellier, 34000 Montpellier, France 3 Department of Biological Hematology, CHU Montpellier, 34295 Montpellier, France 4 Departamento de Microbiología y Genética, Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain * Correspondence: [email protected] (S.O.); [email protected] (M.P.S.); Tel.: +34-923-294808 (M.P.S.) Received: 31 January 2020; Accepted: 18 February 2020; Published: 20 February 2020 Abstract: Fidelity in chromosome duplication and segregation is indispensable for maintaining genomic stability and the perpetuation of life. Challenges to genome integrity jeopardize cell survival and are at the root of different types of pathologies, such as cancer. The following three main sources of genomic instability exist: DNA damage, replicative stress, and chromosome segregation defects. In response to these challenges, eukaryotic cells have evolved control mechanisms, also known as checkpoint systems, which sense under-replicated or damaged DNA and activate specialized DNA repair machineries. Cells make use of these checkpoints throughout interphase to shield genome integrity before mitosis. Later on, when the cells enter into mitosis, the spindle assembly checkpoint (SAC) is activated and remains active until the chromosomes are properly attached to the spindle apparatus to ensure an equal segregation among daughter cells.
    [Show full text]
  • S41467-017-00634-0.Pdf
    ARTICLE DOI: 10.1038/s41467-017-00634-0 OPEN BRCA2 suppresses replication stress-induced mitotic and G1 abnormalities through homologous recombination Weiran Feng 1,2 & Maria Jasin1,2 Mutations in the tumor suppressor BRCA2 predominantly predispose to breast cancer. Paradoxically, while loss of BRCA2 promotes tumor formation, it also causes cell lethality, although how lethality is triggered is unclear. Here, we generate BRCA2 conditional non- transformed human mammary epithelial cell lines using CRISPR-Cas9. Cells are inviable upon BRCA2 loss, which leads to replication stress associated with under replication, causing mitotic abnormalities, 53BP1 nuclear body formation in the ensuing G1 phase, and G1 arrest. Unexpected from other systems, the role of BRCA2 in homologous recombination, but not in stalled replication fork protection, is primarily associated with supporting human mammary epithelial cell viability, and, moreover, preventing replication stress, a hallmark of pre- cancerous lesions. Thus, we uncover a DNA under replication-53BP1 nuclear body formation- G1 arrest axis as an unanticipated outcome of homologous recombination deficiency, which triggers cell lethality and, we propose, serves as a barrier that must be overcome for tumor formation. 1 Developmental Biology Program, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA. 2 Louis V. Gerstner Jr. Graduate School of Biomedical Sciences, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA. Correspondence and requests for materials should be addressed to M.J. (email: [email protected]) NATURE COMMUNICATIONS | 8: 525 | DOI: 10.1038/s41467-017-00634-0 | www.nature.com/naturecommunications 1 ARTICLE NATURE COMMUNICATIONS | DOI: 10.1038/s41467-017-00634-0 onoallelic inheritance of a deleterious mutation in Results the BRCA1 or BRCA2 tumor suppressor confers BRCA2 is essential for human mammary MCF10A cell viability.
    [Show full text]
  • Exploiting DNA Replication Stress for Cancer Treatment Tajinder Ubhi1,2 and Grant W
    Published OnlineFirst April 9, 2019; DOI: 10.1158/0008-5472.CAN-18-3631 Cancer Review Research Exploiting DNA Replication Stress for Cancer Treatment Tajinder Ubhi1,2 and Grant W. Brown1,2 Abstract Complete and accurate DNA replication is fundamental to associated with such therapies. We discuss how replication cellular proliferation and genome stability. Obstacles that stress modulates the cell-intrinsic innate immune response delay, prevent, or terminate DNA replication cause the phe- and highlight the integration of replication stress with immu- nomena termed DNA replication stress. Cancer cells exhibit notherapies. Together, exploiting replication stress for cancer chronic replication stress due to the loss of proteins that treatment seems to be a promising strategy as it provides a protect or repair stressed replication forks and due to the selective means of eliminating tumors, and with continuous continuous proliferative signaling, providing an exploitable advances in our knowledge of the replication stress response therapeutic vulnerability in tumors. Here, we outline current and lessons learned from current therapies in use, we are and pending therapeutic approaches leveraging tumor-specific moving toward honing the potential of targeting replication replication stress as a target, in addition to the challenges stress in the clinic. Introduction mental. In this review, we provide a summary of the therapies centered on enhancing both endogenous and drug-induced rep- The DNA replication machinery successfully carries out accu- lication stress and discuss the rationales associated with them. We rate genome duplication in the face of numerous obstacles, many also highlight the potential of using replication stress to stimulate of which cause DNA replication stress.
    [Show full text]
  • Exploiting DNA Replication Stress for Cancer Treatment Tajinder Ubhi1,2 and Grant W
    Published OnlineFirst April 9, 2019; DOI: 10.1158/0008-5472.CAN-18-3631 Cancer Review Research Exploiting DNA Replication Stress for Cancer Treatment Tajinder Ubhi1,2 and Grant W. Brown1,2 Abstract Complete and accurate DNA replication is fundamental to associated with such therapies. We discuss how replication cellular proliferation and genome stability. Obstacles that stress modulates the cell-intrinsic innate immune response delay, prevent, or terminate DNA replication cause the phe- and highlight the integration of replication stress with immu- nomena termed DNA replication stress. Cancer cells exhibit notherapies. Together, exploiting replication stress for cancer chronic replication stress due to the loss of proteins that treatment seems to be a promising strategy as it provides a protect or repair stressed replication forks and due to the selective means of eliminating tumors, and with continuous continuous proliferative signaling, providing an exploitable advances in our knowledge of the replication stress response therapeutic vulnerability in tumors. Here, we outline current and lessons learned from current therapies in use, we are and pending therapeutic approaches leveraging tumor-specific moving toward honing the potential of targeting replication replication stress as a target, in addition to the challenges stress in the clinic. Introduction mental. In this review, we provide a summary of the therapies centered on enhancing both endogenous and drug-induced rep- The DNA replication machinery successfully carries out accu- lication stress and discuss the rationales associated with them. We rate genome duplication in the face of numerous obstacles, many also highlight the potential of using replication stress to stimulate of which cause DNA replication stress.
    [Show full text]
  • Prevention of DNA Replication Stress by CHK1 Leads to Chemoresistance Despite a DNA Repair Defect in Homologous Recombination in Breast Cancer
    cells Article Prevention of DNA Replication Stress by CHK1 Leads to Chemoresistance Despite a DNA Repair Defect in Homologous Recombination in Breast Cancer 1, 1, 1 1 Felix Meyer y, Saskia Becker y, Sandra Classen , Ann Christin Parplys , Wael Yassin Mansour 1,2, Britta Riepen 1, Sara Timm 3, Claudia Ruebe 3 , Maria Jasin 4, Harriet Wikman 5 , Cordula Petersen 6, Kai Rothkamm 1 and Kerstin Borgmann 1,* 1 Laboratory of Radiobiology and Experimental Radiooncology, Center of Oncology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; [email protected] (F.M.); [email protected] (S.B.); [email protected] (S.C.); [email protected] (A.C.P.); [email protected] (W.Y.M.); [email protected] (B.R.); [email protected] (K.R.) 2 Tumor Biology Department, National Cancer Institute, Cairo University, Cairo 11796, Egypt 3 Department of Radiation Oncology, Saarland University, 66421 Hamburg/Saar, Germany; [email protected] (S.T.); [email protected] (C.R.) 4 Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; [email protected] 5 Department of Tumor Biology, University Center Hamburg-Eppendorf, 20246 Hamburg, Germany; [email protected] 6 Department of Radiotherapy and Radiooncology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; [email protected] * Correspondence: [email protected]; Tel.: +49-40-74105-3596 These authors contributed equally to the manuscript. y Received: 10 December 2019; Accepted: 14 January 2020; Published: 17 January 2020 Abstract: Chromosomal instability not only has a negative effect on survival in triple-negative breast cancer, but also on the well treatable subgroup of luminal A tumors.
    [Show full text]
  • A Pan-Cancer Transcriptome Analysis Identifies Replication Fork and Innate Immunity Genes As Modifiers of Response to the CHK1 Inhibitor Prexasertib
    www.oncotarget.com Oncotarget, 2020, Vol. 11, (No. 3), pp: 216-236 Research Paper A pan-cancer transcriptome analysis identifies replication fork and innate immunity genes as modifiers of response to the CHK1 inhibitor prexasertib Wayne D. Blosser1, Jack A. Dempsey1, Ann M. McNulty1, Xi Rao1, Philip J. Ebert1, Caitlin D. Lowery1, Philip W. Iversen1, Yue Wang Webster1, Gregory P. Donoho1, Xueqian Gong1, Farhana F. Merzoug1, Sean Buchanan1, Karsten Boehnke2, Chunping Yu3, Xin Tian You3, Richard P. Beckmann1, Wenjuan Wu1, Samuel C. McNeely1, Aimee Bence Lin1 and Ricardo Martinez1 1Eli Lilly and Company, Indianapolis, IN, USA 2Eli Lilly and Company, New York, NY, USA 3Eli Lilly and Company, Shanghai, China Correspondence to: Ricardo Martinez, email: [email protected] Keywords: CHK1; prexasertib; replication stress; replication fork; innate immunity Received: September 19, 2019 Accepted: December 02, 2019 Published: January 21, 2020 Copyright: Blosser et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License 3.0 (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. ABSTRACT The combined influence of oncogenic drivers, genomic instability, and/or DNA damage repair deficiencies increases replication stress in cancer. Cells with high replication stress rely on the upregulation of checkpoints like those governed by CHK1 for survival. Previous studies of the CHK1 inhibitor prexasertib demonstrated activity across multiple cancer types. Therefore, we sought to (1) identify markers of prexasertib sensitivity and (2) define the molecular mechanism(s) of intrinsic and acquired resistance using preclinical models representing multiple tumor types.
    [Show full text]
  • CHK1-Targeted Therapy to Deplete DNA Replication-Stressed, P53
    Gut Online First, published on April 7, 2017 as 10.1136/gutjnl-2016-312623 GI cancer ORIGINAL ARTICLE CHK1-targeted therapy to deplete DNA replication- Gut: first published as 10.1136/gutjnl-2016-312623 on 7 April 2017. Downloaded from stressed, p53-deficient, hyperdiploid colorectal cancer stem cells Gwenola Manic,1 Michele Signore,2 Antonella Sistigu,3 Giorgio Russo,3,4 Francesca Corradi,1 Silvia Siteni,3,5 Martina Musella,3,6 Sara Vitale,4 Maria Laura De Angelis,2 Matteo Pallocca,7 Carla Azzurra Amoreo,8 Francesca Sperati,9 Simone Di Franco,10 Sabina Barresi,11 Eleonora Policicchio,2,12 Gabriele De Luca,2 Francesca De Nicola,7 Marcella Mottolese,8 Ann Zeuner,2 Maurizio Fanciulli,7 Giorgio Stassi,10 Marcello Maugeri-Saccà,13 Marta Baiocchi,2 Marco Tartaglia,11 Ilio Vitale,1,3 Ruggero De Maria4 ▸ Additional material is ABSTRACT published online only. To view Objective Cancer stem cells (CSCs) are responsible for Significance of this study please visit the journal online (http://dx.doi.org/10.1136/ tumour formation and spreading, and their targeting is gutjnl-2016-312623). required for tumour eradication. There are limited therapeutic options for advanced colorectal cancer What is already known on this subject? (CRC), particularly for tumours carrying RAS-activating ▸ fi Cancer stem cells (CSCs), the subpopulation of For numbered af liations see mutations. The aim of this study was to identify novel end of article. cells driving tumour initiation and spreading, CSC-targeting strategies. are associated with cancer relapse, therapeutic Correspondence to Design To discover potential therapeutics to be resistance and poor patient prognosis thereby Dr.
    [Show full text]
  • ATR-Chk1 Activation Mitigates Replication Stress Caused by Mismatch Repair-Dependent Processing of DNA Damage
    ATR-Chk1 activation mitigates replication stress caused by mismatch repair-dependent processing of DNA damage Dipika Guptaa,b, Bo Lina,b,1, Ann Cowanc,d, and Christopher D. Heinena,b,2 aNeag Comprehensive Cancer Center, UConn Health, Farmington, CT 06030-3101; bCenter for Molecular Oncology, UConn Health, Farmington, CT 06030- 3101; cR. D. Berlin Center for Cell Analysis and Modeling, UConn Health, Farmington, CT 06030; and dDepartment of Molecular Biology and Biophysics, UConn Health, Farmington, CT 06030 Edited by Richard D. Kolodner, Ludwig Institute for Cancer Research, La Jolla, CA, and approved December 29, 2017 (received for review December 1, 2017) The mismatch repair pathway (MMR) is essential for removing that the cells continue into a second cell cycle is not clear. Per- DNA polymerase errors, thereby maintaining genomic stability. sistent single-stranded gaps remain after MMR activity that are Loss of MMR function increases mutation frequency and is proposed to become double-strand breaks (DSB) in the next associated with tumorigenesis. However, how MMR is executed S phase, causing the G2 arrest (5). A second model suggests that at active DNA replication forks is unclear. This has important im- the MMR proteins recognize MeG/T and directly recruit proteins plications for understanding how MMR repairs O6-methylguanine/ involved in signaling cell cycle arrest such as Ataxia telangiec- thymidine (MeG/T) mismatches created upon exposure to DNA tasia and Rad3-related (ATR), Ataxia telangiectasia mutated alkylating agents. If MeG/T lesion recognition by MMR initiates (ATM), and the checkpoint kinases Chk1 and Chk2 (3). As the mismatch excision, the reinsertion of a mismatched thymidine dur- MMR proteins respond to MeG/T in the first S phase, it is un- ing resynthesis could initiate futile repair cycles.
    [Show full text]
  • DNA Replication Stress and Chromosomal Instability: Dangerous Liaisons
    G C A T T A C G G C A T genes Review DNA Replication Stress and Chromosomal Instability: Dangerous Liaisons Therese Wilhelm 1,2, Maha Said 1 and Valeria Naim 1,* 1 CNRS UMR9019 Genome Integrity and Cancers, Université Paris Saclay, Gustave Roussy, 94805 Villejuif, France; [email protected] (T.W.); [email protected] (M.S.) 2 UMR144 Cell Biology and Cancer, Institut Curie, 75005 Paris, France * Correspondence: [email protected] Received: 11 May 2020; Accepted: 8 June 2020; Published: 10 June 2020 Abstract: Chromosomal instability (CIN) is associated with many human diseases, including neurodevelopmental or neurodegenerative conditions, age-related disorders and cancer, and is a key driver for disease initiation and progression. A major source of structural chromosome instability (s-CIN) leading to structural chromosome aberrations is “replication stress”, a condition in which stalled or slowly progressing replication forks interfere with timely and error-free completion of the S phase. On the other hand, mitotic errors that result in chromosome mis-segregation are the cause of numerical chromosome instability (n-CIN) and aneuploidy. In this review, we will discuss recent evidence showing that these two forms of chromosomal instability can be mechanistically interlinked. We first summarize how replication stress causes structural and numerical CIN, focusing on mechanisms such as mitotic rescue of replication stress (MRRS) and centriole disengagement, which prevent or contribute to specific types of structural chromosome aberrations and segregation errors. We describe the main outcomes of segregation errors and how micronucleation and aneuploidy can be the key stimuli promoting inflammation, senescence, or chromothripsis.
    [Show full text]
  • Replication Stress, Genomic Instability, and Replication Timing: a Complex Relationship
    International Journal of Molecular Sciences Review Replication Stress, Genomic Instability, and Replication Timing: A Complex Relationship Lina-Marie Briu † , Chrystelle Maric † and Jean-Charles Cadoret * Université de Paris, CNRS, Institut Jacques Monod, F-75006 Paris, France; [email protected] (L.-M.B.); [email protected] (C.M.) * Correspondence: [email protected] † First co-authors. Abstract: The replication-timing program constitutes a key element of the organization and coordi- nation of numerous nuclear processes in eukaryotes. This program is established at a crucial moment in the cell cycle and occurs simultaneously with the organization of the genome, thus indicating the vital significance of this process. With recent technological achievements of high-throughput approaches, a very strong link has been confirmed between replication timing, transcriptional activity, the epigenetic and mutational landscape, and the 3D organization of the genome. There is also a clear relationship between replication stress, replication timing, and genomic instability, but the extent to which they are mutually linked to each other is unclear. Recent evidence has shown that replication timing is affected in cancer cells, although the cause and consequence of this effect remain unknown. However, in-depth studies remain to be performed to characterize the molecular mechanisms of replication-timing regulation and clearly identify different cis- and trans-acting factors. The results of these studies will potentially facilitate the discovery of new therapeutic pathways, particularly for personalized medicine, or new biomarkers. This review focuses on the complex relationship between replication timing, replication stress, and genomic instability. Citation: Briu, L.-M.; Maric, C.; Cadoret, J.-C.
    [Show full text]