1
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Orren DK, Machwe A. Response to Replication Stress and Maintenance of Genome Stability by WRN, the Werner Syndrome Protein. Int J Mol Sci 2024; 25:8300. [PMID: 39125869 PMCID: PMC11311767 DOI: 10.3390/ijms25158300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2024] [Revised: 07/16/2024] [Accepted: 07/25/2024] [Indexed: 08/12/2024] Open
Abstract
Werner syndrome (WS) is an autosomal recessive disease caused by loss of function of WRN. WS is a segmental progeroid disease and shows early onset or increased frequency of many characteristics of normal aging. WRN possesses helicase, annealing, strand exchange, and exonuclease activities and acts on a variety of DNA substrates, even complex replication and recombination intermediates. Here, we review the genetics, biochemistry, and probably physiological functions of the WRN protein. Although its precise role is unclear, evidence suggests WRN plays a role in pathways that respond to replication stress and maintain genome stability particularly in telomeric regions.
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Affiliation(s)
- David K. Orren
- Department of Toxicology and Cancer Biology, University of Kentucky College of Medicine, Lexington, KY 40536, USA;
- Markey Cancer Center, University of Kentucky, Lexington, KY 40506, USA
| | - Amrita Machwe
- Department of Toxicology and Cancer Biology, University of Kentucky College of Medicine, Lexington, KY 40536, USA;
- Markey Cancer Center, University of Kentucky, Lexington, KY 40506, USA
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2
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Ito M, Fujita Y, Shinohara A. Positive and negative regulators of RAD51/DMC1 in homologous recombination and DNA replication. DNA Repair (Amst) 2024; 134:103613. [PMID: 38142595 DOI: 10.1016/j.dnarep.2023.103613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 12/10/2023] [Accepted: 12/10/2023] [Indexed: 12/26/2023]
Abstract
RAD51 recombinase plays a central role in homologous recombination (HR) by forming a nucleoprotein filament on single-stranded DNA (ssDNA) to catalyze homology search and strand exchange between the ssDNA and a homologous double-stranded DNA (dsDNA). The catalytic activity of RAD51 assembled on ssDNA is critical for the DNA-homology-mediated repair of DNA double-strand breaks in somatic and meiotic cells and restarting stalled replication forks during DNA replication. The RAD51-ssDNA complex also plays a structural role in protecting the regressed/reversed replication fork. Two types of regulators control RAD51 filament formation, stability, and dynamics, namely positive regulators, including mediators, and negative regulators, so-called remodelers. The appropriate balance of action by the two regulators assures genome stability. This review describes the roles of positive and negative RAD51 regulators in HR and DNA replication and its meiosis-specific homolog DMC1 in meiotic recombination. We also provide future study directions for a comprehensive understanding of RAD51/DMC1-mediated regulation in maintaining and inheriting genome integrity.
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Affiliation(s)
- Masaru Ito
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan.
| | - Yurika Fujita
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan.
| | - Akira Shinohara
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan.
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3
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Shimada M, Tokumiya T, Miyake T, Tsukada K, Kanzaki N, Yanagihara H, Kobayashi J, Matsumoto Y. Implication of E3 ligase RAD18 in UV-induced mutagenesis in human induced pluripotent stem cells and neuronal progenitor cells. JOURNAL OF RADIATION RESEARCH 2023; 64:345-351. [PMID: 36634340 PMCID: PMC10036092 DOI: 10.1093/jrr/rrac099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 11/24/2022] [Accepted: 12/03/2022] [Indexed: 06/17/2023]
Abstract
Pluripotent stem cells (PSCs) have the potential to differentiate to any of the other organs. The genome DNA integrity of PSCs is maintained by a high level of transcription for a number of genes involved in DNA repair, cell cycle and apoptosis. However, it remains unclear how high the frequency of genetic mutation is and how these DNA repair factors function in PSCs. In this study, we employed Sup F assay for the measurement of mutation frequency after UV-C irradiation in induced pluripotent stem cells (iPSCs) as PSC models and neural progenitor cells (NPCs) were derived from iPSCs as differentiated cells. iPSCs and NPCs exhibited a lower mutation frequency compared with the original skin fibroblasts. In RNA-seq analysis, iPSCs and NPCs showed a high expression of RAD18, which is involved in trans-lesion synthesis (TLS) for the emergency tolerance system during the replication process of DNA. Although RAD18 is involved in both error free and error prone TLS in somatic cells, it still remains unknown the function of RAD18 in PSCs. In this study we depleted of the RAD18 by siRNA knockdown resulted in decreased frequency of mutation in iPSCs and NPCs. Our results will provide information on the genome maintenance machinery in PSCs.
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Affiliation(s)
- Mikio Shimada
- Corresponding author. Mikio Shimada, Laboratory for Zero-Carbon Energy, Institute of Innovative Research, Tokyo Institute of Technology, 2-12-1 Oookayama, Meguro-ku, Tokyo, 152-8550, Japan.
| | - Takumi Tokumiya
- Laboratory for Zero-Carbon Energy, Institute of Innovative Research, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 Japan
| | - Tomoko Miyake
- Laboratory for Zero-Carbon Energy, Institute of Innovative Research, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 Japan
| | - Kaima Tsukada
- Laboratory for Zero-Carbon Energy, Institute of Innovative Research, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 Japan
| | - Norie Kanzaki
- Ningyo-toge Environmental Engineering Center, Japan Atomic Energy Agency, 1550 Kamisaibara, Kagamino-cho, Tomata-gun, Okayama 708-0698, Japan
| | - Hiromi Yanagihara
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Junya Kobayashi
- Department of Radiological Sciences, School of Health Science at Narita, International University of Health and Welfare, Kozunomori 4-3, Narita 286-8686, Japan
| | - Yoshihisa Matsumoto
- Laboratory for Zero-Carbon Energy, Institute of Innovative Research, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 Japan
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4
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Zhang S, Zhou T, Wang Z, Yi F, Li C, Guo W, Xu H, Cui H, Dong X, Liu J, Song X, Cao L. Post-Translational Modifications of PCNA in Control of DNA Synthesis and DNA Damage Tolerance-the Implications in Carcinogenesis. Int J Biol Sci 2021; 17:4047-4059. [PMID: 34671219 PMCID: PMC8495385 DOI: 10.7150/ijbs.64628] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 09/19/2021] [Indexed: 11/05/2022] Open
Abstract
The faithful DNA replication is a critical event for cell survival and inheritance. However, exogenous or endogenous sources of damage challenge the accurate synthesis of DNA, which causes DNA lesions. The DNA lesions are obstacles for replication fork progression. However, the prolonged replication fork stalling leads to replication fork collapse, which may cause DNA double-strand breaks (DSB). In order to maintain genomic stability, eukaryotic cells evolve translesion synthesis (TLS) and template switching (TS) to resolve the replication stalling. Proliferating cell nuclear antigen (PCNA) trimer acts as a slide clamp and encircles DNA to orchestrate DNA synthesis and DNA damage tolerance (DDT). The post-translational modifications (PTMs) of PCNA regulate these functions to ensure the appropriate initiation and termination of replication and DDT. The aberrant regulation of PCNA PTMs will result in DSB, which causes mutagenesis and poor response to chemotherapy. Here, we review the roles of the PCNA PTMs in DNA duplication and DDT. We propose that clarifying the regulation of PCNA PTMs may provide insights into understanding the development of cancers.
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Affiliation(s)
- Siyi Zhang
- Institute of Health Sciences, China Medical University, Shenyang, Liaoning Province, 110122, PR China
| | - Tingting Zhou
- Institute of Health Sciences, China Medical University, Shenyang, Liaoning Province, 110122, PR China
| | - Zhuo Wang
- Institute of Health Sciences, China Medical University, Shenyang, Liaoning Province, 110122, PR China
| | - Fei Yi
- Institute of Health Sciences, China Medical University, Shenyang, Liaoning Province, 110122, PR China
| | - Chunlu Li
- Institute of Health Sciences, China Medical University, Shenyang, Liaoning Province, 110122, PR China
| | - Wendong Guo
- Institute of Health Sciences, China Medical University, Shenyang, Liaoning Province, 110122, PR China
| | - Hongde Xu
- Institute of Health Sciences, China Medical University, Shenyang, Liaoning Province, 110122, PR China
| | - Hongyan Cui
- Institute of Health Sciences, China Medical University, Shenyang, Liaoning Province, 110122, PR China
| | - Xiang Dong
- Institute of Health Sciences, China Medical University, Shenyang, Liaoning Province, 110122, PR China
| | - Jingwei Liu
- Institute of Health Sciences, China Medical University, Shenyang, Liaoning Province, 110122, PR China
| | - Xiaoyu Song
- Institute of Health Sciences, China Medical University, Shenyang, Liaoning Province, 110122, PR China
| | - Liu Cao
- College of Basic Medical Science, Key Laboratory of Cell Biology of Ministry of Public Health, Key Laboratory of Medical Cell Biology of Ministry of Education, Liaoning Province Collaborative Innovation Center of Aging Related Disease Diagnosis and Treatment and Prevention, China Medical University, Shenyang, Liaoning Province, 110122, PR China
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5
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Saha P, Mandal T, Talukdar AD, Kumar D, Kumar S, Tripathi PP, Wang QE, Srivastava AK. DNA polymerase eta: A potential pharmacological target for cancer therapy. J Cell Physiol 2020; 236:4106-4120. [PMID: 33184862 DOI: 10.1002/jcp.30155] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 10/21/2020] [Accepted: 11/02/2020] [Indexed: 12/24/2022]
Abstract
In the last two decades, intensive research has been carried out to improve the survival rates of cancer patients. However, the development of chemoresistance that ultimately leads to tumor relapse poses a critical challenge for the successful treatment of cancer patients. Many cancer patients experience tumor relapse and ultimately die because of treatment failure associated with acquired drug resistance. Cancer cells utilize multiple lines of self-defense mechanisms to bypass chemotherapy and radiotherapy. One such mechanism employed by cancer cells is translesion DNA synthesis (TLS), in which specialized TLS polymerases bypass the DNA lesion with the help of monoubiquitinated proliferating cell nuclear antigen. Among all TLS polymerases (Pol η, Pol ι, Pol κ, REV1, Pol ζ, Pol μ, Pol λ, Pol ν, and Pol θ), DNA polymerase eta (Pol η) is well studied and majorly responsible for the bypass of cisplatin and UV-induced DNA damage. TLS polymerases contribute to chemotherapeutic drug-induced mutations as well as therapy resistance. Therefore, targeting these polymerases presents a novel therapeutic strategy to combat chemoresistance. Mounting evidence suggests that inhibition of Pol η may have multiple impacts on cancer therapy such as sensitizing cancer cells to chemotherapeutics, suppressing drug-induced mutagenesis, and inhibiting the development of secondary tumors. Herein, we provide a general introduction of Pol η and its clinical implications in blocking acquired drug resistance. In addition; this review addresses the existing gaps and challenges of Pol η mediated TLS mechanisms in human cells. A better understanding of the Pol η mediated TLS mechanism will not merely establish it as a potential pharmacological target but also open possibilities to identify novel drug targets for future therapy.
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Affiliation(s)
- Priyanka Saha
- Cancer Biology & Inflammatory Disorder Division, CSIR-Indian Institute of Chemical Biology, Kolkata, West Bengal, India
| | - Tanima Mandal
- Cancer Biology & Inflammatory Disorder Division, CSIR-Indian Institute of Chemical Biology, Kolkata, West Bengal, India
| | - Anupam D Talukdar
- Department of Life Science and Bioinformatics, Assam University, Silchar, Assam, India
| | - Deepak Kumar
- Organic & Medicinal Chemistry Division, CSIR-Indian Institute of Chemical Biology, Kolkata, West Bengal, India
| | - Sanjay Kumar
- Division of Biology, Indian Institute of Science Education and Research (IISER) Tirupati, Andhra Pradesh, India
| | - Prem P Tripathi
- Cell Biology & Physiology Division, CSIR-Indian Institute of Chemical Biology, Kolkata, West Bengal, India
| | - Qi-En Wang
- Department of Radiation Oncology, Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio, USA
| | - Amit K Srivastava
- Cancer Biology & Inflammatory Disorder Division, CSIR-Indian Institute of Chemical Biology, Kolkata, West Bengal, India
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6
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Ma X, Tang TS, Guo C. Regulation of translesion DNA synthesis in mammalian cells. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:680-692. [PMID: 31983077 DOI: 10.1002/em.22359] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 12/29/2019] [Accepted: 01/21/2020] [Indexed: 06/10/2023]
Abstract
The genomes of all living cells are under endogenous and exogenous attacks every day, causing diverse genomic lesions. Most of the lesions can be timely repaired by multiple DNA repair pathways. However, some may persist during S-phase, block DNA replication, and challenge genome integrity. Eukaryotic cells have evolved DNA damage tolerance (DDT) to mitigate the lethal effects of arrested DNA replication without prior removal of the offending DNA damage. As one important mode of DDT, translesion DNA synthesis (TLS) utilizes multiple low-fidelity DNA polymerases to incorporate nucleotides opposite DNA lesions to maintain genome integrity. Three different mechanisms have been proposed to regulate the polymerase switching between high-fidelity DNA polymerases in the replicative machinery and one or more specialized enzymes. Additionally, it is known that proliferating cell nuclear antigen (PCNA) mono-ubiquitination is essential for optimal TLS. Given its error-prone property, TLS is closely associated with spontaneous and drug-induced mutations in cells, which can potentially lead to tumorigenesis and chemotherapy resistance. Therefore, TLS process must be tightly modulated to avoid unwanted mutagenesis. In this review, we will focus on polymerase switching and PCNA mono-ubiquitination, the two key events in TLS pathway in mammalian cells, and summarize current understandings of regulation of TLS process at the levels of protein-protein interactions, post-translational modifications as well as transcription and noncoding RNAs. Environ. Mol. Mutagen. 61:680-692, 2020. © 2020 Wiley Periodicals, Inc.
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Affiliation(s)
- Xiaolu Ma
- College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan, China
| | - Tie-Shan Tang
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, China
| | - Caixia Guo
- CAS Key Laboratory of Genomics and Precision Medicine, Beijing Institute of Genomics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, China
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7
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Masuda Y, Masutani C. Spatiotemporal regulation of PCNA ubiquitination in damage tolerance pathways. Crit Rev Biochem Mol Biol 2019; 54:418-442. [PMID: 31736364 DOI: 10.1080/10409238.2019.1687420] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
DNA is constantly exposed to a wide variety of exogenous and endogenous agents, and most DNA lesions inhibit DNA synthesis. To cope with such problems during replication, cells have molecular mechanisms to resume DNA synthesis in the presence of DNA lesions, which are known as DNA damage tolerance (DDT) pathways. The concept of ubiquitination-mediated regulation of DDT pathways in eukaryotes was established via genetic studies in the yeast Saccharomyces cerevisiae, in which two branches of the DDT pathway are regulated via ubiquitination of proliferating cell nuclear antigen (PCNA): translesion DNA synthesis (TLS) and homology-dependent repair (HDR), which are stimulated by mono- and polyubiquitination of PCNA, respectively. Over the subsequent nearly two decades, significant progress has been made in understanding the mechanisms that regulate DDT pathways in other eukaryotes. Importantly, TLS is intrinsically error-prone because of the miscoding nature of most damaged nucleotides and inaccurate replication of undamaged templates by TLS polymerases (pols), whereas HDR is theoretically error-free because the DNA synthesis is thought to be predominantly performed by pol δ, an accurate replicative DNA pol, using the undamaged sister chromatid as its template. Thus, the regulation of the choice between the TLS and HDR pathways is critical to determine the appropriate biological outcomes caused by DNA damage. In this review, we summarize our current understanding of the species-specific regulatory mechanisms of PCNA ubiquitination and how cells choose between TLS and HDR. We then provide a hypothetical model for the spatiotemporal regulation of DDT pathways in human cells.
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Affiliation(s)
- Yuji Masuda
- Department of Genome Dynamics, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan.,Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Chikahide Masutani
- Department of Genome Dynamics, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan.,Graduate School of Medicine, Nagoya University, Nagoya, Japan
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8
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Kawamura K, Qi F, Meng Q, Hayashi I, Kobayashi J. Nucleolar protein nucleolin functions in replication stress-induced DNA damage responses. JOURNAL OF RADIATION RESEARCH 2019; 60:281-288. [PMID: 30839063 PMCID: PMC6530621 DOI: 10.1093/jrr/rry114] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 12/23/2018] [Indexed: 05/05/2023]
Abstract
The nucleolus contains multiple copies of ribosomal (r)DNA, which indicate sites of frequent replication stress and suggest the existence of a mechanism to prevent replication stress-related rDNA instability and the possibility that such a mechanism contributes to the whole genomic stability against replication stress. We have previously reported that nucleolin, a major nucleolar protein, is involved in ionizing radiation-induced DNA damage responses (DDRs) such as ataxia telangiectasia mutated (ATM)-dependent cell cycle checkpoints and homologous recombination (HR) repair. Here, we investigated the role of nucleolin in DDR due to replication stress. The results indicate that following replication stress, nucleolin interacted with the histone γH2AX, proliferating cell nuclear antigen (PCNA), and replication protein A (RPA)32, suggesting that it may be recruited to DNA damage sites on the replication fork. Furthermore, the knockdown of nucleolin by siRNA reduced the activation of ATM and RAD3-related (ATR) kinase and the formation of RAD51 and RPA32 foci after replication stress due to UV or camptothecin exposure, whereas nucleolin overexpression augmented ATR-dependent phosphorylation and RAD51 and RPA accumulation on chromatin. Moreover, these overexpressing cells seemed to increase repair activity and resistance to replication stress. Our results indicate that nucleolin plays an important role in replication stress-induced DDRs such as ATR activation and HR repair. Given that nucleolin overexpression is often observed in many types of cancer cells, our findings suggest that nucleolin is involved in the regulation of resistance to replication stress that may otherwise lead to tumorigenesis and it could be a possible target for chemotherapy and radiotherapy.
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Affiliation(s)
- Kasumi Kawamura
- Department of Interdisciplinary Environment, Graduate School of Human and Environmental Sciences, Kyoto University, Yoshidanihonmatsucho, Sakyo-ku, Kyoto, Japan
| | - Fei Qi
- Department of Interdisciplinary Environment, Graduate School of Human and Environmental Sciences, Kyoto University, Yoshidanihonmatsucho, Sakyo-ku, Kyoto, Japan
| | - Qingmei Meng
- Department of Interdisciplinary Environment, Graduate School of Human and Environmental Sciences, Kyoto University, Yoshidanihonmatsucho, Sakyo-ku, Kyoto, Japan
| | - Ikue Hayashi
- Graduate School of Biomedical Sciences, Hiroshima University, Kasumi1-2-3, Minamiku, Hiroshima, Japan
| | - Junya Kobayashi
- Department of Interdisciplinary Environment, Graduate School of Human and Environmental Sciences, Kyoto University, Yoshidanihonmatsucho, Sakyo-ku, Kyoto, Japan
- Department of Genome Repair Dynamics, Radiation Biology Center, Graduate School of Biostudies, Kyoto University, Yoshidakonoecho, Sakyo-ku, Kyoto, Japan
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9
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Mukherjee S, Sinha D, Bhattacharya S, Srinivasan K, Abdisalaam S, Asaithamby A. Werner Syndrome Protein and DNA Replication. Int J Mol Sci 2018; 19:ijms19113442. [PMID: 30400178 PMCID: PMC6274846 DOI: 10.3390/ijms19113442] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 10/22/2018] [Accepted: 10/25/2018] [Indexed: 01/07/2023] Open
Abstract
Werner Syndrome (WS) is an autosomal recessive disorder characterized by the premature development of aging features. Individuals with WS also have a greater predisposition to rare cancers that are mesenchymal in origin. Werner Syndrome Protein (WRN), the protein mutated in WS, is unique among RecQ family proteins in that it possesses exonuclease and 3' to 5' helicase activities. WRN forms dynamic sub-complexes with different factors involved in DNA replication, recombination and repair. WRN binding partners either facilitate its DNA metabolic activities or utilize it to execute their specific functions. Furthermore, WRN is phosphorylated by multiple kinases, including Ataxia telangiectasia mutated, Ataxia telangiectasia and Rad3 related, c-Abl, Cyclin-dependent kinase 1 and DNA-dependent protein kinase catalytic subunit, in response to genotoxic stress. These post-translational modifications are critical for WRN to function properly in DNA repair, replication and recombination. Accumulating evidence suggests that WRN plays a crucial role in one or more genome stability maintenance pathways, through which it suppresses cancer and premature aging. Among its many functions, WRN helps in replication fork progression, facilitates the repair of stalled replication forks and DNA double-strand breaks associated with replication forks, and blocks nuclease-mediated excessive processing of replication forks. In this review, we specifically focus on human WRN's contribution to replication fork processing for maintaining genome stability and suppressing premature aging. Understanding WRN's molecular role in timely and faithful DNA replication will further advance our understanding of the pathophysiology of WS.
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Affiliation(s)
- Shibani Mukherjee
- Division of Molecular Radiation Biology, Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Debapriya Sinha
- Division of Molecular Radiation Biology, Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Souparno Bhattacharya
- Division of Molecular Radiation Biology, Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Kalayarasan Srinivasan
- Division of Molecular Radiation Biology, Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Salim Abdisalaam
- Division of Molecular Radiation Biology, Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Aroumougame Asaithamby
- Division of Molecular Radiation Biology, Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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10
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Suzuki T, Kuramoto Y, Kamiya H. Reduction of Werner Syndrome Protein Enhances G:C → A:T Transition byO6-Methylguanine in Human Cells. Chem Res Toxicol 2018; 31:319-324. [DOI: 10.1021/acs.chemrestox.8b00009] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tetsuya Suzuki
- Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan
| | - Yoshie Kuramoto
- Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan
| | - Hiroyuki Kamiya
- Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan
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11
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Su F, Bhattacharya S, Abdisalaam S, Mukherjee S, Yajima H, Yang Y, Mishra R, Srinivasan K, Ghose S, Chen DJ, Yannone SM, Asaithamby A. Replication stress induced site-specific phosphorylation targets WRN to the ubiquitin-proteasome pathway. Oncotarget 2016; 7:46-65. [PMID: 26695548 PMCID: PMC4807982 DOI: 10.18632/oncotarget.6659] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 11/23/2015] [Indexed: 12/22/2022] Open
Abstract
Faithful and complete genome replication in human cells is essential for preventing the accumulation of cancer-promoting mutations. WRN, the protein defective in Werner syndrome, plays critical roles in preventing replication stress, chromosome instability, and tumorigenesis. Herein, we report that ATR-mediated WRN phosphorylation is needed for DNA replication and repair upon replication stress. A serine residue, S1141, in WRN is phosphorylated in vivo by the ATR kinase in response to replication stress. ATR-mediated WRN S1141 phosphorylation leads to ubiquitination of WRN, facilitating the reversible interaction of WRN with perturbed replication forks and subsequent degradation of WRN. The dynamic interaction between WRN and DNA is required for the suppression of new origin firing and Rad51-dependent double-stranded DNA break repair. Significantly, ATR-mediated WRN phosphorylation is critical for the suppression of chromosome breakage during replication stress. These findings reveal a unique role for WRN as a modulator of DNA repair, replication, and recombination, and link ATR-WRN signaling to the maintenance of genome stability.
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Affiliation(s)
- Fengtao Su
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Souparno Bhattacharya
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Salim Abdisalaam
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Shibani Mukherjee
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Hirohiko Yajima
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba, Japan
| | - Yanyong Yang
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Ritu Mishra
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Kalayarasan Srinivasan
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Subroto Ghose
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - David J Chen
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Steven M Yannone
- Life Science Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Aroumougame Asaithamby
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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12
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Viziteu E, Kassambara A, Pasero P, Klein B, Moreaux J. RECQ helicases are deregulated in hematological malignancies in association with a prognostic value. Biomark Res 2016; 4:3. [PMID: 26877874 PMCID: PMC4752763 DOI: 10.1186/s40364-016-0057-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 02/08/2016] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND RECQ helicase family members act as guardians of the genome to assure proper DNA metabolism in response to genotoxic stress. Hematological malignancies are characterized by genomic instability that is possibly related to underlying defects in DNA repair of genomic stability maintenance. METHODS We have investigated the expression of RECQ helicases in different hematological malignancies and in their normal counterparts using publicly available gene expression data. Furthermore, we explored whether RECQ helicases expression could be associated with tumor progression and prognosis. RESULTS Expression of at least one RECQ helicase family member was found significantly deregulated in all hematological malignancies investigated when compared to their normal counterparts. In addition, RECQ helicase expression was associated with a prognostic value in acute myeloid leukemia, chronic lymphocytic leukemia, lymphoma and multiple myeloma. CONCLUSION RECQ helicase expression is deregulated in hematological malignancies compared to their normal counterparts in association with a prognostic value. Deregulation of RECQ helicases appears to play a role in tumorigenesis and represent potent therapeutic targets for synthetic lethal approaches in hematological malignancies.
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Affiliation(s)
- Elena Viziteu
- />Institute of Human Genetics, CNRS-UPR1142, Montpellier, F-34396 France
| | - Alboukadel Kassambara
- />Laboratory for Monitoring Innovative Therapies, Department of Biological Hematology, Hôpital Saint-Eloi - CHRU de Montpellier, 80, av. Augustin Fliche, 34295 Montpellier, Cedex 5 France
- />Institute of Human Genetics, CNRS-UPR1142, Montpellier, F-34396 France
| | - Philippe Pasero
- />Institute of Human Genetics, CNRS-UPR1142, Montpellier, F-34396 France
| | - Bernard Klein
- />Laboratory for Monitoring Innovative Therapies, Department of Biological Hematology, Hôpital Saint-Eloi - CHRU de Montpellier, 80, av. Augustin Fliche, 34295 Montpellier, Cedex 5 France
- />Institute of Human Genetics, CNRS-UPR1142, Montpellier, F-34396 France
- />University of Montpellier 1, UFR de Médecine, Montpellier, France
| | - Jerome Moreaux
- />Laboratory for Monitoring Innovative Therapies, Department of Biological Hematology, Hôpital Saint-Eloi - CHRU de Montpellier, 80, av. Augustin Fliche, 34295 Montpellier, Cedex 5 France
- />Institute of Human Genetics, CNRS-UPR1142, Montpellier, F-34396 France
- />University of Montpellier 1, UFR de Médecine, Montpellier, France
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13
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Kobayashi J, Saito Y, Okui M, Miwa N, Komatsu K. Increased oxidative stress in AOA3 cells disturbs ATM-dependent DNA damage responses. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2015; 782:42-50. [PMID: 25868131 DOI: 10.1016/j.mrgentox.2015.03.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2014] [Revised: 03/15/2015] [Accepted: 03/17/2015] [Indexed: 12/29/2022]
Abstract
Ataxia telangiectasia (AT) is caused by a mutation in the ataxia-telangiectasia-mutated (ATM) gene; the condition is associated with hyper-radiosensitivity, abnormal cell-cycle checkpoints, and genomic instability. AT patients also show cerebellar ataxia, possibly due to reactive oxygen species (ROS) sensitivity in neural cells. The ATM protein is a key regulator of the DNA damage response. Recently, several AT-like disorders have been reported. The genes responsible for them are predicted to encode proteins that interact with ATM in the DNA-damage response. Ataxia with oculomotor apraxia types 1-3 (AOA1, 2, and 3) result in a neurodegenerative and cellular phenotype similar to AT; however, the basis of this phenotypic similarity is unclear. Here, we show that the cells of AOA3 patients display aberrant ATM-dependent phosphorylation and apoptosis following γ-irradiation. The ATM-dependent response to H2O2 treatment was abrogated in AOA3 cells. Furthermore, AOA3 cells had reduced ATM activity. Our results suggest that the attenuated ATM-related response is caused by an increase in endogenous ROS in AOA3 cells. Pretreatment of cells with pyocyanin, which induces endogenous ROS production, abolished the ATM-dependent response. Moreover, AOA3 cells had decreased homologous recombination (HR) activity, and pyocyanin pretreatment reduced HR activity in HeLa cells. These results indicate that excess endogenous ROS represses the ATM-dependent cellular response and HR repair in AOA3 cells. Since the ATM-dependent cell-cycle checkpoint is an important block to carcinogenesis, such inactivation of ATM may lead to tumorigenesis as well as neurodegeneration.
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Affiliation(s)
- Junya Kobayashi
- Department of Genome Repair Dynamics, Radiation Biology Center, Kyoto University, Kyoto 606-8501, Japan.
| | - Yuichiro Saito
- Department of Genome Repair Dynamics, Radiation Biology Center, Kyoto University, Kyoto 606-8501, Japan
| | - Michiyo Okui
- Biomedical Engineering Center, Toin University of Yokohama, Yokohama 225-8503, Japan
| | - Noriko Miwa
- Department of Genome Repair Dynamics, Radiation Biology Center, Kyoto University, Kyoto 606-8501, Japan
| | - Kenshi Komatsu
- Department of Genome Repair Dynamics, Radiation Biology Center, Kyoto University, Kyoto 606-8501, Japan
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14
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Lafrance-Vanasse J, Williams GJ, Tainer JA. Envisioning the dynamics and flexibility of Mre11-Rad50-Nbs1 complex to decipher its roles in DNA replication and repair. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2015; 117:182-193. [PMID: 25576492 PMCID: PMC4417436 DOI: 10.1016/j.pbiomolbio.2014.12.004] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 12/20/2014] [Accepted: 12/28/2014] [Indexed: 12/23/2022]
Abstract
The Mre11-Rad50-Nbs1 (MRN) complex is a dynamic macromolecular machine that acts in the first steps of DNA double strand break repair, and each of its components has intrinsic dynamics and flexibility properties that are directly linked with their functions. As a result, deciphering the functional structural biology of the MRN complex is driving novel and integrated technologies to define the dynamic structural biology of protein machinery interacting with DNA. Rad50 promotes dramatic long-range allostery through its coiled-coil and zinc-hook domains. Its ATPase activity drives dynamic transitions between monomeric and dimeric forms that can be modulated with mutants modifying the ATPase rate to control end joining versus resection activities. The biological functions of Mre11's dual endo- and exonuclease activities in repair pathway choice were enigmatic until recently, when they were unveiled by the development of specific nuclease inhibitors. Mre11 dimer flexibility, which may be regulated in cells to control MRN function, suggests new inhibitor design strategies for cancer intervention. Nbs1 has FHA and BRCT domains to bind multiple interaction partners that further regulate MRN. One of them, CtIP, modulates the Mre11 excision activity for homologous recombination repair. Overall, these combined properties suggest novel therapeutic strategies. Furthermore, they collectively help to explain how MRN regulates DNA repair pathway choice with implications for improving the design and analysis of cancer clinical trials that employ DNA damaging agents or target the DNA damage response.
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Affiliation(s)
| | | | - John A Tainer
- Life Science Division, 1 Cyclotron Road, Berkeley, CA 94720, USA; The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
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15
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Su F, Mukherjee S, Yang Y, Mori E, Bhattacharya S, Kobayashi J, Yannone SM, Chen DJ, Asaithamby A. Nonenzymatic role for WRN in preserving nascent DNA strands after replication stress. Cell Rep 2014; 9:1387-401. [PMID: 25456133 DOI: 10.1016/j.celrep.2014.10.025] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 06/11/2014] [Accepted: 10/11/2014] [Indexed: 01/16/2023] Open
Abstract
WRN, the protein defective in Werner syndrome (WS), is a multifunctional nuclease involved in DNA damage repair, replication, and genome stability maintenance. It was assumed that the nuclease activities of WRN were critical for these functions. Here, we report a nonenzymatic role for WRN in preserving nascent DNA strands following replication stress. We found that lack of WRN led to shortening of nascent DNA strands after replication stress. Furthermore, we discovered that the exonuclease activity of MRE11 was responsible for the shortening of newly replicated DNA in the absence of WRN. Mechanistically, the N-terminal FHA domain of NBS1 recruits WRN to replication-associated DNA double-stranded breaks to stabilize Rad51 and to limit the nuclease activity of its C-terminal binding partner MRE11. Thus, this previously unrecognized nonenzymatic function of WRN in the stabilization of nascent DNA strands sheds light on the molecular reason for the origin of genome instability in WS individuals.
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Affiliation(s)
- Fengtao Su
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Shibani Mukherjee
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Yanyong Yang
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Eiichiro Mori
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Souparno Bhattacharya
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Junya Kobayashi
- Division of Genome Repair Dynamics, Radiation Biology Center, Kyoto University, Yoshida-konoecho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Steven M Yannone
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - David J Chen
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Aroumougame Asaithamby
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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16
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Garige M, Sharma S. Cellular deficiency of Werner syndrome protein or RECQ1 promotes genotoxic potential of hydroquinone and benzo[a]pyrene exposure. Int J Toxicol 2014; 33:373-81. [PMID: 25228686 DOI: 10.1177/1091581814547422] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The 5 known RecQ helicases in humans (RECQ1, BLM, WRN, RECQL4, and RECQ5) have demonstrated roles in diverse genome maintenance mechanisms but their functions in safeguarding the genome from environmental toxicants are poorly understood. Here, we have evaluated a potential role of WRN (mutated in Werner syndrome) and RECQ1 (the most abundant homolog of WRN) in hydroquinone (HQ)- and benzo[a]pyrene (BaP)-induced genotoxicity. Silencing of WRN or RECQ1 expression in HeLa cells increased their sensitivity to HQ and BaP but elicited distinct DNA damage response. The RECQ1-depleted cells exhibited increased replication protein A phosphorylation, Chk1 activation, and DNA double-strand breaks (DSBs) as compared to control or WRN-depleted cells following exposure to BaP treatment. The BaP-induced DSBs in RECQ1-depleted cells were dependent on DNA-dependent protein kinase activity. Notably, loss of WRN in RECQ1-depleted cells ameliorated BaP toxicity. Collectively, our results provide first indication of nonredundant participation of WRN and RECQ1 in protection from the potentially carcinogenic effects of BaP and HQ.
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Affiliation(s)
- Mamatha Garige
- Department of Biochemistry and Molecular Biology, College of Medicine, Howard University, NW, Washington, DC, USA
| | - Sudha Sharma
- Department of Biochemistry and Molecular Biology, College of Medicine, Howard University, NW, Washington, DC, USA
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17
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Aggarwal M, Banerjee T, Sommers JA, Brosh RM. Targeting an Achilles' heel of cancer with a WRN helicase inhibitor. Cell Cycle 2013; 12:3329-35. [PMID: 24036544 DOI: 10.4161/cc.26320] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Our recently published work suggests that DNA helicases such as the Werner syndrome helicase (WRN) represent a novel class of proteins to target for anticancer therapy. Specifically, pharmacological inhibition of WRN helicase activity in human cells defective in the Fanconi anemia (FA) pathway of interstrand cross-link (ICL) repair are sensitized to the DNA cross-linking agent and chemotherapy drug mitomycin C (MMC) by the WRN helicase inhibitor NSC 617145. (1) The mechanistic basis for the synergistic interaction between NSC 617145 and MMC is discussed in this paper and extrapolated to potential implications for genetic or chemically induced synthetic lethality provoked by cellular exposure to the WRN helicase inhibitor under the context of relevant DNA repair deficiencies associated with cancers or induced by small-molecule inhibitors. Experimental data are presented showing that small-molecule inhibition of WRN helicase elevates sensitivity to MMC-induced stress in human cells that are deficient in both FANCD2 and DNA protein kinase catalytic subunit (DNA-PKcs). These findings suggest a model in which drug-mediated inhibition of WRN helicase activity exacerbates the deleterious effects of MMC-induced DNA damage when both the FA and NHEJ pathways are defective. We conclude with a perspective for the FA pathway and synthetic lethality and implications for DNA repair helicase inhibitors that can be developed for anticancer strategies.
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Affiliation(s)
- Monika Aggarwal
- Laboratory of Molecular Gerontology; National Institute on Aging; National Institutes of Health; NIH Biomedical Research Center; Baltimore, MD USA
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18
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Kobayashi J, Fujimoto H, Sato J, Hayashi I, Burma S, Matsuura S, Chen DJ, Komatsu K. Nucleolin participates in DNA double-strand break-induced damage response through MDC1-dependent pathway. PLoS One 2012; 7:e49245. [PMID: 23145133 PMCID: PMC3492271 DOI: 10.1371/journal.pone.0049245] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Accepted: 10/05/2012] [Indexed: 01/05/2023] Open
Abstract
H2AX is an important factor for chromatin remodeling to facilitate accumulation of DNA damage-related proteins at DNA double-strand break (DSB) sites. In order to further understand the role of H2AX in the DNA damage response (DDR), we attempted to identify H2AX-interacting proteins by proteomics analysis. As a result, we identified nucleolin as one of candidates. Here, we show a novel role of a major nucleolar protein, nucleolin, in DDR. Nucleolin interacted with γ-H2AX and accumulated to laser micro-irradiated DSB damage sites. Chromatin Immunoprecipitation assay also displayed the accumulation of nucleolin around DSB sites. Nucleolin-depleted cells exhibited repression of both ATM-dependent phosphorylation following exposure to γ-ray and subsequent cell cycle checkpoint activation. Furthermore, nucleolin-knockdown reduced HR and NHEJ activity and showed decrease in IR-induced chromatin accumulation of HR/NHEJ factors, agreeing with the delayed kinetics of γ-H2AX focus. Moreover, nucleolin-knockdown decreased MDC1-related events such as focus formation of 53 BP1, RNF168, phosphorylated ATM, and H2A ubiquitination. Nucleolin also showed FACT-like activity for DSB damage-induced histone eviction from chromatin. Taken together, nucleolin could promote both ATM-dependent cell cycle checkpoint and DSB repair by functioning in an MDC1-related pathway through its FACT-like function.
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Affiliation(s)
- Junya Kobayashi
- Department of Genome Repair Dynamics, Radiation Biology Center, Kyoto University, Kyoto, Japan.
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19
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Larsson LG. Oncogene- and tumor suppressor gene-mediated suppression of cellular senescence. Semin Cancer Biol 2011; 21:367-76. [PMID: 22037160 DOI: 10.1016/j.semcancer.2011.10.005] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Data accumulating during the last two decades suggest that tumorigenesis is held in check by two major intrinsic failsafe mechanisms; apoptosis and cellular senescence. While apoptosis is a programmed cell death process, cellular senescence, which is the focus of this article, is defined as irreversible cell cycle arrest. This process is triggered either by telomere erosion or by acute stress signals including oncogenic stress induced by overactive oncogenes or underactive tumor suppressor genes. The outcome of this is often replication overload and oxidative stress resulting in DNA damage. Oncogenic stress induces at least three intrinsic pathways, p16/pRb-, Arf/p53/p21- and the DNA damage response (DDR)-pathways, that induce premature senescence if the stress exceeds a threshold level. Oncogene-induced senescence (OIS) is frequently observed in premalignant lesions both in animal tumor models and in human patients but is essentially absent in advanced cancers, suggesting that malignant tumor cells have found ways to bypass or escape senescence. This review focuses on cell-autonomous mechanism by which certain oncogenes, tumor suppressor genes and components of the DDR/DNA-repair machinery suppress senescence - mechanisms that are exploited by tumor cells to evade senescence and continue to multiply. In this way, tumor cells become addicted to the continuous activity of senescence suppressor proteins. However, some senescence pathways, although under suppression, may remain intact and can be re-established if senescence suppressor proteins are inactivated or if senescence inducers are reactivated. This can hopefully form the basis for a "pro-senescence therapy" strategy to combat cancer in the future.
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Affiliation(s)
- Lars-Gunnar Larsson
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Box 280, SE-171 77 Stockholm, Sweden.
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20
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Kobayashi J, Okui M, Komatsu K, Chen DJ. Possible Role of WRN Protein in Cellular Response Induced by a Little DNA Damage. FUSION SCIENCE AND TECHNOLOGY 2011. [DOI: 10.13182/fst11-a12627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Junya Kobayashi
- Radiation Biology Center, Kyoto University, Kyoto 606-0025 Japan
| | - Michiyo Okui
- Biomedical Engineering Center, Toin University of Yokohama, Yokohama 225-8502, Japan
| | - Kenshi Komatsu
- Radiation Biology Center, Kyoto University, Kyoto 606-0025 Japan
| | - David J. Chen
- University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-9187, USs
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21
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Arai A, Chano T, Futami K, Furuichi Y, Ikebuchi K, Inui T, Tameno H, Ochi Y, Shimada T, Hisa Y, Okabe H. RECQL1 and WRN proteins are potential therapeutic targets in head and neck squamous cell carcinoma. Cancer Res 2011; 71:4598-607. [PMID: 21571861 DOI: 10.1158/0008-5472.can-11-0320] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RECQL1 and WRN proteins are RecQ DNA helicases that participate in suppression of DNA hyper-recombination and repair. In this study, we report evidence supporting their candidacy as cancer therapeutic targets. In hypopharyngeal carcinomas, which have the worst prognosis among head and neck squamous cell carcinomas (HNSCC) that are rapidly rising in incidence, we found that RECQL1 and WRN proteins are highly expressed and that siRNA-mediated silencing of either gene suppressed carcinoma cell growth in vitro. Similarly, siRNA administration in a murine xenograft model of hypopharyngeal carcinoma markedly inhibited tumor growth. Moreover, combining either siRNA with cis-platinum (II) diammine dichloride significantly augmented the in vivo anticancer effects of this drug that is used commonly in HNSCC treatment. Notably, we observed no recurrence of some tumors following siRNA treatment in this model. Our findings offer a preclinical proof of concept for RECQL1 and WRN proteins as novel therapeutic targets to treat aggressive HNSCC and perhaps other cancers.
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Affiliation(s)
- Akihito Arai
- Department of Clinical Laboratory Medicine, Shiga University of Medical Science, Shiga, Japan
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22
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Jeppesen DK, Bohr VA, Stevnsner T. DNA repair deficiency in neurodegeneration. Prog Neurobiol 2011; 94:166-200. [PMID: 21550379 DOI: 10.1016/j.pneurobio.2011.04.013] [Citation(s) in RCA: 243] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 04/18/2011] [Accepted: 04/22/2011] [Indexed: 01/17/2023]
Abstract
Deficiency in repair of nuclear and mitochondrial DNA damage has been linked to several neurodegenerative disorders. Many recent experimental results indicate that the post-mitotic neurons are particularly prone to accumulation of unrepaired DNA lesions potentially leading to progressive neurodegeneration. Nucleotide excision repair is the cellular pathway responsible for removing helix-distorting DNA damage and deficiency in such repair is found in a number of diseases with neurodegenerative phenotypes, including Xeroderma Pigmentosum and Cockayne syndrome. The main pathway for repairing oxidative base lesions is base excision repair, and such repair is crucial for neurons given their high rates of oxygen metabolism. Mismatch repair corrects base mispairs generated during replication and evidence indicates that oxidative DNA damage can cause this pathway to expand trinucleotide repeats, thereby causing Huntington's disease. Single-strand breaks are common DNA lesions and are associated with the neurodegenerative diseases, ataxia-oculomotor apraxia-1 and spinocerebellar ataxia with axonal neuropathy-1. DNA double-strand breaks are toxic lesions and two main pathways exist for their repair: homologous recombination and non-homologous end-joining. Ataxia telangiectasia and related disorders with defects in these pathways illustrate that such defects can lead to early childhood neurodegeneration. Aging is a risk factor for neurodegeneration and accumulation of oxidative mitochondrial DNA damage may be linked with the age-associated neurodegenerative disorders Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis. Mutation in the WRN protein leads to the premature aging disease Werner syndrome, a disorder that features neurodegeneration. In this article we review the evidence linking deficiencies in the DNA repair pathways with neurodegeneration.
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Affiliation(s)
- Dennis Kjølhede Jeppesen
- Danish Centre for Molecular Gerontology and Danish Aging Research Center, University of Aarhus, Department of Molecular Biology, Aarhus, Denmark
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23
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Williams GJ, Lees-Miller SP, Tainer JA. Mre11-Rad50-Nbs1 conformations and the control of sensing, signaling, and effector responses at DNA double-strand breaks. DNA Repair (Amst) 2010; 9:1299-306. [PMID: 21035407 PMCID: PMC3008338 DOI: 10.1016/j.dnarep.2010.10.001] [Citation(s) in RCA: 158] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/30/2010] [Indexed: 10/18/2022]
Abstract
Repair and integrity of DNA ends at breaks, replication forks and telomeres are essential for life; yet, paradoxically, these responses are, in many cases, controlled by a single protein complex, Mre11-Rad50-Nbs1 (MRN). The MRN complex consists of dimers of each subunit and this heterohexamer controls key sensing, signaling, regulation, and effector responses to DNA double-strand breaks including ATM activation, homologous recombinational repair, microhomology-mediated end joining and, in some organisms, non-homologous end joining. We propose that this is possible because each MRN subunit can exist in three or more distinct states; thus, the trimer of MRN dimers can exist in a stunning 6(3) or 216 states, a number that can be expanded further when post-translational modifications are taken into account. MRN can therefore be considered as a molecular computer that effectively assesses optimal responses and pathway choice based upon its states as set by cell status and the nature of the DNA damage. This extreme multi-state concept demands a paradigm shift from striving to understand DNA damage responses in separate terms of signaling, checkpoint, and effector proteins: we must now endeavor to characterize conformational and assembly states of MRN and other DNA repair machines that couple, coordinate, and control biological outcomes. Addressing the emerging challenge of gaining a detailed molecular understanding of MRN and other multi-state dynamic DNA repair machines promises to provide opportunities to develop master keys for controlling cell biology with probable impacts on therapeutic interventions.
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Affiliation(s)
- Gareth J. Williams
- Life Sciences Division, Department of Molecular Biology, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Susan P. Lees-Miller
- Department of Biochemistry and Molecular Biology and the Southern Alberta Cancer Research Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - John A. Tainer
- Life Sciences Division, Department of Molecular Biology, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Molecular Biology, Skaggs Institute of Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
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24
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Asaithamby A, Chen DJ. Mechanism of cluster DNA damage repair in response to high-atomic number and energy particles radiation. Mutat Res 2010; 711:87-99. [PMID: 21126526 DOI: 10.1016/j.mrfmmm.2010.11.002] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Revised: 10/29/2010] [Accepted: 11/23/2010] [Indexed: 02/07/2023]
Abstract
Low-linear energy transfer (LET) radiation (i.e., γ- and X-rays) induces DNA double-strand breaks (DSBs) that are rapidly repaired (rejoined). In contrast, DNA damage induced by the dense ionizing track of high-atomic number and energy (HZE) particles is slowly repaired or is irreparable. These unrepaired and/or misrepaired DNA lesions may contribute to the observed higher relative biological effectiveness for cell killing, chromosomal aberrations, mutagenesis, and carcinogenesis in HZE particle irradiated cells compared to those treated with low-LET radiation. The types of DNA lesions induced by HZE particles have been characterized in vitro and usually consist of two or more closely spaced strand breaks, abasic sites, or oxidized bases on opposing strands. It is unclear why these lesions are difficult to repair. In this review, we highlight the potential of a new technology allowing direct visualization of different types of DNA lesions in human cells and document the emerging significance of live-cell imaging for elucidation of the spatio-temporal characterization of complex DNA damage. We focus on the recent insights into the molecular pathways that participate in the repair of HZE particle-induced DSBs. We also discuss recent advances in our understanding of how different end-processing nucleases aid in repair of DSBs with complicated ends generated by HZE particles. Understanding the mechanism underlying the repair of DNA damage induced by HZE particles will have important implications for estimating the risks to human health associated with HZE particle exposure.
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Affiliation(s)
- Aroumougame Asaithamby
- Division of Molecular Radiation Biology, Department of Radiation Oncology, The University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, United States.
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