1
|
Cheng X, An J, Lou J, Gu Q, Ding W, Droby GN, Wang Y, Wang C, Gao Y, Anand JR, Shelton A, Satterlee AB, Mann B, Hsiao YC, Liu CW, Lu K, Hingtgen S, Wang J, Liu Z, Miller CR, Wu D, Vaziri C, Yang Y. Trans-lesion synthesis and mismatch repair pathway crosstalk defines chemoresistance and hypermutation mechanisms in glioblastoma. Nat Commun 2024; 15:1957. [PMID: 38438348 PMCID: PMC10912752 DOI: 10.1038/s41467-024-45979-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Accepted: 02/08/2024] [Indexed: 03/06/2024] Open
Abstract
Almost all Glioblastoma (GBM) are either intrinsically resistant to the chemotherapeutical drug temozolomide (TMZ) or acquire therapy-induced mutations that cause chemoresistance and recurrence. The genome maintenance mechanisms responsible for GBM chemoresistance and hypermutation are unknown. We show that the E3 ubiquitin ligase RAD18 (a proximal regulator of TLS) is activated in a Mismatch repair (MMR)-dependent manner in TMZ-treated GBM cells, promoting post-replicative gap-filling and survival. An unbiased CRISPR screen provides an aerial map of RAD18-interacting DNA damage response (DDR) pathways deployed by GBM to tolerate TMZ genotoxicity. Analysis of mutation signatures from TMZ-treated GBM reveals a role for RAD18 in error-free bypass of O6mG (the most toxic TMZ-induced lesion), and error-prone bypass of other TMZ-induced lesions. Our analyses of recurrent GBM patient samples establishes a correlation between low RAD18 expression and hypermutation. Taken together we define molecular underpinnings for the hallmark tumorigenic phenotypes of TMZ-treated GBM.
Collapse
Affiliation(s)
- Xing Cheng
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC, 27599, USA
- Department of Neuro-Oncology, Chongqing University Cancer Hospital, Chongqing, China
| | - Jing An
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC, 27599, USA
- Institute of Cancer Prevention and Treatment, Heilongjiang Academy of Medical Sciences, Harbin Medical University, Harbin, China
| | - Jitong Lou
- Department of Biostatistics, University of North Carolina, Chapel Hill, NC, 27599, USA
- Eli Lilly and Company, Indianapolis, IN, 46285, USA
| | - Qisheng Gu
- Shanghai Institute of Immunity and Infection, Chinese Academy of Sciences, Shanghai, China
- Department of Immunology, Université Paris Cité, Paris, France
| | - Weimin Ding
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, 27599, USA
- Oncology Center, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Gaith Nabil Droby
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC, 27599, USA
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Yilin Wang
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Chenghao Wang
- Department of Biostatistics, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Yanzhe Gao
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Jay Ramanlal Anand
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Abigail Shelton
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Andrew Benson Satterlee
- Eshelman School of Pharmacy, Division of Pharmacoengineering and Molecular Pharmaceutics, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Breanna Mann
- Eshelman School of Pharmacy, Division of Pharmacoengineering and Molecular Pharmaceutics, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Yun-Chung Hsiao
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Chih-Wei Liu
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Kun Lu
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Shawn Hingtgen
- Eshelman School of Pharmacy, Division of Pharmacoengineering and Molecular Pharmaceutics, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Jiguang Wang
- Division of Life Science, Department of Chemical and Biological Engineering, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong SAR, China
- Hong Kong Center for Neurodegenerative Diseases, InnoHK, Hong Kong SAR, China
| | - Zhaoliang Liu
- Institute of Cancer Prevention and Treatment, Heilongjiang Academy of Medical Sciences, Harbin Medical University, Harbin, China
| | - C Ryan Miller
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC, 27599, USA
- Department of Pathology, Division of Neuropathology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Di Wu
- Department of Biostatistics, University of North Carolina, Chapel Hill, NC, 27599, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, 27599, USA
- Division of Oral and Craniofacial Health Science, Adams School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Cyrus Vaziri
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC, 27599, USA.
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, 27599, USA.
| | - Yang Yang
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC, 27599, USA.
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, 27599, USA.
| |
Collapse
|
2
|
Mitsumoto T, Ishii Y, Takimoto N, Takasu S, Namiki M, Nohmi T, Umemura T, Ogawa K. Site-specific genotoxicity of rubiadin: localization and histopathological changes in the kidneys of rats. Arch Toxicol 2023; 97:3273-3283. [PMID: 37794257 DOI: 10.1007/s00204-023-03610-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 09/20/2023] [Indexed: 10/06/2023]
Abstract
Rubiadin (Rub) is a genotoxic component of madder color (MC) that is extracted from the root of Rubia tinctorum L. MC induces renal tumors and preneoplastic lesions that are found in the proximal tubule of the outer stripe of the outer medulla (OSOM), suggesting that the renal carcinogenicity of MC is site specific. To clarify the involvement of Rub in renal carcinogenesis of MC, we examined the distribution of Rub in the kidney of male gpt delta rats that were treated with Rub for 28 days. We used desorption electrospray ionization quadrupole time-of-flight mass spectrometry imaging (DESI-Q-TOF-MSI), along with the histopathological analysis, immunohistochemical staining, and reporter gene mutation assays of the kidney. DESI-Q-TOF-MSI revealed that Rub and its metabolites, lucidin and Rub-sulfation, were specifically distributed in the OSOM. Histopathologically, karyomegaly characterized by enlarged nuclear and microvesicular vacuolar degeneration occurred in proximal tubule epithelial cells in the OSOM. The ɤ-H2AX- and p21-positive cells were also found in the OSOM rather than the cortex. Although dose-dependent increases in gpt and Spi- mutant frequencies were observed in both the medulla and cortex, the mutant frequencies in the medulla were significantly higher. The mutation spectra of gpt mutants showed that A:T-T:A transversion was predominant in Rub-induced gene mutations, consistent with those of MC. Overall, the data showed that the distribution of Rub and its metabolites resulted in site-specific histopathological changes, DNA damage, and gene mutations, suggesting that the distribution of genotoxic components and metabolites is responsible for the site-specific renal carcinogenesis of MC.
Collapse
Affiliation(s)
- Tatsuya Mitsumoto
- Division of Pathology, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-Ku, Kawasaki-Shi, Kanagawa, 210-9501, Japan
- Faculty of Animal Health Technology, Yamazaki University of Animal Health Technology, 4-7-2, Minami-Osawa, Hachihoji, Tokyo, 192-0364, Japan
| | - Yuji Ishii
- Division of Pathology, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-Ku, Kawasaki-Shi, Kanagawa, 210-9501, Japan.
| | - Norifumi Takimoto
- Division of Pathology, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-Ku, Kawasaki-Shi, Kanagawa, 210-9501, Japan
- Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu-Shi, Tokyo, 183-8509, Japan
| | - Shinji Takasu
- Division of Pathology, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-Ku, Kawasaki-Shi, Kanagawa, 210-9501, Japan
| | - Moeka Namiki
- Division of Pathology, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-Ku, Kawasaki-Shi, Kanagawa, 210-9501, Japan
| | - Takehiko Nohmi
- Division of Pathology, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-Ku, Kawasaki-Shi, Kanagawa, 210-9501, Japan
| | - Takashi Umemura
- Faculty of Animal Health Technology, Yamazaki University of Animal Health Technology, 4-7-2, Minami-Osawa, Hachihoji, Tokyo, 192-0364, Japan
| | - Kumiko Ogawa
- Division of Pathology, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-Ku, Kawasaki-Shi, Kanagawa, 210-9501, Japan
| |
Collapse
|
3
|
Ghazi M, Khanna S, Subramaniam Y, Rengaraju J, Sultan F, Gupta I, Sharma K, Chandna S, Gokhale RS, Natarajan V. Sustained pigmentation causes DNA damage and invokes translesion polymerase Polκ for repair in melanocytes. Nucleic Acids Res 2023; 51:10451-10466. [PMID: 37697436 PMCID: PMC10602914 DOI: 10.1093/nar/gkad704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 08/02/2023] [Accepted: 08/14/2023] [Indexed: 09/13/2023] Open
Abstract
Melanin protects skin cells from ultraviolet radiation-induced DNA damage. However, intermediates of eumelanin are highly reactive quinones that are potentially genotoxic. In this study, we systematically investigate the effect of sustained elevation of melanogenesis and map the consequent cellular repair response of melanocytes. Pigmentation increases γH2AX foci, DNA abasic sites, causes replication stress and invokes translesion polymerase Polκ in primary human melanocytes, as well as mouse melanoma cells. Confirming the causal link, CRISPR-based genetic ablation of tyrosinase results in depigmented cells with low Polκ levels. During pigmentation, Polκ activates replication stress response and keeps a check on uncontrolled proliferation of cells harboring melanin-damaged DNA. The mutational landscape observed in human melanoma could in part explain the error-prone bypass of DNA lesions by Polκ, whose absence would lead to genome instability. Thereby, translesion polymerase Polκ is a critical response of pigmenting melanocytes to combat melanin-induced DNA alterations. Our study illuminates the dark side of melanin and identifies (eu)melanogenesis as a key missing link between tanning response and mutagenesis, mediated via the necessary evil translesion polymerase, Polκ.
Collapse
Affiliation(s)
- Madeeha Ghazi
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi 110025, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh 201002, India
| | - Shivangi Khanna
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi 110025, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh 201002, India
| | - Yogaspoorthi Subramaniam
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi 110025, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh 201002, India
| | - Jeyashri Rengaraju
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi 110025, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh 201002, India
| | - Farina Sultan
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi 110025, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh 201002, India
| | - Iti Gupta
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi 110025, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh 201002, India
| | - Kanupriya Sharma
- Institute of Nuclear Medicine and Allied Sciences, Defence Research and Development Organization, Delhi 110054, India
| | - Sudhir Chandna
- Institute of Nuclear Medicine and Allied Sciences, Defence Research and Development Organization, Delhi 110054, India
| | - Rajesh S Gokhale
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi 110025, India
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Vivek T Natarajan
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi 110025, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh 201002, India
| |
Collapse
|
4
|
Egger T, Aze A, Maiorano D. Detection of endogenous translesion DNA synthesis in single mammalian cells. CELL REPORTS METHODS 2023; 3:100501. [PMID: 37426760 PMCID: PMC10326377 DOI: 10.1016/j.crmeth.2023.100501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 02/07/2023] [Accepted: 05/18/2023] [Indexed: 07/11/2023]
Abstract
Translesion DNA synthesis (TLS) is an evolutionarily conserved process that cells activate to tolerate DNA damage. TLS facilitates proliferation under DNA damage conditions and is exploited by cancer cells to gain therapy resistance. It has been so far challenging to analyze endogenous TLS factors such as PCNAmUb and TLS DNA polymerases in single mammalian cells due to a lack of suitable detection tools. We have adapted a flow cytometry-based quantitative method allowing detection of endogenous, chromatin-bound TLS factors in single mammalian cells, either untreated or exposed to DNA-damaging agents. This high-throughput procedure is quantitative, accurate, and allows unbiased analysis of TLS factors' recruitment to chromatin, as well as occurrence of DNA lesions with respect to the cell cycle. We also demonstrate detection of endogenous TLS factors by immunofluorescence microscopy and provide insights into TLS dynamics upon DNA replication forks stalled by UV-C-induced DNA damage.
Collapse
Affiliation(s)
- Tom Egger
- Institut de Génétique Humaine (IGH) CNRS UMR9002, Université de Montpellier, Molecular Bases of Human Pathologies Department, “Genome Surveillance and Stability” Laboratory, 34396 Cedex 5 Montpellier, France
| | - Antoine Aze
- Institut de Génétique Humaine (IGH) CNRS UMR9002, Université de Montpellier, Molecular Bases of Human Pathologies Department, “Genome Surveillance and Stability” Laboratory, 34396 Cedex 5 Montpellier, France
| | - Domenico Maiorano
- Institut de Génétique Humaine (IGH) CNRS UMR9002, Université de Montpellier, Molecular Bases of Human Pathologies Department, “Genome Surveillance and Stability” Laboratory, 34396 Cedex 5 Montpellier, France
| |
Collapse
|
5
|
Volk LB, Cooper KL, Jiang T, Paffett ML, Hudson LG. Impacts of arsenic on Rad18 and translesion synthesis. Toxicol Appl Pharmacol 2022; 454:116230. [PMID: 36087615 PMCID: PMC10144522 DOI: 10.1016/j.taap.2022.116230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/27/2022] [Accepted: 09/02/2022] [Indexed: 10/31/2022]
Abstract
Arsenite interferes with DNA repair protein function resulting in the retention of UV-induced DNA damage. Accumulated DNA damage promotes replication stress which is bypassed by DNA damage tolerance pathways such as translesion synthesis (TLS). Rad18 is an essential factor in initiating TLS through PCNA monoubiquitination and contains two functionally and structurally distinct zinc fingers that are potential targets for arsenite binding. Arsenite treatment displaced zinc from endogenous Rad18 protein and mass spectrometry analysis revealed arsenite binding to both the Rad18 RING finger and UBZ domains. Consequently, arsenite inhibited Rad18 RING finger dependent PCNA monoubiquitination and polymerase eta recruitment to DNA damage in UV exposed keratinocytes, both of which enhance the bypass of cyclobutane pyrimidine dimers during replication. Further analysis demonstrated multiple effects of arsenite, including the reduction in nuclear localization and UV-induced chromatin recruitment of Rad18 and its binding partner Rad6, which may also negatively impact TLS initiation. Arsenite and Rad18 knockdown in UV exposed keratinocytes significantly increased markers of replication stress and DNA strand breaks to a similar degree, suggesting arsenite mediates its effects through Rad18. Comet assay analysis confirmed an increase in both UV-induced single-stranded DNA and DNA double-strand breaks in arsenite treated keratinocytes compared to UV alone. Altogether, this study supports a mechanism by which arsenite inhibits TLS through the altered activity and regulation of Rad18. Arsenite elevated the levels of UV-induced replication stress and consequently, single-stranded DNA gaps and DNA double-strand breaks. These potentially mutagenic outcomes support a role for TLS in the cocarcinogenicity of arsenite.
Collapse
Affiliation(s)
- L B Volk
- Department of Pharmaceutical Sciences, University of New Mexico Health Sciences Center, 1 University of New Mexico, Albuquerque, NM 87131, USA.
| | - K L Cooper
- Department of Pharmaceutical Sciences, University of New Mexico Health Sciences Center, 1 University of New Mexico, Albuquerque, NM 87131, USA.
| | - T Jiang
- Department of Pharmaceutical Sciences, University of New Mexico Health Sciences Center, 1 University of New Mexico, Albuquerque, NM 87131, USA.
| | - M L Paffett
- Fluorescence Microscopy and Cell Imaging Shared Resource, University of New Mexico Comprehensive Cancer Center, 2325 Camino de Salud, Albuquerque, NM 87131, USA.
| | - L G Hudson
- Department of Pharmaceutical Sciences, University of New Mexico Health Sciences Center, 1 University of New Mexico, Albuquerque, NM 87131, USA.
| |
Collapse
|
6
|
Lou J, Yang Y, Gu Q, Price BA, Qiu Y, Fedoriw Y, Desai S, Mose LE, Chen B, Tateishi S, Parker JS, Vaziri C, Wu D. Rad18 mediates specific mutational signatures and shapes the genomic landscape of carcinogen-induced tumors in vivo. NAR Cancer 2021; 3:zcaa037. [PMID: 33447826 PMCID: PMC7787264 DOI: 10.1093/narcan/zcaa037] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 11/01/2020] [Accepted: 12/31/2020] [Indexed: 12/16/2022] Open
Abstract
The E3 ubiquitin ligase Rad18 promotes a damage-tolerant and error-prone mode of DNA replication termed trans-lesion synthesis that is pathologically activated in cancer. However, the impact of vertebrate Rad18 on cancer genomes is not known. To determine how Rad18 affects mutagenesis in vivo, we have developed and implemented a novel computational pipeline to analyze genomes of carcinogen (7, 12-Dimethylbenz[a]anthracene, DMBA)-induced skin tumors from Rad18+/+ and Rad18- / - mice. We show that Rad18 mediates specific mutational signatures characterized by high levels of A(T)>T(A) single nucleotide variations (SNVs). In Rad18- /- tumors, an alternative mutation pattern arises, which is characterized by increased numbers of deletions >4 bp. Comparison with annotated human mutational signatures shows that COSMIC signature 22 predominates in Rad18+/+ tumors whereas Rad18- / - tumors are characterized by increased contribution of COSMIC signature 3 (a hallmark of BRCA-mutant tumors). Analysis of The Cancer Genome Atlas shows that RAD18 expression is strongly associated with high SNV burdens, suggesting RAD18 also promotes mutagenesis in human cancers. Taken together, our results show Rad18 promotes mutagenesis in vivo, modulates DNA repair pathway choice in neoplastic cells, and mediates specific mutational signatures that are present in human tumors.
Collapse
Affiliation(s)
- Jitong Lou
- Department of Biostatistics, University of North Carolina at Chapel Hill, 135 Dauer Drive, 3101 McGavran-Greenberg Hall, Chapel Hill, NC 27599, USA
| | - Yang Yang
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, 614 Brinkhous-Bullitt Building, Chapel Hill, NC 27599, USA
| | - Qisheng Gu
- Division of Oral and Craniofacial Health Sciences, Adam School of Dentistry, University of North Carolina at Chapel Hill, 385 S. Columbia Street, Chapel Hill, NC 27599, USA
| | - Brandon A Price
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, 450 West Drive, Chapel Hill, NC 27599, USA
| | - Yuheng Qiu
- Department of Statistics, Purdue University, 250 N. University St, West Lafayette, IN 47907, USA
| | - Yuri Fedoriw
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, 614 Brinkhous-Bullitt Building, Chapel Hill, NC 27599, USA
| | - Siddhi Desai
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, 614 Brinkhous-Bullitt Building, Chapel Hill, NC 27599, USA
| | - Lisle E Mose
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, 450 West Drive, Chapel Hill, NC 27599, USA
| | - Brian Chen
- Department of Biostatistics, University of North Carolina at Chapel Hill, 135 Dauer Drive, 3101 McGavran-Greenberg Hall, Chapel Hill, NC 27599, USA
| | - Satoshi Tateishi
- Department of Cell Maintenance, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo Chuoku, Kumamoto 860-0811, Japan
| | - Joel S Parker
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, 450 West Drive, Chapel Hill, NC 27599, USA
| | - Cyrus Vaziri
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, 614 Brinkhous-Bullitt Building, Chapel Hill, NC 27599, USA
| | - Di Wu
- Department of Biostatistics, University of North Carolina at Chapel Hill, 135 Dauer Drive, 3101 McGavran-Greenberg Hall, Chapel Hill, NC 27599, USA
| |
Collapse
|
7
|
Santovito A, Gendusa C, Cervella P, Traversi D. In vitro genomic damage induced by urban fine particulate matter on human lymphocytes. Sci Rep 2020; 10:8853. [PMID: 32483266 PMCID: PMC7264132 DOI: 10.1038/s41598-020-65785-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 05/08/2020] [Indexed: 12/30/2022] Open
Abstract
Urban air pollution represents a global problem, since everyday many mutagenic and carcinogens compounds are emitted into the atmosphere, with consequent adverse health effects on humans and biota. Specifically, particulate matter air pollution was associated with increased risks in human mortality and morbidity. In this paper, we analyse the genomic effects on human lymphocytes of different concentrations of annual Turin PM2.5 extract by an in vitro micronuclei assay. Samplings were collected from an urban meteorological-chemical station positioned in Turin (Italy), one of the most polluted cities in Europe. PM2.5 sampled on filters was used for organic extraction in monthly pools and successively aggregated to produce a mixture representative for a full year PM2.5 collection. Lymphocytes were exposed to four concentrations of PM2.5: 5, 10, 15 and 20 μg/mL and micronuclei, nucleoplasmic bridges and nuclear buds were scored. With respect to controls, PM2.5 significantly increased the frequencies of all analysed biomarkers at all tested concentrations, whereas the CBPI index was significantly reduced only at the concentration of 20 μg/mL. Such in vitro effects can both to stimulate local authorities to adopt efficient measures for air pollution mitigation and to improve human monitoring to detect early precancer lesions.
Collapse
Affiliation(s)
- Alfredo Santovito
- University of Turin, Department of Life Sciences and Systems Biology, Torino, Italy.
| | - Claudio Gendusa
- University of Turin, Department of Life Sciences and Systems Biology, Torino, Italy
| | - Piero Cervella
- University of Turin, Department of Life Sciences and Systems Biology, Torino, Italy
| | - Deborah Traversi
- University of Turin, Department of Public Health and Pediatrics, Torino, Italy
| |
Collapse
|
8
|
Ketkar A, Maddukuri L, Penthala NR, Reed MR, Zafar MK, Crooks PA, Eoff RL. Inhibition of Human DNA Polymerases Eta and Kappa by Indole-Derived Molecules Occurs through Distinct Mechanisms. ACS Chem Biol 2019; 14:1337-1351. [PMID: 31082191 DOI: 10.1021/acschembio.9b00304] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Overexpression of human DNA polymerase kappa (hpol κ) in glioblastoma is associated with shorter survival time and resistance to the alkylating agent temozolomide (TMZ), making it an attractive target for the development of small-molecule inhibitors. We previously reported on the development and characterization of indole barbituric acid-derived (IBA) inhibitors of translesion DNA synthesis polymerases (TLS pols). We have now identified a potent and selective inhibitor of hpol κ based on the indole-aminoguanidine (IAG) chemical scaffold. The most promising IAG analogue, IAG-10, exhibited greater inhibitory action against hpol κ than any other human Y-family member, as well as pols from the A-, B-, and X-families. Inhibition of hpol κ by IAG analogues appears to proceed through a mechanism that is distinct from inhibition of hpol η based on changes in DNA binding affinity and nucleotide insertion kinetics. By way of comparison, both IAG and IBA analogues inhibited binary complex formation by hpol κ and ternary complex formation by hpol η. Decreasing the concentration of enzyme and DNA in the reaction mixture lowered the IC50 value of IAG-10 to submicromolar values, consistent with inhibition of binary complex formation for hpol κ. Chemical footprinting experiments revealed that IAG-10 binds to a cleft between the finger, little finger, and N-clasp domains on hpol κ and that this likely disrupts the interaction between the N-clasp and the TLS pol core. In cell culture, IAG-10 potentiated the antiproliferative activity and DNA damaging effects of TMZ in hpol κ-proficient cells but not in hpol κ-deficient cells, indicative of a target-dependent effect. Mutagenic replication across alkylation damage increased in hpol κ-proficient cells treated with IAG-10, while no change in mutation frequency was observed for hpol κ-deficient cells. In summary, we developed a potent and selective small-molecule inhibitor of hpol κ that takes advantage of structural features unique to this TLS enzyme to potentiate TMZ, a standard-of-care drug used in the treatment of malignant brain tumors. Furthermore, the IAG scaffold represents a new chemical space for the exploration of TLS pol inhibitors, which could prove useful as a strategy for improving patient response to genotoxic drugs.
Collapse
Affiliation(s)
- Amit Ketkar
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205-7199, United States
| | - Leena Maddukuri
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205-7199, United States
| | - Narsimha R. Penthala
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205-7199, United States
| | - Megan R. Reed
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205-7199, United States
| | - Maroof K. Zafar
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205-7199, United States
| | - Peter A. Crooks
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205-7199, United States
| | - Robert L. Eoff
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205-7199, United States
| |
Collapse
|
9
|
Beal MA, Meier MJ, Williams A, Rowan-Carroll A, Gagné R, Lindsay SJ, Fitzgerald T, Hurles ME, Marchetti F, Yauk CL. Paternal exposure to benzo(a)pyrene induces genome-wide mutations in mouse offspring. Commun Biol 2019; 2:228. [PMID: 31240266 PMCID: PMC6586636 DOI: 10.1038/s42003-019-0476-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 05/23/2019] [Indexed: 01/14/2023] Open
Abstract
Understanding the effects of environmental exposures on germline mutation rates has been a decades-long pursuit in genetics. We used next-generation sequencing and comparative genomic hybridization arrays to investigate genome-wide mutations in the offspring of male mice exposed to benzo(a)pyrene (BaP), a common environmental pollutant. We demonstrate that offspring developing from sperm exposed during the mitotic or post-mitotic phases of spermatogenesis have significantly more de novo single nucleotide variants (1.8-fold; P < 0.01) than controls. Both phases of spermatogenesis are susceptible to the induction of heritable mutations, although mutations arising from post-fertilization events are more common after post-mitotic exposure. In addition, the mutation spectra in sperm and offspring of BaP-exposed males are consistent. Finally, we report a significant increase in transmitted copy number duplications (P = 0.001) in BaP-exposed sires. Our study demonstrates that germ cell mutagen exposures induce genome-wide mutations in the offspring that may be associated with adverse health outcomes.
Collapse
Affiliation(s)
- Marc A. Beal
- Carleton University, Ottawa, Ontario K1S 5B6 Canada
- Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario K1A 0K9 Canada
| | - Matthew J. Meier
- Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario K1A 0K9 Canada
| | - Andrew Williams
- Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario K1A 0K9 Canada
| | - Andrea Rowan-Carroll
- Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario K1A 0K9 Canada
| | - Rémi Gagné
- Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario K1A 0K9 Canada
| | - Sarah J. Lindsay
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA UK
| | - Tomas Fitzgerald
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA UK
| | - Matthew E. Hurles
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA UK
| | - Francesco Marchetti
- Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario K1A 0K9 Canada
| | - Carole L. Yauk
- Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario K1A 0K9 Canada
| |
Collapse
|
10
|
Tsao WC, Eckert KA. Detours to Replication: Functions of Specialized DNA Polymerases during Oncogene-induced Replication Stress. Int J Mol Sci 2018; 19:ijms19103255. [PMID: 30347795 PMCID: PMC6214091 DOI: 10.3390/ijms19103255] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 10/15/2018] [Accepted: 10/15/2018] [Indexed: 01/10/2023] Open
Abstract
Incomplete and low-fidelity genome duplication contribute to genomic instability and cancer development. Difficult-to-Replicate Sequences, or DiToRS, are natural impediments in the genome that require specialized DNA polymerases and repair pathways to complete and maintain faithful DNA synthesis. DiToRS include non B-DNA secondary structures formed by repetitive sequences, for example within chromosomal fragile sites and telomeres, which inhibit DNA replication under endogenous stress conditions. Oncogene activation alters DNA replication dynamics and creates oncogenic replication stress, resulting in persistent activation of the DNA damage and replication stress responses, cell cycle arrest, and cell death. The response to oncogenic replication stress is highly complex and must be tightly regulated to prevent mutations and tumorigenesis. In this review, we summarize types of known DiToRS and the experimental evidence supporting replication inhibition, with a focus on the specialized DNA polymerases utilized to cope with these obstacles. In addition, we discuss different causes of oncogenic replication stress and its impact on DiToRS stability. We highlight recent findings regarding the regulation of DNA polymerases during oncogenic replication stress and the implications for cancer development.
Collapse
Affiliation(s)
- Wei-Chung Tsao
- Department of Pathology, The Jake Gittlen Laboratories for Cancer Research, Hershey, PA 17033, USA.
| | - Kristin A Eckert
- Department of Pathology, The Jake Gittlen Laboratories for Cancer Research, Hershey, PA 17033, USA.
| |
Collapse
|
11
|
Gao Y, Kardos J, Yang Y, Tamir TY, Mutter-Rottmayer E, Weissman B, Major MB, Kim WY, Vaziri C. The Cancer/Testes (CT) Antigen HORMAD1 promotes Homologous Recombinational DNA Repair and Radioresistance in Lung adenocarcinoma cells. Sci Rep 2018; 8:15304. [PMID: 30333500 PMCID: PMC6192992 DOI: 10.1038/s41598-018-33601-w] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 10/01/2018] [Indexed: 12/24/2022] Open
Abstract
The Cancer/Testes (CT) Antigen HORMAD1 is germ cell-restricted and plays developmental roles in generation and processing of meiotic DNA Double Strand Breaks (DSB). Many tumors aberrantly overexpress HORMAD1 yet the potential impact of this CT antigen on cancer biology is unclear. We tested a potential role of HORMAD1 in genome maintenance in lung adenocarcinoma cells. We show that HORMAD1 re-distributes to nuclear foci and co-localizes with the DSB marker γH2AX in response to ionizing radiation (IR) and chemotherapeutic agents. The HORMA domain and C-term disordered oligomerization motif are necessary for localization of HORMAD1 to IR-induced foci (IRIF). HORMAD1-depleted cells are sensitive to IR and camptothecin. In reporter assays, Homologous Recombination (HR)-mediated repair of targeted ISce1-induced DSBs is attenuated in HORMAD1-depleted cells. In Non-Homologous End Joining (NHEJ) reporter assays, HORMAD1-depletion does not affect repair of ISce1-induced DSB. Early DSB signaling events (including ATM phosphorylation and formation of γH2AX, 53BP1 and NBS1 foci) are intact in HORMAD1-depleted cells. However, generation of RPA-ssDNA foci and redistribution of RAD51 to DSB are compromised in HORMAD1-depleted cells, suggesting that HORMAD1 promotes DSB resection. HORMAD1-mediated HR is a neomorphic activity that is independent of its meiotic partners (including HORMAD2 and CCDC36. Bioinformatic analysis of TCGA data show that similar to known HR pathway genes HORMAD1 is overexpressed in lung adenocarcinomas. Overexpression of HR genes is associated with specific mutational profiles (including copy number variation). Taken together, we identify HORMAD1-dependent DSB repair as a new mechanism of radioresistance and a probable determinant of mutability in lung adenocarcinoma.
Collapse
Affiliation(s)
- Yanzhe Gao
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, 614 Brinkhous-Bullitt Building, Chapel Hill, NC, 27599, USA
| | - Jordan Kardos
- Lineberger Comprehensive Cancer Center, Curriculum in Genetics and Molecular Biology, and Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Yang Yang
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, 614 Brinkhous-Bullitt Building, Chapel Hill, NC, 27599, USA
| | - Tigist Y Tamir
- Department of Cell Biology and Physiology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Elizabeth Mutter-Rottmayer
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, 614 Brinkhous-Bullitt Building, Chapel Hill, NC, 27599, USA
| | - Bernard Weissman
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, 614 Brinkhous-Bullitt Building, Chapel Hill, NC, 27599, USA.,Lineberger Comprehensive Cancer Center, Curriculum in Genetics and Molecular Biology, and Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Michael B Major
- Department of Cell Biology and Physiology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - William Y Kim
- Lineberger Comprehensive Cancer Center, Curriculum in Genetics and Molecular Biology, and Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Cyrus Vaziri
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, 614 Brinkhous-Bullitt Building, Chapel Hill, NC, 27599, USA. .,Lineberger Comprehensive Cancer Center, Curriculum in Genetics and Molecular Biology, and Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC, 27599, USA.
| |
Collapse
|
12
|
Yang Y, Gao Y, Zlatanou A, Tateishi S, Yurchenko V, Rogozin IB, Vaziri C. Diverse roles of RAD18 and Y-family DNA polymerases in tumorigenesis. Cell Cycle 2018; 17:833-843. [PMID: 29683380 PMCID: PMC6056224 DOI: 10.1080/15384101.2018.1456296] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Mutagenesis is a hallmark and enabling characteristic of cancer cells. The E3 ubiquitin ligase RAD18 and its downstream effectors, the ‘Y-family’ Trans-Lesion Synthesis (TLS) DNA polymerases, confer DNA damage tolerance at the expense of DNA replication fidelity. Thus, RAD18 and TLS polymerases are attractive candidate mediators of mutagenesis and carcinogenesis. The skin cancer-propensity disorder xeroderma pigmentosum-variant (XPV) is caused by defects in the Y-family DNA polymerase Pol eta (Polη). However it is unknown whether TLS dysfunction contributes more generally to other human cancers. Recent analyses of cancer genomes suggest that TLS polymerases generate many of the mutational signatures present in diverse cancers. Moreover biochemical studies suggest that the TLS pathway is often reprogrammed in cancer cells and that TLS facilitates tolerance of oncogene-induced DNA damage. Here we review recent evidence supporting widespread participation of RAD18 and the Y-family DNA polymerases in the different phases of multi-step carcinogenesis.
Collapse
Affiliation(s)
- Yang Yang
- a Department of Pathology and Laboratory Medicine , University of North Carolina at Chapel Hill Chapel Hill , NC , USA
| | - Yanzhe Gao
- a Department of Pathology and Laboratory Medicine , University of North Carolina at Chapel Hill Chapel Hill , NC , USA
| | - Anastasia Zlatanou
- a Department of Pathology and Laboratory Medicine , University of North Carolina at Chapel Hill Chapel Hill , NC , USA
| | - Satoshi Tateishi
- b Division of Cell Maintenance , Institute of Molecular Embryology and Genetics (IMEG) , Kumamoto University , Kumamoto , Japan
| | - Vyacheslav Yurchenko
- c Life Science Research Center , University of Ostrava , Ostrava , Czech Republic
| | - Igor B Rogozin
- d National Center for Biotechnology Information, National Library of Medicine , National Institutes of Health , Bethesda , MD , USA
| | - Cyrus Vaziri
- a Department of Pathology and Laboratory Medicine , University of North Carolina at Chapel Hill Chapel Hill , NC , USA
| |
Collapse
|
13
|
Long AS, Wills JW, Krolak D, Guo M, Dertinger SD, Arlt VM, White PA. Benchmark dose analyses of multiple genetic toxicity endpoints permit robust, cross-tissue comparisons of MutaMouse responses to orally delivered benzo[a]pyrene. Arch Toxicol 2018; 92:967-982. [PMID: 29177888 PMCID: PMC5818629 DOI: 10.1007/s00204-017-2099-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 10/17/2017] [Indexed: 12/14/2022]
Abstract
Genetic damage is a key event in tumorigenesis, and chemically induced genotoxic effects are a human health concern. Although genetic toxicity data have historically been interpreted using a qualitative screen-and-bin approach, there is increasing interest in quantitative analysis of genetic toxicity dose-response data. We demonstrate an emerging use of the benchmark dose (BMD)-approach for empirically ranking cross-tissue sensitivity. Using a model environmental carcinogen, we quantitatively examined responses for four genetic damage endpoints over an extended dose range, and conducted cross-tissue sensitivity rankings using BMD100 values and their 90% confidence intervals (CIs). MutaMouse specimens were orally exposed to 11 doses of benzo[a]pyrene. DNA adduct frequency and lacZ mutant frequency (MF) were measured in up to 8 tissues, and Pig-a MF and micronuclei (MN) were assessed in immature (RETs) and mature red blood cells (RBCs). The cross-tissue BMD pattern for lacZ MF is similar to that observed for DNA adducts, and is consistent with an oral route-of-exposure and differences in tissue-specific metabolism and proliferation. The lacZ MF BMDs were significantly correlated with the tissue-matched adduct BMDs, demonstrating a consistent adduct conversion rate across tissues. The BMD CIs, for both the Pig-a and the MN endpoints, overlapped for RETs and RBCs, suggesting comparable utility of both cell populations for protracted exposures. Examination of endpoint-specific response maxima illustrates the difficulty of comparing BMD values for a fixed benchmark response across endpoints. Overall, the BMD-approach permitted robust comparisons of responses across tissues/endpoints, which is valuable to our mechanistic understanding of how benzo[a]pyrene induces genetic damage.
Collapse
Affiliation(s)
- Alexandra S Long
- Mechanistic Studies Division, Environmental Health Science and Research Bureau, Health Canada, 50 Colombine Driveway, Tunney's Pasture, A/L 0803A, Ottawa, ON, K1A 0K9, Canada.
- Department of Biology, University of Ottawa, Ottawa, ON, Canada.
| | - John W Wills
- Mechanistic Studies Division, Environmental Health Science and Research Bureau, Health Canada, 50 Colombine Driveway, Tunney's Pasture, A/L 0803A, Ottawa, ON, K1A 0K9, Canada
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
| | - Dorothy Krolak
- Mechanistic Studies Division, Environmental Health Science and Research Bureau, Health Canada, 50 Colombine Driveway, Tunney's Pasture, A/L 0803A, Ottawa, ON, K1A 0K9, Canada
| | - Matthew Guo
- Mechanistic Studies Division, Environmental Health Science and Research Bureau, Health Canada, 50 Colombine Driveway, Tunney's Pasture, A/L 0803A, Ottawa, ON, K1A 0K9, Canada
| | | | - Volker M Arlt
- Analytical and Environmental Sciences Division, MRC-PHE Centre for Environment and Health, King's College London, London, UK
| | - Paul A White
- Mechanistic Studies Division, Environmental Health Science and Research Bureau, Health Canada, 50 Colombine Driveway, Tunney's Pasture, A/L 0803A, Ottawa, ON, K1A 0K9, Canada
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
| |
Collapse
|
14
|
Mechanism of error-free replication across benzo[a]pyrene stereoisomers by Rev1 DNA polymerase. Nat Commun 2017; 8:965. [PMID: 29042535 PMCID: PMC5645340 DOI: 10.1038/s41467-017-01013-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 08/11/2017] [Indexed: 12/21/2022] Open
Abstract
Benzo[a]pyrene (BP) is a carcinogen in cigarette smoke which, after metabolic activation, can react with the exocyclic N2 amino group of guanine to generate four stereoisomeric BP-N2-dG adducts. Rev1 is unique among translesion synthesis DNA polymerases in employing a protein-template-directed mechanism of DNA synthesis opposite undamaged and damaged guanine. Here we report high-resolution structures of yeast Rev1 with three BP-N2-dG adducts, namely the 10S (+)-trans-BP-N2-dG, 10R (+)-cis-BP-N2-dG, and 10S ( − )-cis-BP-N2-dG. Surprisingly, in all three structures, the bulky and hydrophobic BP pyrenyl residue is entirely solvent-exposed in the major groove of the DNA. This is very different from the adduct alignments hitherto observed in free or protein-bound DNA. All complexes are well poised for dCTP insertion. Our structures provide a view of cis-BP-N2-dG adducts in a DNA polymerase active site, and offer a basis for understanding error-free replication of the BP-derived stereoisomeric guanine adducts. Benzo[a]pyrene (BP) is a carcinogen in cigarette smoke that upon metabolic activation reacts with guanine. Here, the authors present the structures of the translesion DNA synthesis polymerase Rev1 in complex with three of the four possible stereoisomeric BP-N2 -dG adducts, which gives insights how Rev1 achieves error-free replication.
Collapse
|
15
|
Zafar MK, Eoff RL. Translesion DNA Synthesis in Cancer: Molecular Mechanisms and Therapeutic Opportunities. Chem Res Toxicol 2017; 30:1942-1955. [PMID: 28841374 DOI: 10.1021/acs.chemrestox.7b00157] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The genomic landscape of cancer is one marred by instability, but the mechanisms that underlie these alterations are multifaceted and remain a topic of intense research. Cellular responses to DNA damage and/or replication stress can affect genome stability in tumors and influence the response of patients to therapy. In addition to direct repair, DNA damage tolerance (DDT) is an element of genomic maintenance programs that contributes to the etiology of several types of cancer. DDT mechanisms primarily act to resolve replication stress, and this can influence the effectiveness of genotoxic drugs. Translesion DNA synthesis (TLS) is an important component of DDT that facilitates direct bypass of DNA adducts and other barriers to replication. The central role of TLS in the bypass of drug-induced DNA lesions, the promotion of tumor heterogeneity, and the involvement of these enzymes in the maintenance of the cancer stem cell niche presents an opportunity to leverage inhibition of TLS as a way of improving existing therapies. In the review that follows, we summarize mechanisms of DDT, misregulation of TLS in cancer, and discuss the potential for targeting these pathways as a means of improving cancer therapies.
Collapse
Affiliation(s)
- Maroof K Zafar
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences , Little Rock, Arkansas 72205-7199, United States
| | - Robert L Eoff
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences , Little Rock, Arkansas 72205-7199, United States
| |
Collapse
|
16
|
Yang Y, Gao Y, Mutter-Rottmayer L, Zlatanou A, Durando M, Ding W, Wyatt D, Ramsden D, Tanoue Y, Tateishi S, Vaziri C. DNA repair factor RAD18 and DNA polymerase Polκ confer tolerance of oncogenic DNA replication stress. J Cell Biol 2017; 216:3097-3115. [PMID: 28835467 PMCID: PMC5626543 DOI: 10.1083/jcb.201702006] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 06/27/2017] [Accepted: 07/21/2017] [Indexed: 12/30/2022] Open
Abstract
The elevated CDK2 activity of oncogene-expressing cells induces DNA replication stress. Yang et al. show that the DNA repair protein RAD18 facilitates damage-tolerant DNA synthesis via the DNA polymerase κ in cells with aberrantly high CDK2 activity, suggesting an important new role for RAD18 in sustaining neoplastic cell survival. The mechanisms by which neoplastic cells tolerate oncogene-induced DNA replication stress are poorly understood. Cyclin-dependent kinase 2 (CDK2) is a major mediator of oncogenic DNA replication stress. In this study, we show that CDK2-inducing stimuli (including Cyclin E overexpression, oncogenic RAS, and WEE1 inhibition) activate the DNA repair protein RAD18. CDK2-induced RAD18 activation required initiation of DNA synthesis and was repressed by p53. RAD18 and its effector, DNA polymerase κ (Polκ), sustained ongoing DNA synthesis in cells harboring elevated CDK2 activity. RAD18-deficient cells aberrantly accumulated single-stranded DNA (ssDNA) after CDK2 activation. In RAD18-depleted cells, the G2/M checkpoint was necessary to prevent mitotic entry with persistent ssDNA. Rad18−/− and Polκ−/− cells were highly sensitive to the WEE1 inhibitor MK-1775 (which simultaneously activates CDK2 and abrogates the G2/M checkpoint). Collectively, our results show that the RAD18–Polκ signaling axis allows tolerance of CDK2-mediated oncogenic stress and may allow neoplastic cells to breach tumorigenic barriers.
Collapse
Affiliation(s)
- Yang Yang
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Yanzhe Gao
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Liz Mutter-Rottmayer
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Anastasia Zlatanou
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Michael Durando
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Weimin Ding
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC.,Oncology Center, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - David Wyatt
- Lineberger Comprehensive Cancer Center, Curriculumin Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC.,Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Dale Ramsden
- Lineberger Comprehensive Cancer Center, Curriculumin Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC.,Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Yuki Tanoue
- Division of Cell Maintenance, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
| | - Satoshi Tateishi
- Division of Cell Maintenance, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
| | - Cyrus Vaziri
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC .,Lineberger Comprehensive Cancer Center, Curriculumin Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| |
Collapse
|
17
|
Piberger AL, Krüger CT, Strauch BM, Schneider B, Hartwig A. BPDE-induced genotoxicity: relationship between DNA adducts, mutagenicity in the in vitro PIG-A assay, and the transcriptional response to DNA damage in TK6 cells. Arch Toxicol 2017; 92:541-551. [PMID: 28593498 PMCID: PMC5773665 DOI: 10.1007/s00204-017-2003-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 05/31/2017] [Indexed: 12/16/2022]
Abstract
Benzo[a]pyrene is a known human carcinogen. As underlying mechanism, the induction of stable DNA adducts and mutations have been repeatedly demonstrated. Also, the activation of cellular stress response on the transcriptional level has been described. Nevertheless, the interrelationship between these different events is less well understood, especially at low, for human exposure relevant concentrations. Within the present study, we applied the reactive metabolite benzo[a]pyrene diolepoxide (BPDE) in the nanomolar, non-cytotoxic concentration range in human TK6 cells and quantified the induction and repair of stable DNA adducts at the N2-position of guanine by HPLC with fluorescence detection. Significant levels of DNA lesions were detected even at the lowest concentration of 10 nM BPDE, with a linear increase up to 50 nM. Relative repair was similar at all damage levels, reaching about 30% after 8 h and 60% after 24 h. Mutation frequencies were quantified as GPI-deficient cells by the recently established in vitro PIG-A mutagenicity assay. Again, a linear dose–response-relationship in the before-mentioned concentration range was observed, also when plotting the number of GPI-deficient cells against the number of DNA adducts. Furthermore, we explored the time- and concentration-dependent DNA damage response on the transcriptional level via a high-throughput RT-qPCR technique by quantifying the impact of BPDE on the transcription of 95 genes comprising DNA damage response, DNA repair factors, oxidative stress response, cell cycle arrest, cell proliferation, and apoptosis. As expected, BPDE activated DNA damage signaling, p53 and AP-1 dependent signaling, oxidative stress response, and apoptosis. However, in contrast to DNA adducts and mutations, the onset of the transcriptional DNA damage response was restricted to higher concentrations, indicating that its respective activations require a certain level of DNA lesions. Altogether, the results indicate that in case of BPDE, DNA lesions and mutations were correlated at all concentrations, suggesting that repair is not complete even at low levels of DNA damage. Considering the ongoing discussion on potential thresholds also for genotoxic carcinogens, the results are of major relevance, both with respect to basic research as well as to risk assessment of chemical carcinogens.
Collapse
Affiliation(s)
- Ann Liza Piberger
- Food Chemistry and Toxicology, Institute of Applied Bioscience, Karlsruhe Institute of Technology (KIT), Adenauerring 20a, 76131, Karlsruhe, Germany
| | - Christopher T Krüger
- Food Chemistry and Toxicology, Institute of Applied Bioscience, Karlsruhe Institute of Technology (KIT), Adenauerring 20a, 76131, Karlsruhe, Germany
| | - Bettina M Strauch
- Food Chemistry and Toxicology, Institute of Applied Bioscience, Karlsruhe Institute of Technology (KIT), Adenauerring 20a, 76131, Karlsruhe, Germany
| | - Beatrice Schneider
- Food Chemistry and Toxicology, Institute of Applied Bioscience, Karlsruhe Institute of Technology (KIT), Adenauerring 20a, 76131, Karlsruhe, Germany
| | - Andrea Hartwig
- Food Chemistry and Toxicology, Institute of Applied Bioscience, Karlsruhe Institute of Technology (KIT), Adenauerring 20a, 76131, Karlsruhe, Germany.
| |
Collapse
|
18
|
White PA, Douglas GR, Phillips DH, Arlt VM. Quantitative relationships between lacZ mutant frequency and DNA adduct frequency in Muta™Mouse tissues and cultured cells exposed to 3-nitrobenzanthrone. Mutagenesis 2017; 32:299-312. [PMID: 28096451 PMCID: PMC5638019 DOI: 10.1093/mutage/gew067] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 12/13/2016] [Indexed: 02/07/2023] Open
Abstract
The frequency of stable DNA adducts in a target tissue can be used to assess biologically effective dose; however, the utility of the metric in a risk assessment context depends on the likelihood that the DNA damage will be manifested as mutation. Previously, we employed the Muta™Mouse system to examine the induction of lacZ mutants and DNA adducts following exposure to the well-studied mutagenic carcinogen 3-nitrobenzanthrone (3-NBA). In this follow-up work, we examined the empirical relationships between total adduct frequency and mutant frequency (MF) in tissues and cultured cells following acute 3-NBA exposure. The results show a significant induction of DNA damage and lacZ mutants in liver, colon and bone marrow, as well as FE1 pulmonary epithelial cells. In contrast, lung and small intestine samples had low, but significantly elevated adduct levels, with no significant increases in lacZ MF. Additional analyses showed a significant relationship between the mutagenic efficiency of total adducts, measured as the slope of the relationships between MF and total adduct frequency, and tissue-specific mitotic index (MI). The lack of mutation response in lung, in contrast to the high in vitro MF in FE-1 lung cells, is likely related to the 100-fold difference in MI. The lack of small intestine mutagenic response may be related to limited metabolic capacity, differences in DNA repair, and /or chemically induced apoptosis that has been observed for other potent mutagens. The results indicate that interpretation of adduct frequency values in a risk assessment context can be improved by considering the MI of the target tissue; however, more generalised interpretation is hampered by tissue-specific variations in metabolic capacity and damage processing. The work provides a proof of principle regarding the use of the Muta™Mouse system to critically examine the health risks associated with tissue-specific adduct loads.
Collapse
Affiliation(s)
- Paul A White
- Environmental Health Science and Research Bureau, Health Canada, Tunney’s Pasture, Colombine Driveway, Ottawa, Ontario, Canada
| | - George R Douglas
- Environmental Health Science and Research Bureau, Health Canada, Tunney’s Pasture, Colombine Driveway, Ottawa, Ontario, Canada
| | - David H Phillips
- King’s College London, Analytical and Environmental Sciences Division, MRC-PHE Centre for Environment and Health, Franklin-Wilkins Building, London, UK
| | - Volker M Arlt
- King’s College London, Analytical and Environmental Sciences Division, MRC-PHE Centre for Environment and Health, Franklin-Wilkins Building, London, UK
| |
Collapse
|
19
|
Gao Y, Mutter-Rottmayer E, Zlatanou A, Vaziri C, Yang Y. Mechanisms of Post-Replication DNA Repair. Genes (Basel) 2017; 8:genes8020064. [PMID: 28208741 PMCID: PMC5333053 DOI: 10.3390/genes8020064] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 02/03/2017] [Indexed: 12/15/2022] Open
Abstract
Accurate DNA replication is crucial for cell survival and the maintenance of genome stability. Cells have developed mechanisms to cope with the frequent genotoxic injuries that arise from both endogenous and environmental sources. Lesions encountered during DNA replication are often tolerated by post-replication repair mechanisms that prevent replication fork collapse and avert the formation of DNA double strand breaks. There are two predominant post-replication repair pathways, trans-lesion synthesis (TLS) and template switching (TS). TLS is a DNA damage-tolerant and low-fidelity mode of DNA synthesis that utilizes specialized ‘Y-family’ DNA polymerases to replicate damaged templates. TS, however, is an error-free ‘DNA damage avoidance’ mode of DNA synthesis that uses a newly synthesized sister chromatid as a template in lieu of the damaged parent strand. Both TLS and TS pathways are tightly controlled signaling cascades that integrate DNA synthesis with the overall DNA damage response and are thus crucial for genome stability. This review will cover the current knowledge of the primary mediators of post-replication repair and how they are regulated in the cell.
Collapse
Affiliation(s)
- Yanzhe Gao
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; (E.M.-R.); (A.Z.); (C.V.); (Y.Y.)
- Correspondence:
| | - Elizabeth Mutter-Rottmayer
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; (E.M.-R.); (A.Z.); (C.V.); (Y.Y.)
- Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Anastasia Zlatanou
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; (E.M.-R.); (A.Z.); (C.V.); (Y.Y.)
| | - Cyrus Vaziri
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; (E.M.-R.); (A.Z.); (C.V.); (Y.Y.)
| | - Yang Yang
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; (E.M.-R.); (A.Z.); (C.V.); (Y.Y.)
| |
Collapse
|
20
|
Jha V, Ling H. Structural basis of accurate replication beyond a bulky major benzo[a]pyrene adduct by human DNA polymerase kappa. DNA Repair (Amst) 2016; 49:43-50. [PMID: 27894903 DOI: 10.1016/j.dnarep.2016.11.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 11/14/2016] [Accepted: 11/14/2016] [Indexed: 12/19/2022]
Abstract
Human Y-family DNA polymerase kappa (polκ) is specialized to bypass bulky lesions in DNA in an error-free way, thus protecting cells from carcinogenic bulky DNA adducts. Benzo[a]pyrene (BP) is one of the most ubiquitous polycyclic aromatic hydrocarbons and an environmental carcinogen. BP covalently modifies DNA and generates mutagenic, bulky adducts. The major BP adduct formed in cells is 10S (+)-trans-anti-BP-N2-dG adduct (BP-dG), which is associated with cancer. The molecular mechanism of how polκ replicates BP-dG accurately is not clear. Here we report the structure of polκ captured at the lesion-extension stage: the enzyme is extending the primer strand after the base pair containing the BP-dG adduct in the template strand at the -1 position. Polκ accommodates the BP adduct in the nascent DNA's minor groove and keeps the adducted DNA helix in a B-form. Two water molecules cover the edge of the minor groove of the replicating base pair (0 position), which is secured by the BP ring in the -1 position in a 5' orientation. The 5' oriented BP adduct keeps correct Watson-Crick base pairing in the active site and promotes high fidelity replication. Our structural and biochemical data reveal a unique molecular basis for accurate DNA replication right after the bulky lesion BP-dG.
Collapse
Affiliation(s)
- Vikash Jha
- Department of Biochemistry, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, N6A 5C1, Canada
| | - Hong Ling
- Department of Biochemistry, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, N6A 5C1, Canada.
| |
Collapse
|
21
|
Manderville RA, Wetmore SD. Understanding the Mutagenicity of O-Linked and C-Linked Guanine DNA Adducts: A Combined Experimental and Computational Approach. Chem Res Toxicol 2016; 30:177-188. [DOI: 10.1021/acs.chemrestox.6b00323] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Richard A. Manderville
- Departments
of Chemistry and Toxicology, University of Guelph, Guelph, ON, Canada N1G 2W1
| | - Stacey D. Wetmore
- Department of Chemistry & Biochemistry, University of Lethbridge, Lethbridge, AB, Canada T1K 3M4
| |
Collapse
|
22
|
Christmann M, Boisseau C, Kitzinger R, Berac C, Allmann S, Sommer T, Aasland D, Kaina B, Tomicic MT. Adaptive upregulation of DNA repair genes following benzo(a)pyrene diol epoxide protects against cell death at the expense of mutations. Nucleic Acids Res 2016; 44:10727-10743. [PMID: 27694624 PMCID: PMC5159553 DOI: 10.1093/nar/gkw873] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 09/07/2016] [Accepted: 09/21/2016] [Indexed: 12/17/2022] Open
Abstract
A coordinated and faithful DNA damage response is of central importance for maintaining genomic integrity and survival. Here, we show that exposure of human cells to benzo(a)pyrene 9,10-diol-7,8-epoxide (BPDE), the active metabolite of benzo(a)pyrene (B(a)P), which represents a most important carcinogen formed during food preparation at high temperature, smoking and by incomplete combustion processes, causes a prompt and sustained upregulation of the DNA repair genes DDB2, XPC, XPF, XPG and POLH. Induction of these repair factors on RNA and protein level enhanced the removal of BPDE adducts from DNA and protected cells against subsequent BPDE exposure. However, through the induction of POLH the mutation frequency in the surviving cells was enhanced. Activation of these adaptive DNA repair genes was also observed upon B(a)P treatment of MCF7 cells and in buccal cells of human volunteers after cigarette smoking. Our data provide a rational basis for an adaptive response to polycyclic aromatic hydrocarbons, which occurs however at the expense of mutations that may drive cancer formation.
Collapse
Affiliation(s)
- Markus Christmann
- Department of Toxicology, University Medical Center Mainz, Obere Zahlbacher Strasse 67, D-55131 Mainz, Germany
| | - Catherine Boisseau
- Department of Toxicology, University Medical Center Mainz, Obere Zahlbacher Strasse 67, D-55131 Mainz, Germany
| | - Rebekka Kitzinger
- Department of Toxicology, University Medical Center Mainz, Obere Zahlbacher Strasse 67, D-55131 Mainz, Germany
| | - Christian Berac
- Department of Toxicology, University Medical Center Mainz, Obere Zahlbacher Strasse 67, D-55131 Mainz, Germany
| | - Sebastian Allmann
- Department of Toxicology, University Medical Center Mainz, Obere Zahlbacher Strasse 67, D-55131 Mainz, Germany
| | - Tina Sommer
- Department of Toxicology, University Medical Center Mainz, Obere Zahlbacher Strasse 67, D-55131 Mainz, Germany
| | - Dorthe Aasland
- Department of Toxicology, University Medical Center Mainz, Obere Zahlbacher Strasse 67, D-55131 Mainz, Germany
| | - Bernd Kaina
- Department of Toxicology, University Medical Center Mainz, Obere Zahlbacher Strasse 67, D-55131 Mainz, Germany
| | - Maja T Tomicic
- Department of Toxicology, University Medical Center Mainz, Obere Zahlbacher Strasse 67, D-55131 Mainz, Germany
| |
Collapse
|
23
|
Kim JK, Yeom M, Hong JK, Song I, Lee YS, Guengerich FP, Choi JY. Six Germline Genetic Variations Impair the Translesion Synthesis Activity of Human DNA Polymerase κ. Chem Res Toxicol 2016; 29:1741-1754. [PMID: 27603496 DOI: 10.1021/acs.chemrestox.6b00244] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
DNA polymerase (pol) κ efficiently catalyzes error-free translesion DNA synthesis (TLS) opposite bulky N2-guanyl lesions induced by carcinogens such as polycyclic aromatic hydrocarbons. We investigated the biochemical effects of nine human nonsynonymous germline POLK variations on the TLS properties of pol κ, utilizing recombinant pol κ (residues 1-526) enzymes and DNA templates containing an N2-CH2(9-anthracenyl)G (N2-AnthG), 8-oxo-7,8-dihydroguanine (8-oxoG), O6-methyl(Me)G, or an abasic site. In steady-state kinetic analyses, the R246X, R298H, T473A, and R512W variants displayed 7- to 18-fold decreases in kcat/Km for dCTP insertion opposite G and N2-AnthG, with 2- to 3-fold decreases in DNA binding affinity, compared to that of the wild-type, and further showed 5- to 190-fold decreases in kcat/Km for next-base extension from C paired with N2-AnthG. The A471V variant showed 2- to 4-fold decreases in kcat/Km for correct nucleotide insertion opposite and beyond G (or N2-AnthG) compared to that of the wild-type. These five hypoactive variants also showed similar patterns of attenuation of TLS activity opposite 8-oxoG, O6-MeG, and abasic lesions. By contrast, the T44M variant exhibited 7- to 11-fold decreases in kcat/Km for dCTP insertion opposite N2-AnthG and O6-MeG (as well as for dATP insertion opposite an abasic site) but not opposite both G and 8-oxoG, nor beyond N2-AnthG, compared to that of the wild-type. These results suggest that the R246X, R298H, T473A, R512W, and A471V variants cause a general catalytic impairment of pol κ opposite G and all four lesions, whereas the T44M variant induces opposite lesion-dependent catalytic impairment, i.e., only opposite O6-MeG, abasic, and bulky N2-G lesions but not opposite G and 8-oxoG, in pol κ, which might indicate that these hypoactive pol κ variants are genetic factors in modifying individual susceptibility to genotoxic carcinogens in certain subsets of populations.
Collapse
Affiliation(s)
- Jae-Kwon Kim
- Division of Pharmacology, Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine , Suwon, Gyeonggi-do 16419, Republic of Korea
| | - Mina Yeom
- Division of Pharmacology, Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine , Suwon, Gyeonggi-do 16419, Republic of Korea
| | - Jin-Kyung Hong
- Division of Pharmacology, Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine , Suwon, Gyeonggi-do 16419, Republic of Korea
| | - Insil Song
- Division of Pharmacology, Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine , Suwon, Gyeonggi-do 16419, Republic of Korea
| | - Young-Sam Lee
- Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology , Daegu 42988, Republic of Korea
| | - F Peter Guengerich
- Department of Biochemistry, Vanderbilt University School of Medicine , Nashville, Tennessee 37232-0146, United States
| | - Jeong-Yun Choi
- Division of Pharmacology, Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine , Suwon, Gyeonggi-do 16419, Republic of Korea
| |
Collapse
|
24
|
Bostian ACL, Eoff RL. Aberrant Kynurenine Signaling Modulates DNA Replication Stress Factors and Promotes Genomic Instability in Gliomas. Chem Res Toxicol 2016; 29:1369-80. [PMID: 27482758 DOI: 10.1021/acs.chemrestox.6b00255] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Metabolism of the essential amino acid L-tryptophan (TRP) is implicated in a number of neurological conditions including depression, neurodegenerative diseases, and cancer. The TRP catabolite kynurenine (KYN) has recently emerged as an important neuroactive factor in brain tumor pathogenesis, with additional studies implicating KYN in other types of cancer. Often highlighted as a modulator of the immune response and a contributor to immune escape for malignant tumors, it is well-known that KYN has effects on the production of the coenzyme nicotinamide adenine dinucleotide (NAD(+)), which can have a direct impact on DNA repair, replication, cell division, redox signaling, and mitochondrial function. Additional effects of KYN signaling are imparted through its role as an endogenous agonist for the aryl hydrocarbon receptor (AhR), and it is largely through activation of the AhR that KYN appears to mediate malignant progression in gliomas. We have recently reported on the ability of KYN signaling to modulate expression of human DNA polymerase kappa (hpol κ), a translesion enzyme involved in bypass of bulky DNA lesions and activation of the replication stress response. Given the impact of KYN on NAD(+) production, AhR signaling, and translesion DNA synthesis, it follows that dysregulation of KYN signaling in cancer may promote malignancy through alterations in the level of endogenous DNA damage and replication stress. In this perspective, we discuss the connections between KYN signaling, DNA damage tolerance, and genomic instability, as they relate to cancer.
Collapse
Affiliation(s)
- April C L Bostian
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences , 4301 W. Markham Street, Little Rock, Arkansas 72205-7199, United States
| | - Robert L Eoff
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences , 4301 W. Markham Street, Little Rock, Arkansas 72205-7199, United States
| |
Collapse
|
25
|
Long AS, Watson M, Arlt VM, White PA. Oral exposure to commercially available coal tar-based pavement sealcoat induces murine genetic damage and mutations. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2016; 57:535-45. [PMID: 27473530 PMCID: PMC4979669 DOI: 10.1002/em.22032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 06/20/2016] [Accepted: 06/21/2016] [Indexed: 05/12/2023]
Abstract
Coal tar (CT) is a thick black liquid produced as a by-product of coal carbonization to produce coke or manufactured gas. It is comprised a complex mixture of polycyclic aromatic compounds, including a wide range of polycyclic aromatic hydrocarbons (PAHs), many of which are genotoxic and carcinogenic. CT is used in some pavement sealants (also known as sealcoat), which are applied to pavement in order to seal and beautify the surface. Human exposure is known to occur not only during application, but also as a result of the weathering process, as elevated levels of PAHs have been found in settled house dust in residences adjacent to CT-sealed surfaces. In this study we examined the genotoxicity of an extract of a commercially available CT-based sealcoat in the transgenic Muta™Mouse model. Mice were orally exposed to 3 doses of sealcoat extract daily for 28 days. We evaluated genotoxicity by examining: (1) stable DNA adducts and (2) lacZ mutations in bone marrow, liver, lung, small intestine, and glandular stomach, as well as (3) micronucleated red blood cells. Significant increases were seen for each endpoint and in all tissues. The potency of the response differed across tissues, with the highest frequency of adducts occurring in liver and lung, and the highest frequency of mutations occurring in small intestine. The results of this study are the first demonstration of mammalian genotoxicity following exposure to CT-containing pavement sealcoat. This work provides in vivo evidence to support the contention that there may be adverse health effects in mammals, and potentially in humans, from exposure to coal tar. Environ. Mol. Mutagen. 57:535-545, 2016. © 2016 Her Majesty the Queen in Right of Canada.
Collapse
Affiliation(s)
- Alexandra S. Long
- Department of BiologyUniversity of OttawaOttawaOntarioCanada
- Mechanistic Studies DivisionEnvironmental Health Science and Research Bureau, Environmental and Radiation Health Sciences Directorate, HECSB, Health CanadaOttawaOntarioCanada
| | - Margaret Watson
- Mechanistic Studies DivisionEnvironmental Health Science and Research Bureau, Environmental and Radiation Health Sciences Directorate, HECSB, Health CanadaOttawaOntarioCanada
| | - Volker M. Arlt
- Analytical and Environmental Sciences DivisionMRC‐PHE Centre for Environment and Health, King's College LondonLondonUnited Kingdom
| | - Paul A. White
- Department of BiologyUniversity of OttawaOttawaOntarioCanada
- Mechanistic Studies DivisionEnvironmental Health Science and Research Bureau, Environmental and Radiation Health Sciences Directorate, HECSB, Health CanadaOttawaOntarioCanada
| |
Collapse
|
26
|
A neomorphic cancer cell-specific role of MAGE-A4 in trans-lesion synthesis. Nat Commun 2016; 7:12105. [PMID: 27377895 PMCID: PMC4935975 DOI: 10.1038/ncomms12105] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 05/31/2016] [Indexed: 12/11/2022] Open
Abstract
Trans-lesion synthesis (TLS) is an important DNA-damage tolerance mechanism that permits ongoing DNA synthesis in cells harbouring damaged genomes. The E3 ubiquitin ligase RAD18 activates TLS by promoting recruitment of Y-family DNA polymerases to sites of DNA-damage-induced replication fork stalling. Here we identify the cancer/testes antigen melanoma antigen-A4 (MAGE-A4) as a tumour cell-specific RAD18-binding partner and an activator of TLS. MAGE-A4 depletion from MAGE-A4-expressing cancer cells destabilizes RAD18. Conversely, ectopic expression of MAGE-A4 (in cell lines lacking endogenous MAGE-A4) promotes RAD18 stability. DNA-damage-induced mono-ubiquitination of the RAD18 substrate PCNA is attenuated by MAGE-A4 silencing. MAGE-A4-depleted cells fail to resume DNA synthesis normally following ultraviolet irradiation and accumulate γH2AX, thereby recapitulating major hallmarks of TLS deficiency. Taken together, these results demonstrate a mechanism by which reprogramming of ubiquitin signalling in cancer cells can influence DNA damage tolerance and probably contribute to an altered genomic landscape. RAD18 is an important protein in trans-lesion synthesis, an error-prone damage-tolerant mode of DNA replication. Here the authors show that MAGE-A4 stabilizes RAD18 and allows cancer cells to maintain on-going DNA synthesis in the face of genotoxic injury.
Collapse
|
27
|
Jha V, Bian C, Xing G, Ling H. Structure and mechanism of error-free replication past the major benzo[a]pyrene adduct by human DNA polymerase κ. Nucleic Acids Res 2016; 44:4957-67. [PMID: 27034468 PMCID: PMC4889944 DOI: 10.1093/nar/gkw204] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Accepted: 03/16/2016] [Indexed: 01/28/2023] Open
Abstract
Benzo[a]pyrene (BP) is a well-known and frequently encountered carcinogen which generates a bulky DNA adduct (+)-trans-10S-BP-N(2)-dG (BP-dG) in cells. DNA polymerase kappa (polκ) is the only known Y-family polymerase that bypasses BP-dG accurately and thus protects cells from genotoxic BP. Here, we report the structures of human polκ in complex with DNA containing either a normal guanine (G) base or a BP-dG adduct at the active site and a correct deoxycytidine. The structures and supporting biochemical data reveal a unique mechanism for accurate replication by translesion synthesis past the major bulky adduct. The active site of polκ opens at the minor groove side of the DNA substrate to accommodate the bulky BP-dG that is attached there. More importantly, polκ stabilizes the lesion DNA substrate in the same active conformation as for regular B-form DNA substrates and the bulky BPDE ring in a 5' end pointing conformation. The BP-dG adducted DNA substrate maintains a Watson-Crick (BP-dG:dC) base pair within the active site, governing correct nucleotide insertion opposite the bulky adduct. In addition, polκ's unique N-clasp domain supports the open conformation of the enzyme and the extended conformation of the single-stranded template to allow bypass of the bulky lesion. This work illustrates the first molecular mechanism for how a bulky major adduct is replicated accurately without strand misalignment and mis-insertion.
Collapse
Affiliation(s)
- Vikash Jha
- Department of Biochemistry, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, N6A 5C1, Canada
| | - Chuanbing Bian
- Department of Biochemistry, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, N6A 5C1, Canada
| | - Guangxin Xing
- Department of Biochemistry, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, N6A 5C1, Canada
| | - Hong Ling
- Department of Biochemistry, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, N6A 5C1, Canada
| |
Collapse
|
28
|
Yang Y, Poe JC, Yang L, Fedoriw A, Desai S, Magnuson T, Li Z, Fedoriw Y, Araki K, Gao Y, Tateishi S, Sarantopoulos S, Vaziri C. Rad18 confers hematopoietic progenitor cell DNA damage tolerance independently of the Fanconi Anemia pathway in vivo. Nucleic Acids Res 2016; 44:4174-88. [PMID: 26883629 PMCID: PMC4872084 DOI: 10.1093/nar/gkw072] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 01/31/2016] [Indexed: 01/09/2023] Open
Abstract
In cultured cancer cells the E3 ubiquitin ligase Rad18 activates Trans-Lesion Synthesis (TLS) and the Fanconi Anemia (FA) pathway. However, physiological roles of Rad18 in DNA damage tolerance and carcinogenesis are unknown and were investigated here. Primary hematopoietic stem and progenitor cells (HSPC) co-expressed RAD18 and FANCD2 proteins, potentially consistent with a role for Rad18 in FA pathway function during hematopoiesis. However, hematopoietic defects typically associated with fanc-deficiency (decreased HSPC numbers, reduced engraftment potential of HSPC, and Mitomycin C (MMC) -sensitive hematopoiesis), were absent in Rad18−/− mice. Moreover, primary Rad18−/− mouse embryonic fibroblasts (MEF) retained robust Fancd2 mono-ubiquitination following MMC treatment. Therefore, Rad18 is dispensable for FA pathway activation in untransformed cells and the Rad18 and FA pathways are separable in hematopoietic cells. In contrast with responses to crosslinking agents, Rad18−/− HSPC were sensitive to in vivo treatment with the myelosuppressive agent 7,12 Dimethylbenz[a]anthracene (DMBA). Rad18-deficient fibroblasts aberrantly accumulated DNA damage markers after DMBA treatment. Moreover, in vivo DMBA treatment led to increased incidence of B cell malignancy in Rad18−/− mice. These results identify novel hematopoietic functions for Rad18 and provide the first demonstration that Rad18 confers DNA damage tolerance and tumor-suppression in a physiological setting.
Collapse
Affiliation(s)
- Yang Yang
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Jonathan C Poe
- Department of Medicine, Division of Hematological Malignancies & Cellular Therapy, Duke University, Durham, NC 27710, USA
| | - Lisong Yang
- Department of Medicine, Division of Hematological Malignancies & Cellular Therapy, Duke University, Durham, NC 27710, USA
| | - Andrew Fedoriw
- Department of Genetics, Carolina Center for Genome Sciences, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Siddhi Desai
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Terry Magnuson
- Department of Genetics, Carolina Center for Genome Sciences, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Zhiguo Li
- Department of Biostatistics and Bioinformatics, Duke University, Durham, NC 27710, USA
| | - Yuri Fedoriw
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Kimi Araki
- Institute of Resource Development and Analysis (IRDA) Kumamoto University, Kumamoto 860-0811, Japan
| | - Yanzhe Gao
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Satoshi Tateishi
- Division of Cell Maintenance, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Kumamoto 860-0811, Japan
| | - Stefanie Sarantopoulos
- Department of Medicine, Division of Hematological Malignancies & Cellular Therapy, Duke University, Durham, NC 27710, USA
| | - Cyrus Vaziri
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| |
Collapse
|
29
|
Bostian ACL, Maddukuri L, Reed MR, Savenka T, Hartman JH, Davis L, Pouncey DL, Miller GP, Eoff RL. Kynurenine Signaling Increases DNA Polymerase Kappa Expression and Promotes Genomic Instability in Glioblastoma Cells. Chem Res Toxicol 2015; 29:101-8. [PMID: 26651356 DOI: 10.1021/acs.chemrestox.5b00452] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Overexpression of the translesion synthesis polymerase hpol κ in glioblastomas has been linked to poor patient prognosis; however, the mechanism promoting higher expression in these tumors remains unknown. We determined that activation of the aryl hydrocarbon receptor (AhR) pathway in glioblastoma cells leads to increased hpol κ mRNA and protein levels. We blocked nuclear translocation and DNA binding by AhR in glioblastoma cells using a small-molecule and observed decreased hpol κ expression. Pharmacological inhibition of tryptophan-2,3-dioxygenase (TDO), the enzyme largely responsible for activating AhR in glioblastoma, led to a decrease in the endogenous AhR agonist kynurenine and a corresponding decrease in hpol κ protein levels. Importantly, we discovered that inhibiting TDO activity, AhR signaling, or suppressing hpol κ expression with RNA interference led to decreased chromosomal damage in glioblastoma cells. Epistasis assays further supported the idea that TDO activity, activation of AhR signaling, and the resulting overexpression of hpol κ function primarily in the same pathway to increase endogenous DNA damage. These findings indicate that upregulation of hpol κ through glioblastoma-specific TDO activity and activation of AhR signaling likely contributes to the high levels of replication stress and genomic instability observed in these tumors.
Collapse
Affiliation(s)
- April C L Bostian
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences , Little Rock, Arkansas 72205-7199, United States
| | - Leena Maddukuri
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences , Little Rock, Arkansas 72205-7199, United States
| | - Megan R Reed
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences , Little Rock, Arkansas 72205-7199, United States
| | - Tatsiana Savenka
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences , Little Rock, Arkansas 72205-7199, United States
| | - Jessica H Hartman
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences , Little Rock, Arkansas 72205-7199, United States
| | - Lauren Davis
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences , Little Rock, Arkansas 72205-7199, United States
| | - Dakota L Pouncey
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences , Little Rock, Arkansas 72205-7199, United States
| | - Grover P Miller
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences , Little Rock, Arkansas 72205-7199, United States
| | - Robert L Eoff
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences , Little Rock, Arkansas 72205-7199, United States
| |
Collapse
|
30
|
Liu Y, Ma X, Guo C. Effects of the N terminus of mouse DNA polymerase κ on the bypass of a guanine-benzo[a]pyrenyl adduct. J Biochem 2015; 159:471-9. [PMID: 26634445 DOI: 10.1093/jb/mvv118] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 11/14/2015] [Indexed: 12/15/2022] Open
Abstract
DNA polymerase κ (Polκ), one of the typical member of the Y-family DNA polymerases, has been demonstrated to bypass the 10S(+)-trans-anti-benzo[a]pyrene diol epoxide-N(2)-deoxyguanine adducts (BPDE-dG) efficiently and accurately. A large structural gap between the core and little finger as well as an N-clasp domain are essential to its unique translesion capability. However, whether the extreme N-terminus of Polκ is required for its activity is unclear. In this work, we constructed two mouse Polκ deletions, which have either a catalytic core (mPolκ1-516) or a core without the first 21-residues (mPolκ22-516), and tested their activities in the replication of normal and BPDE-DNA. These two Polκ deletions are nearly as efficient as the full length protein (Polκ1-852) in normal DNA synthesis. However, steady-state kinetics reveals a significant reduction in efficiency of dCTP incorporation opposite the lesion by Polκ22-516, along with increased frequencies for misinsertion compared with Polκ1-852 The next nucleotide insertion opposite the template C immediately following the BPDE-dG was also examined, and the bypass differences induced by deletions were highlighted in both insertion and extension step. We conclude that the extreme N-terminal part of Polκ is required for the processivity and fidelity of Polκ during translesion synthesis of BPDE-dG lesions.
Collapse
Affiliation(s)
- Yang Liu
- Key Laboratory of Genomic and Precision Medicine, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiaolu Ma
- Key Laboratory of Genomic and Precision Medicine, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
| | - Caixia Guo
- Key Laboratory of Genomic and Precision Medicine, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
| |
Collapse
|
31
|
Sproviero M, Verwey AMR, Witham AA, Manderville RA, Sharma P, Wetmore SD. Enhancing Bulge Stabilization through Linear Extension of C8-Aryl-Guanine Adducts to Promote Polymerase Blockage or Strand Realignment to Produce a C:C Mismatch. Chem Res Toxicol 2015. [PMID: 26225720 DOI: 10.1021/acs.chemrestox.5b00233] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Aryl radicals can react at the C8-site of 2'-deoxyguanosine (dG) to produce DNA adducts with a C8-C linkage (denoted C-linked). Such adducts are structurally distinct from those possessing a flexible amine (N-linked) or ether (O-linked) linkage, which separates the C8-aryl moiety from the guanine nucleobase. In the current study, two model C-linked C8-dG adducts, namely, C8-benzo[b]thienyl-dG ([BTh]G) and C8-(pyren-1-yl)-dG ([Py]G), were incorporated into the NarI (12mer, NarI(12) and 22mer, NarI(22)) hotspot sequence for frameshift mutations in bacteria. For the first time, C-linked C8-dG adducts are shown to stabilize the -2 deletion duplex within the NarI sequence. Primer-elongation assays employing Sulfolobus solfataricus P2 DNA polymerase IV (Dpo4) demonstrates the influence of C8-aryl ring size and shape in promoting Dpo4 blockage or strand realignment to produce a C:C mismatch downstream of the adduct site. Molecular dynamics simulations of the -2 deletion duplex suggest that both anti and syn adduct structures are energetically accessible. These findings provide a rationale for describing the biochemical outcome induced by C-linked C8-dG adducts when processed by Dpo4.
Collapse
Affiliation(s)
- Michael Sproviero
- †Department of Chemistry and Toxicology, University of Guelph, Guelph, ON Canada N1G 2W1
| | - Anne M R Verwey
- †Department of Chemistry and Toxicology, University of Guelph, Guelph, ON Canada N1G 2W1
| | - Aaron A Witham
- †Department of Chemistry and Toxicology, University of Guelph, Guelph, ON Canada N1G 2W1
| | - Richard A Manderville
- †Department of Chemistry and Toxicology, University of Guelph, Guelph, ON Canada N1G 2W1
| | | | | |
Collapse
|
32
|
Spryszyńska S, Smok-Pieniążek A, Ferlińska M, Roszak J, Nocuń M, Stępnik M. The influence of ATM, ATR, DNA-PK inhibitors on the cytotoxic and genotoxic effects of dibenzo[def,p]chrysene on human hepatocellular cancer cell line HepG2. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2015; 791:12-24. [PMID: 26338538 DOI: 10.1016/j.mrgentox.2015.07.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 07/09/2015] [Accepted: 07/21/2015] [Indexed: 02/06/2023]
Abstract
The effect of inhibitors of phosphatidylinositol-3-kinase related kinases (PIKK): ataxia-telangiectasia mutated (ATM), ATM- and Rad3-related (ATR) and DNA-dependent protein kinase (DNA-PK) on the response of HepG2 human liver cancer cells to dibenzo[def,p]chrysene (DBC) was investigated. High cytotoxicity of DBC (IC50=0.1μM) was observed after 72h incubation. PIKK inhibitors: KU55933 (5μM), NU7026 (10μM) or caffeine (1 and 2mM) when used alone did not significantly influence the cytotoxicity. However, two combinations: KU55933/NU7026 and caffeine/NU7026 significantly increased HepG2 viability (by 25%) after treatment with DBC at 0.5μM. The cytoprotective effect was confirmed by cell cycle and apoptosis/necrosis analysis. DNA damage level after exposure to DBC assessed by comet assay (single strand breaks) showed a long persistence and significant decrease after incubation of the cells in the presence the inhibitors (the combination of KU55933+NU7026 showed the strongest effect). Weak induction of reactive oxygen species (ROS) by DBC (0.5μM) was observed. Although, KU55933 and NU7026 when used alone did not increase ROS levels in the cells, their combination induced the ROS increase and moderately enhanced ROS generation by DBC. We propose a mechanism how cells with damaged DNA after exposure to DBC and under the condition of PIKK inhibition, may be at higher risk of undergoing malignant transformation.
Collapse
Affiliation(s)
- Sylwia Spryszyńska
- Department of Toxicology and Carcinogenesis, Nofer Institute of Occupational Medicine, Łódź, Poland.
| | - Anna Smok-Pieniążek
- Department of Toxicology and Carcinogenesis, Nofer Institute of Occupational Medicine, Łódź, Poland.
| | - Magdalena Ferlińska
- Department of Toxicology and Carcinogenesis, Nofer Institute of Occupational Medicine, Łódź, Poland.
| | - Joanna Roszak
- Department of Toxicology and Carcinogenesis, Nofer Institute of Occupational Medicine, Łódź, Poland.
| | - Marek Nocuń
- Department of Toxicology and Carcinogenesis, Nofer Institute of Occupational Medicine, Łódź, Poland.
| | - Maciej Stępnik
- Department of Toxicology and Carcinogenesis, Nofer Institute of Occupational Medicine, Łódź, Poland.
| |
Collapse
|
33
|
Lemieux CL, Long AS, Lambert IB, Lundstedt S, Tysklind M, White PA. In vitro mammalian mutagenicity of complex polycyclic aromatic hydrocarbon mixtures in contaminated soils. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:1787-1796. [PMID: 25419852 DOI: 10.1021/es504465f] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This study employed an in vitro version of the lacZ transgenic rodent mutation assay to assess the mutagenicity of nonpolar neutral and semipolar aromatic soil fractions from 10 PAH-contaminated sites, and evaluated the assumption of dose additivity that is routinely employed to calculate the risk posed by PAH mixtures. Significant mutagenic activity was detected in all nonpolar neutral fractions, and 8 of 10 semipolar aromatic fractions (nonpolar > semipolar). Mutagenic activity of synthetic PAH mixtures that mimic the PAH content of the soils (i.e., 5-PAH or 16-PAH mix) were greater than that of the PAH-containing soil fractions, with 5-PAH mix >16-PAH-mix. Predictions of mutagenic activity, calculated as the sum of the contributions from the mutagenic mixture components, were all within 2-fold of the observed activity of the nonpolar neutral fractions, with one exception. Observed differences in mutagenic activity are likely the result of dynamic metabolic processes, involving a complex interplay of AhR agonsim and saturation of metabolic machinery by competitive inhibition of mixture components. The presence of hitherto unidentified polar compounds present in PAH-contaminated soils may also contribute to overall hazard; however, these compounds are generally not included in current contaminated site risk assessment protocols.
Collapse
Affiliation(s)
- Christine L Lemieux
- Mechanistic Studies Division, Environmental Health Science and Research Bureau, Health Canada, 50 Columbine Driveway, Tunney's Pasture 0803A, Ottawa, Ontario Canada , K1A 0K9
| | | | | | | | | | | |
Collapse
|
34
|
Takeiri A, Wada NA, Motoyama S, Matsuzaki K, Tateishi H, Matsumoto K, Niimi N, Sassa A, Grúz P, Masumura K, Yamada M, Mishima M, Jishage KI, Nohmi T. In vivo evidence that DNA polymerase kappa is responsible for error-free bypass across DNA cross-links induced by mitomycin C. DNA Repair (Amst) 2014; 24:113-121. [DOI: 10.1016/j.dnarep.2014.09.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 08/04/2014] [Accepted: 09/10/2014] [Indexed: 10/24/2022]
|
35
|
Sharma P, Manderville RA, Wetmore SD. Structural and energetic characterization of the major DNA adduct formed from the food mutagen ochratoxin A in the NarI hotspot sequence: influence of adduct ionization on the conformational preferences and implications for the NER propensity. Nucleic Acids Res 2014; 42:11831-45. [PMID: 25217592 PMCID: PMC4191402 DOI: 10.1093/nar/gku821] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The nephrotoxic food mutagen ochratoxin A (OTA) produces DNA adducts in rat kidneys, the major lesion being the C8-linked-2′-deoxyguanosine adduct (OTB-dG). Although research on other adducts stresses the importance of understanding the structure of the associated adducted DNA, site-specific incorporation of OTB-dG into DNA has yet to be attempted. The present work uses a robust computational approach to determine the conformational preferences of OTB-dG in three ionization states at three guanine positions in the NarI recognition sequence opposite cytosine. Representative adducted DNA helices were derived from over 2160 ns of simulation and ranked via free energies. For the first time, a close energetic separation between three distinct conformations is highlighted, which indicates OTA-adducted DNA likely adopts a mixture of conformations regardless of the sequence context. Nevertheless, the preferred conformation depends on the flanking bases and ionization state due to deviations in discrete local interactions at the lesion site. The structural characteristics of the lesion thus discerned have profound implications regarding its repair propensity and mutagenic outcomes, and support recent experiments suggesting the induction of double-strand breaks and deletion mutations upon OTA exposure. This combined structural and energetic characterization of the OTB-dG lesion in DNA will encourage future biochemical experiments on this potentially genotoxic lesion.
Collapse
Affiliation(s)
- Purshotam Sharma
- Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, Alberta, T1K 3M4, Canada
| | - Richard A Manderville
- Department of Chemistry and Toxicology, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
| | - Stacey D Wetmore
- Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, Alberta, T1K 3M4, Canada
| |
Collapse
|
36
|
Lior-Hoffmann L, Ding S, Geacintov NE, Zhang Y, Broyde S. Structural and dynamic characterization of polymerase κ's minor groove lesion processing reveals how adduct topology impacts fidelity. Biochemistry 2014; 53:5683-91. [PMID: 25148552 PMCID: PMC4159208 DOI: 10.1021/bi5007964] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
![]()
DNA
lesion bypass polymerases process different lesions with varying
fidelities, but the structural, dynamic, and mechanistic origins of
this phenomenon remain poorly understood. Human DNA polymerase κ
(Polκ), a member of the Y family of lesion bypass polymerases,
is specialized to bypass bulky DNA minor groove lesions in a predominantly
error-free manner, by housing them in its unique gap. We have investigated
the role of the unique Polκ gap and N-clasp structural features
in the fidelity of minor groove lesion processing with extensive molecular
modeling and molecular dynamics simulations to pinpoint their functioning
in lesion bypass. Here we consider the N2-dG covalent adduct derived from the carcinogenic aromatic amine,
2-acetylaminofluorene (dG-N2-AAF), that
is produced via the combustion of kerosene and diesel fuel. Our simulations
reveal how the spacious gap directionally accommodates the lesion
aromatic ring system as it transits through the stages of incorporation
of the predominant correct partner dCTP opposite the damaged guanine,
with preservation of local active site organization for nucleotidyl
transfer. Furthermore, flexibility in Polκ’s N-clasp
facilitates the significant misincorporation of dTTP opposite dG-N2-AAF via wobble pairing. Notably, we show that
N-clasp flexibility depends on lesion topology, being markedly reduced
in the case of the benzo[a]pyrene-derived major adduct
to N2-dG, whose bypass by Polκ is
nearly error-free. Thus, our studies reveal how Polκ’s
unique structural and dynamic properties can regulate its bypass fidelity
of polycyclic aromatic lesions and how the fidelity is impacted by
lesion structures.
Collapse
Affiliation(s)
- Lee Lior-Hoffmann
- Department of Biology and ‡Department of Chemistry, New York University , 100 Washington Square East, New York, New York 10003, United States
| | | | | | | | | |
Collapse
|
37
|
Han J, Liu T, Huen MSY, Hu L, Chen Z, Huang J. SIVA1 directs the E3 ubiquitin ligase RAD18 for PCNA monoubiquitination. ACTA ACUST UNITED AC 2014; 205:811-27. [PMID: 24958773 PMCID: PMC4068132 DOI: 10.1083/jcb.201311007] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Translesion DNA synthesis (TLS) is a universal DNA damage tolerance mechanism conserved from yeast to mammals. A key event in the regulation of TLS is the monoubiquitination of proliferating cell nuclear antigen (PCNA). Extensive evidence indicates that the RAD6-RAD18 ubiquitin-conjugating/ligase complex specifically monoubiquitinates PCNA and regulates TLS repair. However, the mechanism by which the RAD6-RAD18 complex is targeted to PCNA has remained elusive. In this study, we used an affinity purification approach to isolate the PCNA-containing complex and have identified SIVA1 as a critical regulator of PCNA monoubiquitination. We show that SIVA1 constitutively interacts with PCNA via a highly conserved PCNA-interacting peptide motif. Knockdown of SIVA1 compromised RAD18-dependent PCNA monoubiquitination and Polη focus formation, leading to elevated ultraviolet sensitivity and mutation. Furthermore, we demonstrate that SIVA1 interacts with RAD18 and serves as a molecular bridge between RAD18 and PCNA, thus targeting the E3 ligase activity of RAD18 onto PCNA. Collectively, our results provide evidence that the RAD18 E3 ligase requires an accessory protein for binding to its substrate PCNA.
Collapse
Affiliation(s)
- Jinhua Han
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Ting Liu
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Michael S Y Huen
- Department of Anatomy and Center for Cancer Research, The University of Hong Kong, Hong Kong, China Department of Anatomy and Center for Cancer Research, The University of Hong Kong, Hong Kong, China
| | - Lin Hu
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Zhiqiu Chen
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Jun Huang
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| |
Collapse
|
38
|
Kamath-Loeb AS, Balakrishna S, Whittington D, Shen JC, Emond MJ, Okabe T, Masutani C, Hanaoka F, Nishimura S, Loeb LA. Sphingosine, a modulator of human translesion DNA polymerase activity. J Biol Chem 2014; 289:21663-72. [PMID: 24928506 DOI: 10.1074/jbc.m114.570242] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Translesion (TLS) DNA polymerases are specialized, error-prone enzymes that synthesize DNA across bulky, replication-stalling DNA adducts. In so doing, they facilitate the progression of DNA synthesis and promote cell proliferation. To potentiate the effect of cancer chemotherapeutic regimens, we sought to identify inhibitors of TLS DNA polymerases. We screened five libraries of ∼ 3000 small molecules, including one comprising ∼ 600 nucleoside analogs, for their effect on primer extension activity of DNA polymerase η (Pol η). We serendipitously identified sphingosine, a lipid-signaling molecule that robustly stimulates the activity of Pol η by ∼ 100-fold at low micromolar concentrations but inhibits it at higher concentrations. This effect is specific to the Y-family DNA polymerases, Pols η, κ, and ι. The addition of a single phosphate group on sphingosine completely abrogates this effect. Likewise, the inclusion of other sphingolipids, including ceramide and sphingomyelin to extension reactions does not elicit this response. Sphingosine increases the rate of correct and incorrect nucleotide incorporation while having no effect on polymerase processivity. Endogenous Pol η activity is modulated similarly as the recombinant enzyme. Importantly, sphingosine-treated cells exhibit increased lesion bypass activity, and sphingosine tethered to membrane lipids mimics the effects of free sphingosine. Our studies have uncovered sphingosine as a modulator of TLS DNA polymerase activity; this property of sphingosine may be associated with its known role as a signaling molecule in regulating cell proliferation in response to cellular stress.
Collapse
Affiliation(s)
- Ashwini S Kamath-Loeb
- From the Departments of Pathology and Biochemistry, The Gottstein Memorial Cancer Research Laboratory, University of Washington, Seattle, Washington 98195
| | - Sharath Balakrishna
- From the Departments of Pathology and Biochemistry, The Gottstein Memorial Cancer Research Laboratory, University of Washington, Seattle, Washington 98195
| | - Dale Whittington
- the Department of Medicinal Chemistry, Mass Spectrometry Center, University of Washington, Seattle, Washington 98195
| | - Jiang-Cheng Shen
- From the Departments of Pathology and Biochemistry, The Gottstein Memorial Cancer Research Laboratory, University of Washington, Seattle, Washington 98195
| | - Mary J Emond
- Biostatistics and Center for Biomedical Statistics, University of Washington, Seattle, Washington 98195
| | - Takayoshi Okabe
- the Open Innovation Center for Drug Discovery, University of Tokyo, Tokyo 113-0033, Japan
| | - Chikahide Masutani
- the Department of Genome Dynamics, Research Institute of Environmental Medicine, Nagoya University, Nagoya 464-8601, Japan
| | - Fumio Hanaoka
- the Institute for Biomolecular Science, Faculty of Science, Gakushuin University, Tokyo 171-8588, Japan, and
| | - Susumu Nishimura
- the Laboratory Animal Resource Center, University of Tsukuba, Tsukuba 305-8575, Japan
| | - Lawrence A Loeb
- From the Departments of Pathology and Biochemistry, The Gottstein Memorial Cancer Research Laboratory, University of Washington, Seattle, Washington 98195,
| |
Collapse
|
39
|
Rossner P, Rossnerova A, Beskid O, Tabashidze N, Libalova H, Uhlirova K, Topinka J, Sram RJ. Nonhomologous DNA end joining and chromosome aberrations in human embryonic lung fibroblasts treated with environmental pollutants. Mutat Res 2014; 763-764:28-38. [PMID: 24694657 DOI: 10.1016/j.mrfmmm.2014.03.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2014] [Revised: 02/25/2014] [Accepted: 03/07/2014] [Indexed: 06/03/2023]
Abstract
In order to evaluate the ability of a representative polycyclic aromatic hydrocarbon (PAH) and PAH-containing complex mixtures to induce double strand DNA breaks (DSBs) and repair of damaged DNA in human embryonic lung fibroblasts (HEL12469 cells), we investigated the effect of benzo[a]pyrene (B[a]P) and extractable organic matter (EOM) from ambient air particles <2.5μm (PM2.5) on nonhomologous DNA end joining (NHEJ) and induction of stable chromosome aberrations (CAs). PM2.5 was collected in winter and summer 2011 in two Czech cities differing in levels and sources of air pollutants. The cells were treated for 24h with the following concentrations of tested chemicals: B[a]P: 1μM, 10μM, 25μM; EOMs: 1μg/ml, 10μg/ml, 25μg/ml. We tested several endpoints representing key steps leading from DSBs to the formation of CAs including histone H2AX phosphorylation, levels of proteins Ku70, Ku80 and XRCC4 participating in NHEJ, in vitro ligation activity of nuclear extracts of the HEL12469 cells and the frequency of stable CAs assessed by whole chromosome painting of chromosomes 1, 2, 4, 5, 7 and 17 using fluorescence in situ hybridization. Our results show that 25μM of B[a]P and most of the tested doses of EOMs induced DSBs as indicated by H2AX phosphorylation. DNA damage was accompanied by induction of XRCC4 expression and an increased frequency of CAs. Translocations most frequently affected chromosome 7. We observed only a weak induction of Ku70/80 expression as well as ligation activity of nuclear extracts. In summary, our data suggest the induction of DSBs and NHEJ after treatment of human embryonic lung fibroblasts with B[a]P and complex mixtures containing PAHs.
Collapse
Affiliation(s)
- Pavel Rossner
- Department of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR, Prague, Czech Republic.
| | - Andrea Rossnerova
- Department of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR, Prague, Czech Republic
| | - Olena Beskid
- Department of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR, Prague, Czech Republic
| | - Nana Tabashidze
- Department of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR, Prague, Czech Republic
| | - Helena Libalova
- Department of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR, Prague, Czech Republic
| | - Katerina Uhlirova
- Department of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR, Prague, Czech Republic
| | - Jan Topinka
- Department of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR, Prague, Czech Republic
| | - Radim J Sram
- Department of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR, Prague, Czech Republic
| |
Collapse
|
40
|
Song I, Kim EJ, Kim IH, Park EM, Lee KE, Shin JH, Guengerich FP, Choi JY. Biochemical characterization of eight genetic variants of human DNA polymerase κ involved in error-free bypass across bulky N(2)-guanyl DNA adducts. Chem Res Toxicol 2014; 27:919-30. [PMID: 24725253 DOI: 10.1021/tx500072m] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
DNA polymerase (pol) κ, one of the Y-family polymerases, has been shown to function in error-free translesion DNA synthesis (TLS) opposite the bulky N(2)-guanyl DNA lesions induced by many carcinogens such as polycyclic aromatic hydrocarbons. We analyzed the biochemical properties of eight reported human pol κ variants positioned in the polymerase core domain, using the recombinant pol κ (residues 1-526) protein and the DNA template containing an N(2)-CH2(9-anthracenyl)G (N(2)-AnthG). The truncation R219X was devoid of polymerase activity, and the E419G and Y432S variants showed much lower polymerase activity than wild-type pol κ. In steady-state kinetic analyses, E419G and Y432S displayed 20- to 34-fold decreases in kcat/Km for dCTP insertion opposite G and N(2)-AnthG compared to that of wild-type pol κ. The L21F, I39T, and D189G variants, as well as E419G and Y432S, displayed 6- to 22-fold decreases in kcat/Km for next-base extension from C paired with N(2)-AnthG, compared to that of wild-type pol κ. The defective Y432S variant had 4- to 5-fold lower DNA-binding affinity than wild-type, while a slightly more efficient S423R variant possessed 2- to 3-fold higher DNA-binding affinity. These results suggest that R219X abolishes and the E419G, Y432S, L21F, I39T, and D189G variations substantially impair the TLS ability of pol κ opposite bulky N(2)-G lesions in the insertion step opposite the lesion and/or the subsequent extension step, raising the possibility that certain nonsynonymous pol κ genetic variations translate into individual differences in susceptibility to genotoxic carcinogens.
Collapse
Affiliation(s)
- Insil Song
- Division of Pharmacology, Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine , Suwon, Gyeonggi-do 440-746, Republic of Korea
| | | | | | | | | | | | | | | |
Collapse
|
41
|
Variants of mouse DNA polymerase κ reveal a mechanism of efficient and accurate translesion synthesis past a benzo[a]pyrene dG adduct. Proc Natl Acad Sci U S A 2014; 111:1789-94. [PMID: 24449898 DOI: 10.1073/pnas.1324168111] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
DNA polymerase κ (Polκ) is the only known Y-family DNA polymerase that bypasses the 10S (+)-trans-anti-benzo[a]pyrene diol epoxide (BPDE)-N(2)-deoxyguanine adducts efficiently and accurately. The unique features of Polκ, a large structure gap between the catalytic core and little finger domain and a 90-residue addition at the N terminus known as the N-clasp, may give rise to its special translesion capability. We designed and constructed two mouse Polκ variants, which have reduced gap size on both sides [Polκ Gap Mutant (PGM) 1] or one side flanking the template base (PGM2). These Polκ variants are nearly as efficient as WT in normal DNA synthesis, albeit with reduced accuracy. However, PGM1 is strongly blocked by the 10S (+)-trans-anti-BPDE-N(2)-dG lesion. Steady-state kinetic measurements reveal a significant reduction in efficiency of dCTP incorporation opposite the lesion by PGM1 and a moderate reduction by PGM2. Consistently, Polκ-deficient cells stably complemented with PGM1 GFP-Polκ remained hypersensitive to BPDE treatment, and complementation with WT or PGM2 GFP-Polκ restored BPDE resistance. Furthermore, deletion of the first 51 residues of the N-clasp in mouse Polκ (mPolκ(52-516)) leads to reduced polymerization activity, and the mutant PGM2(52-516) but not PGM1(52-516) can partially compensate the N-terminal deletion and restore the catalytic activity on normal DNA. However, neither WT nor PGM2 mPolκ(52-516) retains BPDE bypass activity. We conclude that the structural gap physically accommodates the bulky aromatic adduct and the N-clasp is essential for the structural integrity and flexibility of Polκ during translesion synthesis.
Collapse
|
42
|
Sproul CD, Mitchell DL, Rao S, Ibrahim JG, Kaufmann WK, Cordeiro-Stone M. Cyclobutane Pyrimidine Dimer Density as a Predictive Biomarker of the Biological Effects of Ultraviolet Radiation in Normal Human Fibroblast. Photochem Photobiol 2013; 90:145-54. [PMID: 24148148 DOI: 10.1111/php.12194] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Accepted: 10/14/2013] [Indexed: 12/29/2022]
Abstract
This study compared biological responses of normal human fibroblasts (NHF1) to three sources of ultraviolet radiation (UVR), emitting UVC wavelengths, UVB wavelengths, or a combination of UVA and UVB (solar simulator; emission spectrum, 94.3% UVA and 5.7% UVB). The endpoints measured were cytotoxicity, intra-S checkpoint activation, inhibition of DNA replication and mutagenicity. Results show that the magnitude of each response to the indicated radiation sources was best predicted by the density of DNA cyclobutane pyrimidine dimers (CPD). The density of 6-4 pyrimidine-pyrimidone photoproducts was highest in DNA from UVC-irradiated cells (14% of CPD) as compared to those exposed to UVB (11%) or UVA-UVB (7%). The solar simulator source, under the experimental conditions described here, did not induce the formation of 8-oxo-7,8-dihydroguanine in NHF1 above background levels. Taken together, these results suggest that CPD play a dominant role in DNA damage responses and highlight the importance of using endogenous biomarkers to compare and report biological effects induced by different sources of UVR.
Collapse
Affiliation(s)
- Christopher D Sproul
- Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - David L Mitchell
- The University of Texas MD Anderson Cancer Center, Science Park/Research Division, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Shangbang Rao
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Joseph G Ibrahim
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, NC.,Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - William K Kaufmann
- Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, NC.,Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC.,Center for Environmental Health and Susceptibility, University of North Carolina at Chapel Hill, Chapel Hill, NC.,Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Marila Cordeiro-Stone
- Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, NC.,Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC.,Center for Environmental Health and Susceptibility, University of North Carolina at Chapel Hill, Chapel Hill, NC.,Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC
| |
Collapse
|
43
|
Kuroda K, Hibi D, Ishii Y, Takasu S, Kijima A, Matsushita K, Masumura KI, Watanabe M, Sugita-Konishi Y, Sakai H, Yanai T, Nohmi T, Ogawa K, Umemura T. Ochratoxin A induces DNA double-strand breaks and large deletion mutations in the carcinogenic target site of gpt delta rats. Mutagenesis 2013; 29:27-36. [DOI: 10.1093/mutage/get054] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
44
|
Sproul CD, Rao S, Ibrahim JG, Kaufmann WK, Cordeiro-Stone M. Is activation of the intra-S checkpoint in human fibroblasts an important factor in protection against UV-induced mutagenesis? Cell Cycle 2013; 12:3555-63. [PMID: 24091629 DOI: 10.4161/cc.26590] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The ATR/CHK1-dependent intra-S checkpoint inhibits replicon initiation and replication fork progression in response to DNA damage caused by UV (UV) radiation. It has been proposed that this signaling cascade protects against UV-induced mutations by reducing the probability that damaged DNA will be replicated before it can be repaired. Normal human fibroblasts (NHF) were depleted of ATR or CHK1, or treated with the CHK1 kinase inhibitor TCS2312, and the UV-induced mutation frequency at the HPRT locus was measured. Despite clear evidence of S-phase checkpoint abrogation, neither ATR/CHK1 depletion nor CHK1 inhibition caused an increase in the UV-induced HPRT mutation frequency. These results question the premise that the UV-induced intra-S checkpoint plays a prominent role in protecting against UV-induced mutagenesis.
Collapse
Affiliation(s)
- Christopher D Sproul
- Curriculum in Toxicology; University of North Carolina-Chapel Hill; Chapel Hill, NC USA
| | | | | | | | | |
Collapse
|
45
|
Lv L, Wang F, Ma X, Yang Y, Wang Z, Liu H, Li X, Liu Z, Zhang T, Huang M, Friedberg EC, Tang TS, Guo C. Mismatch repair protein MSH2 regulates translesion DNA synthesis following exposure of cells to UV radiation. Nucleic Acids Res 2013; 41:10312-22. [PMID: 24038355 PMCID: PMC3905884 DOI: 10.1093/nar/gkt793] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Translesion DNA synthesis (TLS) can use specialized DNA polymerases to insert and/or extend nucleotides across lesions, thereby limiting stalled replication fork collapse and the potential for cell death. Recent studies have shown that monoubiquitinated proliferating cell nuclear antigen (PCNA) plays an important role in recruitment of Y-family TLS polymerases to stalled replication forks after DNA damage treatment. To explore the possible roles of other factors that regulate the ultraviolet (UV)-induced assembly of specialized DNA polymerases at arrested replication forks, we performed immunoprecipitation experiments combined with mass spectrometry and established that DNA polymerase kappa (Polκ) can partner with MSH2, an important mismatch repair protein associated with hereditary non-polyposis colorectal cancer. We found that depletion of MSH2 impairs PCNA monoubiquitination and the formation of foci containing Polκ and other TLS polymerases after UV irradiation of cells. Interestingly, expression of MSH2 in Rad18-deficient cells increased UV-induced Polκ and REV1 focus formation without detectable changes in PCNA monoubiquitination, indicating that MSH2 can regulate post-UV focus formation by specialized DNA polymerases in both PCNA monoubiquitination-dependent and -independent fashions. Moreover, we observed that MSH2 can facilitate TLS across cyclobutane pyrimidine dimers photoproducts in living cells, presenting a novel role of MSH2 in post-UV cellular responses.
Collapse
Affiliation(s)
- Lingna Lv
- Laboratory of Cancer Genomics and Individualized Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China and Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Singer WD, Osimiri LC, Friedberg EC. Increased dietary cholesterol promotes enhanced mutagenesis in DNA polymerase kappa-deficient mice. DNA Repair (Amst) 2013; 12:817-23. [PMID: 23948094 DOI: 10.1016/j.dnarep.2013.07.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Revised: 07/23/2013] [Accepted: 07/24/2013] [Indexed: 11/26/2022]
Abstract
DNA polymerase kappa (Polκ) bypasses planar polycyclic N2-guanine adducts in an error-free manner. Cholesterol derivatives may interact with DNA to form similarly bulky lesions. In accordance, these studies examined whether increased mutagenesis of DNA accompanies hypercholesterolemia in Polk-/- mice. These mice also carried apoE gene knockouts to ensure increased levels of plasma cholesterol following exposure to a high cholesterol diet. The mice carried a reporter transgene (the λ-phage cII gene) for subsequent quantitative analysis of mutagenesis in various tissues. We observed significantly increased mutation frequencies in several organs of apoE-/-Polk-/- mice following a high cholesterol diet, compared to those remaining on a standard diet. Regardless of dietary regime, the mutation frequency in many organs was significantly higher in apoE-/-Polk-/- than in apoE-/-Polk+/+ mice. As expected for polycyclic guanine adducts, the mutations mainly consisted of G:C transversions. The life expectancy of apoE-/-Polk-/- mice maintained on a high cholesterol diet was reduced compared to apoE-/-Polk+/+ mice. Overall, this study demonstrates a role for Polκ in bypass of cholesterol-induced guanine lesions.
Collapse
Affiliation(s)
- William D Singer
- Department of Pathology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-9072, United States
| | | | | |
Collapse
|
47
|
Bétous R, Pillaire MJ, Pierini L, van der Laan S, Recolin B, Ohl-Séguy E, Guo C, Niimi N, Grúz P, Nohmi T, Friedberg E, Cazaux C, Maiorano D, Hoffmann JS. DNA polymerase κ-dependent DNA synthesis at stalled replication forks is important for CHK1 activation. EMBO J 2013; 32:2172-85. [PMID: 23799366 PMCID: PMC3730229 DOI: 10.1038/emboj.2013.148] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 06/04/2013] [Indexed: 02/04/2023] Open
Abstract
Formation of primed single-stranded DNA at stalled replication forks triggers activation of the replication checkpoint signalling cascade resulting in the ATR-mediated phosphorylation of the Chk1 protein kinase, thus preventing genomic instability. By using siRNA-mediated depletion in human cells and immunodepletion and reconstitution experiments in Xenopus egg extracts, we report that the Y-family translesion (TLS) DNA polymerase kappa (Pol κ) contributes to the replication checkpoint response and is required for recovery after replication stress. We found that Pol κ is implicated in the synthesis of short DNA intermediates at stalled forks, facilitating the recruitment of the 9-1-1 checkpoint clamp. Furthermore, we show that Pol κ interacts with the Rad9 subunit of the 9-1-1 complex. Finally, we show that this novel checkpoint function of Pol κ is required for the maintenance of genomic stability and cell proliferation in unstressed human cells. A vertebrate translesion synthesis DNA polymerase broadly contributes to checkpoint-activating primer synthesis at stalled replication forks, a role previously ascribed only to replicative polymerases.
Collapse
Affiliation(s)
- Rémy Bétous
- Equipe Labellisée La Ligue Contre le Cancer 2013, INSERM UMR 1037, CNRS ERL 505294, CRCT (Cancer Research Center of Toulouse), Toulouse, France
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Mouse DNA polymerase kappa has a functional role in the repair of DNA strand breaks. DNA Repair (Amst) 2013; 12:377-88. [PMID: 23522793 DOI: 10.1016/j.dnarep.2013.02.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 01/20/2013] [Accepted: 02/26/2013] [Indexed: 01/22/2023]
Abstract
The Y-family of DNA polymerases support of translesion DNA synthesis (TLS) associated with stalled DNA replication by DNA damage. Recently, a number of studies suggest that some specialized TLS polymerases also support other aspects of DNA metabolism beyond TLS in vivo. Here we show that mouse polymerase kappa (Polκ) could accumulate at laser-induced sites of damage in vivo resembling polymerases eta and iota. The recruitment was mediated through Polκ C-terminus which contains the PCNA-interacting peptide, ubiquitin zinc finger motif 2 and nuclear localization signal. Interestingly, this recruitment was significantly reduced in MSH2-deficient LoVo cells and Rad18-depleted cells. We further observed that Polκ-deficient mouse embryo fibroblasts were abnormally sensitive to H2O2 treatment and displayed defects in both single-strand break repair and double-strand break repair. We speculate that Polκ may have an important role in strand break repair following oxidative stress in vivo.
Collapse
|
49
|
Yang Y, Durando M, Smith-Roe SL, Sproul C, Greenwalt AM, Kaufmann W, Oh S, Hendrickson EA, Vaziri C. Cell cycle stage-specific roles of Rad18 in tolerance and repair of oxidative DNA damage. Nucleic Acids Res 2013; 41:2296-312. [PMID: 23295675 PMCID: PMC3575850 DOI: 10.1093/nar/gks1325] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The E3 ubiquitin ligase Rad18 mediates tolerance of replication fork-stalling bulky DNA lesions, but whether Rad18 mediates tolerance of bulky DNA lesions acquired outside S-phase is unclear. Using synchronized cultures of primary human cells, we defined cell cycle stage-specific contributions of Rad18 to genome maintenance in response to ultraviolet C (UVC) and H(2)O(2)-induced DNA damage. UVC and H(2)O(2) treatments both induced Rad18-mediated proliferating cell nuclear antigen mono-ubiquitination during G(0), G(1) and S-phase. Rad18 was important for repressing H(2)O(2)-induced (but not ultraviolet-induced) double strand break (DSB) accumulation and ATM S1981 phosphorylation only during G(1), indicating a specific role for Rad18 in processing of oxidative DNA lesions outside S-phase. However, H(2)O(2)-induced DSB formation in Rad18-depleted G1 cells was not associated with increased genotoxin sensitivity, indicating that back-up DSB repair mechanisms compensate for Rad18 deficiency. Indeed, in DNA LigIV-deficient cells Rad18-depletion conferred H(2)O(2)-sensitivity, demonstrating functional redundancy between Rad18 and non-homologous end joining for tolerance of oxidative DNA damage acquired during G(1). In contrast with G(1)-synchronized cultures, S-phase cells were H(2)O(2)-sensitive following Rad18-depletion. We conclude that although Rad18 pathway activation by oxidative lesions is not restricted to S-phase, Rad18-mediated trans-lesion synthesis by Polη is dispensable for damage-tolerance in G(1) (because of back-up non-homologous end joining-mediated DSB repair), yet Rad18 is necessary for damage tolerance during S-phase.
Collapse
Affiliation(s)
- Yang Yang
- Department of Pathology and Laboratory Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Menezes MR, Sweasy JB. Mouse models of DNA polymerases. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2012; 53:645-665. [PMID: 23001998 DOI: 10.1002/em.21731] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Revised: 08/01/2012] [Accepted: 08/07/2012] [Indexed: 06/01/2023]
Abstract
In 1956, Arthur Kornberg discovered the mechanism of the biological synthesis of DNA and was awarded the Nobel Prize in Physiology or Medicine in 1959 for this contribution, which included the isolation and characterization of Escherichia coli DNA polymerase I. Now there are 15 known DNA polymerases in mammalian cells that belong to four different families. These DNA polymerases function in many different cellular processes including DNA replication, DNA repair, and damage tolerance. Several biochemical and cell biological studies have provoked a further investigation of DNA polymerase function using mouse models in which polymerase genes have been altered using gene-targeting techniques. The phenotypes of mice harboring mutant alleles reveal the prominent role of DNA polymerases in embryogenesis, prevention of premature aging, and cancer suppression.
Collapse
Affiliation(s)
- Miriam R Menezes
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT, USA
| | | |
Collapse
|