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Gutierrez R, Chan AY, Tsuen Lai SW, Itoh S, Lee DH, Sun K, Battad A, Chen S, O'Connor TR, Shuck SC. Lack of mismatch repair enhances resistance to methylating agents for cells deficient in oxidative demethylation. J Biol Chem 2024:107492. [PMID: 38925328 DOI: 10.1016/j.jbc.2024.107492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 05/21/2024] [Accepted: 05/31/2024] [Indexed: 06/28/2024] Open
Abstract
The human AlkB homologs, ALKBH2 and ALKBH3, respond to methylation damage to maintain genomic integrity and cellular viability. Both ALKBH2 and ALKBH3 are direct reversal repair (DRR) enzymes that remove 1meA and 3meC lesions commonly generated by alkylating chemotherapeutic agents. Thus, the existence of deficiencies in ALKBH proteins can be exploited in synergy with chemotherapy. In this study, we investigated possible interactions between ALKBH2 and ALKBH3 with other proteins that could alter damage response and discovered an interaction with the mismatch repair (MMR) system. To test whether the lack of active MMR impacts ALKBH2 and/or ALKBH3 response to methylating agents, we generated cells deficient in ALKBH2, ALKBH3, or both in addition to Mlh homolog 1 (MLH1), another MMR protein. We found that MLH1koALKBH3ko cells showed enhanced resistance towards SN1- and SN2-type methylating agents, whereas MLH1koALKBH2ko cells were only resistant to SN1-type methylating agents. Concomitant loss of ALKBH2 and ALKBH3 (ALKBH2ko3ko) rendered cells sensitive to SN1- and SN2-agents, but the additional loss of MLH1 enhanced resistance to both types of damage. We also showed that ALKBH2ko3ko cells have an ATR-dependent arrest at the G2/M checkpoint, increased apoptotic signalling, and replication fork stress in response to methylation. However, these responses were not observed with the loss of functional MLH1 in MLH1koALKBH2ko3ko cells. Finally, in MLH1koALKBH2ko3ko cells, we observed elevated mutant frequency in untreated and temozolomide treated cells. These results suggest that obtaining a more accurate prognosis of chemotherapeutic outcome requires information on the functionality of ALKBH2, ALKBH3, and MLH1.
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Affiliation(s)
- Roberto Gutierrez
- Department of Cancer Biology, Irell & Manella Graduate School of Biological Sciences, Beckman Research Institute at the City of Hope, Duarte California, 91010 United States of America
| | - Annie Yin Chan
- Department of Cancer Biology, Irell & Manella Graduate School of Biological Sciences, Beckman Research Institute at the City of Hope, Duarte California, 91010 United States of America
| | - Seigmund Wai Tsuen Lai
- Department of Diabetes and Cancer Metabolism, Beckman Research Institute at the City of Hope, Duarte California, 91010 United States of America
| | - Shunsuke Itoh
- Department of Cancer Biology, Irell & Manella Graduate School of Biological Sciences, Beckman Research Institute at the City of Hope, Duarte California, 91010 United States of America
| | - Dong-Hyun Lee
- Department of Biological Sciences, College of Natural Sciences, Chonnam National University, Gwangju 61186 South Korea
| | - Kelani Sun
- Department of Diabetes and Cancer Metabolism, Beckman Research Institute at the City of Hope, Duarte California, 91010 United States of America
| | - Alana Battad
- Department of Diabetes and Cancer Metabolism, Beckman Research Institute at the City of Hope, Duarte California, 91010 United States of America
| | - Shiuan Chen
- Department of Cancer Biology, Irell & Manella Graduate School of Biological Sciences, Beckman Research Institute at the City of Hope, Duarte California, 91010 United States of America
| | - Timothy R O'Connor
- Department of Cancer Biology, Irell & Manella Graduate School of Biological Sciences, Beckman Research Institute at the City of Hope, Duarte California, 91010 United States of America.
| | - Sarah C Shuck
- Department of Diabetes and Cancer Metabolism, Beckman Research Institute at the City of Hope, Duarte California, 91010 United States of America.
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Mustafa M, Habib S, Imtiyaz K, Tufail N, Ahmad R, Hamim B, Abbas K, Ahmad W, Khan S, Moinuddin, Rizvi MMA, Hassan MI, Siddiqui SA. Characterization of structural, genotoxic, and immunological effects of methyl methanesulfonate (MMS) induced DNA modifications: Implications for inflammation-driven carcinogenesis. Int J Biol Macromol 2024; 268:131743. [PMID: 38653426 DOI: 10.1016/j.ijbiomac.2024.131743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 02/13/2024] [Accepted: 04/19/2024] [Indexed: 04/25/2024]
Abstract
Genotoxic DNA damaging agents are the choice of chemicals for studying DNA repair pathways and the associated genome instability. One such preferred laboratory chemical is methyl methanesulfonate (MMS). MMS, an SN2-type alkylating agent known for its ability to alkylate adenine and guanine bases, causes strand breakage. Exploring the outcomes of MMS interaction with DNA and the associated cytotoxicity will pave the way to decipher how the cell confronts methylation-associated stress. This study focuses on an in-depth understanding of the structural instability, induced antigenicity on the DNA molecule, cross-reactive anti-DNA antibodies, and cytotoxic potential of MMS in peripheral lymphocytes and cancer cell lines. The findings are decisive in identifying the hazardous nature of MMS to alter the intricacies of DNA and morphology of the cell. Structural alterations were assessed through UV-Vis, fluorescence, liquid chromatography, and mass spectroscopy (LCMS). The thermal instability of DNA was analyzed using duplex melting temperature profiles. Scanning and transmission electron microscopy revealed gross topographical and morphological changes. MMS-modified DNA exhibited increased antigenicity in animal subjects. MMS was quite toxic for the cancer cell lines (HCT116, A549, and HeLa). This research will offer insights into the potential role of MMS in inflammatory carcinogenesis and its progression.
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Affiliation(s)
- Mohd Mustafa
- Department of Biochemistry, J.N. Medical College, Faculty of Medicine, Aligarh Muslim University, Aligarh, India
| | - Safia Habib
- Department of Biochemistry, J.N. Medical College, Faculty of Medicine, Aligarh Muslim University, Aligarh, India.
| | - Khalid Imtiyaz
- Genome Biology Lab, Department of Biosciences, Jamia Millia Islamia, New Delhi, India
| | - Neda Tufail
- Department of Biochemistry, J.N. Medical College, Faculty of Medicine, Aligarh Muslim University, Aligarh, India
| | - Rizwan Ahmad
- Department of Biochemistry, J.N. Medical College, Faculty of Medicine, Aligarh Muslim University, Aligarh, India
| | - Bazigha Hamim
- Department of Biochemistry, J.N. Medical College, Faculty of Medicine, Aligarh Muslim University, Aligarh, India
| | - Kashif Abbas
- Department of Zoology, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, India
| | - Waleem Ahmad
- Department of Medicine, J.N. Medical College, Faculty of Medicine, Aligarh Muslim University, Aligarh, India
| | - Shifa Khan
- Department of Biochemistry, J.N. Medical College, Faculty of Medicine, Aligarh Muslim University, Aligarh, India
| | - Moinuddin
- Department of Biochemistry, J.N. Medical College, Faculty of Medicine, Aligarh Muslim University, Aligarh, India
| | - M Moshahid A Rizvi
- Genome Biology Lab, Department of Biosciences, Jamia Millia Islamia, New Delhi, India
| | - Md Imtaiyaz Hassan
- Center for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi, India
| | - Shahid Ali Siddiqui
- Department of Radiation, Mahatma Gandhi Medical College and Hospital, Rajasthan, India
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3
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Abdelhady R, Senthong P, Eyers CE, Reamtong O, Cowley E, Cannizzaro L, Stimpson J, Cain K, Wilkinson OJ, Williams NH, Barran PE, Margison GP, Williams DM, Povey AC. Mass Spectrometric Analysis of the Active Site Tryptic Peptide of Recombinant O6-Methylguanine-DNA Methyltransferase Following Incubation with Human Colorectal DNA Reveals the Presence of an O6-Alkylguanine Adductome. Chem Res Toxicol 2023; 36:1921-1929. [PMID: 37983188 PMCID: PMC10731659 DOI: 10.1021/acs.chemrestox.3c00207] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 10/31/2023] [Accepted: 11/01/2023] [Indexed: 11/22/2023]
Abstract
Human exposure to DNA alkylating agents is poorly characterized, partly because only a limited range of specific alkyl DNA adducts have been quantified. The human DNA repair protein, O6-methylguanine O6-methyltransferase (MGMT), irreversibly transfers the alkyl group from DNA O6-alkylguanines (O6-alkGs) to an acceptor cysteine, allowing the simultaneous detection of multiple O6-alkG modifications in DNA by mass spectrometric analysis of the MGMT active site peptide (ASP). Recombinant MGMT was incubated with oligodeoxyribonucleotides (ODNs) containing different O6-alkGs, Temozolomide-methylated calf thymus DNA (Me-CT-DNA), or human colorectal DNA of known O6-MethylG (O6-MeG) levels. It was digested with trypsin, and ASPs were detected and quantified by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry. ASPs containing S-methyl, S-ethyl, S-propyl, S-hydroxyethyl, S-carboxymethyl, S-benzyl, and S-pyridyloxobutyl cysteine groups were detected by incubating MGMT with ODNs containing the corresponding O6-alkGs. The LOQ of ASPs containing S-methylcysteine detected after MGMT incubation with Me-CT-DNA was <0.05 pmol O6-MeG per mg CT-DNA. Incubation of MGMT with human colorectal DNA produced ASPs containing S-methylcysteine at levels that correlated with those of O6-MeG determined previously by HPLC-radioimmunoassay (r2 = 0.74; p = 0.014). O6-CMG, a putative O6-hydroxyethylG adduct, and other potential unidentified MGMT substrates were also detected in human DNA samples. This novel approach to the identification and quantitation of O6-alkGs in human DNA has revealed the existence of a human DNA alkyl adductome that remains to be fully characterized. The methodology establishes a platform for characterizing the human DNA O6-alkG adductome and, given the mutagenic potential of O6-alkGs, can provide mechanistic information about cancer pathogenesis.
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Affiliation(s)
- Rasha Abdelhady
- Epidemiology
and Public Health Group, Division of Population Health, Health Services
Research and Primary Care, School of Health Sciences, Faculty of Biology,
Medicine and Health, University of Manchester, Manchester M13 9PL, U.K.
| | - Pattama Senthong
- Epidemiology
and Public Health Group, Division of Population Health, Health Services
Research and Primary Care, School of Health Sciences, Faculty of Biology,
Medicine and Health, University of Manchester, Manchester M13 9PL, U.K.
| | - Claire E. Eyers
- Department
of Chemistry and Manchester Institute of Biotechnology, University of Manchester, Manchester M1 7DN, U.K.
| | - Onrapak Reamtong
- Department
of Chemistry and Manchester Institute of Biotechnology, University of Manchester, Manchester M1 7DN, U.K.
| | - Elizabeth Cowley
- Epidemiology
and Public Health Group, Division of Population Health, Health Services
Research and Primary Care, School of Health Sciences, Faculty of Biology,
Medicine and Health, University of Manchester, Manchester M13 9PL, U.K.
| | - Luca Cannizzaro
- Department
of Chemistry and Manchester Institute of Biotechnology, University of Manchester, Manchester M1 7DN, U.K.
| | - Joanna Stimpson
- Department
of Chemistry and Manchester Institute of Biotechnology, University of Manchester, Manchester M1 7DN, U.K.
| | - Kathleen Cain
- Department
of Chemistry and Manchester Institute of Biotechnology, University of Manchester, Manchester M1 7DN, U.K.
| | - Oliver J. Wilkinson
- Centre
for Chemical Biology, Department of Chemistry, Sheffield Institute
for Nucleic Acids, University of Sheffield, Sheffield S3 7HF, U.K.
| | - Nicholas H. Williams
- Centre
for Chemical Biology, Department of Chemistry, Sheffield Institute
for Nucleic Acids, University of Sheffield, Sheffield S3 7HF, U.K.
| | - Perdita E. Barran
- Department
of Chemistry and Manchester Institute of Biotechnology, University of Manchester, Manchester M1 7DN, U.K.
| | - Geoffrey P. Margison
- Epidemiology
and Public Health Group, Division of Population Health, Health Services
Research and Primary Care, School of Health Sciences, Faculty of Biology,
Medicine and Health, University of Manchester, Manchester M13 9PL, U.K.
| | - David M. Williams
- Centre
for Chemical Biology, Department of Chemistry, Sheffield Institute
for Nucleic Acids, University of Sheffield, Sheffield S3 7HF, U.K.
| | - Andrew C. Povey
- Epidemiology
and Public Health Group, Division of Population Health, Health Services
Research and Primary Care, School of Health Sciences, Faculty of Biology,
Medicine and Health, University of Manchester, Manchester M13 9PL, U.K.
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Saisorn W, Phuengmaung P, Issara-Amphorn J, Makjaroen J, Visitchanakun P, Sae-Khow K, Boonmee A, Benjaskulluecha S, Nita-Lazar A, Palaga T, Leelahavanichkul A. Less Severe Lipopolysaccharide-Induced Inflammation in Conditional mgmt-Deleted Mice with LysM-Cre System: The Loss of DNA Repair in Macrophages. Int J Mol Sci 2023; 24:10139. [PMID: 37373287 DOI: 10.3390/ijms241210139] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 05/28/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023] Open
Abstract
Despite the known influence of DNA methylation from lipopolysaccharide (LPS) activation, data on the O6-methylguanine-DNA methyltransferase (MGMT, a DNA suicide repair enzyme) in macrophages is still lacking. The transcriptomic profiling of epigenetic enzymes from wild-type macrophages after single and double LPS stimulation, representing acute inflammation and LPS tolerance, respectively, was performed. Small interfering RNA (siRNA) silencing of mgmt in the macrophage cell line (RAW264.7) and mgmt null (mgmtflox/flox; LysM-Crecre/-) macrophages demonstrated lower secretion of TNF-α and IL-6 and lower expression of pro-inflammatory genes (iNOS and IL-1β) compared with the control. Macrophage injury after a single LPS dose and LPS tolerance was demonstrated by reduced cell viability and increased oxidative stress (dihydroethidium) compared with the activated macrophages from littermate control mice (mgmtflox/flox; LysM-Cre-/-). Additionally, a single LPS dose and LPS tolerance also caused mitochondrial toxicity, as indicated by reduced maximal respiratory capacity (extracellular flux analysis) in the macrophages of both mgmt null and control mice. However, LPS upregulated mgmt only in LPS-tolerant macrophages but not after the single LPS stimulation. In mice, the mgmt null group demonstrated lower serum TNF-α, IL-6, and IL-10 than control mice after either single or double LPS stimulation. Suppressed cytokine production resulting from an absence of mgmt in macrophages caused less severe LPS-induced inflammation but might worsen LPS tolerance.
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Affiliation(s)
- Wilasinee Saisorn
- Interdisciplinary Program of Biomedical Sciences, Graduate School, Chulalongkorn University, Bangkok 10330, Thailand
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
- Center of Excellence in Translational Research in Inflammation and Immunology (CETRII), Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
| | - Pornpimol Phuengmaung
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
- Center of Excellence in Translational Research in Inflammation and Immunology (CETRII), Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
| | - Jiraphorn Issara-Amphorn
- Functional Cellular Networks Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases NIH, Bethesda, MD 20892-1892, USA
| | - Jiradej Makjaroen
- Center of Excellence in Systems Biology, Research Affairs, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
| | - Peerapat Visitchanakun
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
- Center of Excellence in Translational Research in Inflammation and Immunology (CETRII), Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
| | - Kritsanawan Sae-Khow
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
- Center of Excellence in Translational Research in Inflammation and Immunology (CETRII), Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
| | - Atsadang Boonmee
- Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Salisa Benjaskulluecha
- Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Aleksandra Nita-Lazar
- Functional Cellular Networks Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases NIH, Bethesda, MD 20892-1892, USA
| | - Tanapat Palaga
- Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Asada Leelahavanichkul
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
- Center of Excellence in Translational Research in Inflammation and Immunology (CETRII), Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
- Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
- Division of Nephrology, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
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5
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Tufail M. DNA repair pathways in breast cancer: from mechanisms to clinical applications. Breast Cancer Res Treat 2023:10.1007/s10549-023-06995-z. [PMID: 37289340 DOI: 10.1007/s10549-023-06995-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 05/25/2023] [Indexed: 06/09/2023]
Abstract
BACKGROUND Breast cancer (BC) is a complex disease with various subtypes and genetic alterations that impact DNA repair pathways. Understanding these pathways is essential for developing effective treatments and improving patient outcomes. AREA COVERED This study investigates the significance of DNA repair pathways in breast cancer, specifically focusing on various pathways such as nucleotide excision repair, base excision repair, mismatch repair, homologous recombination repair, non-homologous end joining, fanconi anemia pathway, translesion synthesis, direct repair, and DNA damage tolerance. The study also examines the role of these pathways in breast cancer resistance and explores their potential as targets for cancer treatment. CONCLUSION Recent advances in targeted therapies have shown promise in exploiting DNA repair pathways for BC treatment. However, much research is needed to improve the efficacy of these therapies and identify new targets. Additionally, personalized treatments that target specific DNA repair pathways based on tumor subtype or genetic profile are being developed. Advances in genomics and imaging technologies can potentially improve patient stratification and identify biomarkers of treatment response. However, many challenges remain, including toxicity, resistance, and the need for more personalized treatments. Continued research and development in this field could significantly improve BC treatment.
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Affiliation(s)
- Muhammad Tufail
- Institute of Biomedical Sciences, Shanxi University, Taiyuan, 030006, China.
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6
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Blum K, FitzGerald R, Wilks MF, Barle EL, Hopf NB. Use of the benchmark-dose (BMD) approach to derive occupational exposure limits (OELs) for genotoxic carcinogens: N-nitrosamines. J Appl Toxicol 2023. [PMID: 36840679 DOI: 10.1002/jat.4455] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 01/29/2023] [Accepted: 02/21/2023] [Indexed: 02/26/2023]
Abstract
N-Nitrosamines are potent carcinogens and considered non-threshold carcinogens in various regulatory domains. However, recent data indicate the existence of a threshold for genotoxicity, which can be adequately demonstrated. This aspect has a critical impact on selecting the methodology that is applied to derive occupational exposure limits (OELs). OELs are used to protect workers potentially exposed to various chemicals by supporting the selection of appropriate control measures and ultimately reducing the risk of occupational cancer. Occupational exposures to nitrosamines occur during manufacturing processes, mainly in the rubber and chemical industry. The present study derives OELs for inhaled N-nitrosamines, employing the benchmark dose (BMD) approach if data are adequate and read-across for nitrosamines without adequate data. Additionally, benchmark dose lower confidence limit (BMDL) is preferred and more suitable point-of-departure (PoD) to calculate human health guidance values, including OEL. The lowest OEL (0.2 μg/m3 ) was derived for nitrosodiethylamine (NDEA), and nitrosopiperidine (NPIP) (OEL = 0.2 μg/m3 ), followed by nitrosopyrrolidine (NPYR) (0.4 μg/m3 ), nitrosodimethylamine (NDMA), nitrosodimethylamine (NMEA), and nitrosodipropylamine (NDPA) (0.5 μg/m3 ), nitrosomorpholine (NMOR) (OEL = 1 μg/m3 ), and nitrosodibutylamine (NDBA) (OEL = 2.5 μg/m3 ). Limits based on "non-threshold" TD50 slope calculation were within a 10-fold range. These proposed OELs do not consider skin absorption of nitrosamines, which is also a possible route of entry into the body, nor oral or other environmental sources. Furthermore, we recommend setting a limit for total nitrosamines based on the occupational exposure scenario and potency of components.
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Affiliation(s)
- Kamila Blum
- Environment, Health & Safety Department, GlaxoSmithKline, Munich, Germany.,Faculty of Science and Medicine, University of Geneva, Switzerland
| | - Rex FitzGerald
- Swiss Centre for Applied Human Toxicology (SCAHT) & Department of Pharmaceutical Sciences, University of Basel, Switzerland
| | - Martin F Wilks
- Swiss Centre for Applied Human Toxicology (SCAHT) & Department of Pharmaceutical Sciences, University of Basel, Switzerland
| | | | - Nancy B Hopf
- Swiss Centre for Applied Human Toxicology (SCAHT) & Department of Pharmaceutical Sciences, University of Basel, Switzerland.,Department for Occupational and Environmental Health, Centre for Primary Care and Public Health (Unisanté), University of Lausanne, Lausanne, Switzerland
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7
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Li X, Cao G, Liu X, Tang TS, Guo C, Liu H. Polymerases and DNA Repair in Neurons: Implications in Neuronal Survival and Neurodegenerative Diseases. Front Cell Neurosci 2022; 16:852002. [PMID: 35846567 PMCID: PMC9279898 DOI: 10.3389/fncel.2022.852002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 05/23/2022] [Indexed: 12/22/2022] Open
Abstract
Most of the neurodegenerative diseases and aging are associated with reactive oxygen species (ROS) or other intracellular damaging agents that challenge the genome integrity of the neurons. As most of the mature neurons stay in G0/G1 phase, replication-uncoupled DNA repair pathways including BER, NER, SSBR, and NHEJ, are pivotal, efficient, and economic mechanisms to maintain genomic stability without reactivating cell cycle. In these progresses, polymerases are prominent, not only because they are responsible for both sensing and repairing damages, but also for their more diversified roles depending on the cell cycle phase and damage types. In this review, we summarized recent knowledge on the structural and biochemical properties of distinct polymerases, including DNA and RNA polymerases, which are known to be expressed and active in nervous system; the biological relevance of these polymerases and their interactors with neuronal degeneration would be most graphically illustrated by the neurological abnormalities observed in patients with hereditary diseases associated with defects in DNA repair; furthermore, the vicious cycle of the trinucleotide repeat (TNR) and impaired DNA repair pathway is also discussed. Unraveling the mechanisms and contextual basis of the role of the polymerases in DNA damage response and repair will promote our understanding about how long-lived postmitotic cells cope with DNA lesions, and why disrupted DNA repair contributes to disease origin, despite the diversity of mutations in genes. This knowledge may lead to new insight into the development of targeted intervention for neurodegenerative diseases.
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Affiliation(s)
- Xiaoling Li
- Nano-Biotechnology Key Lab of Hebei Province, Yanshan University, Qinhuangdao, China
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, China
- Xiaoling Li
| | - Guanghui Cao
- Nano-Biotechnology Key Lab of Hebei Province, Yanshan University, Qinhuangdao, China
| | - Xiaokang Liu
- Nano-Biotechnology Key Lab of Hebei Province, Yanshan University, Qinhuangdao, China
| | - Tie-Shan Tang
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China
| | - Caixia Guo
- Beijing Institute of Genomics, University of Chinese Academy of Sciences, Chinese Academy of Sciences/China National Center for Bioinformation, Beijing, China
- *Correspondence: Caixia Guo
| | - Hongmei Liu
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China
- Hongmei Liu
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8
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Savvateeva M, Kudryavtseva A, Lukyanova E, Kobelyatskaya A, Pavlov V, Fedorova M, Pudova E, Guvatova Z, Kalinin D, Golovyuk A, Bulavkina E, Katunina I, Krasnov G, Snezhkina A. Somatic Mutation Profiling in Head and Neck Paragangliomas. J Clin Endocrinol Metab 2022; 107:1833-1842. [PMID: 35460558 PMCID: PMC9202733 DOI: 10.1210/clinem/dgac250] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Indexed: 11/19/2022]
Abstract
CONTEXT Head and neck paragangliomas (HNPGLs) are rare neoplasms with a high degree of heritability. Paragangliomas present as polygenic diseases caused by combined alterations in multiple genes; however, many driver changes remain unknown. OBJECTIVE The objective of the study was to analyze somatic mutation profiles in HNPGLs. METHODS Whole-exome sequencing of 42 tumors and matched normal tissues obtained from Russian patients with HNPGLs was carried out. Somatic mutation profiling included variant calling and utilizing MutSig and SigProfiler packages. RESULTS 57% of patients harbored germline and somatic variants in paraganglioma (PGL) susceptibility genes or potentially related genes. Somatic variants in novel genes were found in 17% of patients without mutations in any known PGL-related genes. The studied cohort was characterized by 6 significantly mutated genes: SDHD, BCAS4, SLC25A14, RBM3, TP53, and ASCC1, as well as 4 COSMIC single base substitutions (SBS)-96 mutational signatures (SBS5, SBS29, SBS1, and SBS7b). Tumors with germline variants specifically displayed SBS11 and SBS19, when an SBS33-specific mutational signature was identified for cases without those. Beta allele frequency analysis of copy number variations revealed loss of heterozygosity of the wild-type allele in 1 patient with germline mutation c.287-2A>G in the SDHB gene. In patients with germline mutation c.A305G in the SDHD gene, frequent potential loss of chromosome 11 was observed. CONCLUSION These results give an understanding of somatic changes and the mutational landscape associated with HNPGLs and are important for the identification of molecular mechanisms involved in tumor development.
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Affiliation(s)
- Maria Savvateeva
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Anna Kudryavtseva
- Anna Kudryavtseva, P.I., Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia.
| | - Elena Lukyanova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | | | - Vladislav Pavlov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Maria Fedorova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Elena Pudova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Zulfiya Guvatova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Dmitry Kalinin
- Vishnevsky Institute of Surgery, Ministry of Health of the Russian Federation, 117997 Moscow, Russia
| | - Alexander Golovyuk
- Vishnevsky Institute of Surgery, Ministry of Health of the Russian Federation, 117997 Moscow, Russia
| | - Elizaveta Bulavkina
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Irina Katunina
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | - George Krasnov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Anastasiya Snezhkina
- Correspondence: Anastasiya Snezhkina, PhD, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia.
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9
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de Alencar MVOB, Islam MT, dos Reis AC, de Oliveira Santos JV, Nunes AMV, da Silva FCC, da Conceição Machado K, de Castro e Sousa JM, Reiner Ž, Martorell M, Fagoonee S, Sharifi-Rad J, de Carvalho Melo-Cavalcante AA. Oxidative stress mediated cytogenotoxicological effects of phytol in wistar albino rats. ADVANCES IN TRADITIONAL MEDICINE 2022. [DOI: 10.1007/s13596-022-00628-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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10
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Tan YM, Barton HA, Boobis A, Brunner R, Clewell H, Cope R, Dawson J, Domoradzki J, Egeghy P, Gulati P, Ingle B, Kleinstreuer N, Lowe K, Lowit A, Mendez E, Miller D, Minucci J, Nguyen J, Paini A, Perron M, Phillips K, Qian H, Ramanarayanan T, Sewell F, Villanueva P, Wambaugh J, Embry M. Opportunities and challenges related to saturation of toxicokinetic processes: Implications for risk assessment. Regul Toxicol Pharmacol 2021; 127:105070. [PMID: 34718074 DOI: 10.1016/j.yrtph.2021.105070] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 10/18/2021] [Accepted: 10/25/2021] [Indexed: 02/08/2023]
Abstract
Top dose selection for repeated dose animal studies has generally focused on identification of apical endpoints, use of the limit dose, or determination of a maximum tolerated dose (MTD). The intent is to optimize the ability of toxicity tests performed in a small number of animals to detect effects for hazard identification. An alternative approach, the kinetically derived maximum dose (KMD), has been proposed as a mechanism to integrate toxicokinetic (TK) data into the dose selection process. The approach refers to the dose above which the systemic exposures depart from being proportional to external doses. This non-linear external-internal dose relationship arises from saturation or limitation of TK process(es), such as absorption or metabolism. The importance of TK information is widely acknowledged when assessing human health risks arising from exposures to environmental chemicals, as TK determines the amount of chemical at potential sites of toxicological responses. However, there have been differing opinions and interpretations within the scientific and regulatory communities related to the validity and application of the KMD concept. A multi-stakeholder working group, led by the Health and Environmental Sciences Institute (HESI), was formed to provide an opportunity for impacted stakeholders to address commonly raised scientific and technical issues related to this topic and, more specifically, a weight of evidence approach is recommended to inform design and dose selection for repeated dose animal studies. Commonly raised challenges related to the use of TK data for dose selection are discussed, recommendations are provided, and illustrative case examples are provided to address these challenges or refute misconceptions.
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Affiliation(s)
- Yu-Mei Tan
- U.S. Environmental Protection Agency, Office of Pesticide Programs, Durham, NC, USA
| | | | | | - Rachel Brunner
- U.S. Environmental Protection Agency, Office of Pesticide Programs, Durham, NC, USA
| | | | - Rhian Cope
- Australian Pesticides and Veterinary Medicines Authority, Sydney, NSW, Australia
| | - Jeffrey Dawson
- U.S. Environmental Protection Agency, Office of Chemical Safety and Pollution Prevention, Washington, DC, USA
| | | | - Peter Egeghy
- U.S. Environmental Protection Agency, Office of Research & Development, Durham, NC, USA
| | - Pankaj Gulati
- Australian Pesticides and Veterinary Medicines Authority, Sydney, NSW, Australia
| | - Brandall Ingle
- U.S. Environmental Protection Agency, Office of Pesticide Programs, Durham, NC, USA
| | - Nicole Kleinstreuer
- National Toxicology Program, Interagency Center for the Evaluation of Alternative Toxicological Methods, Research Triangle Park, NC, USA
| | - Kelly Lowe
- U.S. Environmental Protection Agency, Office of Pesticide Programs, Washington, DC, USA
| | - Anna Lowit
- U.S. Environmental Protection Agency, Office of Pesticide Programs, Washington, DC, USA
| | - Elizabeth Mendez
- U.S. Environmental Protection Agency, Office of Pesticide Programs, Washington, DC, USA
| | - David Miller
- U.S. Environmental Protection Agency, Office of Pesticide Programs, Washington, DC, USA
| | - Jeffrey Minucci
- U.S. Environmental Protection Agency, Office of Research & Development, Durham, NC, USA
| | - James Nguyen
- U.S. Environmental Protection Agency, Office of Pesticide Programs, Washington, DC, USA
| | - Alicia Paini
- European Commission, Joint Research Centre, Ispra, Italy
| | - Monique Perron
- U.S. Environmental Protection Agency, Office of Pesticide Programs, Washington, DC, USA
| | - Katherine Phillips
- U.S. Environmental Protection Agency, Office of Research & Development, Durham, NC, USA
| | - Hua Qian
- ExxonMobil Biomedical Sciences, Inc., Annandale, NJ, USA
| | | | - Fiona Sewell
- National Centre for the Replacement, Refinement, and Reduction of Animals in Research, London, UK
| | - Philip Villanueva
- U.S. Environmental Protection Agency, Office of Pesticide Programs, Washington, DC, USA
| | - John Wambaugh
- U.S. Environmental Protection Agency, Office of Research & Development, Durham, NC, USA
| | - Michelle Embry
- Health and Environmental Sciences Institute, Washington DC, USA.
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11
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Pinter E, Friedl C, Irnesberger A, Czerny T, Piwonka T, Peñarroya A, Tacker M, Riegel E. HepGentox: a novel promising HepG2 reportergene-assay for the detection of genotoxic substances in complex mixtures. PeerJ 2021; 9:e11883. [PMID: 34395098 PMCID: PMC8323594 DOI: 10.7717/peerj.11883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 07/09/2021] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND In risk assessment, genotoxicity is a key factor to determine the safety for the consumer. Most in vitro genotoxicity assays were developed for the assessment of pure substances. However, in recent years more attention has been given to complex mixtures, where usually low amounts of a substance are present. For high-throughput screening, a toxicologically sensitive assay should be used, covering a broad range of genotoxic substances and detecting them at low concentrations. HepG2 cells have been recommended as one of the prime candidates for genotoxicity testing, as they are p53 competent, less prone towards cytotoxic effects and tend to have some metabolic activity. METHODS A HepG2 liver cell line was characterized for its suitability for genotoxicity assessment. For this, a luciferase based reporter gene assay revolving around the p53 pathway was validated for the analysis of pure substances and of complex mixtures. Further, the cell's capability to detect genotoxins correctly with and without an exogenous metabolizing system, namely rat liver S9, was assessed. RESULTS The assay proved to have a high toxicological sensitivity (87.5%) and specificity (94%). Further, the endogenous metabolizing system of the HepG2 cells was able to detect some genotoxins, which are known to depend on an enzymatic system. When complex mixtures were added this did not lead to any adverse effects concerning the assays performance and cytotoxicity was not an issue. DISCUSSION The HepGentox proved to have a high toxicological sensitivity and specificity for the tested substances, with similar or even lower lowest effective concentration (LEC) values, compared to other regulatory mammalian assays. This combines some important aspects in one test system, while also being less time and material consuming and covering several genotoxicity endpoints. As the assay performs well with and without an exogenous metabolizing system, no animal liver fractions have to be used, which application is discussed controversially and is considered to be expensive and laborious in sample testing. Because of this, the HepGentox is suitable for a cost-efficient first screening approach to obtain important information with human cells for further approaches, with a relatively fast and easy method. Therefore, the HepGentox is a promising assay to detect genotoxic substances correctly in complex mixtures even at low concentrations, with the potential for a high throughput application. In a nutshell, as part of an in vitro bioassay test battery, this assay could provide valuable information for complex mixtures.
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Affiliation(s)
- Elisabeth Pinter
- Departement of Applied Life Sciences, University of Applied Sciences Vienna, FH Campus Wien, Vienna, Austria
| | - Christina Friedl
- Departement of Applied Life Sciences, University of Applied Sciences Vienna, FH Campus Wien, Vienna, Austria
| | - Alexandra Irnesberger
- Departement of Applied Life Sciences, University of Applied Sciences Vienna, FH Campus Wien, Vienna, Austria
| | - Thomas Czerny
- Departement of Applied Life Sciences, University of Applied Sciences Vienna, FH Campus Wien, Vienna, Austria
| | - Tina Piwonka
- Departement of Applied Life Sciences, University of Applied Sciences Vienna, FH Campus Wien, Vienna, Austria
| | - Alfonso Peñarroya
- Departement of Applied Life Sciences, University of Applied Sciences Vienna, FH Campus Wien, Vienna, Austria
| | - Manfred Tacker
- Departement of Applied Life Sciences, University of Applied Sciences Vienna, FH Campus Wien, Vienna, Austria
| | - Elisabeth Riegel
- Departement of Applied Life Sciences, University of Applied Sciences Vienna, FH Campus Wien, Vienna, Austria
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12
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Karre S, Kim SB, Kim BS, Khangura RS, Sermons SM, Dilkes B, Johal G, Balint-Kurti P. Maize Plants Chimeric for an Autoactive Resistance Gene Display a Cell-Autonomous Hypersensitive Response but Non-Cell Autonomous Defense Signaling. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2021; 34:606-616. [PMID: 33507801 DOI: 10.1094/mpmi-04-20-0091-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The maize gene Rp1-D21 is a mutant form of the gene Rp1-D that confers resistance to common rust. Rp1-D21 triggers a spontaneous defense response that occurs in the absence of the pathogen and includes a programed cell death called the hypersensitive response (HR). Eleven plants heterozygous for Rp1-D21, in four different genetic backgrounds, were identified that had chimeric leaves with lesioned sectors showing HR abutting green nonlesioned sectors lacking HR. The Rp1-D21 sequence derived from each of the lesioned portions of leaves was unaltered from the expected sequence whereas the Rp1-D21 sequences from nine of the nonlesioned sectors displayed various mutations, and we were unable to amplify Rp1-D21 from the other two nonlesioned sectors. In every case, the borders between the sectors were sharp, with no transition zone, suggesting that HR and chlorosis associated with Rp1-D21 activity was cell autonomous. Expression of defense response marker genes was assessed in the lesioned and nonlesioned sectors as well as in near-isogenic plants lacking and carrying Rp1-D21. Defense gene expression was somewhat elevated in nonlesioned sectors abutting sectors carrying Rp1-D21 compared with near-isogenic plants lacking Rp1-D21. This suggests that, whereas the HR itself was cell autonomous, other aspects of the defense response initiated by Rp1-D21 were not.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Shailesh Karre
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695-7613, U.S.A
| | - Saet-Byul Kim
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695-7613, U.S.A
| | - Bong-Suk Kim
- Botany and Plant Pathology, Purdue University, West Lafayette, IN, U.S.A
| | - Rajdeep S Khangura
- Department of Biochemistry, Purdue University, West Lafayette, IN, U.S.A
| | - Shannon M Sermons
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695-7613, U.S.A
- Plant Science Research Unit, United States Department of Agriculture-Agricultural Research Service, North Carolina State University, Raleigh, NC 27695-7613, U.S.A
| | - Brian Dilkes
- Department of Biochemistry, Purdue University, West Lafayette, IN, U.S.A
| | - Guri Johal
- Botany and Plant Pathology, Purdue University, West Lafayette, IN, U.S.A
| | - Peter Balint-Kurti
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695-7613, U.S.A
- Plant Science Research Unit, United States Department of Agriculture-Agricultural Research Service, North Carolina State University, Raleigh, NC 27695-7613, U.S.A
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13
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Chiara F, Indraccolo S, Trevisan A. Filling the gap between risk assessment and molecular determinants of tumor onset. Carcinogenesis 2020; 42:507-516. [PMID: 33319226 DOI: 10.1093/carcin/bgaa135] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 11/22/2020] [Accepted: 12/11/2020] [Indexed: 12/30/2022] Open
Abstract
In the past two decades, a ponderous epidemiological literature has causally linked tumor onset to environmental exposure to carcinogens. As consequence, risk assessment studies have been carried out with the aim to identify both predictive models of estimating cancer risks within exposed populations and establishing rules for minimizing hazard when handling carcinogenic compounds. The central assumption of these works is that neoplastic transformation is directly related to the mutational burden of the cell without providing further mechanistic clues to explain increased cancer onset after carcinogen exposure. Nevertheless, in the last few years, a growing number of studies have implemented the traditional models of cancer etiology, proposing that neoplastic transformation is a complex process in which several parameters and crosstalk between tumor and microenvironmental cells must be taken into account and integrated with mutagenesis. In this conceptual framework, the current strategies of risk assessment that are solely based on the 'mutator model' require an urgent update and revision to keep pace with advances in our understanding of cancer biology. We will approach this topic revising the most recent theories on the biological mechanisms involved in tumor formation in order to envision a roadmap leading to a future regulatory framework for a new, protective policy of risk assessment.
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Affiliation(s)
- Federica Chiara
- Department of Surgery, Oncology and Gastroenterology, University of Padova, Via Giustiniani, Padua, Italy
| | | | - Andrea Trevisan
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, Via Giustiniani, Padua, Italy
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14
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Overview of New Treatments with Immunotherapy for Breast Cancer and a Proposal of a Combination Therapy. Molecules 2020; 25:molecules25235686. [PMID: 33276556 DOI: 10.3390/molecules25235686] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 11/26/2020] [Accepted: 11/28/2020] [Indexed: 01/08/2023] Open
Abstract
According to data from the U.S. National Cancer Institute, cancer is one of the leading causes of death worldwide with approximately 14 million new cases and 8.2 million cancer-related deaths in 2018. More than 60% of the new annual cases in the world occur in Africa, Asia, Central America, and South America, with 70% of cancer deaths in these regions. Breast cancer is the most common cancer in women, with 266,120 new cases in American women and an estimated 40,920 deaths for 2018. Approximately one in six women diagnosed with breast cancer will die in the coming years. Recently, novel therapeutic strategies have been implemented in the fight against breast cancer, including molecules able to block signaling pathways, an inhibitor of poly [ADP-ribose] polymerase (PARP), growth receptor blocker antibodies, or those that reactivate the immune system by inhibiting the activities of inhibitory receptors like cytotoxic T-lymphocyte antigen 4 (CTLA-4) and programmed death protein 1 (PD-1). However, novel targets include reactivating the Th1 immune response, changing tumor microenvironment, and co-activation of other components of the immune response such as natural killer cells and CD8+ T cells among others. In this article, we review advances in the treatment of breast cancer focused essentially on immunomodulatory drugs in targeted cancer therapy. Based on this knowledge, we formulate a proposal for the implementation of combined therapy using an extracorporeal immune response reactivation model and cytokines plus modulating antibodies for co-activation of the Th1- and natural killer cell (NK)-dependent immune response, either in situ or through autologous cell therapy. The implementation of "combination immunotherapy" is new hope in breast cancer treatment. Therefore, we consider the coordinated activation of each cell of the immune response that would probably produce better outcomes. Although more research is required, the results recently achieved by combination therapy suggest that for most, if not all, cancer patients, this tailored therapy may become a realistic approach in the near future.
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15
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SATMF Suppresses the Premature Senescence Phenotype of the ATM Loss-of-Function Mutant and Improves Its Fertility in Arabidopsis. Int J Mol Sci 2020; 21:ijms21218120. [PMID: 33143308 PMCID: PMC7662627 DOI: 10.3390/ijms21218120] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 10/22/2020] [Accepted: 10/23/2020] [Indexed: 12/13/2022] Open
Abstract
Leaf senescence is the final stage of leaf development. It is accompanied by the remobilization of nutrients from senescent leaves to developing organs. The occurrence of senescence is the consequence of integrating intrinsic and environmental signals. DNA damage triggered by stresses has been regarded as one of the reasons for senescence. To prevent DNA damage, cells have evolved elaborate DNA repair machinery. The ataxia telangiectasia mutated (ATM) functions as the chief transducer of the double-strand breaks (DSBs) signal. Our previous study suggests that ATM functions in lifespan regulation in Arabidopsis. However, ATM regulatory mechanism on plant longevity remains unclear. Here, we performed chemical mutagenesis to identify the components involved in ATM-mediated longevity and obtained three dominant mutants satmf1~3, suppressor of atm in fertility, displaying delayed senescence and restored fertility in comparison with atm mutant. Molecular cloning and functional analysis of SATMF (suppressor of atm in fertility) will help to understand the underlying regulatory mechanism of ATM in plants, and shed light on developing new treatments for the disease Ataxia-telangiectasia.
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16
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Abstract
Cellular DNA is constantly chemically altered by exogenous and endogenous agents. As all processes of life depend on the transmission of the genetic information, multiple biological processes exist to ensure genome integrity. Chemically damaged DNA has been linked to cancer and aging, therefore it is of great interest to map DNA damage formation and repair to elucidate the distribution of damage on a genome-wide scale. While the low abundance and inability to enzymatically amplify DNA damage are obstacles to genome-wide sequencing, new developments in the last few years have enabled high-resolution mapping of damaged bases. Recently, a number of DNA damage sequencing library construction strategies coupled to new data analysis pipelines allowed the mapping of specific DNA damage formation and repair at high and single nucleotide resolution. Strikingly, these advancements revealed that the distribution of DNA damage is heavily influenced by chromatin states and the binding of transcription factors. In the last seven years, these novel approaches have revealed new genomic maps of DNA damage distribution in a variety of organisms as generated by diverse chemical and physical DNA insults; oxidative stress, chemotherapeutic drugs, environmental pollutants, and sun exposure. Preferred sequences for damage formation and repair have been elucidated, thus making it possible to identify persistent weak spots in the genome as locations predicted to be vulnerable for mutation. As such, sequencing DNA damage will have an immense impact on our ability to elucidate mechanisms of disease initiation, and to evaluate and predict the efficacy of chemotherapeutic drugs.
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Affiliation(s)
- Cécile Mingard
- Department of Health Sciences and Technology, ETH Zürich, Schmelzbergstrasse 9, 8092 Zürich, Switzerland.
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17
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Abstract
![]()
The cellular outcomes of chemical
exposure are as much about the
cellular response to the chemical as it is an effect of the chemical. We are growing in our understanding
of the genotoxic interaction between chemistry and biology. For example,
recent data has revealed the biological basis for mutation induction
curves for a methylating chemical, which has been shown to be dependent
on the repair capacity of the cells. However, this is just one end
point in the toxicity pathway from chemical exposure to cell death.
Much remains to be known in order for us to predict how cells will
respond to a certain dose. Methylating agents, a subset of alkylating
agents, are of particular interest, because of the variety of adverse
genetic end points that can result, not only at increasing doses,
but also over time. For instance, methylating agents are mutagenic,
their potency, for this end point, is determined by the cellular repair
capacity of an enzyme called methylguanine DNA-methyltransferase (MGMT)
and its ability to repair the induceed methyl adducts. However, methyl
adducts can become clastogenic. Erroneous biological processing will
convert mutagenic adducts to clastogenic events in the form of double
strand breaks (DSBs). How the cell responds to DSBs is via a cascade
of protein kinases, which is called the DNA damage response (DDR),
which will determine if the damage is repaired effectively, via homologous
recombination, or with errors, via nonhomologous end joining, or whether
the cell dies via apoptosis or enters senescence. The fate of cells
may be determined by the extent of damage and the resulting strength
of DDR signaling. Therefore, thresholds of damage may exist that determine
cell fate. Such thresholds would be dependent on each of the repair
and response mechanisms that these methyl adducts stimulate. The molecular
mechanism of how methyl adducts kill cells is still to be fully resolved.
If we are able to quantify each of these thresholds of damage for
a given cell, then we can ascertain, of the many adducts that are
induced, what proportion of them are mutagenic, what proportion are
clastogenic, and how many of these clastogenic events are toxic. This
review examines the possibility of dose and damage thresholds for
methylating agents, from the perspective of the underlying evolutionary
mechanisms that may be accountable.
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Affiliation(s)
- Adam D Thomas
- Centre for Research in Biosciences, University of the West of England, Frenchay Campus, Bristol BS16 1QY, United Kingdom
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18
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Gooderham NJ, Cohen SM, Eisenbrand G, Fukushima S, Guengerich FP, Hecht SS, Rietjens IMCM, Rosol TJ, Bastaki M, Linman MJ, Taylor SV. The safety evaluation of food flavoring substances: the role of genotoxicity studies. Crit Rev Toxicol 2020; 50:1-27. [PMID: 32162576 DOI: 10.1080/10408444.2020.1712589] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The Flavor and Extract Manufacturers Association (FEMA) Expert Panel relies on the weight of evidence from all available data in the safety evaluation of flavoring substances. This process includes data from genotoxicity studies designed to assess the potential of a chemical agent to react with DNA or otherwise cause changes to DNA, either in vitro or in vivo. The Panel has reviewed a large number of in vitro and in vivo genotoxicity studies during the course of its ongoing safety evaluations of flavorings. The adherence of genotoxicity studies to standardized protocols and guidelines, the biological relevance of the results from those studies, and the human relevance of these studies are all important considerations in assessing whether the results raise specific concerns for genotoxic potential. The Panel evaluates genotoxicity studies not only for evidence of genotoxicity hazard, but also for the probability of risk to the consumer in the context of exposure from their use as flavoring substances. The majority of flavoring substances have given no indication of genotoxic potential in studies evaluated by the FEMA Expert Panel. Examples illustrating the assessment of genotoxicity data for flavoring substances and the consideration of the factors noted above are provided. The weight of evidence approach adopted by the FEMA Expert Panel leads to a rational assessment of risk associated with consumer intake of flavoring substances under the conditions of use.
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Affiliation(s)
| | - Samuel M Cohen
- Havlik-Wall Professor of Oncology, Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Gerhard Eisenbrand
- Food Chemistry & Toxicology, University of Kaiserslautern (retired), Heidelberg, Germany
| | | | - F Peter Guengerich
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Stephen S Hecht
- Masonic Cancer Center and Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, USA
| | | | - Thomas J Rosol
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, USA
| | - Maria Bastaki
- Flavor and Extract Manufacturers Association, Washington, DC, USA
| | - Matthew J Linman
- Flavor and Extract Manufacturers Association, Washington, DC, USA
| | - Sean V Taylor
- Flavor and Extract Manufacturers Association, Washington, DC, USA
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19
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Klapacz J, Gollapudi BB. Considerations for the Use of Mutation as a Regulatory Endpoint in Risk Assessment. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:84-93. [PMID: 31301246 DOI: 10.1002/em.22318] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/08/2019] [Accepted: 07/10/2019] [Indexed: 06/10/2023]
Abstract
Assessment of a chemical's potential to cause permanent changes in the genetic code has been a common practice in the industry and regulatory settings for decades. Furthermore, the genetic toxicity battery of tests has typically been employed during the earliest stages of the research and development programs of new product development. A positive outcome from such battery has a major impact on the chemical's utility, industrial hygiene, product stewardship practices, and product life cycle analysis, among many other decisions that need to be taken by the industry, even before the registration of a chemical is undertaken. Under the prevailing regulatory paradigm, the dichotomous (yes/no) evaluation of the chemical's genotoxic potential leads to a conservative, linear no-threshold (LNT) risk assessment, unless compelling and undeniable data to the contrary can be provided to satisfy regulators, typically in a number of different global jurisdictions. With the current advent of predictive methods, new testing paradigms, mode-of-action/adverse outcome pathways, and quantitative risk assessment approaches, various stakeholders are starting to employ these state-of-the-science methodologies to further the conversation on decision making and advance the regulatory paradigm beyond the dominant LNT status quo. This commentary describes these novel methodologies, relevant biological responses, and how these can affect internal and regulatory risk assessment approaches. Environ. Mol. Mutagen. 61:84-93, 2020. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Joanna Klapacz
- Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, Michigan
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20
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Peterson LA, Ignatovich IV, Grill AE, Beauchamp A, Ho YY, DiLernia AS, Zhang L. Individual Differences in the Response of Human β-Lymphoblastoid Cells to the Cytotoxic, Mutagenic, and DNA-Damaging Effects of a DNA Methylating Agent, N-Methylnitrosourethane. Chem Res Toxicol 2019; 32:2214-2226. [PMID: 31589032 DOI: 10.1021/acs.chemrestox.9b00266] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Metabolic activation of many carcinogens leads to formation of reactive intermediates that form DNA adducts. These adducts are cytotoxic when they interfere with cell division. They can also cause mutations by miscoding during DNA replication. Therefore, an individual's risk of developing cancer will depend on the balance between these processes as well as their ability to repair the DNA damage. Our hypothesis is that variations of genes participating in DNA damage repair and response pathways play significant roles in an individual's risk of developing tobacco-related cancers. To test this hypothesis, 61 human B-lymphocyte cell lines from the International HapMap project were phenotyped for their sensitivity to the cytotoxic and genotoxic properties of a model methylating agent, N-nitroso-N-methylurethane (NMUr). Cell viability was measured using a luciferase-based assay. Repair of the mutagenic and toxic DNA adduct, O6-methylguanine (O6-mG), was monitored by LC-MS/MS analysis. Genotoxic potential of NMUr was assessed employing a flow-cytometry based in vitro mutagenesis assay in the phosphatidylinositol-glycan biosynthesis class-A (PIG-A) gene. A wide distribution of responses to NMUr was observed with no correlation to gender or ethnicity. While the rate of O6-mG repair partially influenced the toxicity of NMUr, it did not appear to be the major factor affecting individual susceptibility to the mutagenic effects of NMUr. Genome-wide analysis identified several novel single nucleotide polymorphisms to be explored in future functional validation studies for a number of the toxicological end points.
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21
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Mammalian DNA Polymerase Kappa Activity and Specificity. Molecules 2019; 24:molecules24152805. [PMID: 31374881 PMCID: PMC6695781 DOI: 10.3390/molecules24152805] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 07/27/2019] [Accepted: 07/30/2019] [Indexed: 12/31/2022] Open
Abstract
DNA polymerase (pol) kappa is a Y-family translesion DNA polymerase conserved throughout all domains of life. Pol kappa is special6 ized for the ability to copy DNA containing minor groove DNA adducts, especially N2-dG adducts, as well as to extend primer termini containing DNA damage or mismatched base pairs. Pol kappa generally cannot copy DNA containing major groove modifications or UV-induced photoproducts. Pol kappa can also copy structured or non-B-form DNA, such as microsatellite DNA, common fragile sites, and DNA containing G quadruplexes. Thus, pol kappa has roles both in maintaining and compromising genomic integrity. The expression of pol kappa is altered in several different cancer types, which can lead to genome instability. In addition, many cancer-associated single-nucleotide polymorphisms have been reported in the POLK gene, some of which are associated with poor survival and altered chemotherapy response. Because of this, identifying inhibitors of pol kappa is an active area of research. This review will address these activities of pol kappa, with a focus on lesion bypass and cellular mutagenesis.
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Serpe M, Forenza C, Adamo A, Russo N, Perugino G, Ciaramella M, Valenti A. The DNA Alkylguanine DNA Alkyltransferase-2 (AGT-2) Of Caenorhabditis Elegans Is Involved In Meiosis And Early Development Under Physiological Conditions. Sci Rep 2019; 9:6889. [PMID: 31053748 PMCID: PMC6499797 DOI: 10.1038/s41598-019-43394-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 04/23/2019] [Indexed: 12/11/2022] Open
Abstract
DNA alkylguanine DNA alkyltransferases (AGTs) are evolutionary conserved proteins that repair alkylation damage in DNA, counteracting the effects of agents inducing such lesions. Over the last years AGTs have raised considerable interest for both the peculiarity of their molecular mechanism and their relevance in cancer biology. AGT knock out mice show increased tumour incidence in response to alkylating agents, and over-expression of the human AGT protein in cancer cells is frequently associated with resistance to alkylating chemotherapy. While all data available point to a function of AGT proteins in the cell response to alkylation lesions, we report for the first time that one of the two AGT paralogs of the model organism C. elegans, called AGT-2, also plays unexpected roles in meiosis and early development under physiological conditions. Our data suggest a role for AGT-2 in conversion of homologous recombination intermediates into post-strand exchange products in meiosis, and show that agt-2 gene down-regulation, or treatment of animals with an AGT inhibitor results in increased number of germ cells that are incompatible with producing viable offspring and are eliminated by apoptosis. These results suggest possible functions for AGTs in cell processes distinct from repair of alkylating damage.
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Affiliation(s)
- Mario Serpe
- Institute of Biosciences and BioResources, National Research Council of Italy, Via Pietro Castellino 111, Naples, 80131, Italy
| | - Chiara Forenza
- Institute of Biosciences and BioResources, National Research Council of Italy, Via Pietro Castellino 111, Naples, 80131, Italy
| | - Adele Adamo
- Institute of Biosciences and BioResources, National Research Council of Italy, Via Pietro Castellino 111, Naples, 80131, Italy
| | - Noemi Russo
- Institute of Biosciences and BioResources, National Research Council of Italy, Via Pietro Castellino 111, Naples, 80131, Italy
| | - Giuseppe Perugino
- Institute of Biosciences and BioResources, National Research Council of Italy, Via Pietro Castellino 111, Naples, 80131, Italy
| | - Maria Ciaramella
- Institute of Biosciences and BioResources, National Research Council of Italy, Via Pietro Castellino 111, Naples, 80131, Italy
| | - Anna Valenti
- Institute of Biosciences and BioResources, National Research Council of Italy, Via Pietro Castellino 111, Naples, 80131, Italy.
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23
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Pottenger LH, Boysen G, Brown K, Cadet J, Fuchs RP, Johnson GE, Swenberg JA. Understanding the importance of low-molecular weight (ethylene oxide- and propylene oxide-induced) DNA adducts and mutations in risk assessment: Insights from 15 years of research and collaborative discussions. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2019; 60:100-121. [PMID: 30536466 PMCID: PMC6590209 DOI: 10.1002/em.22248] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 08/10/2018] [Accepted: 08/23/2018] [Indexed: 05/11/2023]
Abstract
The interpretation and significance of DNA adduct data, their causal relationship to mutations, and their role in risk assessment have been debated for many years. An extended effort to identify key questions and collect relevant data to address them was focused on the ubiquitous low MW N7-alkyl/hydroxyalkylguanine adducts. Several academic, governmental, and industrial laboratories collaborated to gather new data aimed at better understanding the role and potential impact of these adducts in quantifiable genotoxic events (gene mutations/micronucleus). This review summarizes and evaluates the status of dose-response data for DNA adducts and mutations from recent experimental work with standard mutagenic agents and ethylene oxide and propylene oxide, and the importance for risk assessment. This body of evidence demonstrates that small N7-alkyl/hydroxyalkylguanine adducts are not pro-mutagenic and, therefore, adduct formation alone is not adequate evidence to support a mutagenic mode of action. Quantitative methods for dose-response analysis and derivation of thresholds, benchmark dose (BMD), or other points-of-departure (POD) for genotoxic events are now available. Integration of such analyses of genetox data is necessary to properly assess any role for DNA adducts in risk assessment. Regulatory acceptance and application of these insights remain key challenges that only the regulatory community can address by applying the many learnings from recent research. The necessary tools, such as BMDs and PODs, and the example datasets, are now available and sufficiently mature for use by the regulatory community. Environ. Mol. Mutagen. 60: 100-121, 2019. © 2018 The Authors. Environmental and Molecular Mutagenesis published by Wiley Periodicals, Inc. on behalf of Environmental Mutagen Society.
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Affiliation(s)
- L. H. Pottenger
- Olin Corporation/Blue Cube Operations, LLC, retired, LHP TOX CONSULT, LLCMidlandMIUSA
| | - G. Boysen
- Department of Environmental and Occupational Health and The Winthrop P Rockefeller Cancer Institute University of Arkansas for Medical SciencesLittle RockArkansasUSA
| | - K. Brown
- Leicester Cancer Research CentreUniversity of LeicesterLeicesterUnited Kingdom
| | - J. Cadet
- Institut Nanosciences et Cryogénie, CEA‐GrenobleGrenobleFrance
- Université de SherbrookeSherbrookeCanada
| | - R. P. Fuchs
- Centre de Recherche en Cancérologie de Marseille (CRCM), Inserm, U1068Marseille, 13009France
- CNRS, UMR7258Marseille, 13009France
- Institut Paoli‐CalmettesMarseille, 13009France
- Aix‐Marseille UniversityUM 105, 13284, MarseilleFrance
| | - G. E. Johnson
- Swansea University, Institute of Life SciencesSwanseaUnited Kingdom
| | - J. A. Swenberg
- University of North CarolinaChapel HillNorth CarolinaUSA
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24
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Li J, Svilar D, McClellan S, Kim JH, Ahn EYE, Vens C, Wilson DM, Sobol RW. DNA Repair Molecular Beacon assay: a platform for real-time functional analysis of cellular DNA repair capacity. Oncotarget 2018; 9:31719-31743. [PMID: 30167090 PMCID: PMC6114979 DOI: 10.18632/oncotarget.25859] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 07/12/2018] [Indexed: 12/15/2022] Open
Abstract
Numerous studies have shown that select DNA repair enzyme activities impact response and/or toxicity of genotoxins, suggesting a requirement for enzyme functional analyses to bolster precision medicine or prevention. To address this need, we developed a DNA Repair Molecular Beacon (DRMB) platform that rapidly measures DNA repair enzyme activity in real-time. The DRMB assay is applicable for discovery of DNA repair enzyme inhibitors, for the quantification of enzyme rates and is sufficiently sensitive to differentiate cellular enzymatic activity that stems from variation in expression or effects of amino acid substitutions. We show activity measures of several different base excision repair (BER) enzymes, including proteins with tumor-identified point mutations, revealing lesion-, lesion-context- and cell-type-specific repair dependence; suggesting application for DNA repair capacity analysis of tumors. DRMB measurements using lysates from isogenic control and APE1-deficient human cells suggests the major mechanism of base lesion removal by most DNA glycosylases may be mono-functional base hydrolysis. In addition, development of a microbead-conjugated DRMB assay amenable to flow cytometric analysis further advances its application. Our studies establish an analytical platform capable of evaluating the enzyme activity of select DNA repair proteins in an effort to design and guide inhibitor development and precision cancer therapy options.
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Affiliation(s)
- Jianfeng Li
- University of South Alabama Mitchell Cancer Institute, Mobile, AL, USA
| | - David Svilar
- Department of Pharmacology & Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.,University of Pittsburgh Cancer Institute, Hillman Cancer Center, Pittsburgh, PA, USA
| | - Steven McClellan
- University of South Alabama Mitchell Cancer Institute, Mobile, AL, USA
| | - Jung-Hyun Kim
- University of South Alabama Mitchell Cancer Institute, Mobile, AL, USA
| | | | - Conchita Vens
- The Netherlands Cancer Institute, Division of Cell Biology, Amsterdam, The Netherlands
| | - David M Wilson
- Laboratory of Molecular Gerontology, National Institute on Aging, IRP, NIH Baltimore, MD, USA
| | - Robert W Sobol
- University of South Alabama Mitchell Cancer Institute, Mobile, AL, USA.,Department of Pharmacology & Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.,University of Pittsburgh Cancer Institute, Hillman Cancer Center, Pittsburgh, PA, USA
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25
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Yin J, Chen S, Zhang N, Wang H. Multienzyme Cascade Bioreactor for a 10 min Digestion of Genomic DNA into Single Nucleosides and Quantitative Detection of Structural DNA Modifications in Cellular Genomic DNA. ACS APPLIED MATERIALS & INTERFACES 2018; 10:21883-21890. [PMID: 29882639 DOI: 10.1021/acsami.8b05399] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Identification and quantification of chemical DNA modifications provide essential information on genomic DNA changes, for example, epigenetic modifications and abnormal DNA lesions. In this vein, it requires to digest genomic DNA strands into single nucleosides, facilitating the mass spectrometry analysis. However, rapid digestion of such supramacromolecule DNA of several millions Daltons (molecular weight) into single nucleosides remains very challenging. Here, we constructed an immobilized benzonase capillary bioreactor and further tandemly coupled with immobilized snake venom phosphodiesterase and alkaline phosphatase capillary bioreactor to form a novel three-enzyme cascade bioreactor (BenzoSAC bioreactor). In these constructions, the chosen enzymes were immobilized onto synthetic porous capillary silica monoliths. With the tailor-made porous structure and high immobilized capacity and high digestion rate of benzonase, genomic DNA of >99.5% can be digested into single nucleosides within only 10 min when passing through the BenzoSAC bioreactor by microinjection pump. In contrast, traditional digestion requires 8-24 h. By offline coupling this benzoSAC bioreactor with liquid chromatography-tandem mass spectrometry, we detected 5-hydroxymethylcytosine, a major oxidation product of the epigenetically crucial 5-methylcytosine, in genomic DNA isolated from ladder cancer (T24) cells. The newly synthesized BenzoSAC bioreactor and the proposed mass spectrometry detection are promising for fast identification and analysis of structural modifications in DNA.
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Affiliation(s)
- Junfa Yin
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
| | - Shaokun Chen
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Ning Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
| | - Hailin Wang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
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26
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Zanotto-Filho A, Rajamanickam S, Loranc E, Masamsetti VP, Gorthi A, Romero JC, Tonapi S, Gonçalves RM, Reddick RL, Benavides R, Kuhn J, Chen Y, Bishop AJR. Sorafenib improves alkylating therapy by blocking induced inflammation, invasion and angiogenesis in breast cancer cells. Cancer Lett 2018; 425:101-115. [PMID: 29608984 DOI: 10.1016/j.canlet.2018.03.037] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 03/21/2018] [Accepted: 03/23/2018] [Indexed: 12/12/2022]
Abstract
Molecular targeted compounds are emerging as a strategy to improve classical chemotherapy. Herein, we describe that using low dose of the multikinase inhibitor sorafenib improves cyclophosphamide antitumor activity by inhibiting angiogenesis, metastasis and promoting tumor healing in MDA-MB231 xenografts and the 4T1-12B syngeneic breast cancer metastasis model. Mechanistic studies in MDA-MB231 cells revealed that alkylation upregulates inflammatory genes/proteins such as COX-2, IL8, CXCL2 and MMP1 in a MEK1/2-ERK1/2-dependent manner. These proteins enrich the secretome of cancer cells, stimulating cell invasion and angiogenesis via autocrine and paracrine mechanisms. Sorafenib inhibits MEK1/2-ERK1/2 pathway thereby decreasing inflammatory genes and mitigating cell invasion and angiogenesis at basal and alkylation-induced conditions whereas NRF2 and ER stress pathways involved in alkylation survival are not affected. In non-invasive/non-angiogenic breast cancer cells (SKBR3 and MCF7), alkylation did not elicit inflammatory responses with the only sorafenib effect being ERK1/2-independent ROS-dependent cytotoxicity when using higher drug concentrations. In summary, our data show that alkylating agents may elicit inflammatory responses that seems to contribute to malignant progression in specific breast cancer cells. Identifying and targeting drivers of this phenotype may offer opportunities to optimize combined drug regimens between classical chemotherapeutics and targeted agents.
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Affiliation(s)
- Alfeu Zanotto-Filho
- Greehey Children's Cancer Research Institute, University of Texas Health at San Antonio, San Antonio, TX, USA; Departamento de Farmacologia, Universidade Federal de Santa Catarina (UFSC), Florianópolis, SC, Brazil
| | - Subapriya Rajamanickam
- Greehey Children's Cancer Research Institute, University of Texas Health at San Antonio, San Antonio, TX, USA
| | - Eva Loranc
- Greehey Children's Cancer Research Institute, University of Texas Health at San Antonio, San Antonio, TX, USA
| | - V Pragathi Masamsetti
- Greehey Children's Cancer Research Institute, University of Texas Health at San Antonio, San Antonio, TX, USA
| | - Aparna Gorthi
- Greehey Children's Cancer Research Institute, University of Texas Health at San Antonio, San Antonio, TX, USA; Department of Cell Systems and Anatomy, University of Texas Health at San Antonio, San Antonio, TX, USA
| | - July Carolina Romero
- Greehey Children's Cancer Research Institute, University of Texas Health at San Antonio, San Antonio, TX, USA; Department of Cell Systems and Anatomy, University of Texas Health at San Antonio, San Antonio, TX, USA
| | - Sonal Tonapi
- Greehey Children's Cancer Research Institute, University of Texas Health at San Antonio, San Antonio, TX, USA; Department of Cell Systems and Anatomy, University of Texas Health at San Antonio, San Antonio, TX, USA
| | - Rosangela Mayer Gonçalves
- Departamento de Farmacologia, Universidade Federal de Santa Catarina (UFSC), Florianópolis, SC, Brazil
| | - Robert L Reddick
- Department of Pathology, University of Texas Health at San Antonio, San Antonio, TX, USA
| | - Raymond Benavides
- Department of Pathology, University of Texas College of Pharmacy, Austin, TX, USA
| | - John Kuhn
- Department of Pathology, University of Texas Health at San Antonio, San Antonio, TX, USA; Department of Pathology, University of Texas College of Pharmacy, Austin, TX, USA
| | - Yidong Chen
- Department of Epidemiology and Biostatistics, University of Texas Health at San Antonio, San Antonio, TX, USA
| | - Alexander J R Bishop
- Greehey Children's Cancer Research Institute, University of Texas Health at San Antonio, San Antonio, TX, USA; Department of Cell Systems and Anatomy, University of Texas Health at San Antonio, San Antonio, TX, USA.
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27
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Kotsarenko K, Lylo V, Ruban T, Macewicz L, Lukash L. Effects of Some Growth Factors and Cytokines on the Expression of the Repair Enzyme MGMT and Protein MARP in Human Cells In Vitro : Effect of Some Growth Factors and Cytokines. Biochem Genet 2018; 56:459-477. [PMID: 29589213 DOI: 10.1007/s10528-018-9854-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 03/21/2018] [Indexed: 11/28/2022]
Abstract
The inducible repair enzyme O6-methylguanine-DNA methyltransferase (MGMT) eliminates O6-methylguanine adducts in DNA and protects the cells from damaging effects of alkylating agents. We have found that anti-MGMT antibodies recognize both the MGMT protein with a mol. weight ~ 24 kDa and a protein with a mol. weight ~ 48 kDa, which was named MARP (anti-methyltransferase antibody recognizable protein). A number of growth factors and cytokines were shown to regulate the expression of MGMT and MARP proteins. The ranges of concentrations of several growth factors and cytokines that caused increasing or decreasing protein amounts in human cell cultures were determined. The results of special biological experiments have allowed us to assume a possible role of MARP in the repair of alkyl adducts in human cells.
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Affiliation(s)
- Kateryna Kotsarenko
- University of South Bohemia in České Budějovice, Branisovska 1760, 37005, Ceske Budejovice, Czech Republic.
| | - Valentyna Lylo
- Institute of Molecular Biology and Genetics of NAS of Ukraine, Kiev, 03680, Ukraine
| | - Tetiana Ruban
- Institute of Molecular Biology and Genetics of NAS of Ukraine, Kiev, 03680, Ukraine
| | - Larysa Macewicz
- Institute of Molecular Biology and Genetics of NAS of Ukraine, Kiev, 03680, Ukraine
| | - Lyubov Lukash
- Institute of Molecular Biology and Genetics of NAS of Ukraine, Kiev, 03680, Ukraine
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28
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Al Khateeb W. Plants genotoxicity as pollution bioindicator in Jordan using comet assay. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2018; 24:89-97. [PMID: 29398841 PMCID: PMC5787122 DOI: 10.1007/s12298-017-0491-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 11/23/2017] [Accepted: 12/05/2017] [Indexed: 05/03/2023]
Abstract
This study aimed to assess genotoxicity in wild plants grown in Jordan as a pollution bioindicator. Comet assay was used to evaluate the level of DNA damage in plants collected from different areas in Jordan. Significant differences in plant DNA damage index and frequency were observed among sites of collection. Results show that plants collected from Aqaba back road and Ghour Assaal had significantly higher damage values. In contrast, plants collected from Wadi Rum, Al Naqab Heights, Swaimeh/Deadsea and Alshoneh Aljanobyeh showed low levels of DNA damage. A similar trend was observed for lipid peroxidation rates. Furthermore, heavy metal analysis showed that plants collected from Aqaba back road and Aqaba airport had the highest Al, Cr, Fe, Cu, Zn, Cd and Pb contents. A significant correlation was observed between DNA Damage Index, DNA Damage Frequency, lipid peroxidation rate, soil Cu, Cd and Pb biomarkers, indicating that heavy metals pollution is a major source for genotoxicity in these plant species. Finally, our results approved the feasibility of using plants and Comet assay system as a diagnostic tool for pollution in any environment adversely affected by different pollution sources.
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Affiliation(s)
- Wesam Al Khateeb
- Department of Biological Sciences, Yarmouk University, Irbid, Jordan
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29
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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.
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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.
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30
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Yin J, Xu T, Zhang N, Wang H. Three-Enzyme Cascade Bioreactor for Rapid Digestion of Genomic DNA into Single Nucleosides. Anal Chem 2016; 88:7730-7. [DOI: 10.1021/acs.analchem.6b01682] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Junfa Yin
- State
Key Laboratory of Environmental Chemistry and Ecotoxicology, Research
Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Tian Xu
- State
Key Laboratory of Environmental Chemistry and Ecotoxicology, Research
Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ning Zhang
- State
Key Laboratory of Environmental Chemistry and Ecotoxicology, Research
Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Hailin Wang
- State
Key Laboratory of Environmental Chemistry and Ecotoxicology, Research
Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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31
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Clewell RA, Andersen ME. Approaches for characterizing threshold dose-response relationships for DNA-damage pathways involved in carcinogenicity in vivo and micronuclei formation in vitro. Mutagenesis 2016; 31:333-40. [PMID: 26846943 DOI: 10.1093/mutage/gev078] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Assessing the shape of dose-response curves for DNA-damage in cellular systems and for the consequences of DNA damage in intact animals remains a controversial topic. This overview looks at aspects of the pharmacokinetics (PK) and pharmacodynamics (PD) of cellular DNA-damage/repair and their role in defining the shape of dose-response curves using an in vivo example with formaldehyde and in vitro examples for micronuclei (MN) formation with several test compounds. Formaldehyde is both strongly mutagenic and an endogenous metabolite in cells. With increasing inhaled concentrations, there were transitions in gene changes, from activation of selective stress pathway genes at low concentrations, to activation of pathways for cell-cycle control, p53-DNA damage, and stem cell niche pathways at higher exposures. These gene expression changes were more consistent with dose-dependent transitions in the PD responses to formaldehyde in epithelial cells in the intact rat rather than the low-dose linear extrapolation methods currently used for carcinogens. However, more complete PD explanations of non-linear dose response for creation of fixed damage in cells require detailed examination of cellular responses in vitro using measures of DNA damage and repair that are not easily accessible in the intact animal. In the second section of the article, we illustrate an approach from our laboratory that develops fit-for-purpose, in vitro assays and evaluates the PD of DNA damage and repair through studies using prototypical DNA-damaging agents. Examination of a broad range of responses in these cells showed that transcriptional upregulation of cell cycle control and DNA repair pathways only occurred at doses higher than those causing overt damage fixed damage-measured as MN formation. Lower levels of damage appear to be handled by post-translational repair process using pre-existing proteins. In depth evaluation of the PD properties of one such post-translational process (formation of DNA repair centers; DRCs) has indicated that the formation of DRCs and their ability to complete repair before replication are consistent with threshold behaviours for mutagenesis and, by extension, with chemical carcinogenesis.
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Affiliation(s)
- Rebecca A Clewell
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709-2137 , USA
| | - Melvin E Andersen
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709-2137 , USA
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