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Eng ZH, Abdul Aziz A, Ng KL, Mat Junit S. Changes in antioxidant status and DNA repair capacity are corroborated with molecular alterations in malignant thyroid tissue of patients with papillary thyroid cancer. Front Mol Biosci 2023; 10:1237548. [PMID: 37692064 PMCID: PMC10484572 DOI: 10.3389/fmolb.2023.1237548] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 08/14/2023] [Indexed: 09/12/2023] Open
Abstract
Introduction: Papillary thyroid cancer (PTC) accounts for approximately 80% of all thyroid cancer cases. The mechanism of PTC tumourigenesis is not fully understood, but oxidative imbalance is thought to play a role. To gain further insight, this study evaluated antioxidant status, DNA repair capacity and genetic alterations in individuals diagnosed with benign thyroid lesion in one lobe (BTG) and PTC lesion in another. Methods: Individuals with coexisting BTG and PTC lesions in their thyroid lobes were included in this study. Reactive oxygen species (ROS) level, ABTS radical scavenging activity, ferric reducing antioxidant capacity, glutathione peroxidase and superoxide dismutase activities were measured in the thyroid tissue lysate. The expression of selected genes and proteins associated with oxidative stress defence and DNA repair were analysed through quantitative real-time PCR and Western blotting. Molecular alterations in genomic DNA were analysed through whole-exome sequencing and the potentially pathogenic driver genes filtered through Cancer-Related Analysis of Variants Toolkit (CRAVAT) analysis were subjected to pathway enrichment analysis using Metascape. Results: Significantly higher ROS level was detected in the PTC compared to the BTG lesions. The PTC lesions had significantly higher expression of GPX1, SOD2 and OGG1 but significantly lower expression of CAT and PRDX1 genes than the BTG lesions. Pathway enrichment analysis identified "regulation of MAPK cascade," "positive regulation of ERK1 and ERK2 cascade" and "negative regulation of reactive oxygen species metabolic process" to be significantly enriched in the PTC lesions only. Four pathogenic genetic variants were identified in the PTC lesions; BRAF V600E, MAP2K7-rs2145142862, BCR-rs372013175 and CD24 NM_001291737.1:p.Gln23fs while MAP3K9 and G6PD were among 11 genes that were mutated in both BTG and PTC lesions. Conclusion: Our findings provided further insight into the connection between oxidative stress, DNA damage, and genetic changes associated with BTG-to-PTC transformation. The increased oxidative DNA damage due to the heightened ROS levels could have heralded the BTG-to-PTC transformation, potentially through mutations in the genes involved in the MAPK signalling pathway and stress-activated MAPK/JNK cascade. Further in-vitro functional analyses and studies involving a larger sample size would need to be carried out to validate the findings from this pilot study.
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Affiliation(s)
- Zing Hong Eng
- Department of Molecular Medicine, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Azlina Abdul Aziz
- Department of Molecular Medicine, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Khoon Leong Ng
- Department of Surgery, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Sarni Mat Junit
- Department of Molecular Medicine, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
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Calori IR, Bi H, Tedesco AC. Expanding the Limits of Photodynamic Therapy: The Design of Organelles and Hypoxia-Targeting Nanomaterials for Enhanced Photokilling of Cancer. ACS APPLIED BIO MATERIALS 2021; 4:195-228. [PMID: 35014281 DOI: 10.1021/acsabm.0c00945] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Photodynamic therapy (PDT) is a minimally invasive clinical protocol that combines a nontoxic photosensitizer (PS), appropriate visible light, and molecular oxygen for cancer treatment. This triad generates reactive oxygen species (ROS) in situ, leading to different cell death pathways and limiting the arrival of nutrients by irreversible destruction of the tumor vascular system. Despite the number of formulations and applications available, the advancement of therapy is hindered by some characteristics such as the hypoxic condition of solid tumors and the limited energy density (light fluence) that reaches the target. As a result, the use of PDT as a definitive monotherapy for cancer is generally restricted to pretumor lesions or neoplastic tissue of approximately 1 cm in size. To expand this limitation, researchers have synthesized functional nanoparticles (NPs) capable of carrying classical photosensitizers with self-supplying oxygen as well as targeting specific organelles such as mitochondria and lysosomes. This has improved outcomes in vitro and in vivo. This review highlights the basis of PDT, many of the most commonly used strategies of functionalization of smart NPs, and their potential to break the current limits of the classical protocol of PDT against cancer. The application and future perspectives of the multifunctional nanoparticles in PDT are also discussed in some detail.
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Affiliation(s)
- Italo Rodrigo Calori
- Department of Chemistry, Center of Nanotechnology and Tissue Engineering, Photobiology and Photomedicine Research Group, Faculty of Philosophy, Sciences and Letters of Ribeirão Preto, University of São Paulo-Ribeirão Preto, São Paulo 14040-901, Brazil
| | - Hong Bi
- School of Chemistry and Chemical Engineering, Anhui Key Laboratory of Modern Biomanufacturing, Anhui University, 111 Jiulong Road, Hefei 230601, China
| | - Antonio Claudio Tedesco
- Department of Chemistry, Center of Nanotechnology and Tissue Engineering, Photobiology and Photomedicine Research Group, Faculty of Philosophy, Sciences and Letters of Ribeirão Preto, University of São Paulo-Ribeirão Preto, São Paulo 14040-901, Brazil.,School of Chemistry and Chemical Engineering, Anhui Key Laboratory of Modern Biomanufacturing, Anhui University, 111 Jiulong Road, Hefei 230601, China
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Bétous R, Renoud M, Hoede C, Gonzalez I, Jones N, Longy M, Sensebé L, Cazaux C, Hoffmann J. Human Adipose-Derived Stem Cells Expanded Under Ambient Oxygen Concentration Accumulate Oxidative DNA Lesions and Experience Procarcinogenic DNA Replication Stress. Stem Cells Transl Med 2016; 6:68-76. [PMID: 28170194 PMCID: PMC5442744 DOI: 10.5966/sctm.2015-0401] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 04/08/2016] [Indexed: 01/15/2023] Open
Abstract
Adipose‐derived stem cells (ADSCs) have led to growing interest in cell‐based therapy because they can be easily harvested from an abundant tissue. ADSCs must be expanded in vitro before transplantation. This essential step causes concerns about the safety of adult stem cells in terms of potential transformation. Tumorigenesis is driven in its earliest step by DNA replication stress, which is characterized by the accumulation of stalled DNA replication forks and activation of the DNA damage response. Thus, to evaluate the safety of ADSCs during ex vivo expansion, we monitored DNA replication under atmospheric (21%) or physiologic (1%) oxygen concentration. Here, by combining immunofluorescence and DNA combing, we show that ADSCs cultured under 21% oxygen accumulate endogenous oxidative DNA lesions, which interfere with DNA replication by increasing fork stalling events, thereby leading to incomplete DNA replication and fork collapse. Moreover, we found by RNA sequencing (RNA‐seq) that culture of ADSCs under atmospheric oxygen concentration leads to misexpression of cell cycle and DNA replication genes, which could contribute to DNA replication stress. Finally, analysis of acquired small nucleotide polymorphism shows that expansion of ADSCs under 21% oxygen induces a mutational bias toward deleterious transversions. Overall, our results suggest that expanding ADSCs at a low oxygen concentration could reduce the risk for DNA replication stress‐associated transformation, as occurs in neoplastic tissues. Stem Cells Translational Medicine2017;6:68–76
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Affiliation(s)
- Rémy Bétous
- Equipe Labellisée La Ligue Contre Le Cancer, Paris, France
- Laboratoire d'Excellence Toulouse Cancer Labex Toucan, Cancer Research Center of Toulouse, INSERM U1037, CNRS ERL5294, Toulouse, France
- University Paul Sabatier, Toulouse, France
| | - Marie‐Laure Renoud
- University Paul Sabatier, Toulouse, France
- Etablissement Français du Sang Pyrénées Méditerranée, Toulouse, France
- INSERM U1031, UMR5273, Toulouse, France
| | - Claire Hoede
- Institut National de la Recherche Agronomique (INRA), UR 875, Unité de Mathématique et Informatique Appliquées, PF Bioinfo Genotoul, Castanet Tolosan, France
| | - Ignacio Gonzalez
- Institut National de la Recherche Agronomique (INRA), UR 875, Unité de Mathématique et Informatique Appliquées, PF Bioinfo Genotoul, Castanet Tolosan, France
| | - Natalie Jones
- INSERM U916 Vinco, Université de Bordeaux, Institut Bergonié, Bordeaux, France
| | - Michel Longy
- INSERM U916 Vinco, Université de Bordeaux, Institut Bergonié, Bordeaux, France
| | - Luc Sensebé
- University Paul Sabatier, Toulouse, France
- Etablissement Français du Sang Pyrénées Méditerranée, Toulouse, France
- INSERM U1031, UMR5273, Toulouse, France
| | - Christophe Cazaux
- Equipe Labellisée La Ligue Contre Le Cancer, Paris, France
- Laboratoire d'Excellence Toulouse Cancer Labex Toucan, Cancer Research Center of Toulouse, INSERM U1037, CNRS ERL5294, Toulouse, France
- University Paul Sabatier, Toulouse, France
| | - Jean‐Sébastien Hoffmann
- Equipe Labellisée La Ligue Contre Le Cancer, Paris, France
- Laboratoire d'Excellence Toulouse Cancer Labex Toucan, Cancer Research Center of Toulouse, INSERM U1037, CNRS ERL5294, Toulouse, France
- University Paul Sabatier, Toulouse, France
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Fleming AM, Burrows CJ. G-quadruplex folds of the human telomere sequence alter the site reactivity and reaction pathway of guanine oxidation compared to duplex DNA. Chem Res Toxicol 2013; 26:593-607. [PMID: 23438298 DOI: 10.1021/tx400028y] [Citation(s) in RCA: 122] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Telomere shortening occurs during oxidative and inflammatory stress with guanine (G) as the major site of damage. In this work, a comprehensive profile of the sites of oxidation and structures of products observed from G-quadruplex and duplex structures of the human telomere sequence was studied in the G-quadruplex folds (hybrid (K(+)), basket (Na(+)), and propeller (K(+) + 50% CH3CN)) resulting from the sequence 5'-(TAGGGT)4T-3' and in an appropriate duplex containing one telomere repeat. Oxidations with four oxidant systems consisting of riboflavin photosensitization, carbonate radical generation, singlet oxygen, and the copper Fenton-like reaction were analyzed under conditions of low product conversion to determine relative reactivity. The one-electron oxidants damaged the 5'-G in G-quadruplexes leading to spiroiminodihydantoin (Sp) and 2,2,4-triamino-2H-oxazol-5-one (Z) as major products as well as 8-oxo-7,8-dihydroguanine (OG) and 5-guanidinohydantoin (Gh) in low relative yields, while oxidation in the duplex context produced damage at the 5'- and middle-Gs of GGG sequences and resulted in Gh being the major product. Addition of the reductant N-acetylcysteine (NAC) to the reaction did not alter the riboflavin-mediated damage sites but decreased Z by 2-fold and increased OG by 5-fold, while not altering the hydantoin ratio. However, NAC completely quenched the CO3(•-) reactions. Singlet oxygen oxidations of the G-quadruplex showed reactivity at all Gs on the exterior faces of G-quartets and furnished the product Sp, while no oxidation was observed in the duplex context under these conditions, and addition of NAC had no effect. Because a long telomere sequence would have higher-order structures of G-quadruplexes, studies were also conducted with 5'-(TAGGGT)8-T-3', and it provided oxidation profiles similar to those of the single G-quadruplex. Lastly, Cu(II)/H2O2-mediated oxidations were found to be indiscriminate in the damage patterns, and 5-carboxamido-5-formamido-2-iminohydantoin (2Ih) was found to be a major duplex product, while nearly equal yields of 2Ih and Sp were observed in G-quadruplex contexts. These findings indicate that the nature of the secondary structure of folded DNA greatly alters both the reactivity of G toward oxidative stress as well as the product outcome and suggest that recognition of damage in telomeric sequences by repair enzymes may be profoundly different from that of B-form duplex DNA.
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Affiliation(s)
- Aaron M Fleming
- Department of Chemistry, University of Utah , 315 South 1400 East, Salt Lake City, Utah 84112-0850, United States
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Ling D, Bae BC, Park W, Na K. Photodynamic efficacy of photosensitizers under an attenuated light dose via lipid nano-carrier-mediated nuclear targeting. Biomaterials 2012; 33:5478-86. [DOI: 10.1016/j.biomaterials.2012.04.023] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Accepted: 04/10/2012] [Indexed: 10/28/2022]
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Agnez-Lima LF, Melo JTA, Silva AE, Oliveira AHS, Timoteo ARS, Lima-Bessa KM, Martinez GR, Medeiros MHG, Di Mascio P, Galhardo RS, Menck CFM. DNA damage by singlet oxygen and cellular protective mechanisms. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2012; 751:15-28. [PMID: 22266568 DOI: 10.1016/j.mrrev.2011.12.005] [Citation(s) in RCA: 133] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 12/14/2011] [Accepted: 12/21/2011] [Indexed: 12/23/2022]
Abstract
Reactive oxygen species, as singlet oxygen ((1)O(2)) and hydrogen peroxide, are continuously generated by aerobic organisms, and react actively with biomolecules. At excessive amounts, (1)O(2) induces oxidative stress and shows carcinogenic and toxic effects due to oxidation of lipids, proteins and nucleic acids. Singlet oxygen is able to react with DNA molecule and may induce G to T transversions due to 8-oxodG generation. The nucleotide excision repair, base excision repair and mismatch repair have been implicated in the correction of DNA lesions induced by (1)O(2) both in prokaryotic and in eukaryotic cells. (1)O(2) is also able to induce the expression of genes involved with the cellular responses to oxidative stress, such as NF-κB, c-fos and c-jun, and genes involved with tissue damage and inflammation, as ICAM-1, interleukins 1 and 6. The studies outlined in this review reinforce the idea that (1)O(2) is one of the more dangerous reactive oxygen species to the cells, and deserves our attention.
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Affiliation(s)
- Lucymara F Agnez-Lima
- Departamento de Biologia Celular e Genética, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil
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Serrentino ME, Catalfo A, Angelin AR, de Guidi G, Sage E. Photosensitization induced by the antibacterial fluoroquinolone Rufloxacin leads to mutagenesis in yeast. Mutat Res 2010; 692:34-41. [PMID: 20696178 DOI: 10.1016/j.mrfmmm.2010.07.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Revised: 07/20/2010] [Accepted: 07/30/2010] [Indexed: 05/29/2023]
Abstract
Rufloxacin (RFX) is an antibacterial fluoroquinolone that exhibits UVA photosensitization properties. Photosensitization reactions lead to the formation of oxidative damage, mainly via singlet oxygen. Here we explore the phototoxic and photomutagenic potency of RFX using a panel of yeast (Saccharomyces cerevisiae) mutants affected in different DNA repair pathways. Yeast mutants provide a sensitive tool to identify the photodamage and the DNA repair pathways that cope with it. Cell viability test at increasing dose of UVA shows that both the DNA repair deficient and wild type cells are equally sensitive to RFX-induced photosensitization, demonstrating that phototoxic effect is not due to DNA injury. Photomutagenicity of RFX is evaluated by measuring the frequency of forward Can(R) mutations. The mutation induction is low in wild type cells. A high increase in mutation frequency is observed in strains affected in Ogg1 gene, compared to wild type and other base excision repair deficient strains. The mutation spectrum photomediated by RFX in wild type cells reveals a bias in favour of GC>TA transversions, whereas transition and frameshift mutations are less represented. Altogether data demonstrates that 8-oxo-7,8-dihydroguanine (8-oxoGua) is by far the major DNA damage produced by RFX photosensitization, leading to mutagenesis. We also explore the role played by DNA mismatch repair, translesion synthesis and post-replication repair in the prevention of mutagenic effects due to RFX exposure. In addition, we show that most of RFX photodegradation products are not mutagenic. This study defines the phototoxic and photomutagenic properties of antibacterial RFX and point out possible unwanted side effects in skin under sunlight.
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Characterization of photoactivated singlet oxygen damage in single-molecule optical trap experiments. Biophys J 2010; 97:2128-36. [PMID: 19843445 DOI: 10.1016/j.bpj.2009.07.048] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2009] [Revised: 07/20/2009] [Accepted: 07/23/2009] [Indexed: 11/20/2022] Open
Abstract
Optical traps or "tweezers" use high-power, near-infrared laser beams to manipulate and apply forces to biological systems, ranging from individual molecules to cells. Although previous studies have established that optical tweezers induce photodamage in live cells, the effects of trap irradiation have yet to be examined in vitro, at the single-molecule level. In this study, we investigate trap-induced damage in a simple system consisting of DNA molecules tethered between optically trapped polystyrene microspheres. We show that exposure to the trapping light affects the lifetime of the tethers, the efficiency with which they can be formed, and their structure. Moreover, we establish that these irreversible effects are caused by oxidative damage from singlet oxygen. This reactive state of molecular oxygen is generated locally by the optical traps in the presence of a sensitizer, which we identify as the trapped polystyrene microspheres. Trap-induced oxidative damage can be reduced greatly by working under anaerobic conditions, using additives that quench singlet oxygen, or trapping microspheres lacking the sensitizers necessary for singlet state photoexcitation. Our findings are relevant to a broad range of trap-based single-molecule experiments-the most common biological application of optical tweezers-and may guide the development of more robust experimental protocols.
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Cavalcante AKD, Martinez GR, Di Mascio P, Menck CFM, Agnez-Lima LF. Cytotoxicity and mutagenesis induced by singlet oxygen in wild type and DNA repair deficient Escherichia coli strains. DNA Repair (Amst) 2002; 1:1051-6. [PMID: 12531014 DOI: 10.1016/s1568-7864(02)00164-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Singlet oxygen ((1)O(2)) is a product of several biological processes and can be generated in photodynamic therapy, through a photosensitization type II mechanism. (1)O(2) is able to interact with lipids, proteins and DNA, leading to cell killing and mutagenesis, and can be directly involved with degenerative processes such as cancer and aging. In this work, we analyzed the cytotoxicity and mutagenesis induced after direct treatment of wild type and the DNA repair fpg and/or mutY deficient Escherichia coli strains with disodium 3,3'-(1,4-naphthylidene) diproprionate endoperoxide (NDPO(2)), which releases (1)O(2) by thermodissociation. The treatment induced cell killing and mutagenesis in all strains, but the mutY strain showed to be more sensitive. These results indicate that even (1)O(2) generated outside bacterial cells may lead to DNA damage that could be repaired by pathways that employ MutY protein. As (1)O(2) is highly reactive, its interaction with cell membranes may generate secondary products that could react with DNA, leading to mutagenic lesions.
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Affiliation(s)
- Ana Karina Dias Cavalcante
- Departamento de Biologia Celular e Genética, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal CEP 59072970, RN, Brazil
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Guetens G, De Boeck G, Highley M, van Oosterom AT, de Bruijn EA. Oxidative DNA damage: biological significance and methods of analysis. Crit Rev Clin Lab Sci 2002; 39:331-457. [PMID: 12385502 DOI: 10.1080/10408360290795547] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
All forms of aerobic life are subjected constantly to oxidant pressure from molecular oxygen and also reactive oxygen species (ROS), produced during the biochemical utilization of O2 and prooxidant stimulation of O2 metabolism. ROS are thought to influence the development of human cancer and more than 50 other human diseases. To prevent oxidative DNA damage (protection) or to reverse damage, thereby preventing mutagenesis and cancer (repair), the aerobic cell possesses antioxidant defense systems and DNA repair mechanisms. During the last 20 years, many analytical techniques have been developed to monitor oxidative DNA base damage. High-performance liquid chromatography-electrochemical detection and gas chromatography-mass spectrometry are the two pioneering contributions to the field. Currently, the arsenal of methods available include the promising high-performance liquid chromatography-tandem mass spectrometry technique, capillary electrophoresis, 32P-postlabeling, fluorescence postlabeling, 3H-postlabeling, antibody-base immunoassays, and assays involving the use of DNA repair glycosylases such as the comet assay, the alkaline elution assay, and the alkaline unwinding method. Recently, the use of liquid chromatography-mass spectrometry has been introduced for the measurement of a number of modified nucleosides in oxidatively damaged DNA. The bulk of available chromatographic methods aimed at measuring individual DNA base lesions require either chemical hydrolysis or enzymatic digestion of oxidized DNA, following extraction from cells or tissues. The effect of experimental conditions (DNA isolation, hydrolysis, and/or derivatization) on the levels of oxidatively modified bases in DNA is enormous and has been studied intensively in the last 10 years.
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Agnez-Lima LF, Napolitano RL, Fuchs RP, Mascio PD, Muotri AR, Menck CF. DNA repair and sequence context affect (1)O(2)-induced mutagenesis in bacteria. Nucleic Acids Res 2001; 29:2899-903. [PMID: 11433036 PMCID: PMC55764 DOI: 10.1093/nar/29.13.2899] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Electronic excited molecular oxygen (singlet oxygen, (1)O(2)) is known to damage DNA, yielding mutations. In this work, the mutagenicity induced by (1)O(2) in a defined sequence of DNA was investigated after replication in Escherichia coli mutants deficient for nucleotide and base excision DNA repair pathways. For this purpose a plasmid containing a (1)O(2)-damaged 14 base oligonucleotide was introduced into E.coli by transfection and mutations were screened by hybridization with an oligonucleotide with the original sequence. Mutagenesis was observed in all strains tested, but it was especially high in the BH20 (fpg), AYM57 (fpg mutY) and AYM84 (fpg mutY uvrC) strains. The frequency of mutants in the fpg mutY strain was higher than in the triple mutant fpg mutY uvrC, suggesting that activity of the UvrABC excinuclease can favor the mutagenesis of these lesions. Additionally, most of the mutations were G-->T and G-->C transversions, but this was dependent on the position of the guanine in the sequence and on repair deficiency in the host bacteria. Thus, the kind of repair and the mutagenesis associated with (1)O(2)-induced DNA damage are linked to the context of the damaged sequence.
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Affiliation(s)
- L F Agnez-Lima
- Departamento de Biologia Celular e Genética-Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil
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Stief TW. The blood fibrinolysis/deep-sea analogy: a hypothesis on the cell signals singlet oxygen/photons as natural antithrombotics. Thromb Res 2000; 99:1-20. [PMID: 10904099 DOI: 10.1016/s0049-3848(00)00213-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- T W Stief
- Institute of Clinical Chemistry and Molecular Diagnostics, Philipps University, Marburg, Germany.
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Abstract
Although a number of risk factors have been identified for breast cancer, mechanisms by which they increase risk of the disease are not clear. Breast cancer etiology could, in part, be related to oxidative stress. Recognized risk factors for breast cancer include a family history of the disease. BRCA1 is needed for post-transcriptional repair of oxidative damage, indicating that oxidative stress may be an important risk factor for women with a family history of the disease. Reproductive and hormonal factors that result in greater exposure to circulating estrogens also increase risk, and steroid hormones are metabolized to reactive quinones and hydroquinones, which can directly damage DNA. Alcohol consumption is associated with increased risk, and the metabolism of alcohol results in production of DNA-damaging reactive oxygen species (ROS). Finally, the inverse relationship noted with consumption of fruits and vegetables could be related to their being a source of antioxidant vitamins. Endogenous factors may play an equally important role in the effects of oxidative stress on breast carcinogenesis. Genetic variability in enzymes that result in increased production of ROS and those that protect the cell from oxidative stress could also have an impact for risk of the disease. In this review, a rationale is given for linking breast cancer risk factors to oxidative stress. The possible role of genetic polymorphisms in a number of enzymes that may be important in affecting levels of ROS to which the cell is exposed, as well as those that protect the cell from oxidative stress, is discussed.
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Affiliation(s)
- C B Ambrosone
- Derald H. Ruttenberg Cancer Center, Mount Sinai School of Medicine, New York, NY 10029, USA.
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Agnez-Lima LF, Mascio PD, Napolitano RL, Fuchs RP, Menck CFM. Mutation Spectrum Induced by Singlet Oxygen in Escherichia coli Deficient in Exonuclease III. Photochem Photobiol 1999. [DOI: 10.1111/j.1751-1097.1999.tb08245.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
Alcohol consumption increases the risk for breast cancer in women by still undefined means. Alcohol metabolism is known to produce reactive oxygen species (ROS), and breast cancer is associated with high levels of hydroxyl radical (*OH) modified DNA, point mutations, single strand nicks, and chromosome rearrangement. Furthermore, ROS modification of DNA can produce the mutations and DNA damage found in breast cancer. Alcohol dehydrogenase (ADH) and xanthine oxidoreductase (XOR) are expressed and regulated in breast tissues and aldehyde oxidase (AOX) may be present as well. Mammary gland XOR is an efficient source of ROS. Recently, hepatic XOR and AOX were found to generate ROS in two ways from alcohol metabolism: by acetaldehyde consumption and by the intrinsic NADH oxidase activity of both XOR and AOX. The data obtained suggests that: (1) expression of ADH and XOR or AOX in breast tissue provides the enzymes that generate ROS; (2) metabolism of alcohol produces acetaldehyde and NADH that can both be substrates for XOR or AOX and thereby result in ROS formation; and (3) ROS generated by XOR or AOX can induce the carcinogenic mutations and DNA damage found in breast cancer. Accumulation of iron coupled with diminished antioxidant defenses in breast tissue with advancing age provide additional support for this hypothesis because both result in elevated ROS damage that may exacerbate the risk for ROS-induced breast cancer.
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Affiliation(s)
- R M Wright
- Webb-Waring Antioxidant Research Institute and University of Colorado Health Sciences Center, Denver 80262, USA.
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Wiseman H, Halliwell B. Damage to DNA by reactive oxygen and nitrogen species: role in inflammatory disease and progression to cancer. Biochem J 1996; 313 ( Pt 1):17-29. [PMID: 8546679 PMCID: PMC1216878 DOI: 10.1042/bj3130017] [Citation(s) in RCA: 1503] [Impact Index Per Article: 53.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- H Wiseman
- Department of Nutrition and Dietetics, King's College, London, U.K
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