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Current update on the molecular genetics and management of hereditary ovarian cancers: a primer for radiologists. Abdom Radiol (NY) 2021; 46:2281-2292. [PMID: 33847772 DOI: 10.1007/s00261-020-02911-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 12/09/2020] [Accepted: 12/11/2020] [Indexed: 12/24/2022]
Abstract
More than one-fifth of ovarian cancers are hereditary, with most of them caused by BRCA genes. Malignant ovarian neoplasms are primarily epithelial tumors, a heterogeneous group of tumors with variable genetic backgrounds that translate into different biologic behaviors and morphologic features. Radiologists play an increasingly important role in the diagnosis and management of oncology patients. Familiarity with hereditary ovarian cancers will have a positive impact on patient management and radiologists' involvement in the multidisciplinary approach needed for this delicate patient population. In this paper, we review the basic histologic and genetic backgrounds of ovarian tumors with an emphasis on hereditary ovarian cancers, as well as the effects that these factors have on patient workup, primarily with regard to imaging studies.
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Okada F, Izutsu R, Goto K, Osaki M. Inflammation-Related Carcinogenesis: Lessons from Animal Models to Clinical Aspects. Cancers (Basel) 2021; 13:cancers13040921. [PMID: 33671768 PMCID: PMC7926701 DOI: 10.3390/cancers13040921] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/11/2021] [Accepted: 02/12/2021] [Indexed: 12/13/2022] Open
Abstract
Simple Summary In multicellular organisms, inflammation is the body’s most primitive and essential protective response against any external agent. Inflammation, however, not only causes various modern diseases such as cardiovascular disorders, neurological disorders, autoimmune diseases, metabolic syndrome, infectious diseases, and cancer but also shortens the healthy life expectancy. This review focuses on the onset of carcinogenesis due to chronic inflammation caused by pathogen infections and inhalation/ingestion of foreign substances. This study summarizes animal models associated with inflammation-related carcinogenesis by organ. By determining factors common to inflammatory carcinogenesis models, we examined strategies for the prevention and treatment of inflammatory carcinogenesis in humans. Abstract Inflammation-related carcinogenesis has long been known as one of the carcinogenesis patterns in humans. Common carcinogenic factors are inflammation caused by infection with pathogens or the uptake of foreign substances from the environment into the body. Inflammation-related carcinogenesis as a cause for cancer-related death worldwide accounts for approximately 20%, and the incidence varies widely by continent, country, and even region of the country and can be affected by economic status or development. Many novel approaches are currently available concerning the development of animal models to elucidate inflammation-related carcinogenesis. By learning from the oldest to the latest animal models for each organ, we sought to uncover the essential common causes of inflammation-related carcinogenesis. This review confirmed that a common etiology of organ-specific animal models that mimic human inflammation-related carcinogenesis is prolonged exudation of inflammatory cells. Genotoxicity or epigenetic modifications by inflammatory cells resulted in gene mutations or altered gene expression, respectively. Inflammatory cytokines/growth factors released from inflammatory cells promote cell proliferation and repair tissue injury, and inflammation serves as a “carcinogenic niche”, because these fundamental biological events are common to all types of carcinogenesis, not just inflammation-related carcinogenesis. Since clinical strategies are needed to prevent carcinogenesis, we propose the therapeutic apheresis of inflammatory cells as a means of eliminating fundamental cause of inflammation-related carcinogenesis.
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Affiliation(s)
- Futoshi Okada
- Division of Experimental Pathology, Faculty of Medicine, Tottori University, Yonago 683-8503, Japan; (R.I.); (K.G.); (M.O.)
- Chromosome Engineering Research Center, Tottori University, Yonago 683-8503, Japan
- Correspondence: ; Tel.: +81-859-38-6241
| | - Runa Izutsu
- Division of Experimental Pathology, Faculty of Medicine, Tottori University, Yonago 683-8503, Japan; (R.I.); (K.G.); (M.O.)
| | - Keisuke Goto
- Division of Experimental Pathology, Faculty of Medicine, Tottori University, Yonago 683-8503, Japan; (R.I.); (K.G.); (M.O.)
- Division of Gastrointestinal and Pediatric Surgery, Faculty of Medicine, Tottori University, Yonago 683-8503, Japan
| | - Mitsuhiko Osaki
- Division of Experimental Pathology, Faculty of Medicine, Tottori University, Yonago 683-8503, Japan; (R.I.); (K.G.); (M.O.)
- Chromosome Engineering Research Center, Tottori University, Yonago 683-8503, Japan
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Neff RT, Senter L, Salani R. BRCA mutation in ovarian cancer: testing, implications and treatment considerations. Ther Adv Med Oncol 2017; 9:519-531. [PMID: 28794804 PMCID: PMC5524247 DOI: 10.1177/1758834017714993] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 05/22/2017] [Indexed: 12/11/2022] Open
Abstract
Ovarian cancer is a heterogeneous disease that encompasses a number of different cellular subtypes, the most common of which is high-grade serous ovarian cancer (HGSOC). Still today, ovarian cancer is primarily treated with chemotherapy and surgery. Recent advances in the hereditary understanding of this disease have shown a significant role for the BRCA gene. While only a minority of patients with HGSOC will have a germline BRCA mutation, many others may have tumor genetic aberrations within BRCA or other homologous recombination proteins. Genetic screening for these BRCA mutations has allowed improved preventative measures and therapeutic development. This review focuses on the understanding of BRCA mutations and their relationship with ovarian cancer development, as well as future therapeutic targets.
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Affiliation(s)
- Robert T Neff
- Department of Obstetrics and Gynecology, Division of Gynecologic Oncology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Leigha Senter
- Department of Internal Medicine, Division of Human Genetics, The Ohio State University Wexner Medical Center Columbus, OH, USA
| | - Ritu Salani
- Ohio State University Wexner Medical Center - James Comprehensive Cancer Center, 320 West 10th Avenue, M210 Starling-Loving Hall, Columbus, OH 43210, USA
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Kanda Y, Osaki M, Okada F. Chemopreventive Strategies for Inflammation-Related Carcinogenesis: Current Status and Future Direction. Int J Mol Sci 2017; 18:E867. [PMID: 28422073 PMCID: PMC5412448 DOI: 10.3390/ijms18040867] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 04/14/2017] [Accepted: 04/17/2017] [Indexed: 02/07/2023] Open
Abstract
A sustained and chronically-inflamed environment is characterized by the presence of heterogeneous inflammatory cellular components, including neutrophils, macrophages, lymphocytes and fibroblasts. These infiltrated cells produce growth stimulating mediators (inflammatory cytokines and growth factors), chemotactic factors (chemokines) and genotoxic substances (reactive oxygen species and nitrogen oxide) and induce DNA damage and methylation. Therefore, chronic inflammation serves as an intrinsic niche for carcinogenesis and tumor progression. In this article, we summarize the up-to-date findings regarding definitive/possible causes and mechanisms of inflammation-related carcinogenesis derived from experimental and clinical studies. We also propose 10 strategies, as well as candidate agents for the prevention of inflammation-related carcinogenesis.
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Affiliation(s)
- Yusuke Kanda
- Division of Pathological Biochemistry, Tottori University Faculty of Medicine, Yonago, Tottori 683-8503, Japan.
| | - Mitsuhiko Osaki
- Division of Pathological Biochemistry, Tottori University Faculty of Medicine, Yonago, Tottori 683-8503, Japan.
- Chromosome Engineering Research Center, Tottori University, Yonago, Tottori 683-8503, Japan.
| | - Futoshi Okada
- Division of Pathological Biochemistry, Tottori University Faculty of Medicine, Yonago, Tottori 683-8503, Japan.
- Chromosome Engineering Research Center, Tottori University, Yonago, Tottori 683-8503, Japan.
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De Picciotto N, Cacheux W, Roth A, Chappuis PO, Labidi-Galy SI. Ovarian cancer: Status of homologous recombination pathway as a predictor of drug response. Crit Rev Oncol Hematol 2016; 101:50-9. [DOI: 10.1016/j.critrevonc.2016.02.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2015] [Revised: 12/23/2015] [Accepted: 02/24/2016] [Indexed: 12/20/2022] Open
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Fridlich R, Annamalai D, Roy R, Bernheim G, Powell SN. BRCA1 and BRCA2 protect against oxidative DNA damage converted into double-strand breaks during DNA replication. DNA Repair (Amst) 2015; 30:11-20. [PMID: 25836596 DOI: 10.1016/j.dnarep.2015.03.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2013] [Revised: 02/27/2015] [Accepted: 03/03/2015] [Indexed: 12/20/2022]
Abstract
BRCA1 and BRCA2 mutation carriers are predisposed to develop breast and ovarian cancers, but the reasons for this tissue specificity are unknown. Breast epithelial cells are known to contain elevated levels of oxidative DNA damage, triggered by hormonally driven growth and its effect on cell metabolism. BRCA1- or BRCA2-deficient cells were found to be more sensitive to oxidative stress, modeled by treatment with patho-physiologic concentrations of hydrogen peroxide. Hydrogen peroxide exposure leads to oxidative DNA damage induced DNA double strand breaks (DSB) in BRCA-deficient cells causing them to accumulate in S-phase. In addition, after hydrogen peroxide treatment, BRCA deficient cells showed impaired Rad51 foci which are dependent on an intact BRCA1-BRCA2 pathway. These DSB resulted in an increase in chromatid-type aberrations, which are characteristic for BRCA1 and BRCA2-deficient cells. The most common result of oxidative DNA damage induced processing of S-phase DSB is an interstitial chromatid deletion, but insertions and exchanges were also seen in BRCA deficient cells. Thus, BRCA1 and BRCA2 are essential for the repair of oxidative DNA damage repair intermediates that persist into S-phase and produce DSB. The implication is that oxidative stress plays a role in the etiology of hereditary breast cancer.
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Affiliation(s)
- Ram Fridlich
- Department of Radiation Oncology and Molecular Biology Program, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, United States
| | - Devi Annamalai
- Department of Radiation Oncology and Molecular Biology Program, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, United States
| | - Rohini Roy
- Department of Radiation Oncology and Molecular Biology Program, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, United States
| | - Giana Bernheim
- Department of Radiation Oncology and Molecular Biology Program, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, United States
| | - Simon N Powell
- Department of Radiation Oncology and Molecular Biology Program, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, United States.
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Abstract
The proteins encoded by the two major breast cancer susceptibility genes, BRCA1 and BRCA2, work in a common pathway of genome protection. However, the two proteins work at different stages in the DNA damage response (DDR) and in DNA repair. BRCA1 is a pleiotropic DDR protein that functions in both checkpoint activation and DNA repair, whereas BRCA2 is a mediator of the core mechanism of homologous recombination. The links between the two proteins are not well understood, but they must exist to explain the marked similarity of human cancer susceptibility that arises with germline mutations in these genes. As discussed here, the proteins work in concert to protect the genome from double-strand DNA damage during DNA replication.
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Affiliation(s)
- Rohini Roy
- Molecular Biology Program and Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, USA
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Pandey PR, Okuda H, Watabe M, Pai SK, Liu W, Kobayashi A, Xing F, Fukuda K, Hirota S, Sugai T, Wakabayashi G, Koeda K, Kashiwaba M, Suzuki K, Chiba T, Endo M, Fujioka T, Tanji S, Mo YY, Cao D, Wilber AC, Watabe K. Resveratrol suppresses growth of cancer stem-like cells by inhibiting fatty acid synthase. Breast Cancer Res Treat 2011; 130:387-98. [PMID: 21188630 PMCID: PMC3404809 DOI: 10.1007/s10549-010-1300-6] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Accepted: 12/08/2010] [Indexed: 02/05/2023]
Abstract
Resveratrol is a natural polyphenolic compound and has been shown to exhibit cardio-protective as well as anti-neoplastic effects on various types of cancers. However, the exact mechanism of its anti-tumor effect is not clearly defined. Resveratrol has been shown to have strong hypolipidemic effect on normal adipocytes and as hyper-lipogenesis is a hallmark of cancer cell physiology, the effect of resveratrol on lipid synthesis in cancer stem-like cells (CD24(-)/CD44(+)/ESA(+)) that were isolated from both ER+ and ER- breast cancer cell lines was examined. The authors found that resveratrol significantly reduced the cell viability and mammosphere formation followed by inducing apoptosis in cancer stem-like cells. This inhibitory effect of resveratrol is accompanied by a significant reduction in lipid synthesis which is caused by the down-regulation of the fatty acid synthase (FAS) gene followed by up-regulation of pro-apoptotic genes, DAPK2 and BNIP3. The activation of apoptotic pathway in the cancer stem-like cells was suppressed by TOFA and by Fumonisin B1, suggesting that resveratrol-induced apoptosis is indeed through the modulation of FAS-mediated cell survival signaling. Importantly, resveratrol was able to significantly suppress the growth of cancer stem-like cells in an animal model of xenograft without showing apparental toxicity. Taken together, the results of this study indicate that resveratrol is capable of inducing apoptosis in the cancer stem-like cells through suppression of lipogenesis by modulating FAS expression, which highlights a novel mechanism of anti-tumor effect of resveratrol.
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Affiliation(s)
- Puspa R. Pandey
- Department of Medical Microbiology, Immunology & Cell Biology, Southern Illinois University School of Medicine, Springfield, Illinois, USA
| | - Hiroshi Okuda
- Department of Medical Microbiology, Immunology & Cell Biology, Southern Illinois University School of Medicine, Springfield, Illinois, USA
| | - Misako Watabe
- Department of Medical Microbiology, Immunology & Cell Biology, Southern Illinois University School of Medicine, Springfield, Illinois, USA
| | - Sudha K. Pai
- Department of Medical Microbiology, Immunology & Cell Biology, Southern Illinois University School of Medicine, Springfield, Illinois, USA
| | - Wen Liu
- Department of Medical Microbiology, Immunology & Cell Biology, Southern Illinois University School of Medicine, Springfield, Illinois, USA
| | - Aya Kobayashi
- Department of Medical Microbiology, Immunology & Cell Biology, Southern Illinois University School of Medicine, Springfield, Illinois, USA
| | - Fei Xing
- Department of Medical Microbiology, Immunology & Cell Biology, Southern Illinois University School of Medicine, Springfield, Illinois, USA
| | - Koji Fukuda
- Department of Medical Microbiology, Immunology & Cell Biology, Southern Illinois University School of Medicine, Springfield, Illinois, USA
| | | | | | | | | | | | | | | | - Masaki Endo
- Iwate Medical University, School of Medicine, Japan
| | | | - Susumu Tanji
- Iwate Medical University, School of Medicine, Japan
| | - Yin-Yuan Mo
- Department of Medical Microbiology, Immunology & Cell Biology, Southern Illinois University School of Medicine, Springfield, Illinois, USA
| | - Deliang Cao
- Department of Medical Microbiology, Immunology & Cell Biology, Southern Illinois University School of Medicine, Springfield, Illinois, USA
| | - Andrew C. Wilber
- Department of Surgery, Southern Illinois University School of Medicine, Springfield, Illinois, USA
| | - Kounosuke Watabe
- Department of Medical Microbiology, Immunology & Cell Biology, Southern Illinois University School of Medicine, Springfield, Illinois, USA
- Corresponding author: Kounosuke Watabe, Ph.D., Department of Medical Microbiology, Immunology & Cell Biology, Southern Illinois University School of Medicine, 801 N. Rutledge St., P.O. Box 19626, Springfield, Illinois 62794-9626, Tel: [217] 545-3969, Fax: [217] 545-3227,
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Yusuf R, Frenkel K. Morphologic transformation of human breast epithelial cells MCF-10A: dependence on an oxidative microenvironment and estrogen/epidermal growth factor receptors. Cancer Cell Int 2010; 10:30. [PMID: 20809984 PMCID: PMC2944135 DOI: 10.1186/1475-2867-10-30] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Accepted: 09/01/2010] [Indexed: 11/19/2022] Open
Abstract
Background MCF-10A, immortalized but non-transformed human breast epithelial cells, are widely used in research examining carcinogenesis. The studies presented here were initiated with the observation that MCF-10A cells left in continuous culture for prolonged periods without re-feeding were prone to the development of transformed foci. We hypothesized that the depletion of labile culture components led to the onset of processes culminating in the observed cell transformation. The purpose of this study was to define the factors which promoted transformation of this cell line. Results Changes in levels of phenol red (PHR), hydrocortisone (HC), and epidermal growth factor (EGF) with or without estrogen treatment indicated that both oxidative stress- and estrogen receptor alpha (ERα)-mediated pathways contribute to cell transformation. Gene array and Western blotting analyses of cells maintained in our laboratory and of those from other sources documented detectable ERα and ERbeta (ERβ) in this ERα-negative cataloged cell line. Results also indicate the possibility of a direct association of EGF receptor (EGFR) and ERα in these cells as well as the formation and high induction of a novel ternary complex that includes ERβ (ERα/ERβ/EGFR) in cells grown under conditions facilitating transformation. Conclusions Our studies resulted in the development of a growth protocol where the effects of chronic, physiologically relevant alterations in the microenvironment on cellular transformation were examined. From our results, we were able to propose a model of transformation within the MCF-10A cell line in which oxidative stress, ER and EGFR play essential roles. Overall, our work indicates that the immediate microenvironment of cells exerts powerful growth cues which ultimately determine their transformation potential.
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Affiliation(s)
- Rita Yusuf
- Department of Environmental Medicine, NYU School of Medicine, PHL Room 802, 550 First Avenue, New York, NY 10016, USA.
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Kim J, Lee JH, Park HS, Hwang J, Han IO, Bae YS, Oh ES. Syndecan-4 regulates platelet-derived growth factor-mediated MAP kinase activation by altering intracellular reactive oxygen species. FEBS Lett 2008; 582:2725-30. [PMID: 18619965 DOI: 10.1016/j.febslet.2008.06.055] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2008] [Accepted: 06/23/2008] [Indexed: 11/19/2022]
Abstract
The cell adhesion receptor, syndecan-4, regulates cellular interactions with both the extracellular matrix and soluble ligands. Accumulating evidence also suggests that cell adhesion is involved in generating reactive oxygen species (ROS). Here, we investigated the role of syndecan-4 in regulating growth factor-induced ROS generation. Rat embryo fibroblasts (REFs) overexpressing syndecan-4 exhibited increased ROS levels compared to control cells. Expression of the non-phagocytic NADH oxidase component Nox1 was increased in syndecan-4-overexpressing REFs and syndecan-4-mediated ROS generation was diminished when levels of Nox1 were knocked-down with small inhibitory RNAs. In addition, syndecan-4 enhanced platelet-derived growth factor (PDGF)-induced MAP kinase activity in parallel with ROS generation. Collectively, these data suggest that syndecan-4 regulates PDGF-induced MAP kinase activation by altering ROS generation.
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Affiliation(s)
- Jungyean Kim
- Department of Life Sciences, Division of Life and Pharmaceutical Sciences and the Center for Cell Signaling and Drug Discovery Research, Ewha Womans University, Daehyun-dong, Seodaemoon-Gu, Seoul 120-750, Republic of Korea
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11
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Okada F. Beyond foreign-body-induced carcinogenesis: Impact of reactive oxygen species derived from inflammatory cells in tumorigenic conversion and tumor progression. Int J Cancer 2007; 121:2364-72. [PMID: 17893867 DOI: 10.1002/ijc.23125] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Foreign-body-induced carcinogenesis is a traditional, maybe old, way of understanding cancer development. A number of novel approaches are available today to elucidate cancer development. However, there are things we learn from the old, and thus I bring out some examples of various clinical cases and experimental models of foreign-body-induced tumorigenesis. What is notable is that the foreign bodies themselves are unrelated to each other, whereas commonly underlying in them is to induce inflammatory reaction, especially stromal proliferation, where those exogenous materials are incorporated and undigested. Such foreign-body-induced carcinogenesis is also recognized in the step of tumor progression, the final step of carcinogenesis that tumor cells acquire malignant phenotypes including metastatic properties. And the phenomenon is universally observed in several cell lines of different origins. In this review I would like to show the evidence that tumor development and progression are accelerated inevitably by inflammation caused from foreign bodies, and that reactive oxygen species derived from inflammatory cells are one of the most important genotoxic mediators to accelerate the process.
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Affiliation(s)
- Futoshi Okada
- Department of Biomolecular Function, Graduate School of Medical Science, Yamagata University, Yamagata, Japan
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Su M, Yang Y, Yang G. Quantitative measurement of hydroxyl radical induced DNA double-strand breaks and the effect of N-acetyl-L-cysteine. FEBS Lett 2006; 580:4136-42. [PMID: 16828758 DOI: 10.1016/j.febslet.2006.06.060] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2006] [Revised: 06/15/2006] [Accepted: 06/16/2006] [Indexed: 01/09/2023]
Abstract
Reactive oxygen species, such as hydroxyl or superoxide radicals, can be generated by exogenous agents as well as from normal cellular metabolism. Those radicals are known to induce various lesions in DNA, including strand breaks and base modifications. These lesions have been implicated in a variety of diseases such as cancer, arteriosclerosis, arthritis, neurodegenerative disorders and others. To assess these oxidative DNA damages and to evaluate the effects of the antioxidant N-acetyl-L-cysteine (NAC), atomic force microscopy (AFM) was used to image DNA molecules exposed to hydroxyl radicals generated via Fenton chemistry. AFM images showed that the circular DNA molecules became linear after incubation with hydroxyl radicals, indicating the development of double-strand breaks. The occurrence of the double-strand breaks was found to depend on the concentration of the hydroxyl radicals and the duration of the reaction. Under the conditions of the experiments, NAC was found to exacerbate the free radical-induced DNA damage.
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Affiliation(s)
- Meihong Su
- Department of Physics, Drexel University, Philadelphia, PA 19104, USA
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Abstract
Adducts arise from the chemical modification of bases in DNA or amino acids in proteins by toxic chemicals. Many chemicals known to be carcinogenic in humans have been shown to form adducts or to cause oxidative damage to genomic DNA in model systems. Biomarkers of carcinogenesis reflect biological events that take place between exposure to external or endogenous carcinogens and the subsequent development of cancer. Therapeutic intervention for the purpose of cancer chemoprevention may modify these biomarkers. In this article, the potential efficacy of DNA adducts as biomarkers of carcinogenesis and chemoprevention is discussed using criteria defined for phases of biomarker development. The sensitivity of adduct detection in histologically normal tissue offers opportunities for the early detection of carcinogenesis. Extensive evidence for aflatoxin B(1) adducts as biomarkers of risk and progression of hepatic carcinogenesis and for oxidative DNA adducts as biomarkers of the development of prostate carcinogenesis is reviewed together with the clinical trials measuring these adducts as biomarkers of the efficacy of chemoprevention. Favorable modification of oxidative DNA adducts by dietary intervention and chemoprevention has been demonstrated in preclinical and clinical studies. Protein adducts and DNA adducts in blood constituents or urine may act as useful surrogates for the target organ. Additional information regarding reliability, reproducibility, specificity, and confounding variables are required at the clinical level to validate adducts as suitable biomarkers of chemoprevention. "We do not administer antihypertensive drugs to patients in clinical trials without checking their blood pressure, so why should we give antioxidants without checking that they have decreased oxidant status.
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Affiliation(s)
- Ricky A Sharma
- Cancer Biomarkers and Prevention Group, Oncology Department, University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom.
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Abstract
Inflammation is thought to be one of the major contributors to carcinogenesis. Accumulated studies in this field revealed that free radicals produced by inflammatory cells not only cause direct damage to DNA but also exert indirect effects such as de-regulation of cell proliferation and apoptosis, stimulation of angiogenesis, and modification of gene/protein expressions and protein activities, all of which are a critical step toward carcinogenesis. Free radicals have also been reported to act as both initiator and promoter of carcinogenic process. Recent evidence shows that free radicals convert benign tumors to more malignant ones (i.e. tumor progression) leading to the final stage of carcinogenesis. This article reviews the current findings linking inflammation and cancer, and shed light on inflammatory cell-derived free radicals as major endogenous reactive substances for tumor development and progression.
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Affiliation(s)
- Futoshi Okada
- Division of Cancer Pathobiology, Research Section of Pathophysiology, Institute for Genetic Medicine, Hokkaido University, Kita-15, Nishi-7, Kita-ku, Sapporo 060-0815, Japan.
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