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Abdollahi E, Mozdarani H, Alizadeh BZ. Role of circ-FOXO3 and miR-23a in radiosensitivity of breast cancer. Breast Cancer 2023; 30:714-726. [PMID: 37222952 DOI: 10.1007/s12282-023-01463-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 04/25/2023] [Indexed: 05/25/2023]
Abstract
Identifying the radiosensitivity of cells before radiotherapy (RT) in breast cancer (BC) patients allows appropriate switching between routinely used treatment regimens and reduces adverse side effects in exposed patients. In this study, blood was collected from 60 women diagnosed with Invasive Ductal Carcinoma (IDC) BC and 20 healthy women. To predict cellular radiosensitivity, a standard G2-chromosomal assay was performed. From these 60 samples, 20 BC patients were found to be radiosensitive based on the G2 assay. Therefore, molecular studies were finally performed on two equal groups (20 samples each) of patients with and without cellular radiosensitivity. QPCR was performed to examine the expression levels of circ-FOXO3 and miR-23a in peripheral blood mononuclear cells (PBMCs) and RNA sensitivity and specificity were determined by plotting Receiver Operating Characteristic (ROC) curves. Binary logistic regression was performed to identify RNA involvement in BC and cellular radiosensitivity (CR) in BC patients. Meanwhile, qPCR was used to compare differential RNA expression in the radiosensitive MCF-7 and radioresistant MDA-MB-231 cell lines. An annexin -V FITC/PI binding assay was used to measure cell apoptosis 24 and 48 h after 2 Gy, 4 Gy, and 8 Gy gamma-irradiation. Results indicated that circ-FOXO3 was downregulated and miR-23a was upregulated in BC patients. RNA expression levels were directly associated with CR. Cell line results showed that circ-FOXO3 overexpression induced apoptosis in the MCF-7 cell line and miR-23a overexpression inhibited apoptosis in the MDA-MB-231 cell line. Evaluation of the ROC curves revealed that both RNAs had acceptable specificity and sensitivity in predicting CR in BC patients. Binary logistic regression showed that both RNAs were also successful in predicting breast cancer. Although only circ-FOXO3 has been shown to predict CR in BC patients, circ-FOXO3 may function as a tumor suppressor and miR-23a may function as oncomiR in BC. Circ-FOXO3 and miR-23a may be promising potential biomarkers for BC prediction. Furthermore, Circ-FOXO3 could be a potential biomarker for predicting CR in BC patients.
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Affiliation(s)
- Elahe Abdollahi
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Hossein Mozdarani
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Behrooz Z Alizadeh
- Unit of Personalized Medicine, Department of Epidemiology, University Medical Center Groningen, Groningen, The Netherlands
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Chumsuwan N, Khongkow P, Kaewsuwan S, Kanokwiroon K. Interruptin C, a Radioprotective Agent, Derived from Cyclosorus terminans Protect Normal Breast MCF-10A and Human Keratinocyte HaCaT Cells against Radiation-Induced Damage. Molecules 2022; 27:3298. [PMID: 35630775 PMCID: PMC9142933 DOI: 10.3390/molecules27103298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/12/2022] [Accepted: 05/14/2022] [Indexed: 01/27/2023] Open
Abstract
Radiotherapy is a common method to treat cancers, with the goal of maximizing the dose to tumors while minimizing the dose to normal tissues. Radioprotectors can reduce the toxicity to normal tissues during radiotherapy. Several plant-derived compounds can function as radioprotectors by scavenging free radicals. We investigated the radioprotective activity of interruptin C from the fern Cyclosorus terminans. The molecular mechanism of interruptin C's activity in X-ray-irradiated cells was evaluated. Superoxide dismutase activity was examined to investigate the antioxidant enzyme activity. Clonogenic cell survival was also investigated following radiation exposure. DNA damage and cell cycle progression were detected using micronuclei formation assays. DNA repair after irradiation was analyzed in a γH2AX assay. The levels of the proteins related to the radioprotective responses were analyzed by Western blotting. Interruptin C increased the antioxidant enzyme activity and significantly decreased the DNA damage by reducing the γH2AX foci and micronucleus formation in irradiated MCF-10A normal breast and HaCaT human keratinocyte cells. The apoptotic protein levels decreased, whereas the antiapoptotic protein levels increased. Interruptin C pretreatment increased the survival rate of irradiated MCF-10A and HaCaT cells. Moreover, the compound did not promote the survival of MDA-MB-231 and Hs578T breast cancer cells. Therefore, interruptin C may exert radioprotective activity without enhancing cancer cell proliferation.
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Affiliation(s)
- Nipha Chumsuwan
- Department of Biomedical Sciences and Biomedical Engineering, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla 90110, Thailand; (N.C.); (P.K.)
- Department of Radiology, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla 90110, Thailand
| | - Pasarat Khongkow
- Department of Biomedical Sciences and Biomedical Engineering, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla 90110, Thailand; (N.C.); (P.K.)
| | - Sireewan Kaewsuwan
- Department of Pharmacognosy and Pharmaceutical Botany, Faculty of Pharmaceutical Sciences, Prince of Songkla University, Hat Yai, Songkhla 90110, Thailand;
- Phytomedicine and Pharmaceutical Biotechnology Excellence Center, Faculty of Pharmaceutical Sciences, Prince of Songkla University, Hat Yai, Songkhla 90110, Thailand
| | - Kanyanatt Kanokwiroon
- Department of Biomedical Sciences and Biomedical Engineering, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla 90110, Thailand; (N.C.); (P.K.)
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3
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A 4-Gene Signature of CDKN1, FDXR, SESN1 and PCNA Radiation Biomarkers for Prediction of Patient Radiosensitivity. Int J Mol Sci 2021; 22:ijms221910607. [PMID: 34638945 PMCID: PMC8508881 DOI: 10.3390/ijms221910607] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 09/17/2021] [Accepted: 09/27/2021] [Indexed: 12/16/2022] Open
Abstract
The quest for the discovery and validation of radiosensitivity biomarkers is ongoing and while conventional bioassays are well established as biomarkers, molecular advances have unveiled new emerging biomarkers. Herein, we present the validation of a new 4-gene signature panel of CDKN1, FDXR, SESN1 and PCNA previously reported to be radiation-responsive genes, using the conventional G2 chromosomal radiosensitivity assay. Radiation-induced G2 chromosomal radiosensitivity at 0.05 Gy and 0.5 Gy IR is presented for a healthy control (n = 45) and a prostate cancer (n = 14) donor cohort. For the prostate cancer cohort, data from two sampling time points (baseline and Androgen Deprivation Therapy (ADT)) is provided, and a significant difference (p > 0.001) between 0.05 Gy and 0.5 Gy was evident for all donor cohorts. Selected donor samples from each cohort also exposed to 0.05 Gy and 0.5 Gy IR were analysed for relative gene expression of the 4-gene signature. In the healthy donor cohort, there was a significant difference in gene expression between IR dose for CDKN1, FXDR and SESN1 but not PCNA and no significant difference found between all prostate cancer donors, unless they were classified as radiation-induced G2 chromosomal radiosensitive. Interestingly, ADT had an effect on radiation response for some donors highlighting intra-individual heterogeneity of prostate cancer donors.
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4
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El-Nachef L, Al-Choboq J, Restier-Verlet J, Granzotto A, Berthel E, Sonzogni L, Ferlazzo ML, Bouchet A, Leblond P, Combemale P, Pinson S, Bourguignon M, Foray N. Human Radiosensitivity and Radiosusceptibility: What Are the Differences? Int J Mol Sci 2021; 22:7158. [PMID: 34281212 PMCID: PMC8267933 DOI: 10.3390/ijms22137158] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 06/25/2021] [Accepted: 06/28/2021] [Indexed: 12/27/2022] Open
Abstract
The individual response to ionizing radiation (IR) raises a number of medical, scientific, and societal issues. While the term "radiosensitivity" was used by the pioneers at the beginning of the 20st century to describe only the radiation-induced adverse tissue reactions related to cell death, a confusion emerged in the literature from the 1930s, as "radiosensitivity" was indifferently used to describe the toxic, cancerous, or aging effect of IR. In parallel, the predisposition to radiation-induced adverse tissue reactions (radiosensitivity), notably observed after radiotherapy appears to be caused by different mechanisms than those linked to predisposition to radiation-induced cancer (radiosusceptibility). This review aims to document these differences in order to better estimate the different radiation-induced risks. It reveals that there are very few syndromes associated with the loss of biological functions involved directly in DNA damage recognition and repair as their role is absolutely necessary for cell viability. By contrast, some cytoplasmic proteins whose functions are independent of genome surveillance may also act as phosphorylation substrates of the ATM protein to regulate the molecular response to IR. The role of the ATM protein may help classify the genetic syndromes associated with radiosensitivity and/or radiosusceptibility.
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Affiliation(s)
- Laura El-Nachef
- Inserm, U1296 unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 28, rue Laennec, 69008 Lyon, France; (L.E.-N.); (J.A.-C.); Juliette.Restier-- (J.R.-V.); (A.G.); (E.B.); (L.S.); (M.L.F.); (A.B.); (M.B.)
| | - Joelle Al-Choboq
- Inserm, U1296 unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 28, rue Laennec, 69008 Lyon, France; (L.E.-N.); (J.A.-C.); Juliette.Restier-- (J.R.-V.); (A.G.); (E.B.); (L.S.); (M.L.F.); (A.B.); (M.B.)
| | - Juliette Restier-Verlet
- Inserm, U1296 unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 28, rue Laennec, 69008 Lyon, France; (L.E.-N.); (J.A.-C.); Juliette.Restier-- (J.R.-V.); (A.G.); (E.B.); (L.S.); (M.L.F.); (A.B.); (M.B.)
| | - Adeline Granzotto
- Inserm, U1296 unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 28, rue Laennec, 69008 Lyon, France; (L.E.-N.); (J.A.-C.); Juliette.Restier-- (J.R.-V.); (A.G.); (E.B.); (L.S.); (M.L.F.); (A.B.); (M.B.)
| | - Elise Berthel
- Inserm, U1296 unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 28, rue Laennec, 69008 Lyon, France; (L.E.-N.); (J.A.-C.); Juliette.Restier-- (J.R.-V.); (A.G.); (E.B.); (L.S.); (M.L.F.); (A.B.); (M.B.)
- Neolys Diagnostics, 67960 Entzheim, France
| | - Laurène Sonzogni
- Inserm, U1296 unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 28, rue Laennec, 69008 Lyon, France; (L.E.-N.); (J.A.-C.); Juliette.Restier-- (J.R.-V.); (A.G.); (E.B.); (L.S.); (M.L.F.); (A.B.); (M.B.)
| | - Mélanie L. Ferlazzo
- Inserm, U1296 unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 28, rue Laennec, 69008 Lyon, France; (L.E.-N.); (J.A.-C.); Juliette.Restier-- (J.R.-V.); (A.G.); (E.B.); (L.S.); (M.L.F.); (A.B.); (M.B.)
| | - Audrey Bouchet
- Inserm, U1296 unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 28, rue Laennec, 69008 Lyon, France; (L.E.-N.); (J.A.-C.); Juliette.Restier-- (J.R.-V.); (A.G.); (E.B.); (L.S.); (M.L.F.); (A.B.); (M.B.)
| | - Pierre Leblond
- Centre Léon-Bérard, 28, rue Laennec, 69008 Lyon, France; (P.L.); (P.C.)
| | - Patrick Combemale
- Centre Léon-Bérard, 28, rue Laennec, 69008 Lyon, France; (P.L.); (P.C.)
| | - Stéphane Pinson
- Hospices Civils de Lyon, Quai des Célestins, 69002 Lyon, France;
| | - Michel Bourguignon
- Inserm, U1296 unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 28, rue Laennec, 69008 Lyon, France; (L.E.-N.); (J.A.-C.); Juliette.Restier-- (J.R.-V.); (A.G.); (E.B.); (L.S.); (M.L.F.); (A.B.); (M.B.)
- Université Paris Saclay Versailles St Quentin en Yvelines, 78035 Versailles, France
| | - Nicolas Foray
- Inserm, U1296 unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 28, rue Laennec, 69008 Lyon, France; (L.E.-N.); (J.A.-C.); Juliette.Restier-- (J.R.-V.); (A.G.); (E.B.); (L.S.); (M.L.F.); (A.B.); (M.B.)
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Manoharan D, Chang LC, Wang LC, Shan YS, Lin FC, Wu LC, Sheu HS, Su WP, Yeh CS. Synchronization of Nanoparticle Sensitization and Radiosensitizing Chemotherapy through Cell Cycle Arrest Achieving Ultralow X-ray Dose Delivery to Pancreatic Tumors. ACS NANO 2021; 15:9084-9100. [PMID: 33974409 DOI: 10.1021/acsnano.1c02283] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Pancreatic cancer is among the leading causes of cancer-related death and remains a formidable therapeutic challenge. To date, surgical resection and chemotherapy have been the standards of care. Methotrexate (MTX), which is recognized as a refractory drug for pancreatic cells, was conjugated to the surface of LiYF4:Ce3+ nanoparticles (NP-MTX) through a photocleavable linker molecule. When LiYF4:Ce3+ NPs are stimulated by X-rays, they emit light, which induces the photocleavage of the photolabile linker molecule to release MTX. MTX can target pancreatic tumors, which overexpress folic acid (FA) receptors and are internalized into the cell through receptor-mediated endocytosis. The synergistic effect of the NP-MTX treatment initiated by X-ray irradiation occurs due to the combination of nanoparticle sensitization and the radiosensitizing chemotherapy of the photocleaved MTX molecule. This dual sensitization effect mediated by NP-MTX enabled 40% dose enhancement, which corresponded with an increase in the generation of cytotoxic cellular reactive oxygen species (ROS) and enhanced S phase arrest within the cell cycle. The delivery of an ultralow radiation dose of 0.1 Gy resulted in the photocleavage of MTX from NP-MTX, and this strategy demonstrated in vivo efficacy against AsPC-1 and PANC-1 xenografted pancreatic tumors.
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Affiliation(s)
- Divinah Manoharan
- Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan
| | - Li-Chan Chang
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 704, Taiwan
| | - Liu-Chun Wang
- Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan
| | - Yan-Shen Shan
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 704, Taiwan
- Department of Surgery, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 704, Taiwan
| | - Forn-Chia Lin
- Department of Radiation Oncology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 704, Taiwan
| | - Lai-Chin Wu
- National Synchrotron Radiation Research Center, Hsinchu 300, Taiwan
| | - Hwo-Shuenn Sheu
- National Synchrotron Radiation Research Center, Hsinchu 300, Taiwan
| | - Wen-Pin Su
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 704, Taiwan
- Departments of Oncology and Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 704, Taiwan
| | - Chen-Sheng Yeh
- Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan
- Center of Applied Nanomedicine, National Cheng Kung University, Tainan 704, Taiwan
- Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 807, Taiwan
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6
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van Gisbergen MW, Zwilling E, Dubois LJ. Metabolic Rewiring in Radiation Oncology Toward Improving the Therapeutic Ratio. Front Oncol 2021; 11:653621. [PMID: 34041023 PMCID: PMC8143268 DOI: 10.3389/fonc.2021.653621] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 03/22/2021] [Indexed: 12/12/2022] Open
Abstract
To meet the anabolic demands of the proliferative potential of tumor cells, malignant cells tend to rewire their metabolic pathways. Although different types of malignant cells share this phenomenon, there is a large intracellular variability how these metabolic patterns are altered. Fortunately, differences in metabolic patterns between normal tissue and malignant cells can be exploited to increase the therapeutic ratio. Modulation of cellular metabolism to improve treatment outcome is an emerging field proposing a variety of promising strategies in primary tumor and metastatic lesion treatment. These strategies, capable of either sensitizing or protecting tissues, target either tumor or normal tissue and are often focused on modulating of tissue oxygenation, hypoxia-inducible factor (HIF) stabilization, glucose metabolism, mitochondrial function and the redox balance. Several compounds or therapies are still in under (pre-)clinical development, while others are already used in clinical practice. Here, we describe different strategies from bench to bedside to optimize the therapeutic ratio through modulation of the cellular metabolism. This review gives an overview of the current state on development and the mechanism of action of modulators affecting cellular metabolism with the aim to improve the radiotherapy response on tumors or to protect the normal tissue and therefore contribute to an improved therapeutic ratio.
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Affiliation(s)
- Marike W van Gisbergen
- The M-Lab, Department of Precision Medicine, GROW-School for Oncology and Developmental Biology, Maastricht University, Maastricht, Netherlands.,Department of Dermatology, GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center+, Maastricht, Netherlands
| | - Emma Zwilling
- The M-Lab, Department of Precision Medicine, GROW-School for Oncology and Developmental Biology, Maastricht University, Maastricht, Netherlands
| | - Ludwig J Dubois
- The M-Lab, Department of Precision Medicine, GROW-School for Oncology and Developmental Biology, Maastricht University, Maastricht, Netherlands
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7
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Fekrvand S, Mozdarani H, Delavari S, Sohani M, Nazari F, Kiaee F, Bagheri Y, Azizi G, Hassanpour G, Mozdarani S, Abolhassani H, Aghamohammadi A, Yazdani R. Evaluation of Radiation Sensitivity in Patients with Hyper IgM Syndrome. Immunol Invest 2020; 50:580-596. [PMID: 32584193 DOI: 10.1080/08820139.2020.1779288] [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] [Indexed: 01/02/2023]
Abstract
BACKGROUND HIGM syndrome is a rare form of primary immunodeficiencies characterized by normal/increased amounts of serum IgM and decreased serum levels of other switched immunoglobulin classes. Since the affected patients are continuously infected with various types of pathogens and are susceptible for cancers, diagnostic and therapeutic tests including imaging techniques are recommended for the diagnosis and treatment of these patients, which predispose them to higher accumulated doses of radiation. Given the evidence of class switching recombination machinery defect and its association with an increased rate of DNA repair, we aimed to evaluate radiation sensitivity among a group of patients diagnosed with HIGM syndrome. METHODS 19 HIGM patients (14 CD40 L and 3 AID deficiencies and 2 unsolved cases without known genetic defects) and 17 control subjects (10 healthy subjects as negative control group, 7 ataxia-telangiectasia patients as positive control group) were enrolled. G2 assay was carried out for the determination of radiosensitivity. RESULTS Based on radiation-induced chromosomal changes among the studied HIGM patients and their comparison with the controls, almost all (95%) the patients had degrees of radiosensitivity: 6 patients with low to moderate, 1 patient with moderate, 11 patients with severe and 1 patient without radiation sensitivity. CONCLUSION Today, X-ray radiation plays a very important role in diagnostic and therapeutic procedures; while increased exposure has devastating effects especially in radiosensitive patients. Considering higher sensitivity in HIGM patients, utilizing radiation-free techniques could partly avoid unnecessary and high-level exposure to radiation, thus preventing or reducing its harmful effects on the affected patients.
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Affiliation(s)
- Saba Fekrvand
- Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center,Tehran University of Medical Sciences, Tehran, Iran
| | - Hossein Mozdarani
- Department of Medical Genetics, Faculty of Medical Sciences,Tarbiat Modares University, Tehran, Iran
| | - Samaneh Delavari
- Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center,Tehran University of Medical Sciences, Tehran, Iran
| | - Mahsa Sohani
- Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center,Tehran University of Medical Sciences, Tehran, Iran
| | - Farzad Nazari
- Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center,Tehran University of Medical Sciences, Tehran, Iran
| | - Fatemeh Kiaee
- Department of Immunology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Yasser Bagheri
- Clinical Research Development Unit (CRDU), 5 Azar Hospital, Golestan University of Medical Sciences, Gorgan, Iran
| | - Gholamreza Azizi
- Non-communicable Diseases Research Center, Alborz University of Medical Sciences, Karaj, Iran
| | - Gholamreza Hassanpour
- Center for Research of Endemic Parasites of Iran, Tehran University of Medical Sciences, Tehran, Iran
| | | | - Hassan Abolhassani
- Research Center for Primary Immunodeficiencies, Iran University of Medical Sciences, Tehran, Iran.,Division of Clinical Immunology, Department of Laboratory Medicine, Karolinska Institute at Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Asghar Aghamohammadi
- Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center,Tehran University of Medical Sciences, Tehran, Iran
| | - Reza Yazdani
- Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center,Tehran University of Medical Sciences, Tehran, Iran
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8
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G2 Chromosomal Radiosensitivity Assay for Testing Individual Radiation Sensitivity. Methods Mol Biol 2019. [PMID: 31267418 DOI: 10.1007/978-1-4939-9432-8_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
The G2 chromosomal radiosensitivity assay or, simply G2 assay, measures the number of chromatid type aberrations induced by radiation in G2 phase. Typically, asynchronous growing cells are irradiated with less than 1 Gy and allowed 0.5-1 h for cells in mitosis, at the time of irradiation, to transit into G1. Later, the G2 phase cells, at the time irradiation, are blocked by colcemid for 1-4 h at metaphase. Cells are collected by standard hypotonic solution and Carnoy solution fixation or directly fixed onto the culture vessels. The G2 assay can detect severe radiosensitivity in ATM homozygous mutated cells and relatively small differences among cellular radiosensitivity such as heterozygous mutation carriers of ATM and BRCA1/2 mutation carriers. The G2 assay also has the capability to detect cancer prone individuals. This assay only requires a conventional cell culture facility and the standard microscopic observation.
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9
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Flunkert J, Maierhofer A, Dittrich M, Müller T, Horvath S, Nanda I, Haaf T. Genetic and epigenetic changes in clonal descendants of irradiated human fibroblasts. Exp Cell Res 2018; 370:322-332. [PMID: 29964050 DOI: 10.1016/j.yexcr.2018.06.034] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Revised: 06/12/2018] [Accepted: 06/27/2018] [Indexed: 10/28/2022]
Abstract
To study delayed genetic and epigenetic radiation effects, which may trigger radiation-induced carcinogenesis, we have established single-cell clones from irradiated and non-irradiated primary human fibroblasts. Stable clones were endowed with the same karyotype in all analyzed metaphases after 20 population doublings (PDs), whereas unstable clones displayed mosaics of normal and abnormal karyotypes. To account for variation in radiation sensitivity, all experiments were performed with two different fibroblast strains. After a single X-ray dose of 2 Gy more than half of the irradiated clones exhibited radiation-induced genome instability (RIGI). Irradiated clones displayed an increased rate of loss of chromosome Y (LOY) and copy number variations (CNVs), compared to controls. CNV breakpoints clustered in specific chromosome regions, in particular 3p14.2 and 7q11.21, coinciding with common fragile sites. CNVs affecting the FHIT gene in FRA3B were observed in independent unstable clones and may drive RIGI. Bisulfite pyrosequencing of control clones and the respective primary culture revealed global hypomethylation of ALU, LINE-1, and alpha-satellite repeats as well as rDNA hypermethylation during in vitro ageing. Irradiated clones showed further reduced ALU and alpha-satellite methylation and increased rDNA methylation, compared to controls. Methylation arrays identified several hundred differentially methylated genes and several enriched pathways associated with in vitro ageing. Methylation changes in 259 genes and the MAP kinase signaling pathway were associated with delayed radiation effects (after 20 PDs). Collectively, our results suggest that both genetic (LOY and CNVs) and epigenetic changes occur in the progeny of exposed cells that were not damaged directly by irradiation, likely contributing to radiation-induced carcinogenesis. We did not observe epigenetic differences between stable and unstable irradiated clones. The fact that the DNA methylation (DNAm) age of clones derived from the same primary culture varied greatly suggests that DNAm age of a single cell (represented by a clone) can be quite different from the DNAm age of a tissue. We propose that DNAm age reflects the emergent property of a large number of individual cells whose respective DNAm ages can be highly variable.
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Affiliation(s)
- Julia Flunkert
- Institute of Human Genetics, Julius Maximilians University, 97074 Würzburg, Germany
| | - Anna Maierhofer
- Institute of Human Genetics, Julius Maximilians University, 97074 Würzburg, Germany
| | - Marcus Dittrich
- Institute of Human Genetics, Julius Maximilians University, 97074 Würzburg, Germany; Department of Bioinformatics, Julius Maximilians University, 97074 Würzburg, Germany
| | - Tobias Müller
- Department of Bioinformatics, Julius Maximilians University, 97074 Würzburg, Germany
| | - Steve Horvath
- Department of Human Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Indrajit Nanda
- Institute of Human Genetics, Julius Maximilians University, 97074 Würzburg, Germany
| | - Thomas Haaf
- Institute of Human Genetics, Julius Maximilians University, 97074 Würzburg, Germany.
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10
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Meade AD, Maguire A, Bryant J, Cullen D, Medipally D, White L, McClean B, Shields L, Armstrong J, Dunne M, Noone E, Bradshaw S, Finn M, Shannon AM, Howe O, Lyng FM. Prediction of DNA damage and G2 chromosomal radio-sensitivity ex vivo in peripheral blood mononuclear cells with label-free Raman micro-spectroscopy. Int J Radiat Biol 2018. [DOI: 10.1080/09553002.2018.1451006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Aidan D. Meade
- School of Physics, Dublin Institute of Technology, Dublin, Ireland
- DIT Centre for Radiation and Environmental Science, Focas Research Institute, Dublin Institute of Technology, Dublin, Ireland
| | - Adrian Maguire
- School of Physics, Dublin Institute of Technology, Dublin, Ireland
- DIT Centre for Radiation and Environmental Science, Focas Research Institute, Dublin Institute of Technology, Dublin, Ireland
| | - Jane Bryant
- DIT Centre for Radiation and Environmental Science, Focas Research Institute, Dublin Institute of Technology, Dublin, Ireland
| | - Daniel Cullen
- DIT Centre for Radiation and Environmental Science, Focas Research Institute, Dublin Institute of Technology, Dublin, Ireland
- School of Biological Sciences, Dublin Institute of Technology, Dublin, Ireland
| | - Dinesh Medipally
- DIT Centre for Radiation and Environmental Science, Focas Research Institute, Dublin Institute of Technology, Dublin, Ireland
- School of Biological Sciences, Dublin Institute of Technology, Dublin, Ireland
| | - Lisa White
- DIT Centre for Radiation and Environmental Science, Focas Research Institute, Dublin Institute of Technology, Dublin, Ireland
- School of Biological Sciences, Dublin Institute of Technology, Dublin, Ireland
| | - Brendan McClean
- Department of Medical Physics, Saint Luke's Radiation Oncology Network, St Luke's Hospital, Dublin, Ireland
| | - Laura Shields
- Department of Medical Physics, Saint Luke's Radiation Oncology Network, St Luke's Hospital, Dublin, Ireland
| | - John Armstrong
- Department of Radiation Oncology, Saint Luke's Radiation Oncology Network, St Luke's Hospital, Dublin, Ireland
- Cancer Trials Ireland, Dublin, Ireland
| | - Mary Dunne
- Department of Radiation Oncology, Saint Luke's Radiation Oncology Network, St Luke's Hospital, Dublin, Ireland
| | - Emma Noone
- Department of Radiation Oncology, Saint Luke's Radiation Oncology Network, St Luke's Hospital, Dublin, Ireland
| | - Shirley Bradshaw
- Department of Radiation Oncology, Saint Luke's Radiation Oncology Network, St Luke's Hospital, Dublin, Ireland
| | - Marie Finn
- Department of Radiation Oncology, Saint Luke's Radiation Oncology Network, St Luke's Hospital, Dublin, Ireland
| | | | - Orla Howe
- DIT Centre for Radiation and Environmental Science, Focas Research Institute, Dublin Institute of Technology, Dublin, Ireland
- School of Biological Sciences, Dublin Institute of Technology, Dublin, Ireland
| | - Fiona M. Lyng
- School of Physics, Dublin Institute of Technology, Dublin, Ireland
- DIT Centre for Radiation and Environmental Science, Focas Research Institute, Dublin Institute of Technology, Dublin, Ireland
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11
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Individual response to ionizing radiation. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2016; 770:369-386. [PMID: 27919342 DOI: 10.1016/j.mrrev.2016.09.001] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 08/31/2016] [Accepted: 09/02/2016] [Indexed: 12/18/2022]
Abstract
The human response to ionizing radiation (IR) varies among individuals. The first evidence of the individual response to IR was reported in the beginning of the 20th century. Considering nearly one century of observations, we here propose three aspects of individual IR response: radiosensitivity for early or late adverse tissue events after radiotherapy on normal tissues (non-cancer effects attributable to cell death); radiosusceptibility for IR-induced cancers; and radiodegeneration for non-cancer effects that are often attributable to mechanisms other than cell death (e.g., cataracts and circulatory disease). All the molecular and cellular mechanisms behind IR-induced individual effects are not fully elucidated. However, some specific assays may help their quantification according to the dose and to the genetic status. Accumulated data on individual factors have suggested that the individual IR response cannot be ignored and raises some clinical and societal issues. The individual IR response therefore needs to be taken into account to better evaluate the risks related to IR exposure.
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HERD OLIVIA, FRANCIES FLAVIA, KOTZEN JEFFREY, SMITH TRUDY, NXUMALO ZWIDE, MULLER XANTHENE, SLABBERT JACOBUS, VRAL ANNE, BAEYENS ANS. Chromosomal radiosensitivity of human immunodeficiency virus positive/negative cervical cancer patients in South Africa. Mol Med Rep 2016; 13:130-6. [PMID: 26549042 PMCID: PMC4686097 DOI: 10.3892/mmr.2015.4504] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 07/28/2015] [Indexed: 12/01/2022] Open
Abstract
Cervical cancer is the second most common cancer amongst South African women and is the leading cause of cancer-associated mortality in this region. Several international studies on radiation‑induced DNA damage in lymphocytes of cervical cancer patients have remained inconclusive. Despite the high incidence of cervical cancer in South Africa, and the extensive use of radiotherapy to treat it, the chromosomal radiosensitivity of South African cervical cancer patients has not been studied to date. Since a high number of these patients are human immunodeficiency virus (HIV)‑positive, the effect of HIV infection on chromosomal radiosensitivity was also investigated. Blood samples from 35 cervical cancer patients (20 HIV‑negative and 15 HIV‑positive) and 20 healthy controls were exposed to X‑rays at doses of 6 MV of 2 and 4 Gy in vitro. Chromosomal radiosensitivity was assessed using the micronucleus (MN) assay. MN scores were obtained using the Metafer 4 platform, an automated microscopic system. Three scoring methods of the MNScore module of Metafer were applied and compared. Cervical cancer patients had higher MN values than healthy controls, with HIV‑positive patients having the highest MN values. Differences between groups were significant when using a scoring method that corrects for false positive and false negative MN. The present study suggested increased chromosomal radiosensitivity in HIV-positive South African cervical cancer patients.
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Affiliation(s)
- OLIVIA HERD
- Department of Radiation Biophysics, NRF-iThemba LABS, Somerset West 7129, South Africa
- Department of Radiation Sciences, University of Witwatersrand, Johannesburg 2193, South Africa
| | - FLAVIA FRANCIES
- Department of Radiation Biophysics, NRF-iThemba LABS, Somerset West 7129, South Africa
- Department of Radiation Sciences, University of Witwatersrand, Johannesburg 2193, South Africa
| | - JEFFREY KOTZEN
- Department of Radiation Oncology, Charlotte Maxeke Johannesburg Academic Hospital, Johannesburg 2193, South Africa
| | - TRUDY SMITH
- Department of Obstetrics and Gynaecology, Charlotte Maxeke Johannesburg Academic Hospital, Johannesburg 2193, South Africa
| | - ZWIDE NXUMALO
- Department of Obstetrics and Gynaecology, Charlotte Maxeke Johannesburg Academic Hospital, Johannesburg 2193, South Africa
| | - XANTHENE MULLER
- Department of Radiation Biophysics, NRF-iThemba LABS, Somerset West 7129, South Africa
| | - JACOBUS SLABBERT
- Department of Radiation Biophysics, NRF-iThemba LABS, Somerset West 7129, South Africa
| | - ANNE VRAL
- Department of Basic Medical Sciences, Ghent University, Ghent B-9000, Belgium
| | - ANS BAEYENS
- Department of Radiation Biophysics, NRF-iThemba LABS, Somerset West 7129, South Africa
- Department of Radiation Sciences, University of Witwatersrand, Johannesburg 2193, South Africa
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13
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Baskar R, Dai J, Wenlong N, Yeo R, Yeoh KW. Biological response of cancer cells to radiation treatment. Front Mol Biosci 2014; 1:24. [PMID: 25988165 PMCID: PMC4429645 DOI: 10.3389/fmolb.2014.00024] [Citation(s) in RCA: 349] [Impact Index Per Article: 34.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 10/31/2014] [Indexed: 12/15/2022] Open
Abstract
Cancer is a class of diseases characterized by uncontrolled cell growth and has the ability to spread or metastasize throughout the body. In recent years, remarkable progress has been made toward the understanding of proposed hallmarks of cancer development, care, and treatment modalities. Radiation therapy or radiotherapy is an important and integral component of cancer management, mostly conferring a survival benefit. Radiation therapy destroys cancer by depositing high-energy radiation on the cancer tissues. Over the years, radiation therapy has been driven by constant technological advances and approximately 50% of all patients with localized malignant tumors are treated with radiation at some point in the course of their disease. In radiation oncology, research and development in the last three decades has led to considerable improvement in our understanding of the differential responses of normal and cancer cells. The biological effectiveness of radiation depends on the linear energy transfer (LET), total dose, number of fractions and radiosensitivity of the targeted cells or tissues. Radiation can either directly or indirectly (by producing free radicals) damages the genome of the cell. This has been challenged in recent years by a newly identified phenomenon known as radiation induced bystander effect (RIBE). In RIBE, the non-irradiated cells adjacent to or located far from the irradiated cells/tissues demonstrate similar responses to that of the directly irradiated cells. Understanding the cancer cell responses during the fractions or after the course of irradiation will lead to improvements in therapeutic efficacy and potentially, benefitting a significant proportion of cancer patients. In this review, the clinical implications of radiation induced direct and bystander effects on the cancer cell are discussed.
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Affiliation(s)
- Rajamanickam Baskar
- Division of Cellular and Molecular Research, Department of Radiation Oncology, National Cancer Centre Singapore, Singapore
| | - Jiawen Dai
- Division of Cellular and Molecular Research, Department of Radiation Oncology, National Cancer Centre Singapore, Singapore
| | - Nei Wenlong
- Division of Cellular and Molecular Research, Department of Radiation Oncology, National Cancer Centre Singapore, Singapore
| | - Richard Yeo
- Division of Cellular and Molecular Research, Department of Radiation Oncology, National Cancer Centre Singapore, Singapore
| | - Kheng-Wei Yeoh
- Division of Cellular and Molecular Research, Department of Radiation Oncology, National Cancer Centre Singapore, Singapore
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14
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Multiplexed DNA repair assays for multiple lesions and multiple doses via transcription inhibition and transcriptional mutagenesis. Proc Natl Acad Sci U S A 2014; 111:E1823-32. [PMID: 24757057 DOI: 10.1073/pnas.1401182111] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The capacity to repair different types of DNA damage varies among individuals, making them more or less susceptible to the detrimental health consequences of damage exposures. Current methods for measuring DNA repair capacity (DRC) are relatively labor intensive, often indirect, and usually limited to a single repair pathway. Here, we describe a fluorescence-based multiplex flow-cytometric host cell reactivation assay (FM-HCR) that measures the ability of human cells to repair plasmid reporters, each bearing a different type of DNA damage or different doses of the same type of DNA damage. FM-HCR simultaneously measures repair capacity in any four of the following pathways: nucleotide excision repair, mismatch repair, base excision repair, nonhomologous end joining, homologous recombination, and methylguanine methyltransferase. We show that FM-HCR can measure interindividual DRC differences in a panel of 24 cell lines derived from genetically diverse, apparently healthy individuals, and we show that FM-HCR may be used to identify inhibitors or enhancers of DRC. We further develop a next-generation sequencing-based HCR assay (HCR-Seq) that detects rare transcriptional mutagenesis events due to lesion bypass by RNA polymerase, providing an added dimension to DRC measurements. FM-HCR and HCR-Seq provide powerful tools for exploring relationships among global DRC, disease susceptibility, and optimal treatment.
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15
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Lin YF, Nagasawa H, Little JB, Kato TA, Shih HY, Xie XJ, Wilson Jr. PF, Brogan JR, Kurimasa A, Chen DJ, Bedford JS, Chen BPC. Differential radiosensitivity phenotypes of DNA-PKcs mutations affecting NHEJ and HRR systems following irradiation with gamma-rays or very low fluences of alpha particles. PLoS One 2014; 9:e93579. [PMID: 24714417 PMCID: PMC3979685 DOI: 10.1371/journal.pone.0093579] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 03/04/2014] [Indexed: 12/03/2022] Open
Abstract
We have examined cell-cycle dependence of chromosomal aberration induction and cell killing after high or low dose-rate γ irradiation in cells bearing DNA-PKcs mutations in the S2056 cluster, the T2609 cluster, or the kinase domain. We also compared sister chromatid exchanges (SCE) production by very low fluences of α-particles in DNA-PKcs mutant cells, and in homologous recombination repair (HRR) mutant cells including Rad51C, Rad51D, and Fancg/xrcc9. Generally, chromosomal aberrations and cell killing by γ-rays were similarly affected by mutations in DNA-PKcs, and these mutant cells were more sensitive in G1 than in S/G2 phase. In G1-irradiated DNA-PKcs mutant cells, both chromosome- and chromatid-type breaks and exchanges were in excess than wild-type cells. For cells irradiated in late S/G2 phase, mutant cells showed very high yields of chromatid breaks compared to wild-type cells. Few exchanges were seen in DNA-PKcs-null, Ku80-null, or DNA-PKcs kinase dead mutants, but exchanges in excess were detected in the S2506 or T2609 cluster mutants. SCE induction by very low doses of α-particles is resulted from bystander effects in cells not traversed by α-particles. SCE seen in wild-type cells was completely abolished in Rad51C- or Rad51D-deficient cells, but near normal in Fancg/xrcc9 cells. In marked contrast, very high levels of SCEs were observed in DNA-PKcs-null, DNA-PKcs kinase-dead and Ku80-null mutants. SCE induction was also abolished in T2609 cluster mutant cells, but was only slightly reduced in the S2056 cluster mutant cells. Since both non-homologous end-joining (NHEJ) and HRR systems utilize initial DNA lesions as a substrate, these results suggest the possibility of a competitive interference phenomenon operating between NHEJ and at least the Rad51C/D components of HRR; the level of interaction between damaged DNA and a particular DNA-PK component may determine the level of interaction of such DNA with a relevant HRR component.
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Affiliation(s)
- Yu-Fen Lin
- Department of Radiation Oncology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, United States of America
| | - Hatsumi Nagasawa
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - John B. Little
- Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston, Massachusetts, United States of America
| | - Takamitsu A. Kato
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Hung-Ying Shih
- Department of Radiation Oncology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, United States of America
| | - Xian-Jin Xie
- Department of Clinical Sciences, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, United States of America
| | - Paul F. Wilson Jr.
- Department of Biosciences, Brookhaven National Laboratory, Upton, New York, United States of America
| | - John R. Brogan
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Akihiro Kurimasa
- Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, Tottori, Japan
| | - David J. Chen
- Department of Radiation Oncology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, United States of America
| | - Joel S. Bedford
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Benjamin P. C. Chen
- Department of Radiation Oncology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, United States of America
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16
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Genetic predisposition to radiation-related cancer and potential implications for risk assessment. Ann ICRP 2012; 41:108-16. [PMID: 23089009 DOI: 10.1016/j.icrp.2012.06.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Several lines of evidence suggest that risk estimates for cancer associated with radiation exposure incorporate individuals who are more and less inherently susceptible to the carcinogenic effects of radiation, and the technology to further evaluate this issue is now available. For example, genome-wide association scan studies could be undertaken to address, at least in part, the direction of causality in the observations of differential sensitivity to radiomimetic agents in cancer cases compared with normal individuals, thereby building on previous observations that sensitivity to these agents is higher in apparently normal individuals carrying gene mutations in NBS and ATM. Direct studies of risk of second cancers in relation to radiation are underway, and some results have been reported (e.g. for the PRDM1 gene as related to sensitivity to radiation-related cancers after treatment for Hodgkin's lymphoma). It is important to understand the risk synergies between variants affecting associations with various cancers defining susceptibility in unexposed populations and the excess risk in populations therapeutically or occupationally exposed to radiation for the purpose of risk protection, especially as additional baseline risk variants are discovered in increasingly large-scale analyses. While there are studies that are beginning to address these questions, there have been no compelling new discoveries, to date, to indicate that predisposition information should be included in risk assessment. The conclusions in ICRP Publications 79 and 103 appear relevant today.
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17
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Mozdarani H. Biological complexities in radiation carcinogenesis and cancer radiotherapy: impact of new biological paradigms. Genes (Basel) 2012; 3:90-114. [PMID: 24704845 PMCID: PMC3899963 DOI: 10.3390/genes3010090] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2011] [Revised: 01/07/2012] [Accepted: 01/13/2012] [Indexed: 12/31/2022] Open
Abstract
Although radiation carcinogenesis has been shown both experimentally and epidemiologically, the use of ionizing radiation is also one of the major modalities in cancer treatment. Various known cellular and molecular events are involved in carcinogenesis. Apart from the known phenomena, there could be implications for carcinogenesis and cancer prevention due to other biological processes such as the bystander effect, the abscopal effect, intrinsic radiosensitivity and radioadaptation. Bystander effects have consequences for mutation initiated cancer paradigms of radiation carcinogenesis, which provide the mechanistic justification for low-dose risk estimates. The abscopal effect is potentially important for tumor control and is mediated through cytokines and/or the immune system (mainly cell-mediated immunity). It results from loss of growth and stimulatory and/or immunosuppressive factors from the tumor. Intrinsic radiosensitivity is a feature of some cancer prone chromosomal breakage syndromes such as ataxia telangectiasia. Radiosensitivity is manifested as higher chromosomal aberrations and DNA repair impairment is now known as a good biomarker for breast cancer screening and prediction of prognosis. However, it is not yet known whether this effect is good or bad for those receiving radiation or radiomimetic agents for treatment. Radiation hormesis is another major concern for carcinogenesis. This process which protects cells from higher doses of radiation or radio mimic chemicals, may lead to the escape of cells from mitotic death or apoptosis and put cells with a lower amount of damage into the process of cancer induction. Therefore, any of these biological phenomena could have impact on another process giving rise to genome instability of cells which are not in the field of radiation but still receiving a lower amount of radiation. For prevention of radiation induced carcinogenesis or risk assessment as well as for successful radiation therapy, all these phenomena should be taken into account.
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Affiliation(s)
- Hossein Mozdarani
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran P.O. Box 14115-111, Iran.
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18
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Ricks-Santi LJ, Sucheston LE, Yang Y, Freudenheim JL, Isaacs CJ, Schwartz MD, Dumitrescu RG, Marian C, Nie J, Vito D, Edge SB, Shields PG. Association of Rad51 polymorphism with DNA repair in BRCA1 mutation carriers and sporadic breast cancer risk. BMC Cancer 2011; 11:278. [PMID: 21708019 PMCID: PMC3146938 DOI: 10.1186/1471-2407-11-278] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Accepted: 06/27/2011] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Inter-individual variation in DNA repair capacity is thought to modulate breast cancer risk. The phenotypic mutagen sensitivity assay (MSA) measures DNA strand breaks in lymphocytes; women with familial and sporadic breast cancers have a higher mean number of breaks per cell (MBPC) than women without breast cancer. Here, we explore the relationships between the MSA and the Rad51 gene, which encodes a DNA repair enzyme that interacts with BRCA1 and BRCA2, in BRCA1 mutation carriers and women with sporadic breast cancer. METHODS Peripheral blood lymphoblasts from women with known BRCA1 mutations underwent the MSA (n = 138 among 20 families). BRCA1 and Rad51 genotyping and sequencing were performed to identify SNPs and haplotypes associated with the MSA. Positive associations from the study in high-risk families were subsequently examined in a population-based case-control study of breast cancer (n = 1170 cases and 2115 controls). RESULTS Breast cancer diagnosis was significantly associated with the MSA among women from BRCA1 families (OR = 3.2 95%CI: 1.5-6.7; p = 0.004). The Rad51 5'UTR 135 C>G genotype (OR = 3.64; 95% CI: 1.38, 9.54; p = 0.02), one BRCA1 haplotype (p = 0.03) and in a polygenic model, the E1038G and Q356R BRCA1 SNPs were significantly associated with MBPC (p = 0.009 and 0.002, respectively). The Rad51 5'UTR 135C genotype was not associated with breast cancer risk in the population-based study. CONCLUSIONS Mutagen sensitivity might be a useful biomarker of penetrance among women with BRCA1 mutations because the MSA phenotype is partially explained by genetic variants in BRCA1 and Rad51.
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Affiliation(s)
- Luisel J Ricks-Santi
- Howard University Cancer Center, 2041 Georgia Ave, NW Washington, DC 20060, USA
- National Human Genome Center at Howard University, 2041 Georgia Ave, NW #615, Washington, DC 20059, USA
| | - Lara E Sucheston
- Department of Biostatistics, University at Buffalo, State University of New York, Buffalo, NY 14214, USA
| | - Yang Yang
- Lombardi Comprehensive Cancer Center, Georgetown University Medical Cancer, 3800 Reservoir Rd, NW, Washington, DC 20057, USA
| | - Jo L Freudenheim
- Department of Social and Preventive Medicine, University at Buffalo, State University of New York, Buffalo, NY 14214, USA
| | - Claudine J Isaacs
- Lombardi Comprehensive Cancer Center, Georgetown University Medical Cancer, 3800 Reservoir Rd, NW, Washington, DC 20057, USA
| | - Marc D Schwartz
- Lombardi Comprehensive Cancer Center, Georgetown University Medical Cancer, 3800 Reservoir Rd, NW, Washington, DC 20057, USA
| | - Ramona G Dumitrescu
- Lombardi Comprehensive Cancer Center, Georgetown University Medical Cancer, 3800 Reservoir Rd, NW, Washington, DC 20057, USA
| | - Catalin Marian
- Lombardi Comprehensive Cancer Center, Georgetown University Medical Cancer, 3800 Reservoir Rd, NW, Washington, DC 20057, USA
| | - Jing Nie
- Department of Social and Preventive Medicine, University at Buffalo, State University of New York, Buffalo, NY 14214, USA
| | - Dominica Vito
- Department of Social and Preventive Medicine, University at Buffalo, State University of New York, Buffalo, NY 14214, USA
| | - Stephen B Edge
- Department of Surgery, University at Buffalo, State University of New York, Buffalo, NY 14214, USA
| | - Peter G Shields
- Lombardi Comprehensive Cancer Center, Georgetown University Medical Cancer, 3800 Reservoir Rd, NW, Washington, DC 20057, USA
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19
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Wilson DM, Kim D, Berquist BR, Sigurdson AJ. Variation in base excision repair capacity. Mutat Res 2010; 711:100-12. [PMID: 21167187 DOI: 10.1016/j.mrfmmm.2010.12.004] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Revised: 11/29/2010] [Accepted: 12/07/2010] [Indexed: 01/20/2023]
Abstract
The major DNA repair pathway for coping with spontaneous forms of DNA damage, such as natural hydrolytic products or oxidative lesions, is base excision repair (BER). In particular, BER processes mutagenic and cytotoxic DNA lesions such as non-bulky base modifications, abasic sites, and a range of chemically distinct single-strand breaks. Defects in BER have been linked to cancer predisposition, neurodegenerative disorders, and immunodeficiency. Recent data indicate a large degree of sequence variability in DNA repair genes and several studies have associated BER gene polymorphisms with disease risk, including cancer of several sites. The intent of this review is to describe the range of BER capacity among individuals and the functional consequences of BER genetic variants. We also discuss studies that associate BER deficiency with disease risk and the current state of BER capacity measurement assays.
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Affiliation(s)
- David M Wilson
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, United States.
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20
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Nagasawa H, Little JB, Lin YF, So S, Kurimasa A, Peng Y, Brogan JR, Chen DJ, Bedford JS, Chen BPC. Differential role of DNA-PKcs phosphorylations and kinase activity in radiosensitivity and chromosomal instability. Radiat Res 2010; 175:83-9. [PMID: 21175350 DOI: 10.1667/rr2092.1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) is the key functional element in the DNA-PK complex that drives nonhomologous end joining (NHEJ), the predominant DNA double-strand break (DSB) repair mechanism operating to rejoin such breaks in mammalian cells after exposure to ionizing radiation. It has been reported that DNA-PKcs phosphorylation and kinase activity are critical determinants of radiosensitivity, based on responses reported after irradiation of asynchronously dividing populations of various mutant cell lines. In the present study, the relative radiosensitivity to cell killing as well as chromosomal instability of 13 DNA-PKcs site-directed mutant cell lines (defective at phosphorylation sites or kinase activity) were examined after exposure of synchronized G(1) cells to (137)Cs γ rays. DNA-PKcs mutant cells defective in phosphorylation at multiple sites within the T2609 cluster or within the PI3K domain displayed extreme radiosensitivity. Cells defective at the S2056 cluster or T2609 single site alone were only mildly radiosensitive, but cells defective at even one site in both the S2056 and T2609 clusters were maximally radiosensitive. Thus a synergism between the capacity for phosphorylation at the S2056 and T2609 clusters was found to be critical for induction of radiosensitivity.
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Affiliation(s)
- Hatsumi Nagasawa
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, Colorado 80523, USA
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21
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Sigurdson AJ, Jones IM, Wei Q, Wu X, Spitz MR, Stram DA, Gross MD, Huang WY, Wang LE, Gu J, Thomas CB, Reding DJ, Hayes RB, Caporaso NE. Prospective analysis of DNA damage and repair markers of lung cancer risk from the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial. Carcinogenesis 2010; 32:69-73. [PMID: 20929901 DOI: 10.1093/carcin/bgq204] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Mutagen challenge and DNA repair assays have been used in case-control studies for nearly three decades to assess human cancer risk. The findings still engender controversy because blood was drawn after cancer diagnosis so the results may be biased, a type called 'reverse causation'. We therefore used Epstein-Barr virus-transformed lymphoblastoid cell lines established from prospectively collected peripheral blood samples to evaluate lung cancer risk in relation to three DNA repair assays: alkaline Comet assay, host cell reactivation (HCR) assay with the mutagen benzo[a]pyrene diol epoxide and the bleomycin mutagen sensitivity assay. Cases (n = 117) were diagnosed with lung cancer between 0.3 and 6 years after blood collection and controls (n = 117) were frequency matched on calendar year and age at blood collection, gender and smoking history; all races were included. Case and control status was unknown to laboratory investigators. In unconditional logistic regression analyses, statistically significantly increased lung cancer odds ratios (OR(adjusted)) were observed for bleomycin mutagen sensitivity as quartiles of chromatid breaks/cell [relative to the lowest quartile, OR = 1.2, 95% confidence interval (CI): 0.5-2.5; OR = 1.4, 95% CI: 0.7-3.1; OR = 2.1, 95% CI: 1.0-4.4, respectively, P(trend) = 0.04]. The magnitude of the association between the bleomycin assay and lung cancer risk was modest compared with those reported in previous lung cancer studies but was strengthened when we included only incident cases diagnosed more than a year after blood collection (P(trend) = 0.02), supporting the notion the assay may be a measure of cancer susceptibility. The Comet and HCR assays were unrelated to lung cancer risk.
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Affiliation(s)
- Alice J Sigurdson
- Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, USA.
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22
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Kato TA, Wilson PF, Nagasaw H, Peng Y, Weil MM, Little JB, Bedford JS. Variations in radiosensitivity among individuals: a potential impact on risk assessment? HEALTH PHYSICS 2009; 97:470-480. [PMID: 19820456 DOI: 10.1097/hp.0b013e3181b08eee] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
To have an impact on risk assessment for purposes of radiation protection recommendations, significantly broad variations in carcinogenic radiosensitivity would have to exist in significant proportions in the human population. Even if we knew all the genes where mutations would have major effects, individual genome sequencing does not seem useful, since we do not know all these genes, nor can we be certain of the phenotypic effect of polymorphisms discovered. Further, sequencing would not reveal epigenetic changes in gene expression. Another approach to develop phenotypic biomarkers for cells or tissues for which variations in radiation response may reflect the variations in carcinogenic sensitivity. To be useful, experimental evidence for such a correlation would be crucial, and it is also evident that correlations may be tissue or tumor specific. Some cellular markers are discussed that have shown promise in this regard. They include chromosome aberration induction and DNA repair assays that are sufficiently sensitive to measure after modest or low doses or dose rates. To this end we summarize here some of these assays and review the results of a number of experiments from our laboratory that show clear differences in DNA repair capacity reflected by gamma-H2AX foci formation in cells from a high proportion (perhaps 1/3) of apparently normal individuals. A low dose-rate assay was used to amplify such differences. Another promising assay combines G(2) chromosomal radiosensitivity with the above gamma-H2AX foci on mitotic chromosomes. There are other potentially useful assays as well.
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Affiliation(s)
- Takamitsu A Kato
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523, USA
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Kuhnert VM, Kachnic LA, Li L, Purschke M, Gheorghiu L, Lee R, Held KD, Willers H. FANCD2-deficient human fibroblasts are hypersensitive to ionising radiation at oxygen concentrations of 0% and 3% but not under normoxic conditions. Int J Radiat Biol 2009; 85:523-31. [PMID: 19466639 DOI: 10.1080/09553000902883810] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
PURPOSE Individuals suffering from Fanconi Anemia (FA) exhibit a pronounced hypersensitivity to agents that cause DNA inter-strand crosslinks and frequently also to ionising radiation. However, fibroblast lines derived from FA patients generally show little or no radiosensitivity in vitro. Here, we sought to elucidate the role of the central FA protein D2 (FANCD2) in determining cellular radioresistance. MATERIAL AND METHODS Clonogenic radiation survival was assessed in an isogenic pair of human fibroblasts with or without wild-type FANCD2 under varying oxygen concentrations. Additional endpoints included single-cell gel electrophoresis, RAD51 foci formation, and apoptosis. RESULTS At 20% oxygen, there was no reduction in the survival of FANCD2-deficient fibroblasts compared to wild-type complemented cells. However, at 0% oxygen FANCD2-deficient cells were more radiosensitive than wild-type cells. Interestingly, at 3% oxygen, which more closely resembles the physiological environment in human tissues, the difference in radiosensitivity was maintained. Our data also suggest that the increased radiosensitivity of FANCD2-deficient cells seen under conditions of reduced oxygen is associated with apoptotic cell death, but not secondary to a defect in the homologous recombination repair pathway that is required for crosslink repair. CONCLUSIONS Our data may help explain the previously described discrepancy between the clinical and cellular radiosensitivity of FA patients.
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Affiliation(s)
- Verena M Kuhnert
- Department of Radiation Oncology, University of Lübeck, Lübeck, Germany
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24
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Mohseni-Meybodi A, Mozdarani H, Mozdarani S. DNA damage and repair of leukocytes from Fanconi anaemia patients, carriers and healthy individuals as measured by the alkaline comet assay. Mutagenesis 2008; 24:67-73. [PMID: 18836100 DOI: 10.1093/mutage/gen052] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Fanconi anaemia (FA) patients show cellular sensitivity to a variety of clastogens and prominently to cross-linking agents. Although there is a long-standing clinical impression of radiosensitivity, in vitro studies have yielded conflicting results. In this study, initial radiation-induced DNA damage and kinetics of DNA repair in (60)Co gamma-irradiated leukocytes from healthy volunteers, FA patients and heterozygotes were assessed using alkaline comet assay. Results showed higher levels of baseline DNA damage in leukocytes of patients and heterozygotes than in controls. Gamma-ray-induced initial DNA damage in leukocytes of FA cases was not significantly different from that of healthy donors and heterozygotes. However, after a repair time of 4 h, following irradiation, samples from the healthy individuals and carriers showed less residual DNA damage in their leukocytes, whereas FA patients revealed more DNA damages than their baseline. Although similar initial induced DNA damage was observed for all groups, the repair kinetics of radiation-induced DNA damage of leukocytes from FA patients was statistically different from healthy and carrier subjects. These findings may suggest that hypersensitivity of FA cells to cross-linking and clastogenic agents might be due to inefficient and delayed repair machinery of these cells. Also, the amount of residual DNA damage after irradiation could be used as a putative predictor of FA screening and cellular radiosensitivity.
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Affiliation(s)
- Anahita Mohseni-Meybodi
- Department of Medical Genetics, School of Medical Sciences, Tarbiat Modares University, Tehran, Iran
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25
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Agarwal M, Pandita S, Hunt CR, Gupta A, Yue X, Khan S, Pandita RK, Pratt D, Shay JW, Taylor JSA, Pandita TK. Inhibition of telomerase activity enhances hyperthermia-mediated radiosensitization. Cancer Res 2008; 68:3370-8. [PMID: 18451164 DOI: 10.1158/0008-5472.can-07-5831] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Hyperthermia is a potent sensitizer of cell killing by ionizing radiation (IR); however, hyperthermia also induces heat shock protein 70 (HSP70) synthesis and HSP70 expression is associated with radioresistance. Because HSP70 interacts with the telomerase complex and expression of the telomerase catalytic unit (hTERT) extends the life span of the human cells, we determined if heat shock influences telomerase activity and whether telomerase inhibition enhances heat-mediated IR-induced cell killing. In the present study, we show that moderate hyperthermia (43 degrees C) enhances telomerase activity. Inhibition of telomerase activity with human telomerase RNA-targeted antisense agents, and in particular GRN163L, results in enhanced hyperthermia-mediated IR-induced cell killing, and ectopic expression of catalytic unit of telomerase (TERT) decreased hyperthermia-mediated IR-induced cell killing. The increased cell killing by heat and IR exposure in telomerase-inhibited cells correlates with delayed appearance and disappearance of gamma-H2AX foci as well as decreased chromosome repair. These results suggest that inactivation of telomerase before combined hyperthermia and radiotherapy could improve tumor killing.
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Affiliation(s)
- Manjula Agarwal
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO 63108, USA
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26
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Kato TA, Wilson PF, Nagasawa H, Fitzek MM, Weil MM, Little JB, Bedford JS. A defect in DNA double strand break processing in cells from unaffected parents of retinoblastoma patients and other apparently normal humans. DNA Repair (Amst) 2007; 6:818-29. [PMID: 17339135 DOI: 10.1016/j.dnarep.2007.01.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2006] [Revised: 01/16/2007] [Accepted: 01/22/2007] [Indexed: 12/15/2022]
Abstract
Cells from unaffected parents of retinoblastoma (RB) patients were previously shown to be hypersensitive to radiation induced G(1) arrest and cell killing [1]. The hypersensitivity was similar to that reported for cells from ATM heterozygotes. The latter was consistent with a mild DNA DSB rejoining defect which we demonstrated using a gamma-H2AX focus assay after low dose-rate (LDR) irradiation of non-cycling G(0) cells [2,3]. Since neither parent carried the mutant RB allele of the RB heterozygous probands, these results suggested the possibility of an enhanced germline mutation rate, perhaps resulting from some mild defect in genome maintenance. We therefore examined levels of gamma-H2AX foci for cells from these RB parents in this G(0) LDR assay, which reflects the non-homologous end joining (NHEJ) capacity of cells and in a G(2)/M assay, which reflects additional contributions from other G(2)-related damage processing systems. For several of the cell strains parallel radiosensitivity comparisons were made for cell killing and for G(2) chromosomal radiosensitivities. G(0) cells from the RB parents were clearly hypersensitive both in the LDR gamma-H2AX assay, and for cell killing. In addition, cultured fibroblasts from 6 of 15 apparently normal individuals in this study (and one of six in a previous study) were also hypersensitive in the same assays. In the G(2)/M gamma-H2AX assay, the relative sensitivities were similar to those seen in the low dose-rate G(0) assay and tracked with chromosomal radiosensitivity, but some differences were observed.
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Affiliation(s)
- Takamitsu A Kato
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523, United States
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27
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Hunt CR, Pandita RK, Laszlo A, Higashikubo R, Agarwal M, Kitamura T, Gupta A, Rief N, Horikoshi N, Baskaran R, Lee JH, Löbrich M, Paull TT, Roti Roti JL, Pandita TK. Hyperthermia activates a subset of ataxia-telangiectasia mutated effectors independent of DNA strand breaks and heat shock protein 70 status. Cancer Res 2007; 67:3010-7. [PMID: 17409407 DOI: 10.1158/0008-5472.can-06-4328] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
All cells have intricately coupled sensing and signaling mechanisms that regulate the cellular outcome following exposure to genotoxic agents such as ionizing radiation (IR). In the IR-induced signaling pathway, specific protein events, such as ataxia-telangiectasia mutated protein (ATM) activation and histone H2AX phosphorylation (gamma-H2AX), are mechanistically well characterized. How these mechanisms can be altered, especially by clinically relevant agents, is not clear. Here we show that hyperthermia, an effective radiosensitizer, can induce several steps associated with IR signaling in cells. Hyperthermia induces gamma-H2AX foci formation similar to foci formed in response to IR exposure, and heat-induced gamma-H2AX foci formation is dependent on ATM but independent of heat shock protein 70 expression. Hyperthermia also enhanced ATM kinase activity and increased cellular ATM autophosphorylation. The hyperthermia-induced increase in ATM phosphorylation was independent of Mre11 function. Similar to IR, hyperthermia also induced MDC1 foci formation; however, it did not induce all of the characteristic signals associated with irradiation because formation of 53BP1 and SMC1 foci was not observed in heated cells but occurred in irradiated cells. Additionally, induction of chromosomal DNA strand breaks was observed in IR-exposed but not in heated cells. These results indicate that hyperthermia activates signaling pathways that overlap with those activated by IR-induced DNA damage. Moreover, prior activation of ATM or other components of the IR-induced signaling pathway by heat may interfere with the normal IR-induced signaling required for chromosomal DNA double-strand break repair, thus resulting in increased cellular radiosensitivity.
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Affiliation(s)
- Clayton R Hunt
- Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri, USA
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28
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Wilding CS, Curwen GB, Tawn EJ, Sheng X, Winther JF, Chakraborty R, Boice JD. Influence of polymorphisms at loci encoding DNA repair proteins on cancer susceptibility and G2 chromosomal radiosensitivity. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2007; 48:48-57. [PMID: 17177211 PMCID: PMC2730149 DOI: 10.1002/em.20274] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Sixteen candidate polymorphisms (13 SNPs and 3 microsatellites) in nine genes from four DNA repair pathways were examined in 83 subjects, comprising 23 survivors of childhood cancer, their 23 partners, and 37 offspring, all of whom had previously been studied for G(2) chromosomal radiosensitivity. Genotype at the Asp148Glu SNP site in the APEX gene of the base excision repair (BER) pathway was associated with childhood cancer in survivors (P = 0.001, significant even after multiple test adjustment), due to the enhanced frequency of the APEX Asp148 allele among survivors in comparison to that of their partners. Analysis of variance (ANOVA) of G(2) radiosensitivity in the pooled sample, as well as family-based association test (FBAT) of the family-wise data, showed sporadic suggestions of associations between G(2) radiosensitivity and polymorphisms at two sites (the Thr241Met SNP site in the XRCC3 gene of the homologous recombinational pathway by ANOVA, and the Ser326Cys site in the hOGG1 gene of the BER pathway by FBAT analysis), but neither of these remained significant after multiple-test adjustment. This pilot study provides an intriguing indication that DNA repair gene polymorphisms may underlie cancer susceptibility and variation in radiosensitivity.
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Affiliation(s)
- Craig S. Wilding
- Genetics Department, Westlakes Research Institute, Westlakes Science and Technology Park, Moor Row, Cumbria, United Kingdom
| | - Gillian B. Curwen
- Genetics Department, Westlakes Research Institute, Westlakes Science and Technology Park, Moor Row, Cumbria, United Kingdom
| | - E. Janet Tawn
- Genetics Department, Westlakes Research Institute, Westlakes Science and Technology Park, Moor Row, Cumbria, United Kingdom
- Correspondence to: Dr. E. J. Tawn, Genetics Department, Westlakes Research Institute, Westlakes Science and Technology Park, Moor Row, Cumbria CA24 3JY, UK. E-mail:
| | - Xiaohua Sheng
- Center for Genome Information, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Jeanette F. Winther
- Institute of Cancer Epidemiology, Danish Cancer Society, Copenhagen, Denmark
| | - Ranajit Chakraborty
- Center for Genome Information, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - John D. Boice
- International Epidemiology Institute, Rockville, Maryland
- Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee
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29
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Kato TA, Nagasawa H, Weil MM, Little JB, Bedford JS. Levels of gamma-H2AX Foci after low-dose-rate irradiation reveal a DNA DSB rejoining defect in cells from human ATM heterozygotes in two at families and in another apparently normal individual. Radiat Res 2006; 166:443-53. [PMID: 16953663 DOI: 10.1667/rr3604.1] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
We have investigated the use of the gamma-H2AX assay, reflecting the presence of DNA double-strand breaks, as a possible means for identifying individuals who are mildly hypersensitive to ionizing radiation, such as some ATM heterozygotes. We compared levels of gamma-H2AX foci after irradiation in cells from six apparently normal individuals as well as from individuals from two separate AT families including the proband, mother, father and three unaffected siblings in each family. After a 1-Gy single acute (high-dose-rate) gamma-ray dose delivered to noncycling contact-inhibited monolayers of cells, clear differences were seen between samples from normal individuals (ATM(+/+)) and probands (ATM(-/-)) at nearly all sampling times after irradiation, but no clear distinctions were seen for cells from normal compared to obligate heterozygotes (ATM(+/-)). In contrast, after 24 h of continuous irradiation at a dose rate of 10 cGy/h, appreciable differences in numbers of foci per cell were observed for cells from individuals for all the known ATM genotypes compared with controls. Four unaffected siblings had mean numbers of foci per cell similar to that for the obligate heterozygotes, whereas the other two had mean values similar to that for normal controls. We determined independently that those siblings with mean numbers of foci per cell in the range of ATM heterozygotes carried the mutant allele, while both siblings with a normal number of foci per cell after irradiation had normal alleles. A more limited set of experiments using lymphoblastoid cell strains in the low-dose-rate assay also revealed distinct differences for normal compared to ATM heterozygotes from the same families and opens the possibility of using peripheral blood lymphocytes as a more suitable material for an assay to detect mild hypersensitivities to radiation among individuals.
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Affiliation(s)
- Takamitsu A Kato
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523, USA
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30
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Kato TA, Nagasawa H, Weil MM, Genik PC, Little JB, Bedford JS. γ-H2AX Foci after Low-Dose-Rate Irradiation RevealAtmHaploinsufficiency in Mice. Radiat Res 2006; 166:47-54. [PMID: 16808619 DOI: 10.1667/rr3587.1] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
We have investigated the use of the gamma-H2AX assay, reflecting the presence of DNA double-strand breaks (DSBs), as a possible means for identifying individuals who may be intermediate with respect to the extremes of hyper-radiosensitivity phenotypes. In this case, cells were studied from mice that were normal (Atm+/+), heterozygous (Atm+/-), or homozygous recessive (Atm-/-) for a truncating mutation in the Atm gene. After single acute (high-dose-rate) exposures, differences in mean numbers of gamma-H2AX foci per cell between samples from Atm+/+ and Atm-/- mice were clear at nearly all sampling times, but at no sampling time was there a clear distinction for cells from Atm+/+ and Atm+/- mice. In contrast, under conditions of low-dose-rate irradiation at 10 cGy/h, appreciable differences in the levels of gamma-H2AX foci per cell were observed in synchronized G1 cells derived from Atm+/- mice relative to cells from Atm+/+ mice. The levels were intermediate between those for cells from Atm+/+ and Atm-/- mice. After 24 h exposure at this dose rate, measurements in cells from four different mice for each genotype yielded mean frequencies of foci per cell of 1.77 +/- 0.13 (SEM) for Atm+/+ cells, 4.75 +/- 0.20 for the Atm+/- cells, and 11.10 +/- 0.33 for the Atm-/-cells. The distributions of foci per G1 cell were not significantly different from Poisson. To the extent that variations in sensitivity with respect to gamma-H2AX focus formation reflect variations in radiosensitivity for biological effects of concern, such as carcinogenesis, and that similar differences are seen for other genetic DNA DSB processing defects in general, this assay may provide a relatively straightforward means for distinguishing individuals who may be mildly hypersensitive to radiation such as we observed for Atm heterozygous mice.
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Affiliation(s)
- Takamitsu A Kato
- Department of Environmental and Radiological Health Sciences, Colorado State University. Fort Collins, Colorado 80523, USA
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31
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Howe O, O'Malley K, Lavin M, Gardner RA, Seymour C, Lyng F, Mulvin D, Quinlan DM, Mothersill C. Cell death mechanisms associated with G2 radiosensitivity in patients with prostate cancer and benign prostatic hyperplasia. Radiat Res 2005; 164:627-34. [PMID: 16238439 DOI: 10.1667/rr3454.1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Cells respond to genotoxic insults such as ionizing radiation by halting in the G2 phase of the cell cycle. Delayed cell death (mitotic death) can occur when the cell is released from G2, and specific spindle defects form endopolyploid cells (endoreduplication/tetraploidy). Enhanced G2 chromosomal radiosensitivity has been observed in many cancers and genomic instability syndromes, and it is manifested by radiation-induced chromatid aberrations observed in lymphocytes of patients. Here we compare the G2 chromosomal radiosensitivity in prostate patients with benign prostatic hyperplasia (BPH) or prostate cancer with disease-free controls. We also investigated whether there is a correlation between G2 chromosomal radiosensitivity and aneuploidy (tetraploidy and endoreduplication), which are indicative of mitotic cell death. The G2 assay was carried out on all human blood samples. Metaphase analysis was conducted on the harvested chromosomes by counting the number of aberrations and the mitotic errors (endoreduplication/tetraploidy) separately per 100 metaphases. A total of 1/14 of the controls were radiosensitive in G2 compared to 6/15 of the BPH patients and 15/17 of the prostate cancer patients. Radiation-induced mitotic inhibition was assessed to determine the efficacy of G2 checkpoint control in the prostate patients. There was no significant correlation of G2 radiosensitivity scores and mitotic inhibition in BPH patients (P = 0.057), in contrast to prostate cancer patients, who showed a small but significant positive correlation (P = 0.029). Furthermore, there was no significant correlation between G2 radiosensitivity scores of BPH patients and endoreduplication/ tetraploidy (P = 0.136), which contrasted with an extremely significant correlation observed in prostate cancer patients (P < 0.0001). In conclusion, cells from prostate cancer patients show increased sensitivity to the induction of G2 aberrations from ionizing radiation exposure but paradoxically show reduced mitotic indices and aneuploidy as a function of aberration frequency.
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Affiliation(s)
- Orla Howe
- Radiation and Environmental Science Centre, Focus Institute, Dublin Institute of Technology, Dublin 8, Ireland
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32
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Dequen F, St-Laurent JF, Gagnon SN, Carreau M, Desnoyers S. The Caenorhabditis elegans FancD2 ortholog is required for survival following DNA damage. Comp Biochem Physiol B Biochem Mol Biol 2005; 141:453-60. [PMID: 15979372 DOI: 10.1016/j.cbpc.2005.05.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2004] [Revised: 05/10/2005] [Accepted: 05/11/2005] [Indexed: 01/04/2023]
Abstract
Fanconi anemia (FA) is an autosomal recessive disease characterized by bone-marrow failure, congenital abnormalities, and cancer susceptibility. There are 11 FA complementation groups in human where 8 genes have been identified. We found that FancD2 is conserved in evolution and present in the genome of the nematode Caenorhabditis elegans. The gene Y41E3.9 (CeFancD2) encodes a structural ortholog of human FANCD2 and is composed of 10 predicted exons. Our analysis showed that exons 6 and 7 were absent from a CeFancD2 EST suggesting the presence of a splice variant. In an attempt to characterize its role in DNA damage, we depleted worms of CeFANCD2 using RNAi. When the CeFANCD2(RNAi) worms were treated with a crosslinking agent, a significant drop in the progeny survival was noted. These worms were also sensitive, although to a lesser extent, to ionizing radiation (IR). Therefore, these data support an important role for CeFANCD2 in DNA damage response as for its human counterpart. The data also support the usefulness of C. elegans to study the Fanconi anemia pathway, and emphasize the biological importance of FANCD2 in DNA damage response throughout evolution.
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Affiliation(s)
- Florence Dequen
- CHUL Research Centre, Pediatrics Research Unit and Laval University, Department of Pediatrics, Canada
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33
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Mozdarani H, Mansouri Z, Haeri SA. Cytogenetic radiosensitivity of g0-lymphocytes of breast and esophageal cancer patients as determined by micronucleus assay. JOURNAL OF RADIATION RESEARCH 2005; 46:111-116. [PMID: 15802866 DOI: 10.1269/jrr.46.111] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Enhanced chromosomal radiosensitivity is a feature of many cancer predisposition conditions, indicative of the important role of chromosomal alterations in carcinogenesis. In this study the cytokinesis-blocked micronucleous assay was used to compare the radiosensitivity of blood lymphocytes obtained from Iranian breast or esophageal cancer patients (n = 50, n = 16; respectively) with that of control individuals (n = 40). For each sample, one thousand binucleate lymphocytes were analyzed before and after in vitro exposure to 3 Gy of gamma rays. The radiation-induced frequency of micronucleus was significantly higher in the breast cancer group (261/1,000 binucleated cells) than in esophageal cancer group (241/1,000 binucleated cells, P < 0.01) or in the control group (240/1,000 binucleated cells, P < 0.01). The results indicate that breast cancer patients are more radiosensitive compared to normal healthy individuals or esophageal cancer patients. Increased radiosensitivity could be due to defects in DNA repair genes involved in breast cancer formation. Since patients with esophageal cancer did not show elevated radiosensitivity, it is assumed that the contribution of radiosensitivity-related genes to the development of esophageal cancer may be smaller than the contribution of those genes to breast cancer.
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Affiliation(s)
- Hossein Mozdarani
- Dept. of Medical Genetics, School of Medical Sciences, Tarbiat Modarres University, Tehran, Iran.
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34
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Ban S, Konomi C, Iwakawa M, Yamada S, Ohno T, Tsuji H, Noda S, Matui Y, Harada Y, Cologne JB, Imai T. Radiosensitivity of peripheral blood lymphocytes obtained from patients with cancers of the breast, head and neck or cervix as determined with a micronucleus assay. JOURNAL OF RADIATION RESEARCH 2004; 45:535-541. [PMID: 15635263 DOI: 10.1269/jrr.45.535] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The in vitro radiation sensitivities of peripheral blood lymphocytes obtained from 48 normal females and 168 female cancer patients were measured with the cytokinesis-blocking micronucleus assay. Cancer patients group had significantly higher mean baseline micronucleus frequency than normal healthy controls. Breast cancer patients were more radiosensitive than normal individuals. Cervical cancer cases were less radiation sensitive than normal subjects. The relative lack of radiation sensitivity in cervical-cancer cases could be due to modification of the radiosensitivity of patients' immune-responsible cells by human papillomaviruses infection. Normal individuals and cancer patients were classified according to their radiation sensitivity which was evaluated with the radiation-induced micronucleus frequencies. Such a classification will be an important initial step to characterize the radiosensitive, radioresistant, or cancer-prone individuals using specific SNP typing.
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Affiliation(s)
- Sadayuki Ban
- Frontier Research Center, National Institute of Radiological Sciences (NIRS), Chiba, Japan.
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35
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Taniguchi T, Garcia-Higuera I, Xu B, Andreassen PR, Gregory RC, Kim ST, Lane WS, Kastan MB, D'Andrea AD. Convergence of the fanconi anemia and ataxia telangiectasia signaling pathways. Cell 2002; 109:459-72. [PMID: 12086603 DOI: 10.1016/s0092-8674(02)00747-x] [Citation(s) in RCA: 399] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Fanconi anemia (FA) and ataxia telangiectasia (AT) are clinically distinct autosomal recessive disorders characterized by spontaneous chromosome breakage and hematological cancers. FA cells are hypersensitive to mitomycin C (MMC), while AT cells are hypersensitive to ionizing radiation (IR). Here, we identify the Fanconi anemia protein, FANCD2, as a link between the FA and ATM damage response pathways. ATM phosphorylates FANCD2 on serine 222 in vitro. This site is also phosphorylated in vivo in an ATM-dependent manner following IR. Phosphorylation of FANCD2 is required for activation of an S phase checkpoint. The ATM-dependent phosphorylation of FANCD2 on S222 and the FA pathway-dependent monoubiquitination of FANCD2 on K561 are independent posttranslational modifications regulating discrete cellular signaling pathways. Biallelic disruption of FANCD2 results in both MMC and IR hypersensitivity.
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Affiliation(s)
- Toshiyasu Taniguchi
- Department of Pediatric Oncology, Dana-Farber Cancer Institute and Department of Pediatrics, Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
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36
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Djuzenova CS, Rothfuss A, Oppitz U, Spelt G, Schindler D, Hoehn H, Flentje M. Response to X-irradiation of Fanconi anemia homozygous and heterozygous cells assessed by the single-cell gel electrophoresis (comet) assay. J Transl Med 2001; 81:185-92. [PMID: 11232640 DOI: 10.1038/labinvest.3780226] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Fanconi anemia (FA) is an autosomal recessive disorder characterized by bone marrow failure and cancer susceptibility. Patient cells are sensitive to a variety of clastogens, most prominently cross-linking agents. Although there is the long-standing clinical impression of radiosensitivity, in vitro studies have yielded conflicting results. We exposed peripheral blood mononuclear cells from FA patients and carriers to x-rays and determined their DNA damage and repair profiles using the alkaline single-cell gel electrophoresis (comet) assay. Studies were carried out in two independent series of experiments by two laboratories using different protocols. The cells of both FA patients and carriers showed uniformly high initial DNA damage rates as assessed by the total initial tail moment. In addition, the average residual tail moment at 30 to 50 minutes and the repair half-time parameters were significantly elevated. These findings suggest an increased release of fragmented DNA following x-ray exposure in cells that carry one or two mutations in one of the FA genes. The comet assay may be a useful adjunct for heterozygote detection in families of FA patients.
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Affiliation(s)
- C S Djuzenova
- Klinik für Strahlentherapie der Universität Würzburg, Germany
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37
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Parshad R, Sanford KK. Radiation-induced chromatid breaks and deficient DNA repair in cancer predisposition. Crit Rev Oncol Hematol 2001; 37:87-96. [PMID: 11166582 DOI: 10.1016/s1040-8428(00)00111-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Deficient repair of DNA double-strand breaks, resulting in an abnormally high frequency of chromatid breaks after G(2) exposure of cells to radiation, appears to be associated with cancer predisposition. Unrepaired DNA strand breaks contribute to genomic instability. Unrepaired chromatid breaks representing DNA strand breaks can result in chromosome deletions, translocations and gene amplifications seen in human cancers. This cytogenetic response of cells to radiation may be useful as a marker of cancer susceptibility and in identifying individuals at risk of developing cancer in cancer families.
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Affiliation(s)
- R Parshad
- Department of Pathology, Howard University College of Medicine, 520 West Street, Washington, DC 20059, USA.
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Saraswathy R, Natarajan A. Frequencies of X-ray induced chromosome aberrations in lymphocytes of xeroderma pigmentosum and Fanconi anemia patients estimated by Giemsa and fluorescence in situ hybridization staining techniques. Genet Mol Biol 2000. [DOI: 10.1590/s1415-47572000000400031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Blood lymphocytes from xeroderma pigmentosum (XP) and Fanconi anemia (FA) patients were assessed for their sensitivity to ionizing radiation by estimating the frequency of X-ray (1 and 2 Gy)-induced chromosome aberrations (CA). The frequencies of aberrations in the whole genome were estimated in Giemsa-stained preparations of lymphocytes irradiated at G0 or G2 stages. The frequencies of translocations and dicentrics involving chromosomes 1 and 3 as well as the X-chromosome were determined in slides stained by fluorescence in situ hybridization (FISH) technique. An increase in all types of CA was observed in XP and FA lymphocytes irradiated at G0 when compared to controls. The frequency of dicentrics and rings was 6 to 27% higher (at 1 and 2 Gy) in XP lymphocytes and 37% higher (at 2 Gy) in FA lymphocytes than in controls, while chromosome deletions were higher in irradiated (30% in 1 Gy and 72% in 2 Gy) than in control XP lymphocytes and 28 to 102% higher in FA lymphocytes. In G2-irradiated lymphocytes the frequency of CA was 24 to 55% higher in XP lymphocytes than in controls. In most cases the translocation frequencies were higher than the frequencies of dicentrics (21/19).
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Ferguson AT, Evron E, Umbricht CB, Pandita TK, Chan TA, Hermeking H, Marks JR, Lambers AR, Futreal PA, Stampfer MR, Sukumar S. High frequency of hypermethylation at the 14-3-3 sigma locus leads to gene silencing in breast cancer. Proc Natl Acad Sci U S A 2000; 97:6049-54. [PMID: 10811911 PMCID: PMC18556 DOI: 10.1073/pnas.100566997] [Citation(s) in RCA: 344] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Expression of 14-3-3 final sigma (final sigma) is induced in response to DNA damage, and causes cells to arrest in G(2). By SAGE (serial analysis of gene expression) analysis, we identified final sigma as a gene whose expression is 7-fold lower in breast carcinoma cells than in normal breast epithelium. We verified this finding by Northern blot analysis. Remarkably, final sigma mRNA was undetectable in 45 of 48 primary breast carcinomas. Genetic alterations at final sigma such as loss of heterozygosity were rare (1/20 informative cases), and no mutations were detected (0/34). On the other hand, hypermethylation of CpG islands in the final sigma gene was detected in 91% (75/82) of breast tumors and was associated with lack of gene expression. Hypermethylation of final sigma is functionally important, because treatment of final sigma-non-expressing breast cancer cell lines with the drug 5-aza-2'-deoxycytidine resulted in demethylation of the gene and synthesis of final sigma mRNA. Breast cancer cells lacking final sigma expression showed increased number of chromosomal breaks and gaps when exposed to gamma-irradiation. Therefore, it is possible that loss of final sigma expression contributes to malignant transformation by impairing the G(2) cell cycle checkpoint function, thus allowing an accumulation of genetic defects. Hypermethylation and loss of final sigma expression are the most consistent molecular alterations in breast cancer identified so far.
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Affiliation(s)
- A T Ferguson
- Johns Hopkins Oncology Center, 410 BBCRB, 1650 Orleans Street, Baltimore, MD 21231-1000, USA
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Terzoudi GI, Jung T, Hain J, Vrouvas J, Margaritis K, Donta-Bakoyianni C, Makropoulos V, Angelakis P, Pantelias GE. Increased G2 chromosomal radiosensitivity in cancer patients: the role of cdk1/cyclin-B activity level in the mechanisms involved. Int J Radiat Biol 2000; 76:607-15. [PMID: 10866282 DOI: 10.1080/095530000138268] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
PURPOSE To test the hypothesis that deficient DNA repair as measured by increased G2 chromosomal radiosensitivity results from up-regulation of cdk1/cyclinB and cell cycle control mechanisms during the G2 to M transition. MATERIALS AND METHODS A total of 185 cancer patients and 25 normal individuals were tested for G2 chromosomal radiosensitivity. The chromatid breaks were analysed in metaphase using the G2 assay or directly in G0 and G2 phase using premature chromosome condensation (PCC). The activity of cdk1/cyclinB, a key regulator of the G2 to M-phase transition, was measured by histone H1 kinase activity and correlated with the development of chromatid breaks after irradiation of cell lines in vitro. RESULTS Based on the G2 assay, cancer patients on average showed increased chromosomal radiosensitivity above controls. When the analysis was carried out directly in G0 or G2 lymphocytes using PCC, no differences in the induction of chromosomal damage and its repair were observed between G2 assay-sensitive and G2-normal donors. Using the G2 assay to test G2 radiosensitivity in various cell lines, it was found that the higher the cdk1/cyclinB activity level of the cell line tested, the higher the yield of chromatid breaks scored. Furthermore, when mitotic cells from these cell lines were used for PCC induction in irradiated G2 lymphocytes it was observed that the higher the cdk1/cyclinB activity level of mitotic cells used, the higher was the induced yield of chromatid breaks. CONCLUSION The cdk1/cyclin-B activity levels during the G2 to M transition impair DNA repair processes and play a major role in the yield of chromatid breaks induced after G2-irradiation. Regulation of cdk1/cyclinB complex activity rather than deficient repair enzymes of DNA damage may underlie the mechanisms of G2 radiosensitivity.
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Affiliation(s)
- G I Terzoudi
- Institute of Nuclear Technology and Radiation Protection, National Centre for Scientific Research Demokritos, Athens, Greece
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41
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Lunn RM, Helzlsouer KJ, Parshad R, Umbach DM, Harris EL, Sanford KK, Bell DA. XPD polymorphisms: effects on DNA repair proficiency. Carcinogenesis 2000; 21:551-5. [PMID: 10753184 DOI: 10.1093/carcin/21.4.551] [Citation(s) in RCA: 316] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
XPD codes for a DNA helicase involved in transcription and nucleotide excision repair. Rare XPD mutations diminish nucleotide excision repair resulting in hypersensitivity to UV light and increased risk of skin cancer. Several polymorphisms in this gene have been identified but their impact on DNA repair is not known. We compared XPD genotypes at codons 312 and 751 with DNA repair proficiency in 31 women. XPD genotypes were measured by PCR-RFLP. DNA repair proficiency was assessed using a cytogenetic assay that detects X-ray induced chromatid aberrations (breaks and gaps). Chromatid aberrations were scored per 100 metaphase cells following incubation at 37 degrees C (1.5 h after irradiation) to allow for repair of DNA damage. Individuals with the Lys/Lys codon 751 XPD genotype had a higher number of chromatid aberrations (132/100 metaphase cells) than those having a 751Gln allele (34/100 metaphase cells). Individuals having greater than 60 chromatid breaks plus gaps were categorized as having sub-optimal repair. Possessing a Lys/Lys751 genotype increased the risk of sub-optimal DNA repair (odds ratio = 7.2, 95% confidence interval = 1.01-87.7). The Asp312Asn XPD polymorphism did not appear to affect DNA repair proficiency. These results suggest that the Lys751 (common) allele may alter the XPD protein product resulting in sub-optimal repair of X-ray-induced DNA damage.
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Affiliation(s)
- R M Lunn
- Laboratory of Computational Biology and Risk Analysis, National Institute of Environmental Health Sciences, National Institutes of Health, MD C3-03, PO Box 12233, Research Triangle Park, NC 27709, USA
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42
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Macieira-Coelho A. Comparative biology of cell immortalization. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 1999; 24:51-80. [PMID: 10547858 DOI: 10.1007/978-3-662-06227-2_3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
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43
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Andersson HC, Lewensohn R, Månsson-Brahme E. Chromosomal sensitivity to X-ray irradiation during the G2 phase in lymphocytes of patients with hereditary cutaneous malignant melanoma as compared to healthy controls. Mutat Res 1999; 425:9-20. [PMID: 10082912 DOI: 10.1016/s0027-5107(98)00245-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Recent reports have suggested that elevated chromosomal aberration yields following X-ray irradiation of skin fibroblasts and peripheral lymphocytes in the G2 phase of the cell cycle are characteristic of affected members of cancer-prone families. These studies propose that the phenomenon is a consequence of impaired caffeine- and arabinofuranosylcytosine (ara-C)-sensitive DNA repair and might be a useful indicator of genetic susceptibility to cancer. We have tested G2 chromosomal X-ray sensitivity in peripheral blood lymphocytes from members of kindreds with hereditary cutaneous malignant melanoma (HCMM) combined with the dysplastic nevus syndrome (DNS), disorders in which susceptibility to skin cancer is inherited in an autosomal dominant pattern. In the assay lymphocytes from patients with HCMM/DNS exhibited responses indistinguishable from normal healthy controls. Furthermore, the radiation-induced aberration yields were potentiated to the same strong extent by post-treatments with caffeine, or a combination of ara-C and hydroxyurea, both in lymphocytes from individuals with HCMM/DNS and lymphocytes from healthy controls. Thus, lymphocytes of affected patients with HCMM/DNS do not have an increased sensitivity to X-ray irradiation in the G2 phase of the cell cycle.
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Affiliation(s)
- H C Andersson
- Department of Genetics, University of Uppsala, Box 7003, SE-750 07, Uppsala, Sweden
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44
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Sanford KK, Parshad R. The contribution of deficient DNA repair to chromosomal radiosensitivity of CHO cells after G2 irradiation. CANCER GENETICS AND CYTOGENETICS 1999; 108:38-41. [PMID: 9973922 DOI: 10.1016/s0165-4608(98)00108-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We compared cytogenetic responses of the parental Chinese hamster ovary (CHO) cell line and its DNA repair-deficient strains to irradiation during the G2 phase. Chromatid breaks were quantified in cells entering metaphase in the presence or absence of cytosine arabinoside (ara-C) 0.5-1.5 hours after exposure to x-rays or UV-C. Addition of ara-C, an inhibitor of DNA repair replication, significantly increased chromatid break frequency (CBF) in the parental line, but not in the strains deficient in nucleotide excision repair (NER). This increase (ara-C effect) was comparable to that in repair-proficient normal human lymphocytes. We conclude that CBF in cells entering metaphase in the presence of ara-C 0.5-1.5 hours after DNA damage represents a functional in vitro assay for evaluating the DNA repair capacity of mammalian cells in culture.
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Affiliation(s)
- K K Sanford
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, Bethesda, Maryland, USA
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45
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Scott D, Barber JB, Levine EL, Burrill W, Roberts SA. Radiation-induced micronucleus induction in lymphocytes identifies a high frequency of radiosensitive cases among breast cancer patients: a test for predisposition? Br J Cancer 1998; 77:614-20. [PMID: 9484819 PMCID: PMC2149942 DOI: 10.1038/bjc.1998.98] [Citation(s) in RCA: 120] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Enhanced sensitivity to the chromosome-damaging effects of ionizing radiation is a feature of many cancer-predisposing conditions. We previously showed that 42% of an unselected series of breast cancer patients and 9% of healthy control subjects showed elevated chromosomal radiosensitivity of lymphocytes irradiated in the G2 phase of the cell cycle. We suggested that, in addition to the highly penetrant genes BRCA1 and BRCA2, which confer a very high risk of breast cancer and are carried by about 5% of all breast cancer patients, there are also low-penetrance predisposing genes carried by a much higher proportion of breast cancer patients, a view supported by recent epidemiological studies. Ideally, testing for the presence of these putative genes should involve the use of simpler methods than the G2 assay, which requires metaphase analysis of chromosome damage. Here we report on the use of a simple, rapid micronucleus assay in G0 lymphocytes exposed to high dose rate (HDR) or low dose rate gamma-irradiation, with delayed mitogenic stimulation. Good assay reproducibility was obtained, particularly with the HDR protocol, which identified 31% (12 out of 39) of breast cancer patients compared with 5% (2 out of 42) of healthy controls as having elevated radiation sensitivity. In the long term, such cytogenetic assays may have the potential for selecting women for intensive screening for breast cancer.
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Affiliation(s)
- D Scott
- Paterson Institute for Cancer Research, Christie CRC Research Centre, Manchester, UK
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46
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Patel RK, Trivedi AH, Arora DC, Bhatavdekar JM, Patel DD. DNA repair proficiency in breast cancer patients and their first-degree relatives. Int J Cancer 1997; 73:20-4. [PMID: 9334804 DOI: 10.1002/(sici)1097-0215(19970926)73:1<20::aid-ijc4>3.0.co;2-3] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Defective DNA repair capacity as measured by enumerating chromatid aberrations induced in G2 phase by X-irradiation may explain increased risk of breast cancer among relatives of patients. In the present study, chromatid damage was determined in peripheral blood lymphocytes (PBL) following in vitro exposure to 50R X-irradiation in G2 phase from 14 breast cancer (BrCa) patients, 19 first-degree relatives (FDR) of BrCa patients and 17 control women who had no family history of cancer for the last 3 generations. Controls, BrCa patients and their FDR had comparable frequency of gaps and breaks when cells were arrested with Colcemid (30 min) after X-irradiation. A steep decline in chromatid damage was observed in cells of controls when arrested after 30, 90 and 120 min of X-irradiation. BrCa patients and their FDR showed higher frequencies of lymphocytic chromatid damage as compared to controls. Chromatid damage (95 gaps + breaks per 100 cells) observed among controls at 90 min post X-irradiation was considered as the optimal level of efficient DNA repair. Thirty-five percent of controls, 93% of BrCa patients and 79% of FDR showed sub-optimal DNA repair. Amongst the FDR, the likelihood of having suboptimal DNA repair was 7 times higher and the risk of developing breast cancer was 2.7 times higher as compared to controls. Moreover, in the BrCa patients, there was frequent involvement of chromosomes 1 and 2, and chromosomes of B, D and E groups, while in FDR, involvement of chromosome 2 and chromosomes of B, D and E groups was more frequent.
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Affiliation(s)
- R K Patel
- Cell Biology Division, Gujarat Cancer Society, Ahmedabad, India
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47
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Gallo O, Franchi A, Chiarelli I, Porfirio B, Grande A, Simonetti L, Bocciolini C, Fini-Storchi O. Potential biomarkers in predicting progression of epithelial hyperplastic lesions of the larynx. ACTA OTO-LARYNGOLOGICA. SUPPLEMENTUM 1997; 527:30-8. [PMID: 9197477 DOI: 10.3109/00016489709124030] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Factors contributing to malignant transformation of laryngeal pre-neoplastic lesions remain largely unknown. Potential etiologic factors may be related to a genetically controlled sensitivity to environmental carcinogens. In this study, we investigated bleomycin-induced chromosome fragility in 15 patients with laryngeal keratoses who experienced a malignant transformation of pre-neoplastic lesions during follow-up, as compared with chromosome fragility in 15 historical controls with no progression of laryngeal keratoses during a 10-year follow-up, in a match-paired analysis. Chromosomal analysis demonstrated a higher sensitivity to clastogens in patients with malignant progression of laryngeal pre-neoplastic lesions than that of control patients with no evolution of their original laryngeal keratoses (p < 0.01). Furthermore, in the attempt to identify possible prognostic markers we studied proliferative activity (MIB-1 expression) and p53 gene aberration in biopsy samples from non-invasive and invasive laryngeal lesions in both groups. p53 immunostaining was observed in 10/15 (66.7%) of pre-neoplastic lesions and in 11/15 (73.3%) of metachronous laryngeal cancers. No differences in terms of p53 expression were noted between transformed and not-transformed lesions. Mutations at p53 gene were observed in 3/15 (20%) of pre-invasive biopsies and in 4/5 (80%) of the laryngeal cancers analyzed. Our data suggest that p53 alteration is an early event in the genesis of a subset of laryngeal carcinomas and that there is no conclusive data about the possible clonal development of metachronous laryngeal carcinoma from a p53 mutated pre-invasive disease in the same patient. MIB-1 expression was found to progressively increase with degree of epithelial hyperplasia and dysplasia in both transformed (p = 0.007) and not-transformed (p < 0.1) lesions. Surprisingly, pre-invasive lesions with tumor evolution showed a lower proliferative activity when compared with laryngeal lesions without malignant transformation (p = 0.013). These data suggests that subjects with pre-neoplastic laryngeal lesion showing an increased susceptibility to carcinogens and with less proliferative disease could be at a higher risk for development of laryngeal carcinoma.
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Affiliation(s)
- O Gallo
- Institute of Otolaryngology-Head & Neck Surgery, University of Florence, Italy
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48
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Gallo O, Santoro R, Lenzi S, Boddi V, Giovannucci-Uzielli ML. Increased mutagen-induced chromosome damage in patients with transformed laryngeal pre-cancerosis. Int J Cancer 1996; 68:700-3. [PMID: 8980169 DOI: 10.1002/(sici)1097-0215(19961211)68:6<700::aid-ijc2>3.0.co;2-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Factors that contribute to malignant transformation of laryngeal pre-neoplastic lesions remain largely unknown. Potential etiological factors may be related to a genetically controlled sensitivity to environmental carcinogens. In this study, we investigated bleomycin-induced chromosome damage in 15 patients who experienced a malignant transformation of preneoplastic laryngeal lesions during follow-up, as compared with chromosome fragility in 30 historical controls with no progression of keratoses during a 10-year follow-up, in a match-paired analysis. Chromosomal analysis demonstrated higher sensitivity to clastogens in patients with malignant progression of laryngeal pre-neoplastic lesions than that of control patients with no evolution of their original laryngeal keratoses (p = 0.003). Furthermore, among the study patients, chromosome sensitivity was most apparent in non-tobacco users with malignant transformation of laryngeal disease. Our data suggest that subjects with pre-neoplastic laryngeal lesion showing increased susceptibility to carcinogens could be at higher risk for development of laryngeal carcinoma.
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Affiliation(s)
- O Gallo
- Institute of Otolaryngology-Head-and-Neck Surgery, University of Florence, Italy
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Kerr B, Ashcroft GS, Scott D, Horan MA, Ferguson MW, Donnai D. Rothmund-Thomson syndrome: two case reports show heterogeneous cutaneous abnormalities, an association with genetically programmed ageing changes, and increased chromosomal radiosensitivity. J Med Genet 1996; 33:928-34. [PMID: 8950673 PMCID: PMC1050787 DOI: 10.1136/jmg.33.11.928] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Rothmund-Thomson syndrome is a rare, autosomal recessive disorder associated with characteristic cutaneous changes, sparse hair, juvenile cataracts, short stature, skeletal defects, dystrophic teeth and nails, and hypogonadism. Mental retardation is unusual. An increased incidence of certain malignancies has been reported. Clonal or mosaic chromosome abnormalities and abnormalities in DNA repair mechanisms have been reported in some cases. We report two cases of Rothmund-Thomson syndrome, both with intellectual handicap, associated in one with a previously undescribed histological appearance of involved skin, suggesting that the spectrum of abnormalities is even more heterogeneous than previously presumed. Both cases exhibited chromosomal radiosensitivity of lymphocytes which may be an indication of a DNA repair defect. This is the first report of an association between Rothmund-Thomson syndrome and unique, intrinsic, age related skin changes.
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Affiliation(s)
- B Kerr
- Department of Medical Genetics, St Mary's Hospital, Manchester, UK
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50
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Parshad R, Price FM, Bohr VA, Cowans KH, Zujewski JA, Sanford KK. Deficient DNA repair capacity, a predisposing factor in breast cancer. Br J Cancer 1996; 74:1-5. [PMID: 8679441 PMCID: PMC2074608 DOI: 10.1038/bjc.1996.307] [Citation(s) in RCA: 131] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Women with breast cancer and a family history of breast cancer and some with sporadic breast cancer are deficient in the repair of radiation-induced DNA damage compared with normal donors with no family history of breast cancer. DNA repair was measured indirectly by quantifying chromatid breaks in phytohaemagglutinin (PHA)-stimulated blood lymphocytes after either X-irradiation or UV-C exposure, with or without post treatment with the DNA repair inhibitor, 1-beta-D-arabinofuranosylcytosine (ara-C). We have correlated chromatid breaks with unrepaired DNA strand breaks using responses to X-irradiation of cells from xeroderma pigmentosum patients with well-characterised DNA repair defects or responses of repair-deficient mutant Chinese hamster ovary (CHO) cells with or without transfected human DNA repair genes. Deficient DNA repair appears to be a predisposing factor in familial breast cancer and in some sporadic breast cancers.
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Affiliation(s)
- R Parshad
- Department of Pathology, Howard University College of Medicine, Washington, DC 20059, USA
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