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Sarkar S, Tribedi P, Bhadra K. Structure-activity insights of harmine targeting DNA, ROS inducing cytotoxicity with PARP mediated apoptosis against cervical cancer, anti-biofilm formation and in vivo therapeutic study. J Biomol Struct Dyn 2021; 40:5880-5902. [PMID: 33480316 DOI: 10.1080/07391102.2021.1874533] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Harmine exhibits pH dependent structural equilibrium and possesses numerous biological and pharmacological activities. Mode and mechanism of DNA binding and its cytotoxicity were studied by multiple spectroscopic, calorimetric, molecular docking and in vitro apoptotic as well as in vivo biochemical and histological studies. It exists as cationic (structure I) and decationic form (structure II) in the pH range 3.0-7.8 and 8.5-12.4, respectively, with a pKa of 8.0. Structure I at pH 6.8 binds strongly to DNA with a cooperative mode of binding of Kiω 1.03 × 106 M-1and stoichiometry of 5.0 nucleotide phosphates. Structure I stabilized DNA by 10 °C, showed85%quenching of fluorescence intensity, perturbation in circular dichroism, partial intercalation and enthalpy driven exothermic binding. While, structure II at pH 8.5 has very weak interaction with CT DNA. Cytotoxic potencies of structure I was tested on four different cancer cell lines along with normal embryonic cell. It showed maximum cytotoxicity with GI50of 20 µM, against HeLa causing several apoptotic induction abilities. Harmine exhibited G2M arrest with ROS induced effective role in PARP mediated apoptosis as well as anti-inflammatory action on HeLa cells. Harmine further presented MIC and antibiofilm activity against Staphylococcus aureus in presence of <160 and 30 µg/ml, respectively. Mice with post harmine treatment (30 mg/kg b.w., I.P.) showed maximum recovery from damaged to near normal architecture of cervical epithelial cells. This study may be of prospective use in a framework to design novel beta carboline compounds for improved therapeutic applications in future against cervical cancer. HighlightsHarmine exists in structure I and structure II forms in the pH 6.8 and 8.5with a pKa of 8.0.Structure I at pH 6.8 binds strongly to DNA compared to structure II.Structure I showed maximum cytotoxicity with GI50 of 20 µM against HeLa.ROS mediated cytotoxicitywithG2M arrest with PARP mediated apoptosis was studied.Harmine (30µg/ml) exhibited antibiofilm activity against Staphylococcus aureus.Post harmine dose (30 mg/kg b.w., I.P.) in mice showed recovery of cervical epithelial cells.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Sarita Sarkar
- Department of Zoology, University of Kalyani, Nadia, West Bengal, India
| | - Prosun Tribedi
- Department of Biotechnology, The Neotia University, Sarisha, West Bengal, India
| | - Kakali Bhadra
- Department of Zoology, University of Kalyani, Nadia, West Bengal, India
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Ramos-Ibeas P, Gimeno I, Cañón-Beltrán K, Gutiérrez-Adán A, Rizos D, Gómez E. Senescence and Apoptosis During in vitro Embryo Development in a Bovine Model. Front Cell Dev Biol 2020; 8:619902. [PMID: 33392207 PMCID: PMC7775420 DOI: 10.3389/fcell.2020.619902] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 12/01/2020] [Indexed: 12/15/2022] Open
Abstract
According to the World Health Organization, infertility affects up to 14% of couples under reproductive age, leading to an exponential rise in the use of assisted reproduction as a route for conceiving a baby. In the same way, thousands of embryos are produced in cattle and other farm animals annually, leading to increased numbers of individuals born. All reproductive manipulations entail deviations of natural phenotypes and genotypes, with in vitro embryo technologies perhaps showing the biggest effects, although these alterations are still emerging. Most of these indications have been provided by animal models, in particular the bovine species, due to its similarities to human early embryo development. Oocytes and embryos are highly sensitive to environmental stress in vivo and in vitro. Thus, during in vitro culture, a number of stressful conditions affect embryonic quality and viability, inducing subfertility and/or long-term consequences that may reach the offspring. A high proportion of the embryos produced in vitro are arrested at a species-specific stage of development during the first cell divisions. These arrested embryos do not show signs of programmed cell death during early cleavage stages. Instead, defective in vitro produced embryos would enter a permanent cell cycle arrest compatible with cellular senescence, in which they show active metabolism and high reactive oxygen species levels. Later in development, mainly during the morula and blastocyst stages, apoptosis would mediate the elimination of certain cells, accomplishing both a physiological role in to balancing cell proliferation and death, and a pathological role preventing the transmission of damaged cells with an altered genome. The latter would acquire relevant importance in in vitro produced embryos that are submitted to stressful environmental stimuli. In this article, we review the mechanisms mediating apoptosis and senescence during early embryo development, with a focus on in vitro produced bovine embryos. Additionally, we shed light on the protective role of senescence and apoptosis to ensure that unhealthy cells and early embryos do not progress in development, avoiding long-term detrimental effects.
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Affiliation(s)
- Priscila Ramos-Ibeas
- Department of Animal Reproduction, National Institute for Agriculture and Food Research and Technology (INIA), Madrid, Spain
| | - Isabel Gimeno
- Servicio Regional de Investigación y Desarrollo Agroalimentario (SERIDA), Gijón, Spain
| | - Karina Cañón-Beltrán
- Department of Animal Reproduction, National Institute for Agriculture and Food Research and Technology (INIA), Madrid, Spain
| | - Alfonso Gutiérrez-Adán
- Department of Animal Reproduction, National Institute for Agriculture and Food Research and Technology (INIA), Madrid, Spain
| | - Dimitrios Rizos
- Department of Animal Reproduction, National Institute for Agriculture and Food Research and Technology (INIA), Madrid, Spain
| | - Enrique Gómez
- Servicio Regional de Investigación y Desarrollo Agroalimentario (SERIDA), Gijón, Spain
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Tay IJ, Park JJH, Price AL, Engelward BP, Floyd SR. HTS-Compatible CometChip Enables Genetic Screening for Modulators of Apoptosis and DNA Double-Strand Break Repair. SLAS DISCOVERY 2020; 25:906-922. [PMID: 32452708 DOI: 10.1177/2472555220918367] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Dysfunction of apoptosis and DNA damage response pathways often drive cancer, and so a better understanding of these pathways can contribute to new cancer therapeutic strategies. Diverse discovery approaches have identified many apoptosis regulators, DNA damage response, and DNA damage repair proteins; however, many of these approaches rely on indirect detection of DNA damage. Here, we describe a novel discovery platform based on the comet assay that leverages previous technical advances in assay precision by incorporating high-throughput robotics. The high-throughput screening (HTS) CometChip is the first high-throughput-compatible assay that can directly detect physical damage in DNA. We focused on DNA double-strand breaks (DSBs) and utilized our HTS CometChip technology to perform a first-of-its-kind screen using an shRNA library targeting 2564 cancer-relevant genes. Conditions of the assay enable detection of DNA fragmentation from both exogenous (ionizing radiation) and endogenous (apoptosis) sources. Using this approach, we identified LATS2 as a novel DNA repair factor as well as a modulator of apoptosis. We conclude that the HTS CometChip is an effective assay for HTS to identify modulators of physical DNA damage and repair.
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Affiliation(s)
- Ian J Tay
- Department of Biological Engineering, Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA.,Agency of Science, Technology and Research Graduate Academy, A*STAR Singapore, Singapore.,Institute of Molecular and Cellular Biology, A*STAR Singapore, Singapore
| | - James J H Park
- Department of Radiation Oncology, Duke University School of Medicine, Durham, NC, USA
| | - Anna L Price
- Department of Radiation Oncology, Duke University School of Medicine, Durham, NC, USA
| | - Bevin P Engelward
- Department of Biological Engineering, Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Scott R Floyd
- Department of Radiation Oncology, Duke University School of Medicine, Durham, NC, USA.,Koch Institute for Integrative Cancer Research, Cambridge, MA, USA
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5-Aminolevulinic Acid-Based Photodynamic Therapy Pretreatment Mitigates Ultraviolet A-Induced Oxidative Photodamage. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:9420745. [PMID: 30524664 PMCID: PMC6247436 DOI: 10.1155/2018/9420745] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 08/30/2018] [Accepted: 09/16/2018] [Indexed: 01/04/2023]
Abstract
Aim To determine whether 5-aminolevulinic acid-based photodynamic therapy (ALA-PDT) is effective in combating ultraviolet A- (UVA-) induced oxidative photodamage of hairless mice skin in vivo and human epidermal keratinocytes in vitro. Methods In in vitro experiments, the human keratinocyte cell line (HaCaT cells) was divided into two groups: the experimental group was treated with ALA-PDT and the control group was left untreated. Then, the experimental group and the control group of cells were exposed to 10 J/m2 of UVA radiation. ROS, O2− species, and MMP were determined by fluorescence microscopy; p53, OGG1, and XPC were determined by Western blot analysis; apoptosis was determined by flow cytometry; and 8-oxo-dG was determined by immunofluorescence. Moreover, HaCaT cells were also treated with ALA-PDT. Then, SOD1 and SOD2 were examined by Western blot analysis. In in vivo experiments, the dorsal skin of hairless mice was treated with ALA-PDT or saline-PDT, and then, they were exposed to 20 J/m2 UVA light. The compound 8-oxo-dG was detected by immunofluorescence. Conclusion In human epidermal keratinocytes and hairless mice skin, UVA-induced oxidative damage can be prevented effectively with ALA-PDT pretreatment.
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Kim HJ, Jang CH. Imaging DNA single-strand breaks generated by reactive oxygen species using a liquid crystal-based sensor. Anal Biochem 2018; 556:1-6. [DOI: 10.1016/j.ab.2018.06.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 06/05/2018] [Accepted: 06/12/2018] [Indexed: 11/17/2022]
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Bailey LA, Nascarella MA, Kerper LE, Rhomberg LR. Hypothesis-based weight-of-evidence evaluation and risk assessment for naphthalene carcinogenesis. Crit Rev Toxicol 2015; 46:1-42. [PMID: 26202831 PMCID: PMC4732411 DOI: 10.3109/10408444.2015.1061477] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 06/09/2015] [Indexed: 11/13/2022]
Abstract
Inhalation of naphthalene causes olfactory epithelial nasal tumors in rats (but not in mice) and benign lung adenomas in mice (but not in rats). The limited available human data have not identified an association between naphthalene exposure and increased respiratory cancer risk. Assessing naphthalene's carcinogenicity in humans, therefore, depends entirely on experimental evidence from rodents. We evaluated the respiratory carcinogenicity of naphthalene in rodents, and its potential relevance to humans, using our Hypothesis-Based Weight-of-Evidence (HBWoE) approach. We systematically and comparatively reviewed data relevant to key elements in the hypothesized modes of action (MoA) to determine which is best supported by the available data, allowing all of the data from each realm of investigation to inform interpretation of one another. Our analysis supports a mechanism that involves initial metabolism of naphthalene to the epoxide, followed by GSH depletion, cytotoxicity, chronic inflammation, regenerative hyperplasia, and tumor formation, with possible weak genotoxicity from downstream metabolites occurring only at high cytotoxic doses, strongly supporting a non-mutagenic threshold MoA in the rat nose. We also conducted a dose-response analysis, based on the likely MoA, which suggests that the rat nasal MoA is not relevant in human respiratory tissues at typical environmental exposures. Our analysis illustrates how a thorough WoE evaluation can be used to support a MoA, even when a mechanism of action cannot be fully elucidated. A non-mutagenic threshold MoA for naphthalene-induced rat nasal tumors should be considered as a basis to determine human relevance and to guide regulatory and risk-management decisions.
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Selenium reduces bradykinesia and DNA damage in a rat model of Parkinson's disease. Nutrition 2015; 31:359-65. [DOI: 10.1016/j.nut.2014.07.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 05/27/2014] [Accepted: 07/14/2014] [Indexed: 12/25/2022]
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Hseu YC, Tsai YC, Huang PJ, Ou TT, Korivi M, Hsu LS, Chang SH, Wu CR, Yang HL. The dermato-protective effects of lucidone from Lindera erythrocarpa through the induction of Nrf2-mediated antioxidant genes in UVA-irradiated human skin keratinocytes. J Funct Foods 2015. [DOI: 10.1016/j.jff.2014.10.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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Nisar MF, Parsons KSG, Bian CX, Zhong JL. UVA irradiation induced heme oxygenase-1: a novel phototherapy for morphea. Photochem Photobiol 2014; 91:210-20. [PMID: 25207998 DOI: 10.1111/php.12342] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2014] [Accepted: 08/21/2014] [Indexed: 12/21/2022]
Abstract
Long wave UVA radiation (340-400 nm) causes detrimental as well as beneficial effects on human skin. Studies of human skin fibroblasts irradiated with UVA demonstrate increased expression of both antifibrotic heme oxygenase-1 (HO-1) and matrix metalloproteinase 1 (MMP-1). The use of UVA-induced MMP-1 is well-studied in treating skin fibrotic conditions such as localized scleroderma, now called morphea. However, the role that UVA-induced HO-1 plays in phototherapy of morphea has not been characterized. In the present manuscript, we have illustrated and reviewed the biological function of HO-1 and the use of UVA1 wavebands (340-400 nm) for phototherapy; the potential use of HO-1 induction in UVA therapy of morphea is also discussed.
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Affiliation(s)
- Muhammad Farrukh Nisar
- The Base of "111 Project" for Biomechanics & Tissue Repair Engineering, Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College, Chongqing University, Chongqing, China
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Guérard M, Marchand C, Plappert-Helbig U. Influence of experimental conditions on data variability in the liver comet assay. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2014; 55:114-121. [PMID: 24346955 DOI: 10.1002/em.21835] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 11/19/2013] [Accepted: 11/20/2013] [Indexed: 06/03/2023]
Abstract
The in vivo comet assay has increasingly been used for regulatory genotoxicity testing in recent years. While it has been demonstrated that the experimental execution of the assay, for example, electrophoresis or scoring, can have a strong impact on the results; little is known on how initial steps, that is, from tissue sampling during necropsy up to slide preparation, can influence the comet assay results. Therefore, we investigated which of the multitude of steps in processing the liver for the comet assay are most critical. All together eight parameters were assessed by using liver samples of untreated animals. In addition, two of those parameters (temperature and storage time of liver before embedding into agarose) were further investigated in animals given a single oral dose of ethyl methanesulfonate at dose levels of 50, 100, and 200 mg/kg, 3 hr prior to necropsy. The results showed that sample cooling emerged as the predominant influence factor, whereas variations in other elements of the procedure (e.g., size of the liver piece sampled, time needed to process the liver tissue post-mortem, agarose temperature, or time of lysis) seem to be of little relevance. Storing of liver samples of up to 6 hr under cooled conditions did not cause an increase in tail intensity. In contrast, storing the tissue at room temperature, resulted in a considerable time-dependent increase in comet parameters.
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Affiliation(s)
- M Guérard
- pRED, Pharma Research and Early Development, F. Hoffmann-La Roche Ltd., Basel, Switzerland
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Abstract
Solar ultraviolet (UV) radiation, mainly UV-B (280-315 nm), is one of the most potent genotoxic agents that adversely affects living organisms by altering their genomic stability. DNA through its nucleobases has absorption maxima in the UV region and is therefore the main target of the deleterious radiation. The main biological relevance of UV radiation lies in the formation of several cytotoxic and mutagenic DNA lesions such as cyclobutane pyrimidine dimers (CPDs), 6-4 photoproducts (6-4PPs), and their Dewar valence isomers (DEWs), as well as DNA strand breaks. However, to counteract these DNA lesions, organisms have developed a number of highly conserved repair mechanisms such as photoreactivation, excision repair, and mismatch repair (MMR). Photoreactivation involving the enzyme photolyase is the most frequently used repair mechanism in a number of organisms. Excision repair can be classified as base excision repair (BER) and nucleotide excision repair (NER) involving a number of glycosylases and polymerases, respectively. In addition to this, double-strand break repair, SOS response, cell-cycle checkpoints, and programmed cell death (apoptosis) are also operative in various organisms to ensure genomic stability. This review concentrates on the UV-induced DNA damage and the associated repair mechanisms as well as various damage detection methods.
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Affiliation(s)
- Richa
- Laboratory of Photobiology and Molecular Microbiology, Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, 221005, India
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Badding MA, Stefaniak AB, Fix NR, Cummings KJ, Leonard SS. Cytotoxicity and characterization of particles collected from an indium-tin oxide production facility. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2014; 77:1193-1209. [PMID: 25208660 PMCID: PMC4192900 DOI: 10.1080/15287394.2014.920757] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 04/30/2014] [Indexed: 06/01/2023]
Abstract
Occupational exposure to indium compound particles has recently been associated with lung disease among workers in the indium-tin oxide (ITO) industry. Previous studies suggested that excessive alveolar surfactant and reactive oxygen species (ROS) may play a role in the development of pulmonary lesions following exposure to indium compounds. However, toxicity at the cellular level has not been comprehensively evaluated. Thus, the aim of this study was to assess which, if any, compounds encountered during ITO production are toxic to cultured cells and ultimately contribute to the pathogenesis of indium lung disease. The compounds used in this study were collected from eight different processing stages at an ITO production facility. Enhanced dark field imaging showed 5 of the compounds significantly associated with cells within 1 h, suggesting that cellular reactions to the compound particles may be occurring rapidly. To examine the potential cytotoxic effects of these associations, ROS generation, cell viability, and apoptosis were evaluated following exposures in RAW 264.7 mouse monocyte macrophage and BEAS-2B human bronchial epithelial cell lines. Both exhibited reduced viability with exposures, while apoptosis only occurred in RAW 264.7 cells. Our results suggested that excessive ROS production is likely not the predominant mechanism underlying indium-induced lung disease. However, the effects on cell viability reveal that several of the compounds are cytotoxic, and therefore, exposures need to be carefully monitored in the industrial setting.
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Affiliation(s)
- Melissa A. Badding
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, West Virginia, USA
| | - Aleksandr B. Stefaniak
- Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Morgantown, West Virginia, USA
| | - Natalie R. Fix
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, West Virginia, USA
| | - Kristin J. Cummings
- Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Morgantown, West Virginia, USA
| | - Stephen S. Leonard
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, West Virginia, USA
- West Virginia University, Pharmaceutical and Pharmacological Sciences, Morgantown, West Virginia, USA
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Sikdar S, Mukherjee A, Ghosh S, Khuda-Bukhsh AR. Condurango glycoside-rich components stimulate DNA damage-induced cell cycle arrest and ROS-mediated caspase-3 dependent apoptosis through inhibition of cell-proliferation in lung cancer, in vitro and in vivo. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2014; 37:300-314. [PMID: 24384279 DOI: 10.1016/j.etap.2013.12.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 11/28/2013] [Accepted: 12/06/2013] [Indexed: 06/03/2023]
Abstract
Chemotherapeutic potential of Condurango glycoside-rich components (CGS) was evaluated in NSCLC, in vitro and in BaP-intoxicated rats, in vivo. NSCLC cells were treated with different concentrations of CGS to test their effect on cell viability. Cellular morphology, DNA-damage, AnnexinV-FITC/PI, cell cycle regulation, ROS-accumulation, MMP, and expressions of related signalling genes were critically analysed. 0.22 μg/μl CGS (IC₅₀ dose at 24 h) was selected for the study. CGS-induced apoptosis via DNA damage was evidenced by DNA-ladder formation, increase of AnnexinV-positive cells, cell cycle arrest at subG0/G1 and differential expressions of apoptotic genes. ROS-elevation and MMP-depolarization with significant caspase-3 activation might lead to apoptotic cell death. Anti-proliferative activity was confirmed by EGFR-expression modulation. ROS accumulation and DNA-nick formation with tissue damage-repair activity after post-cancerous CGS treatment, in vivo, supported the in vitro findings. Overall results advocate considerable apoptosis-inducing potential of CGS against NSCLC, validating its use against lung cancer by CAM practitioners.
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Affiliation(s)
- Sourav Sikdar
- Cytogenetics and Molecular Biology Laboratory, Department of Zoology, University of Kalyani, Kalyani 741235, West Bengal, India
| | - Avinaba Mukherjee
- Cytogenetics and Molecular Biology Laboratory, Department of Zoology, University of Kalyani, Kalyani 741235, West Bengal, India
| | - Samrat Ghosh
- Cytogenetics and Molecular Biology Laboratory, Department of Zoology, University of Kalyani, Kalyani 741235, West Bengal, India
| | - Anisur Rahman Khuda-Bukhsh
- Cytogenetics and Molecular Biology Laboratory, Department of Zoology, University of Kalyani, Kalyani 741235, West Bengal, India.
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Mukherjee A, Sikdar S, Bishayee K, Paul A, Ghosh S, Boujedaini N, Khuda-Bukhsh AR. Ethanolic extract of Thuja occidentalis blocks proliferation of A549 cells and induces apoptosis in vitro. ACTA ACUST UNITED AC 2013; 10:1451-9. [PMID: 23257140 DOI: 10.3736/jcim20121218] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To study the possible anticancer and antiproliferative activities of ethanolic leaf extract of Thuja occidentalis (TO) on A549 non-small lung carcinoma cells in vitro. METHODS Cell viability was ascertained through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay after deployment of TO in different doses. The half maximal inhibitory concentration (IC50) dose (282 μg/mL) was determined, and two other doses for dose-dependence study, one below the IC50 dose (IC35=188 μg/mL) and one above the IC50 dose (IC65=376 μg/mL) were selected. Bromodeoxyuridine (BrdU) incorporation assay and migration studies were performed to elucidate antiproliferative activity of the drug, if any. Fluorescence-activated cell sorting analysis after annexin V-fluorescein isothiocyanate and propidium iodide (annexin V-FITC-PI) dual staining method was done to ascertain early stage of apoptosis, if any. DNA fragmentation assay was done through Hoechst 33258 and acridine orange-ethidium bromide staining. DNA damage was quantified through comet assay. Bax-Bcl2 regulation and expression studies were performed through indirect enzyme-linked immunosorbent assay (ELISA). Caspase 3 activity was measured at gene level through reverse transcription-polymerase chain reaction (RT-PCR) analysis. Its activation at protein level was analyzed through indirect ELISA and Western blot analysis. RESULTS TO demonstrated a dose-dependent decrease in viability of A549 cells after 24 h of exposure. Cell proliferation was reduced in a time-dependent manner of drug exposure as revealed from BrdU incorporation and migration studies. Annexin-V-FITC positivity of cells up to 11.72% as compared to the untreated control revealed early state of TO-induced apoptosis. Occurrence of comet tail and increased fluorescence of Hoechst after 24 h of drug exposure revealed significant DNA nick generation and chromatin condensation. Bax up-regulation and Bcl-2 down-regulation suitably altered ratio of Bax/Bcl-2 in favor of apoptosis. From RT-PCR, indirect ELISA and Western blot studies, caspase 3 activity was also found to be significantly increased along with cleaved poly ADP-ribose polymerase expression. CONCLUSION Ethanolic leaf extract of TO demonstrated apoptotic and antiproliferative potentials against A549 cell line.
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Affiliation(s)
- Avinaba Mukherjee
- Cytogenetics and Molecular Biology Laboratory, Department of Zoology, University of Kalyani, Kalyani 741235, West Bengal, India
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Åsgård R, Hellman B. Effect of β-carotene on catechol-induced genotoxicity in vitro: evidence of both enhanced and reduced DNA damage. Free Radic Res 2013; 47:692-8. [PMID: 23767930 DOI: 10.3109/10715762.2013.815346] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Intake of antioxidants from the diet has been recognized to have beneficial health effects, but the potential benefit of taking antioxidants such as β-carotene as supplements is controversial. The aim of the present study was to evaluate the potential protective effects of a physiologically relevant concentration (2 μM) of β-carotene on the DNA damaging effects of catechol in mouse lymphoma L5178Y cells. Two different exposure protocols were used: simultaneous exposure to β-carotene and catechol for 3 h; and exposure to catechol for 3 h after 18 h pre-treatment with the vitamin. DNA damage was evaluated using the comet assay (employing one procedure for general damage, and another procedure, which also included oxidative DNA damage). Independent of exposure protocol and procedure for comet assay, β-carotene did not increase the basal level of DNA damage. However, at the highest concentration of catechol (1 mM), β-carotene was found to clearly increase the level of catechol-induced DNA damage, especially in the pre-treated cells. Interestingly, an opposite effect was observed at lower concentrations of catechol, but the β-carotene related reduction of catechol-induced genotoxicity was significant (P < 0.05) only for the procedure including oxidative damage induced by 0.5 mM catechol. Taken together our results indicate that β- carotene can both reduce and enhance the DNA damaging effects of a genotoxic agent such as catechol. This indicates that it is the level of catechol-induced DNA damage that seems to determine whether β-carotene should be regarded as a beneficial or detrimental agent when it comes to its use as a dietary supplement.
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Affiliation(s)
- R Åsgård
- Division of Toxicology, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
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Saha SK, Sikdar S, Mukherjee A, Bhadra K, Boujedaini N, Khuda-Bukhsh AR. Ethanolic extract of the Goldenseal, Hydrastis canadensis, has demonstrable chemopreventive effects on HeLa cells in vitro: Drug-DNA interaction with calf thymus DNA as target. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2013; 36:202-214. [PMID: 23628949 DOI: 10.1016/j.etap.2013.03.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 03/25/2013] [Accepted: 03/31/2013] [Indexed: 06/02/2023]
Abstract
This study tested chemotherapeutic potential of Hydrastis canadensis (HC) extract in HeLa cells in vitro, with emphasis on its drug-DNA interaction and apoptosis induction ability. Nuclear uptake of HC by DAPI, Ao/Eb staining and internucleosomal DNA damage by comet assay was studied through fluorescence microscopy. Possible changes in MMP and apoptotic signalling events were critically analyzed. Cell cycle progression studied through FACS and fragmented DNA through "TUNEL" assay were critically analyzed. RT-PCR studies were conducted for analyzing Cyt-C and Bax translocation in mitochondrial and cytosolic extracts, and Caspase 3 in whole cell lysate. Role of p53-mediated regulation of NF-κβ and TNF-α was elucidated by Western blot analysis. Data of CD and Tm profile of CT-DNA were analyzed. Overall results indicated anti-cancer potential of HC through its ability to induce apoptosis, and interaction with CT-DNA that changed structural conformation of DNA, proving HC to be a promising candidate for chemoprevention.
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Affiliation(s)
- Santu Kumar Saha
- Cytogenetics and Molecular Biology Laboratory, Department of Zoology, University of Kalyani, Kalyani 741235, India
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Weber L, Carvalho L, Sá N, Silva V, Beraldini N, Souza V, Conceição M. Genotoxic effects of the water-soluble fraction of heavy oil in the brackish/freshwater amphipod Quadrivisio aff. lutzi (Gammaridea) as assessed using the comet assay. ECOTOXICOLOGY (LONDON, ENGLAND) 2013; 22:642-655. [PMID: 23479060 DOI: 10.1007/s10646-013-1055-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/27/2013] [Indexed: 06/01/2023]
Abstract
Amphipod crustaceans have been widely used as invertebrate models in ecotoxicology due to their importance in the food chain. However, few studies have evaluated the genotoxic effects of pollutants in this model using the comet assay. The main obstacle to using amphipods in the comet assay is the difficulty in obtaining enough blood cells from a single individual. In this study, we evaluated the genotoxic effects of the water-soluble fraction (WSF) of heavy oil on the brackish/freshwater amphipod Quadrivisio aff. lutzi, which is common in the coastal lagoons of southeastern Brazil, using hemocytes obtained from single amphipods (without pooling) after optimizing hemolymph extraction. The comet assay revealed significantly higher DNA damage levels (2- to 6-fold higher) in treated amphipods compared to untreated ones with a sublethal concentration of 17.6 % of the WSF within 72 h of treatment. Two independent experiments confirmed an "up and down" pattern of DNA damage, measured as the % of DNA contained in the tail of the comets. Elevations in DNA damage levels were observed at the 6 and 48 h time points, while very low levels of DNA damage were observed at the 24 and 72 h time points. Furthermore, the comet assay revealed gender variability in the levels of DNA damage after short-term exposure.
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Affiliation(s)
- Laura Weber
- Laboratório de Biologia Molecular, NUPEM/UFRJ, Universidade Federal do Rio de Janeiro, Macae, Brazil,
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Charron CS, Clevidence BA, Albaugh GA, Kramer MH, Vinyard BT, Milner JA, Novotny JA. Assessment of DNA damage and repair in adults consuming allyl isothiocyanate or Brassica vegetables. J Nutr Biochem 2013; 24:894-902. [PMID: 22902324 PMCID: PMC3504633 DOI: 10.1016/j.jnutbio.2012.06.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Revised: 05/18/2012] [Accepted: 06/02/2012] [Indexed: 01/28/2023]
Abstract
Allyl isothiocyanate (AITC) is a dietary component with possible anticancer effects, though much information about AITC and cancer has been obtained from cell studies. To investigate the effect of AITC on DNA integrity in vivo, a crossover study was conducted. Adults (n=46) consumed AITC, AITC-rich vegetables [mustard and cabbage (M/C)] or a control treatment with a controlled diet for 10 days each. On day 11, volunteers provided blood and urine before and after consuming treatments. Volunteers were characterized for genotype for GSTM1 and GSTT1 (glutathione S-transferases) and XPD (DNA repair). DNA integrity in peripheral blood mononuclear cells was assessed by single-cell gel electrophoresis. Urine was analyzed for 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) and creatinine. Ten-day intake of neither AITC nor M/C resulted in statistically significant differences in DNA strand breaks [least squares mean (LSmean) % DNA in tail±S.E.M.: 4.8±0.6 for control, 5.7±0.7 for AITC, 5.3±0.6 for M/C] or urinary 8-oxodG (LSmean μg 8-oxodG/g creatinine±S.E.M.: 2.95±0.09 for control, 2.88±0.09 for AITC, 3.06±0.09 for M/C). Both AITC and M/C increased DNA strand breaks 3 h postconsumption (LSmean % DNA in tail±S.E.M.: 3.2±0.7 for control, 8.3±1.7 for AITC, 8.0±1.7 for M/C), and this difference disappeared at 6 h (4.2±0.9 for control, 5.7±1.2 for AITC, 5.5±1.2 for M/C). Genotypes for GSTM1, GSTT1 and XPD were not associated with treatment effects. In summary, DNA damage appeared to be induced in the short term by AITC and AITC-rich products, but that damage disappeared quickly, and neither AITC nor AITC-rich products affected DNA base excision repair.
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Affiliation(s)
- Craig S. Charron
- U. S. Department of Agriculture, Agricultural Research Service, Beltsville Human Nutrition Research Center, Beltsville, MD 20705
| | - Beverly A. Clevidence
- U. S. Department of Agriculture, Agricultural Research Service, Beltsville Human Nutrition Research Center, Beltsville, MD 20705
| | - George A. Albaugh
- U. S. Department of Agriculture, Agricultural Research Service, Beltsville Human Nutrition Research Center, Beltsville, MD 20705
| | - Matthew H. Kramer
- U. S. Department of Agriculture, Agricultural Research Service, Biometrical Consulting Services, Beltsville, MD 20705
| | - Bryan T. Vinyard
- U. S. Department of Agriculture, Agricultural Research Service, Biometrical Consulting Services, Beltsville, MD 20705
| | - John A. Milner
- National Institutes of Health, National Cancer Institute, Division of Cancer Prevention, Nutritional Science Research Group, Rockville, MD 20892
| | - Janet A. Novotny
- U. S. Department of Agriculture, Agricultural Research Service, Beltsville Human Nutrition Research Center, Beltsville, MD 20705
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Sikdar S, Mukherjee A, Boujedaini N, Khuda-Bukhsh AR. Ethanolic extract of Condurango (Marsdenia condurango) used in traditional systems of medicine including homeopathy against cancer can induce DNA damage and apoptosis in non small lung cancer cells, A549 and H522, in vitro. ACTA ACUST UNITED AC 2013. [DOI: 10.5667/tang.2012.0044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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20
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Fenech M, Kirsch-Volders M. RE: Insensitivity of the in vitro cytokinesis-block micronucleus assay with human lymphocytes for the detection of DNA damage present at the start of the cell culture (Mutagenesis, 27, 743–747, 2012). Mutagenesis 2013; 28:367-9. [DOI: 10.1093/mutage/ges081] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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21
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Otsu K, Sato K, Sato M, Ono H, Ohba Y, Katagata Y. Impaired activation of caspase cascade during cell death induced by newly synthesized singlet oxygen generator, 1-buthylnaphthalene-4-propionate endoperoxide. Cell Biol Int 2013; 32:1380-7. [DOI: 10.1016/j.cellbi.2008.08.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2007] [Revised: 04/28/2008] [Accepted: 08/12/2008] [Indexed: 10/21/2022]
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22
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Staneva D, Peycheva E, Georgieva M, Efremov T, Miloshev G. Application of comet assay for the assessment of DNA damage caused by chemical genotoxins in the dairy yeast Kluyveromyces lactis. Antonie van Leeuwenhoek 2012; 103:143-52. [PMID: 22914887 DOI: 10.1007/s10482-012-9793-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Accepted: 08/07/2012] [Indexed: 10/28/2022]
Abstract
Kluyveromyces lactis, also known as dairy yeast, has numerous applications in scientific research and practice. It has been approved as a GRAS (Generally Recognized As Safe) organism, a probiotic, a biotechnological producer of important enzymes at industrial scale and a bioremediator of waste water from the dairy industry. Despite these important practical applications the sensitivity of this organism to genotoxic substances has not yet been assessed. In order to evaluate the response of K. lactis cells to genotoxic agents we have applied several compounds with well-known cyto- and genotoxic activity. The method of comet assay (CA) widely used for the assessment of DNA damages is presented here with new special modifications appropriate for K. lactis cells. The comparison of the response of K. lactis to genotoxins with that of Saccharomyces cerevisiae showed that both yeasts, although considered close relatives, exhibit species-specific sensitivity toward the genotoxins examined.
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Affiliation(s)
- Dessislava Staneva
- Laboratory of Yeast Molecular Genetics, Institute of Molecular Biology Roumen Tsanev, Bulgarian Academy of Sciences, Acad. G. Bonchev str., 1113, Sofia, Bulgaria
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23
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Recommendations for safety testing with the in vivo comet assay. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2012; 747:142-156. [DOI: 10.1016/j.mrgentox.2012.05.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 05/03/2012] [Accepted: 05/08/2012] [Indexed: 01/08/2023]
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Ellagic acid protects human keratinocyte (HaCaT) cells against UVA-induced oxidative stress and apoptosis through the upregulation of the HO-1 and Nrf-2 antioxidant genes. Food Chem Toxicol 2012; 50:1245-55. [PMID: 22386815 DOI: 10.1016/j.fct.2012.02.020] [Citation(s) in RCA: 174] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Revised: 02/04/2012] [Accepted: 02/13/2012] [Indexed: 12/11/2022]
Abstract
UV radiation from the sun is a potent environmental risk factor in the pathogenesis of skin damage. Much of the skin damage caused by ultraviolet A (UVA) irradiation from the sun is associated with oxidative stress. The aim of this study was to investigate the protective role of ellagic acid (25-75 μM), a natural antioxidant, against UVA (5-20 J/cm(2))-induced oxidative stress and apoptosis in human keratinocyte (HaCaT) cells and to reveal the possible mechanisms underlying this protective efficacy. Ellagic acid pre-treatment markedly increased HaCaT cell viability and suppressed UVA-induced ROS generation and MDA formation. Moreover, ellagic acid pre-treatment prevented UVA-induced DNA damage as evaluated by the comet assay. Ellagic acid treatment also significantly inhibited the UVA-induced apoptosis of HaCaT cells, as measured by a reduction of DNA fragmentation, mitochondria dysfunction, ER stress, caspase-3 activation, and Bcl-2/Bax deregulation. Notably, the antioxidant potential of ellagic acid was directly correlated with the increased expression of HO-1 and SOD, which was followed by the downregulation of Keap1 and the augmented nuclear translocation and transcriptional activation of Nrf2 with or without UVA irradiation. Nrf2 knockdown diminished the protective effects of ellagic acid. Therefore, ellagic acid may be useful for the treatment of UVA-induced skin damage.
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Wu YF, Zhou YL, Mao WF, Avanessian B, Liu PY, Tang JB. Cellular apoptosis and proliferation in the middle and late intrasynovial tendon healing periods. J Hand Surg Am 2012; 37:209-16. [PMID: 22209211 DOI: 10.1016/j.jhsa.2011.10.049] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 10/25/2011] [Accepted: 10/25/2011] [Indexed: 02/02/2023]
Abstract
PURPOSE Cellular apoptosis might be an important molecular event in the middle or late healing periods of intrasynovial tendons, but this has not been studied. We aimed to investigate cellular apoptosis and corresponding cellular proliferation in the middle and late healing stages of intrasynovial tendons. METHODS The flexor digitorum profundus tendons of 48 long toes (24 chickens) were completely transected within the sheath region and were repaired surgically. At days 28, 42, 56, and 84 after surgery, tendons were harvested and sectioned. In situ terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was performed to detect apoptotic cells. The sections were stained immunofluorescently with antibodies to proliferating cell nuclear antigen to assess proliferation and to Bcl-2 (an anti-apoptotic protein). Positively stained tenocytes were counted, and their distributional differences were verified in 3-dimensional images. RESULTS The repaired intrasynovial tendons exhibited generally greater apoptosis in the surface region than in the core. The differences were more remarkable in the extended region than in the junction region of the cut tendon. At the core of the junction site, apoptosis of tenocytes was pronounced at all time points, but it was less severe at the core of the extended region. The proliferating cell nuclear antigen-positive and Bcl-2-positive tenocytes decreased significantly and continually at days 28, 42, and 56, respectively; these tenocytes were at a minimum at days 56 and 84. CONCLUSIONS Apoptotic changes of tenocytes are most marked in the surface region and in the junction region of the healing tendon in the middle and late healing stages. Apoptosis in the core is less dramatic compared to that in the surface in the extended tendon regions. Cellular proliferation declines drastically and is minimal at days 56 and 84. CLINICAL RELEVANCE Tenocyte apoptosis in the middle and late stages might be an important event contributing to intrasynovial tendon remodeling, which affects the healing strength and formation of adhesions.
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Affiliation(s)
- Ya Fang Wu
- Hand Surgery Research Center, Department of Hand Surgery, Affiliated Hospital of Nantong University, Nantong, China
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26
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Antiproliferative, proapoptotic and morphogenic effects of the flavonoid rutin on human glioblastoma cells. Food Chem 2011; 127:404-11. [DOI: 10.1016/j.foodchem.2010.12.131] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2010] [Revised: 10/21/2010] [Accepted: 12/31/2010] [Indexed: 12/18/2022]
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27
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Biswas R, Mandal SK, Dutta S, Bhattacharyya SS, Boujedaini N, Khuda-Bukhsh AR. Thujone-Rich Fraction of Thuja occidentalis Demonstrates Major Anti-Cancer Potentials: Evidences from In Vitro Studies on A375 Cells. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2011; 2011:568148. [PMID: 21647317 PMCID: PMC3106972 DOI: 10.1093/ecam/neq042] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Accepted: 04/09/2010] [Indexed: 12/23/2022]
Abstract
Crude ethanolic extract of Thuja occidentalis (Fam: Cupressaceae) is used as homeopathic mother tincture (TOΦ) to treat various ailments, particularly moles and tumors, and also used in various other systems of traditional medicine. Anti-proliferative and apoptosis-inducing properties of TOΦ and the thujone-rich fraction (TRF) separated from it have been evaluated for their possible anti-cancer potentials in the malignant melanoma cell line A375. On initial trial by S-diphenyltetrazolium bromide assay, both TOΦ and TRF showed maximum cytotoxic effect on A375 cell line while the other three principal fractions separated by chromatography had negligible or no such effect, because of which only TRF was further characterized and subjected to certain other assays for determining its precise anti-proliferative and apoptotic potentials. TRF was reported to have a molecular formula of C10H16O with a molecular weight of 152. Exposure of TRF of Thuja occidentalis to A375 cells in vitro showed more cytotoxic, anti-proliferative and apoptotic effects as compared with TOΦ, but had minimal growth inhibitory responses when exposed to normal cells (peripheral blood mononuclear cell). Furthermore, both TOΦ and TRF also caused a significant decrease in cell viability, induced inter-nucleosomal DNA fragmentation, mitochondrial transmembrane potential collapse, increase in ROS generation, and release of cytochrome c and caspase-3 activation, all of which are closely related to the induction of apoptosis in A375 cells. Thus, TRF showed and matched all the anti-cancer responses of TOΦ and could be the main bio-active fraction. The use of TOΦ in traditional medicines against tumors has, therefore, a scientific basis.
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Affiliation(s)
- Raktim Biswas
- Cytogenetics and Molecular Biology Laboratory, Department of Zoology, University of Kalyani, Kalyani 741235, India
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Rastogi RP, Richa, Kumar A, Tyagi MB, Sinha RP. Molecular mechanisms of ultraviolet radiation-induced DNA damage and repair. J Nucleic Acids 2010; 2010:592980. [PMID: 21209706 PMCID: PMC3010660 DOI: 10.4061/2010/592980] [Citation(s) in RCA: 603] [Impact Index Per Article: 43.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2010] [Revised: 08/15/2010] [Accepted: 09/28/2010] [Indexed: 11/20/2022] Open
Abstract
DNA is one of the prime molecules, and its stability is of utmost importance for proper functioning and existence of all living systems. Genotoxic chemicals and radiations exert adverse effects on genome stability. Ultraviolet radiation (UVR) (mainly UV-B: 280-315 nm) is one of the powerful agents that can alter the normal state of life by inducing a variety of mutagenic and cytotoxic DNA lesions such as cyclobutane-pyrimidine dimers (CPDs), 6-4 photoproducts (6-4PPs), and their Dewar valence isomers as well as DNA strand breaks by interfering the genome integrity. To counteract these lesions, organisms have developed a number of highly conserved repair mechanisms such as photoreactivation, base excision repair (BER), nucleotide excision repair (NER), and mismatch repair (MMR). Additionally, double-strand break repair (by homologous recombination and nonhomologous end joining), SOS response, cell-cycle checkpoints, and programmed cell death (apoptosis) are also operative in various organisms with the expense of specific gene products. This review deals with UV-induced alterations in DNA and its maintenance by various repair mechanisms.
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Affiliation(s)
- Rajesh P Rastogi
- Laboratory of Photobiology and Molecular Microbiology, Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi 221005, India
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Benassi-Evans B, Clifton P, Noakes M, Fenech M. High-protein/high red meat and high-carbohydrate weight-loss diets do not differ in their effect on faecal water genotoxicity tested by use of the WIL2-NS cell line and with other biomarkers of bowel health. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2010; 703:130-6. [DOI: 10.1016/j.mrgentox.2010.08.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Revised: 06/17/2010] [Accepted: 08/11/2010] [Indexed: 12/24/2022]
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Håkanson M, Textor M, Charnley M. Engineered 3D environments to elucidate the effect of environmental parameters on drug response in cancer. Integr Biol (Camb) 2010; 3:31-8. [PMID: 21049126 DOI: 10.1039/c0ib00074d] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Traditional in vitro models used for the development of anti-cancer drugs are based on the monolayer culture of cells, which has a limited predictivity of in vivo efficacy. A number of cell culture platforms have been developed in recent years to improve predictivity and further to elucidate the mechanisms governing the differing responses observed in vitro versus in vivo. One detrimental aspect of current in vitro models is their inability to decouple the effect of different extrinsic factors on the responsiveness of the cells to drug treatment. Here, we have used an engineered poly(dimethylsiloxane) (PDMS) microwell array as a reductionist approach to study the effect of environmental parameters, independently of each other. It is observed for MCF-7 breast cancer cells, that culture within the three-dimensional (3D) environment of the microwells alone had an effect on the response to Taxol and results in a reduction of cell death in comparison to cells cultured on flat substrates. Additionally the microwells allowed the response of single versus multicell clusters to be differentiated. It was found that the formation of cell-cell contacts alters the drug response, depending on the type of adhesive protein present. Thus, with this microwell platform it is revealed that the presence of cell-cell contacts in addition to the dimensionality and the matrix composition of the environment are important mediators of altered drug responses. In conclusion the microwell array can not only serve as a platform to reveal which parameters of the extracellular environment affect drug response but further the interdependence of these parameters.
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Qu X, Li Y, Liu J, Xu L, Zhang Y, Hu X, Hou K, Liu Y. Cbl-b promotes chemotherapy-induced apoptosis in rat basophilic leukemia cells by suppressing PI3K/Akt activation and enhancing MEK/ERK activation. Mol Cell Biochem 2010; 340:107-14. [PMID: 20177738 DOI: 10.1007/s11010-010-0407-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2009] [Accepted: 02/09/2010] [Indexed: 01/14/2023]
Abstract
The ubiquitin ligase Cbl-b is a negative regulator of the PI3K/Akt pathway, the survival pathway implicated in chemotherapy resistance. However, it remains unclear whether Cbl-b can regulate chemosensitivity through modulating Akt activation. In this study, VP-16-induced RBL-2H3 cells apoptosis was accompanied by the activation of Akt and ERK. The PI3K inhibitor LY294002, not the ERK inhibitor PD98059, enhanced the apoptosis. In addition, down-regulation of Cbl-b was also detected. Over expression of Cbl-b significantly enhanced VP-16-induced cell apoptosis with inhibition of Akt activity, while a dominant negative (DN) RING Finger domain mutation completely abolished this enhancement. On the other hand, ERK activity was enhanced by Cbl-b, and the ERK inhibitor PD98059 reversed Cbl-b-enhanced apoptosis. The consistent results were also showed in the process of Ara-c treatment. These observations indicate that Cbl-b promotes RBL-2H3 apoptosis induced by VP-16 or Ara-c, probably through inhibition of Akt and activation of ERK.
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MESH Headings
- Adaptor Proteins, Signal Transducing/genetics
- Adaptor Proteins, Signal Transducing/metabolism
- Animals
- Antimetabolites, Antineoplastic/pharmacology
- Antineoplastic Agents, Phytogenic/pharmacology
- Apoptosis/drug effects
- Cell Line, Tumor
- Cell Survival
- Cytarabine/pharmacology
- Dose-Response Relationship, Drug
- Enzyme Activation
- Enzyme Inhibitors/pharmacology
- Etoposide/pharmacology
- Extracellular Signal-Regulated MAP Kinases/antagonists & inhibitors
- Extracellular Signal-Regulated MAP Kinases/metabolism
- Inhibitory Concentration 50
- Leukemia, Basophilic, Acute/enzymology
- Leukemia, Basophilic, Acute/genetics
- Leukemia, Basophilic, Acute/pathology
- Mitogen-Activated Protein Kinase Kinases/metabolism
- Mutation
- Phosphatidylinositol 3-Kinases/metabolism
- Phosphoinositide-3 Kinase Inhibitors
- Proto-Oncogene Proteins c-akt/metabolism
- Proto-Oncogene Proteins c-cbl/genetics
- Proto-Oncogene Proteins c-cbl/metabolism
- Rats
- Time Factors
- Transfection
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Affiliation(s)
- Xiujuan Qu
- Department of Medical Oncology, The First Hospital of China Medical University, No. 155, North Nanjing Street, Heping District, 110001 Shenyang, China
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Mandal SK, Biswas R, Bhattacharyya SS, Paul S, Dutta S, Pathak S, Khuda-Bukhsh AR. Lycopodine from Lycopodium clavatum extract inhibits proliferation of HeLa cells through induction of apoptosis via caspase-3 activation. Eur J Pharmacol 2010; 626:115-22. [DOI: 10.1016/j.ejphar.2009.09.033] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Revised: 08/31/2009] [Accepted: 09/10/2009] [Indexed: 11/16/2022]
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Wu YF, Chen CH, Cao Y, Avanessian B, Wang XT, Tang JB. Molecular events of cellular apoptosis and proliferation in the early tendon healing period. J Hand Surg Am 2010; 35:2-10. [PMID: 20117302 DOI: 10.1016/j.jhsa.2009.10.021] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2009] [Revised: 10/15/2009] [Accepted: 10/20/2009] [Indexed: 02/02/2023]
Abstract
PURPOSE Cellular proliferation is accompanied by cellular apoptosis. In the healing digital flexor tendon, molecular events concerning cellular apoptosis have not been investigated. This study aimed to investigate the relationship between cellular apoptosis and proliferation in early tendon healing. METHODS The flexor digitorum profundus tendons of 50 long toes in 25 chickens were transected and were repaired surgically. On postoperative days 3, 7, 14, 21, and 28, we subjected tendons to in situ terminal deoxynucleotide transferase dUTP nick end labeling (TUNEL) assay to detect apoptotic cells, immunofluorescence staining with antibodies to proliferating cell nuclear antigen to assess proliferation, and Bcl-2, an anti-apoptotic protein, to assess responses suppressive to apoptosis. The positively labeled tenocytes were counted microscopically and compared statistically. We also stained sections with hematoxylin and eosin to observe their healing status. An additional 12 tendons (6 chickens) served as day 0 controls. RESULTS Compared with tendons at day 0, the healing tendons had notably greater cellularity in both epitenon and endotenon areas. The total number of cells and number of TUNEL-positive cells peaked at day 3. At days 7 to 21, the number of proliferating cell nuclear antigen-positive cells peaked. At days 7 and 14, the cells positively stained with Bcl-2 peaked. At days 14 to 28, the total number of cells and TUNEL-positive cells decreased significantly compared with those at days 3 and 7, yet the numbers remained greater than those on day 0. CONCLUSIONS Apoptosis in the healing tendons peaks at day 3, followed about 10 days later by the peak proliferation period. Because Bcl-2 serves to inhibit apoptosis, a later increase in Bcl-2-positive cells indicates that tendon apoptosis is inhibited. These findings indicate that tenocyte apoptosis is accelerated within several days after injury, followed by increases in cellular proliferation and activation of molecular events to inhibit apoptosis in 2 to 4 weeks.
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Affiliation(s)
- Ya Fang Wu
- Department of Hand Surgery, Affiliated Hospital of Nantong University, Nantong, Jiangsu, China
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Vasquez MZ. Combining the in vivo comet and micronucleus assays: a practical approach to genotoxicity testing and data interpretation. Mutagenesis 2009; 25:187-99. [PMID: 19969526 PMCID: PMC2825345 DOI: 10.1093/mutage/gep060] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Despite regulatory directives requiring the reduction of animal use in safety testing, recent modifications to genotoxicity testing guidelines now propose the use of two in vivo genotoxicity assays as a follow-up to an in vitro positive (International Conference on Harmonization Consensus Draft Guidance S2[R1] released March, 2008). To address both goals, the in vivo comet and micronucleus (MN) assays can be successfully combined into one informative study. Combining these two assays with such differences in sensitivity, endpoints measured and the type of data generated significantly improves upon the current standard capabilities for detecting genotoxicity without requiring additional animals. But to take full advantage of the benefits of incorporating the comet assay in safety testing, these same differences must be recognized and considered. Developed from over 15 years experience using the in vivo comet and MN assays in genotoxicity testing of chemicals and pharmaceuticals, this paper presents guidelines for the appropriate experimental design, dose selection and data interpretation for combined in vivo comet/MN assay studies. To illustrate the approach, data from combined assay studies are presented and discussed.
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35
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Genotoxicity testing in vitro – Development of a higher throughput analysis method based on the comet assay. Toxicol In Vitro 2009; 23:1570-5. [DOI: 10.1016/j.tiv.2009.07.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2008] [Revised: 06/16/2009] [Accepted: 07/06/2009] [Indexed: 11/24/2022]
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Norman KG, Canter JA, Shi M, Milne GL, Morrow JD, Sligh JE. Cyclosporine A suppresses keratinocyte cell death through MPTP inhibition in a model for skin cancer in organ transplant recipients. Mitochondrion 2009; 10:94-101. [PMID: 19836469 DOI: 10.1016/j.mito.2009.10.001] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2009] [Revised: 09/25/2009] [Accepted: 10/13/2009] [Indexed: 01/16/2023]
Abstract
Transplant recipients have an elevated risk of skin cancer, with a 65- to 250-fold increase in squamous cell carcinoma. Usage of the immunosuppressant cyclosporine A (CsA) is associated with the development of skin cancer. We hypothesized that the increased incidence of skin cancer was due to the action of CsA within keratinocyte mitochondria where it can inhibit mitochondrial permeability transition pore (MPTP) opening. Normally, MPTP opening is induced by oxidative stress such as that caused by UV light and leads to cell death, thereby eliminating a cell that has been exposed to genotoxic insult. However, in the presence of CsA, damaged cells may survive and consequently form tumors. To test this hypothesis, we treated keratinocytes with levels of CsA used therapeutically in transplant patients and assessed their viability following UVA-irradiation. CsA prevented cell death by inhibiting MPTP opening, even though the levels of oxidative stress were increased markedly. Nim811, a non-immunosuppressive drug that can block the MPTP had a similar effect while the immunosuppressive drug tacrolimus that does not interact with the mitochondria had no effect. These findings suggest that CsA may promote skin cancer in transplant patients by allowing keratinocyte survival under conditions of increased genotoxic stress.
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Affiliation(s)
- Kimberly G Norman
- Department of Medicine, Division of Dermatology, VA Tennessee Valley Healthcare System and Vanderbilt University Medical Center, Nashville, TN, USA
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Dhawan A, Bajpayee M, Parmar D. The Comet Assay: A Versatile Tool for Assessing DNA Damage. THE COMET ASSAY IN TOXICOLOGY 2009. [DOI: 10.1039/9781847559746-00003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Alok Dhawan
- Developmental Toxicology Division Indian Institute of Toxicology Research (Formerly Industrial Toxicology Research Centre) P.O. Box 80 M.G. Marg Lucknow 226 001 India
| | - Mahima Bajpayee
- Developmental Toxicology Division Indian Institute of Toxicology Research (Formerly Industrial Toxicology Research Centre) P.O. Box 80 M.G. Marg Lucknow 226 001 India
| | - Devendra Parmar
- Developmental Toxicology Division Indian Institute of Toxicology Research (Formerly Industrial Toxicology Research Centre) P.O. Box 80 M.G. Marg Lucknow 226 001 India
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McCall JL, Burich RA, Mack PC. GCP, a genistein-rich compound, inhibits proliferation and induces apoptosis in lymphoma cell lines. Leuk Res 2009; 34:69-76. [PMID: 19394691 DOI: 10.1016/j.leukres.2009.03.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2009] [Revised: 03/17/2009] [Accepted: 03/17/2009] [Indexed: 11/19/2022]
Abstract
Genistein combined polysaccharide (GCP), derived from soy bean extract, is comprised of deglycosylated isoflavones, such as genistein and daidzein. The goal of this work was to determine if GCP is effective in lymphoid cancers. In three human and four canine lymphoid cell lines, GCP inhibited proliferation and induced G2/M arrest. Additionally, increased apoptosis was observed in Ramos and Jurkat lines. These results demonstrate that GCP is effective in lymphoid cell lines of both human and canine origin. Due to its minimal toxicities, increased bioavailability, and in vitro efficacy, GCP may have clinical utility in the treatment of patients with lymphoma.
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Affiliation(s)
- Jamie L McCall
- Division of Hematology/Oncology, Department of Internal Medicine, University of California, Davis Cancer Center, Sacramento, CA 95817, USA
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McMillan TJ, Leatherman E, Ridley A, Shorrocks J, Tobi SE, Whiteside JR. Cellular effects of long wavelength UV light (UVA) in mammalian cells. J Pharm Pharmacol 2008; 60:969-76. [PMID: 18644190 DOI: 10.1211/jpp.60.8.0004] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
UVA should receive significant consideration as a human health risk as it is a large proportion of the solar spectrum that reaches the earth's surface and because of its ability to penetrate human skin. It is only relatively recently that this has been recognized and this previously under-researched part of the UV spectrum is becoming increasingly well characterized at doses that are quite low in relation to those experienced by humans. Absorption of UVA in a cell leads to the production of reactive oxygen and nitrogen species that can damage major biomolecules including DNA and membrane lipids. Various types of damage induced in these molecules lead to significant biological effects including cytotoxicity, mutations and alterations in cell signalling pathways. Longer-term effects such as persistent genomic instability and bystander effects have also been observed following UVA treatment of mammalian cells and, as with ionizing radiation, this changes some of the fundamental thinking around tissue effects of irradiation. Antioxidants have been assessed extensively for their ability to protect against the biological effects of UVA and a number have been shown to be successful at least in-vitro, for example vitamin E and epigallocatechin-3-gallate. Other potential targets for protection are suggested through the increased understanding of some of the signalling mechanisms activated following treatment, for example the inhibition of NADPH oxidase is seen to reduce a bystander effect. The search for appropriate and successful photoprotective agents remains an important area of research.
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Affiliation(s)
- T J McMillan
- Biomedical Sciences Unit, Department of Biological Sciences, Lancaster University Lancaster, LA1 4YQ, UK.
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Dhawan A, Bajpayee M, Parmar D. Comet assay: a reliable tool for the assessment of DNA damage in different models. Cell Biol Toxicol 2008; 25:5-32. [PMID: 18427939 DOI: 10.1007/s10565-008-9072-z] [Citation(s) in RCA: 241] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2007] [Accepted: 03/17/2008] [Indexed: 11/29/2022]
Abstract
New chemicals are being added each year to the existing burden of toxic substances in the environment. This has led to increased pollution of ecosystems as well as deterioration of the air, water, and soil quality. Excessive agricultural and industrial activities adversely affect biodiversity, threatening the survival of species in a particular habitat as well as posing disease risks to humans. Some of the chemicals, e.g., pesticides and heavy metals, may be genotoxic to the sentinel species and/or to non-target species, causing deleterious effects in somatic or germ cells. Test systems which help in hazard prediction and risk assessment are important to assess the genotoxic potential of chemicals before their release into the environment or commercial use as well as DNA damage in flora and fauna affected by contaminated/polluted habitats. The Comet assay has been widely accepted as a simple, sensitive, and rapid tool for assessing DNA damage and repair in individual eukaryotic as well as some prokaryotic cells, and has increasingly found application in diverse fields ranging from genetic toxicology to human epidemiology. This review is an attempt to comprehensively encase the use of Comet assay in different models from bacteria to man, employing diverse cell types to assess the DNA-damaging potential of chemicals and/or environmental conditions. Sentinel species are the first to be affected by adverse changes in their environment. Determination of DNA damage using the Comet assay in these indicator organisms would thus provide information about the genotoxic potential of their habitat at an early stage. This would allow for intervention strategies to be implemented for prevention or reduction of deleterious health effects in the sentinel species as well as in humans.
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Affiliation(s)
- Alok Dhawan
- Developmental Toxicology Division, Indian Institute of Toxicology Research (formerly Industrial Toxicology Research Centre), PO Box 80, M.G. Marg, Lucknow, 226 001, India.
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Yang X, Yuan J, Sun J, Wang H, Liang H, Bai Y, Guo L, Tan H, Yang M, Wang J, Su J, Chen Y, Tanguay RM, Wu T. Association between heat-shock protein 70 gene polymorphisms and DNA damage in peripheral blood lymphocytes among coke-oven workers. Mutat Res 2008; 649:221-229. [PMID: 17988935 DOI: 10.1016/j.mrgentox.2007.09.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Revised: 09/19/2007] [Accepted: 09/23/2007] [Indexed: 05/25/2023]
Abstract
Hsp70 has been shown to act as a chaperone and be associated with cytoprotection against DNA damage caused by environmental stresses. However, it is unknown whether genetic variation in HSP70 plays a role in stress tolerance and cytoprotection against DNA damage. We determined the frequencies of three polymorphisms, HSP70-1 G190C, HSP70-2 G1267A, and HSP70-hom T2437C from 251 steel-plant workers exposed to coke-oven emission and 130 controls. We estimated the association between the HSP70variants/haplotypes and the levels of DNA damage in their peripheral blood lymphocytes detected by single-cell gel electrophoresis assay. Our results showed that overall coke-oven workers had higher levels of the Olive tail moment (Olive TM) (1.27+/-1.12) than that of the controls (0.56+/-0.99, P<0.001). Coke-oven workers with the HSP70-1 C/C genotype had higher levels of Olive TM (2.19+/-0.65), compared with HSP70-1 G/C and G/G carriers (Olive TM=1.34+/-1.09 and 1.14+/-1.08, respectively, P=0.022 and 0.003, respectively). However, the HSP70-2 G1267A and HSP70-hom T2437C polymorphisms were not associated with the levels of Olive TM (P=0.929 and 0.795, respectively). Haplotype analysis showed that carriers of TCG/TCG haplotype pairs had the highest levels of Olive TM among both the exposed subjects (2.04+/-0.59) and the controls (0.81+/-0.59). Our results suggest that the individuals with the homozygous HSP70-1 C/C genotype among the coke-oven workers may be susceptible to DNA damage.
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Affiliation(s)
- X Yang
- Institute of Occupational Medicine and Ministry of Education Key Lab for Environment and Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, PR China
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Tayama S, Nakagawa Y, Tayama K. Genotoxic effects of environmental estrogen-like compounds in CHO-K1 cells. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2008; 649:114-25. [PMID: 17913570 DOI: 10.1016/j.mrgentox.2007.08.006] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2006] [Revised: 08/03/2007] [Accepted: 08/08/2007] [Indexed: 11/25/2022]
Abstract
Some environmental estrogen-like compounds, such as bisphenol A (BPA), 4-nonylphenol (NP), 4-octylphenol (OP), propyl p-hydroxybenzoate (P-PHBA), and butyl p-hydroxybenzoate (B-PHBA), synthetic estrogen, diethylstilbestrol (DES), and natural estrogen, 17beta-estradiol (E2), were studied for their genotoxicity in CHO-K1 cells using sister-chromatid exchange (SCE), chromosome aberration (CA), and DNA strand break (comet) assays. Six of the chemicals, excluding E2, caused DNA migration in the comet assay and induced SCEs at one or more of the highest doses. Among the chemicals, OP produced an especially high incidence of SCEs. Structural CA was induced by five of the chemicals, excluding OP and NP, and BPA, E2, and DES also induced aneuploid cells. E2 and DES particularly increased the rate of polyploidy at high doses. The incidence of colchicine-mitosis-like (c-mitotic) figures suggesting spindle disrupting effects was also detected with five of the chemicals, excluding OP and NP, and six of the chemicals, excluding E2, caused endoreduplication (ERD), a form of nuclear polyploidization induced by block of cell cycle at G2 phase, at one or more high doses. Our present results suggest that OP and NP cause repairable DNA damage, including SCEs, and do not result in CA, while the damage caused by DES, BPA, P-PHBA, and B-PHBA results in the induction of CAs together with SCEs probably because of imperfect repair. We are unable to explain the observation that the DNA damage caused by E2 resulted in CA induction but not DNA migration or SCE induction, except for speculating that the DNA damage is different from that caused by DES and the estrogen-like chemicals. Our findings also suggest that E2, DES and BPA have aneuploidogenic properties, and that the former two of chemicals also are polyploidy-inducing agents.
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Affiliation(s)
- Sumiko Tayama
- Department of Toxicology, Tokyo Metropolitan Institute of Public Health, Tokyo, Japan.
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Bao X, Isaacsohn I, Drew AF, Smithrud DB. Determining the Intracellular Transport Mechanism of a Cleft−[2]Rotaxane. J Am Chem Soc 2006; 128:12229-38. [PMID: 16967974 DOI: 10.1021/ja063667f] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Rotaxanes are a class of interlocked compounds that have been extensively investigated for their potential utility as switches or sensors. We recently demonstrated that rotaxanes have further application as agents that transport material into cells. This novel finding prompted our investigation into the mechanism by which rotaxanes are involved in transmembrane transport. Two-dimensional NMR analysis showed that a cleft-containing rotaxane exists in two dominant conformations ("closed" and "open"). To determine the importance of conformational flexibility on the ability of the rotaxanes to bind guests and transport material into cells, the rotaxane was chemically modified to lock it in the closed conformation. Charged guests interact less favorably with the locked rotaxane, as compared to the unmodified rotaxane, both in an aqueous solution and in DMSO. In a chloroform solution, both rotaxanes bind the guests with similar affinities. The locked rotaxane exhibited a reduced capacity to transport a fluoresceinated peptide into cells, whereas the unmodified rotaxane efficiently delivers the peptide. Flow cytometry experiments demonstrated that a high percentage of the cells contained the delivered peptide (89-98%), the level of delivery is concentration dependent, and the rotaxanes and peptide have low toxicity. Cellular uptake of the peptide was largely temperature and ATP independent, suggesting that the rotaxane-peptide complex passes through the cellular membrane without requiring active cell-mediated processes. The results show that the sliding motion of the wheel is necessary for the delivery of materials into cells and can enhance the association of guests. These studies demonstrate the potential for rotaxanes as a new class of mechanical devices that deliver a variety of therapeutic agents into targeted cell populations.
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Affiliation(s)
- Xiaofeng Bao
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, USA
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