1
|
Tam A, Mercier BD, Thomas RM, Tizpa E, Wong IG, Shi J, Garg R, Hampel H, Gray SW, Williams T, Bazan JG, Li YR. Moving the Needle Forward in Genomically-Guided Precision Radiation Treatment. Cancers (Basel) 2023; 15:5314. [PMID: 38001574 PMCID: PMC10669735 DOI: 10.3390/cancers15225314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 10/06/2023] [Accepted: 10/13/2023] [Indexed: 11/26/2023] Open
Abstract
Radiation treatment (RT) is a mainstay treatment for many types of cancer. Recommendations for RT and the radiation plan are individualized to each patient, taking into consideration the patient's tumor pathology, staging, anatomy, and other clinical characteristics. Information on germline mutations and somatic tumor mutations is at present rarely used to guide specific clinical decisions in RT. Many genes, such as ATM, and BRCA1/2, have been identified in the laboratory to confer radiation sensitivity. However, our understanding of the clinical significance of mutations in these genes remains limited and, as individual mutations in such genes can be rare, their impact on tumor response and toxicity remains unclear. Current guidelines, including those from the National Comprehensive Cancer Network (NCCN), provide limited guidance on how genetic results should be integrated into RT recommendations. With an increasing understanding of the molecular underpinning of radiation response, genomically-guided RT can inform decisions surrounding RT dose, volume, concurrent therapies, and even omission to further improve oncologic outcomes and reduce risks of toxicities. Here, we review existing evidence from laboratory, pre-clinical, and clinical studies with regard to how genetic alterations may affect radiosensitivity. We also summarize recent data from clinical trials and explore potential future directions to utilize genetic data to support clinical decision-making in developing a pathway toward personalized RT.
Collapse
Affiliation(s)
- Andrew Tam
- Department of Radiation Oncology, City of Hope Comprehensive Cancer Center, 1500 E Duarte Rd., Duarte, CA 91010, USA; (A.T.); (B.D.M.); (R.M.T.); (E.T.); (I.G.W.); (J.S.); (R.G.); (T.W.)
| | - Benjamin D. Mercier
- Department of Radiation Oncology, City of Hope Comprehensive Cancer Center, 1500 E Duarte Rd., Duarte, CA 91010, USA; (A.T.); (B.D.M.); (R.M.T.); (E.T.); (I.G.W.); (J.S.); (R.G.); (T.W.)
- Department of Medical Oncology & Therapeutics Research, City of Hope Comprehensive Cancer Center, 1500 E Duarte Rd., Duarte, CA 91010, USA; (H.H.); (S.W.G.)
| | - Reeny M. Thomas
- Department of Radiation Oncology, City of Hope Comprehensive Cancer Center, 1500 E Duarte Rd., Duarte, CA 91010, USA; (A.T.); (B.D.M.); (R.M.T.); (E.T.); (I.G.W.); (J.S.); (R.G.); (T.W.)
| | - Eemon Tizpa
- Department of Radiation Oncology, City of Hope Comprehensive Cancer Center, 1500 E Duarte Rd., Duarte, CA 91010, USA; (A.T.); (B.D.M.); (R.M.T.); (E.T.); (I.G.W.); (J.S.); (R.G.); (T.W.)
| | - Irene G. Wong
- Department of Radiation Oncology, City of Hope Comprehensive Cancer Center, 1500 E Duarte Rd., Duarte, CA 91010, USA; (A.T.); (B.D.M.); (R.M.T.); (E.T.); (I.G.W.); (J.S.); (R.G.); (T.W.)
| | - Juncong Shi
- Department of Radiation Oncology, City of Hope Comprehensive Cancer Center, 1500 E Duarte Rd., Duarte, CA 91010, USA; (A.T.); (B.D.M.); (R.M.T.); (E.T.); (I.G.W.); (J.S.); (R.G.); (T.W.)
| | - Rishabh Garg
- Department of Radiation Oncology, City of Hope Comprehensive Cancer Center, 1500 E Duarte Rd., Duarte, CA 91010, USA; (A.T.); (B.D.M.); (R.M.T.); (E.T.); (I.G.W.); (J.S.); (R.G.); (T.W.)
| | - Heather Hampel
- Department of Medical Oncology & Therapeutics Research, City of Hope Comprehensive Cancer Center, 1500 E Duarte Rd., Duarte, CA 91010, USA; (H.H.); (S.W.G.)
| | - Stacy W. Gray
- Department of Medical Oncology & Therapeutics Research, City of Hope Comprehensive Cancer Center, 1500 E Duarte Rd., Duarte, CA 91010, USA; (H.H.); (S.W.G.)
| | - Terence Williams
- Department of Radiation Oncology, City of Hope Comprehensive Cancer Center, 1500 E Duarte Rd., Duarte, CA 91010, USA; (A.T.); (B.D.M.); (R.M.T.); (E.T.); (I.G.W.); (J.S.); (R.G.); (T.W.)
| | - Jose G. Bazan
- Department of Radiation Oncology, City of Hope Comprehensive Cancer Center, 1500 E Duarte Rd., Duarte, CA 91010, USA; (A.T.); (B.D.M.); (R.M.T.); (E.T.); (I.G.W.); (J.S.); (R.G.); (T.W.)
| | - Yun R. Li
- Department of Radiation Oncology, City of Hope Comprehensive Cancer Center, 1500 E Duarte Rd., Duarte, CA 91010, USA; (A.T.); (B.D.M.); (R.M.T.); (E.T.); (I.G.W.); (J.S.); (R.G.); (T.W.)
- Department of Cancer Genetics and Epigenetics, City of Hope National Medical Center, Duarte, CA 91010, USA
- Division of Quantitative Medicine & Systems Biology, Translational Genomics Research Institute, 445 N. Fifth Street, Phoenix, AZ 85022, USA
| |
Collapse
|
2
|
Szeliga A, Zysnarska A, Szklarska Z, Truszkowska E, Podfigurna A, Czyzyk A, Genazzani AR, Chrzanowska K, Meczekalski B. A case of premature ovarian insufficiency in Nijmegen breakage syndrome patient and review of literature. From gene mutation to clinical management. Gynecol Endocrinol 2019; 35:999-1002. [PMID: 31187634 DOI: 10.1080/09513590.2019.1626366] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Background: Nijmegen breakage syndrome (NBS) is an autosomal recessive disorder leading to chromosomal instability and an array of symptoms, including characteristic facial features (bird-like face), predisposition to malignancies, as well as hypergonadotropic hypogonadism. This case report discusses the diagnostic process and management of a 23-year-old Polish female patient who was admitted to hospital with symptoms of secondary amenorrhea and clinical features corresponding to NBS. Methods: Clinical examination, per-rectal ultrasound, laboratory diagnostics (including serum concentrations of FSH, LH, estradiol, testosterone, and TSH), as well as SSCP analysis and classic karyotyping were performed. Results: During hormonal evaluation elevated serum concentration of FSH and LH and decreased serum concentration of estradiol were measured. The genetic testing revealed translocation 7;14 (t(7;14)) and inversion 7 in 22% of examined cells which confirmed the initial hypothesis of NBS. The diagnosis was finally verified by identifying a Slavic founder mutation, c.657_661del5, on both allels of the NBN gene. Furthermore, hormonal serum evaluation conducted after four weeks allowed the patient to be diagnosed with premature ovarian insufficiency (POI) suspected earlier on the grounds of preliminary examinations (ultrasound imaging and laboratory tests). Conclusions: Chromosomal instability resulting from a mutation present in Nijmegen breakage syndrome patients might be a causative factor of premature ovarian insufficiency. Therefore, females diagnosed with NBS should undergo additional diagnostic procedures in order to determine further management and treatment.
Collapse
Affiliation(s)
- Anna Szeliga
- Department of Gynecological Endocrinology, Poznan University of Medical Sciences , Poznan , Poland
| | - Aleksandra Zysnarska
- Students Scientific Society of the Department of Gynecological Endocrinology, Poznan University of Medical Sciences , Poznan , Poland
| | - Zuzanna Szklarska
- Students Scientific Society of the Department of Gynecological Endocrinology, Poznan University of Medical Sciences , Poznan , Poland
| | - Ewelina Truszkowska
- Students Scientific Society of the Department of Gynecological Endocrinology, Poznan University of Medical Sciences , Poznan , Poland
| | - Agnieszka Podfigurna
- Department of Gynecological Endocrinology, Poznan University of Medical Sciences , Poznan , Poland
| | - Adam Czyzyk
- Department of Gynecological Endocrinology, Poznan University of Medical Sciences , Poznan , Poland
| | - Andrea R Genazzani
- Department of Reproductive Medicine and Child Development, Division of Gynecology and Obstetrics, University of Pisa , Pisa , Italy
| | - Krystyna Chrzanowska
- Department of Medical Genetics, The Children's Memorial Health Institute , Warsaw , Poland
| | - Blazej Meczekalski
- Department of Gynecological Endocrinology, Poznan University of Medical Sciences , Poznan , Poland
| |
Collapse
|
3
|
Mlody B, Wruck W, Martins S, Sperling K, Adjaye J. Nijmegen Breakage Syndrome fibroblasts and iPSCs: cellular models for uncovering disease-associated signaling pathways and establishing a screening platform for anti-oxidants. Sci Rep 2017; 7:7516. [PMID: 28790359 PMCID: PMC5548734 DOI: 10.1038/s41598-017-07905-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 07/04/2017] [Indexed: 12/28/2022] Open
Abstract
Nijmegen Breakage Syndrome (NBS) is associated with cancer predisposition, premature aging, immune deficiency, microcephaly and is caused by mutations in the gene coding for NIBRIN (NBN) which is involved in DNA damage repair. Dermal-derived fibroblasts from NBS patients were reprogrammed into induced pluripotent stem cells (iPSCs) in order to bypass premature senescence. The influence of antioxidants on intracellular levels of ROS and DNA damage were screened and it was found that EDHB-an activator of the hypoxia pathway, decreased DNA damage in the presence of high oxidative stress. Furthermore, NBS fibroblasts but not NBS-iPSCs were found to be more susceptible to the induction of DNA damage than their healthy counterparts. Global transcriptome analysis comparing NBS to healthy fibroblasts and NBS-iPSCs to embryonic stem cells revealed regulation of P53 in NBS fibroblasts and NBS-iPSCs. Cell cycle related genes were down-regulated in NBS fibroblasts. Furthermore, oxidative phosphorylation was down-regulated and glycolysis up-regulated specifically in NBS-iPSCs compared to embryonic stem cells. Our study demonstrates the utility of NBS-iPSCs as a screening platform for anti-oxidants capable of suppressing DNA damage and a cellular model for studying NBN de-regulation in cancer and microcephaly.
Collapse
Affiliation(s)
- Barbara Mlody
- Max-Delbrück-Centrum für Molekulare Medizin (MDC), 13092, Berlin, Germany
| | - Wasco Wruck
- Institute for Stem Cell Research and Regenerative Medicine, Medical Faculty, Heinrich Heine University, 40225, Düsseldorf, Germany
| | - Soraia Martins
- Institute for Stem Cell Research and Regenerative Medicine, Medical Faculty, Heinrich Heine University, 40225, Düsseldorf, Germany
| | - Karl Sperling
- Charité - Universitätsmedizin Berlin, Institute of Medical and Human Genetics, 13353, Berlin, Germany
| | - James Adjaye
- Institute for Stem Cell Research and Regenerative Medicine, Medical Faculty, Heinrich Heine University, 40225, Düsseldorf, Germany.
| |
Collapse
|
4
|
Cui J, Yang Y, Cheng Y, Gao F, Liu C, Zhou C, Cheng Y, Li B, Cai J. Protective effects of carboxyfullerene in irradiated cells and BALB/c mice. Free Radic Res 2013; 47:301-8. [DOI: 10.3109/10715762.2013.771397] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
5
|
Savina NV, Smal MP, Kuzhir TD, Egorova TM, Khurs OM, Polityko AD, Goncharova RI. Biomarkers for genome instability in some genetic disorders: a pilot study. Biomarkers 2012; 17:201-8. [DOI: 10.3109/1354750x.2011.651157] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
6
|
Dzikiewicz-Krawczyk A, Mosor M, Januszkiewicz D, Nowak J. Impact of heterozygous c.657-661del, p.I171V and p.R215W mutations in NBN on nibrin functions. Mutagenesis 2011; 27:337-43. [PMID: 22131123 DOI: 10.1093/mutage/ger084] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Nibrin, product of the NBN gene, together with MRE11 and RAD50 is involved in DNA double-strand breaks (DSBs) sensing and repair, induction of apoptosis and cell cycle control. Biallelic NBN mutations cause the Nijmegen breakage syndrome, a chromosomal instability disorder characterised by, among other things, radiosensitivity, immunodeficiency and an increased cancer risk. Several studies have shown an association of heterozygous c.657-661del, p.I171V and p.R215W mutations in the NBN gene with a variety of malignancies but the data are controversial. Little is known, however, whether and to what extent do these mutations in heterozygous state affect nibrin functions. We examined frequency of chromatid breaks, DSB repair, defects in S-phase checkpoint and radiosensitivity in X-ray-irradiated cells from control individuals, NBS patients and heterozygous carriers of the c.657-661del, p.I171V and p.R215W mutations. While cells homozygous for c.657-661del displayed a significantly increased number of chromatid breaks and residual γ-H2AX foci, as well as abrogation of the intra-S-phase checkpoint following irradiation, which resulted in increased radiosensitivity, cells with heterozygous c.657-661del, p.I171V and p.R215W mutations behaved similarly to control cells. Significant differences in the frequency of spontaneous and ionising radiation-induced chromatid breaks and the level of persistent γ-H2AX foci were observed when comparing control and mutant cells heterozygous for c.657-661del. However, it is still possible that heterozygous NBN mutations may contribute to cancer development.
Collapse
|
7
|
Tomás Vila M, Verdú JP, Piera MR, Alonso CO. [Nijmegen breakage syndrome phenotype: a disorder to consider in the diagnosis of microcephaly]. An Pediatr (Barc) 2010; 74:58-60. [PMID: 21147050 DOI: 10.1016/j.anpedi.2010.09.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Revised: 07/29/2010] [Accepted: 09/13/2010] [Indexed: 11/29/2022] Open
|
8
|
Ciara E, Piekutowska-Abramczuk D, Popowska E, Grajkowska W, Barszcz S, Perek D, Dembowska-Bagińska B, Perek-Polnik M, Kowalewska E, Czajńska A, Syczewska M, Czornak K, Krajewska-Walasek M, Roszkowski M, Chrzanowska KH. Heterozygous germ-line mutations in the NBN gene predispose to medulloblastoma in pediatric patients. Acta Neuropathol 2010; 119:325-34. [PMID: 19908051 DOI: 10.1007/s00401-009-0608-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Revised: 10/30/2009] [Accepted: 10/31/2009] [Indexed: 01/23/2023]
Abstract
The NBN (NBS1) gene belongs to a group of double-strand break repair genes. Mutations in any of these genes cause genome instability syndromes and contribute to carcinogenesis. NBN gene mutations cause increased tumor risk in Nijmegen breakage syndrome (NBS) homozygotes as well as in NBN heterozygotes. NBS patients develop different types of malignancies; among solid tumors, medulloblastoma (MB), an embryonal tumor of the cerebellum, has been reported most frequently. The majority of medulloblastomas occur sporadically, some of them manifest within familial cancer syndromes. Several signaling pathways are known to be engaged in hereditary and sporadic MB. The aim of our study was to identify mutations in selected exons of the NBN gene and to determine the frequency of the most common NBN gene mutations in pediatric patients with different types of medulloblastoma. We screened a total of 104 patients with MB and identified 7 heterozygous carriers (6.7%) of two different germ-line mutations of NBN gene; all of them had classic MB. Our results indicate that heterozygous carriers of the germ-line NBN gene mutations (c.511A>G and c.657_661del5) may exhibit increased susceptibility to developing MB. The risk of medulloblastoma is estimated to be 3.0 (for c.511A>G) and 4.86 (for c.657_661del5) times higher than in the general Polish population (p<0.05). These results suggest that heterozygous NBN germ-line mutations may contribute to the etiology of medulloblastoma.
Collapse
Affiliation(s)
- Elżbieta Ciara
- Department of Medical Genetics, The Children's Memorial Health Institute, Al. Dzieci Polskich 20, 04-730, Warsaw, Poland
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
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
| |
Collapse
|
10
|
Trzeciak AR, Barnes J, Ejiogu N, Foster K, Brant LJ, Zonderman AB, Evans MK. Age, sex, and race influence single-strand break repair capacity in a human population. Free Radic Biol Med 2008; 45:1631-41. [PMID: 18845243 PMCID: PMC3072751 DOI: 10.1016/j.freeradbiomed.2008.08.031] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2007] [Revised: 08/08/2008] [Accepted: 08/28/2008] [Indexed: 10/21/2022]
Abstract
Recently, we developed an improved comet assay protocol for evaluating single-strand break repair capacity (SSB-RC) in unstimulated cryopreserved human peripheral blood mononuclear cells (PBMCs). This methodology facilitates control of interexperimental variability [A.R. Trzeciak, J. Barnes, M.K. Evans, A modified alkaline comet assay for measuring DNA repair capacity in human populations. Radiat. Res. 169 (2008) 110-121]. The fast component of SSB repair (F-SSB-RC) was assessed using a novel parameter, the initial rate of DNA repair, and the widely used half-time of DNA repair. The slow component of SSB repair (S-SSB-RC) was estimated using the residual DNA damage after 60 min. We have examined repair of gamma-radiation-induced DNA damage in PBMCs from four age-matched groups of male and female whites and African-Americans between ages 30 and 64. There is an increase in F-SSB-RC with age in white females (P<0.01) and nonsignificant decrease in F-SSB-RC in African-American females (P=0.061). F-SSB-RC is lower in white females than in white males (P<0.01). There is a decrease in F-SSB-RC with age in African-American females as compared to white females (P<0.002) and African-American males (nonsignificant, P=0.059). Age, sex, and race had a similar effect on intercellular variability of DNA damage in gamma-irradiated and repairing PBMCs. Our findings suggest that age, sex, and race influence SSB-RC as measured by the alkaline comet assay. SSB-RC may be a useful clinical biomarker.
Collapse
Affiliation(s)
- Andrzej R Trzeciak
- Laboratory of Cellular and Molecular Biology, National Institute on Aging, NIH, Baltimore, MD 21224, USA
| | | | | | | | | | | | | |
Collapse
|
11
|
Rzeszowska-Wolny J, Palyvoda O, Polanska J, Wygoda A, Hancock R. Relationships between acute reactions to radiotherapy in head and neck cancer patients and parameters of radiation-induced DNA damage and repair in their lymphocytes. Int J Radiat Biol 2008; 84:635-42. [PMID: 18608641 DOI: 10.1080/09553000802087041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
PURPOSE To study the relationship between lymphocyte radiosensitivity measured in vitro and acute reactions to radiotherapy in patients with head and neck cancer. MATERIALS AND METHODS Acute reactions were measured in 34 patients using the Dische scale. Lymphocyte radiosensitivity was measured using the alkaline comet assay, the micronucleus assay, the nuclear division index and morphological assessment of apoptosis. RESULTS There was a weak, statistically significant correlation between in vitro radiosensitivity measured as the rate of DNA damage repair and the cumulative radiation dose exerting the maximum acute reaction scored (r = -0.366, p = 0.039, n = 34). Subgroup analyses showed that for patients with a low level of radiation-induced DNA damage there was a statistically significant relationship between lymphocyte radiosensitivity measured as inhibition of proliferation and acute toxicity (r = -0.621, p = 0.007, n = 18). For patients with a high level of residual DNA damage, there was a relationship between lymphocyte radiosensitivity measured using the micronucleus assay and acute toxicity (r = -0.597, p = 0.023, n = 14). CONCLUSIONS Combining two measures of radiosensitivity improves the ability to correlate in vitro lymphocyte radiosensitivity and acute radiotherapy toxicity data.
Collapse
Affiliation(s)
- J Rzeszowska-Wolny
- Department of Experimental and Clinical Radiobiology, M. Sklodowska-Curie Memorial Cancer Center and Institute, Wybrze_ze Armii Krajowej 15, 44-100 Gliwice, Poland.
| | | | | | | | | |
Collapse
|
12
|
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.
Collapse
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.
| | | | | |
Collapse
|
13
|
Swennen ELR, Dagnelie PC, Van den Beucken T, Bast A. Radioprotective effects of ATP in human blood ex vivo. Biochem Biophys Res Commun 2007; 367:383-7. [PMID: 18164682 DOI: 10.1016/j.bbrc.2007.12.125] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Accepted: 12/20/2007] [Indexed: 11/19/2022]
Abstract
Damage to healthy tissue is a major limitation of radiotherapy treatment of cancer patients, leading to several side effects and complications. Radiation-induced release of pro-inflammatory cytokines is thought to be partially responsible for the radiation-associated complications. The aim of the present study was to investigate the protective effects of extracellular ATP on markers of oxidative stress, radiation-induced inflammation and DNA damage in irradiated blood ex vivo. ATP inhibited radiation-induced TNF-alpha release and increased IL-10 release. The inhibitory effect of ATP on TNF- alpha release was completely reversed by adenosine 5'-O-thiomonophosphate, indicating a P2Y(11) mediated effect. Furthermore, ATP attenuated radiation-induced DNA damage immediate, 3 and 6h after irradiation. Our study indicates that ATP administration alleviates radiation-toxicity to blood cells, mainly by inhibiting radiation-induced inflammation and DNA damage.
Collapse
Affiliation(s)
- Els L R Swennen
- Department of Epidemiology, NUTRIM Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
| | | | | | | |
Collapse
|