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Camassa LMA, Ervik TK, Zegeye FD, Mdala I, Valen H, Ansteinsson V, Zienolddiny S. Characterization and toxicity evaluation of air-borne particles released by grinding from two dental resin composites in vitro. Dent Mater 2021; 37:1121-1133. [PMID: 33846018 DOI: 10.1016/j.dental.2021.03.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 03/29/2021] [Accepted: 03/29/2021] [Indexed: 01/02/2023]
Abstract
OBJECTIVE The project aims to evaluate whether inhalation of particles released upon grinding of dental composites may pose a health hazard to dentists. The main objective of the study was to characterize the dust from polymer-based dental composites ground with different grain sized burs and investigate particle uptake and the potential cytotoxic effects in human bronchial cells. METHODS Polymerized blocks of two dental composites, Filtek™ Z250 and Filtek™ Z500 from 3M™ ESPE, were ground with super coarse (black) and fine (red) burs inside a glass chamber. Ultrafine airborne dust concentration and particle size distribution was measured real-time during grinding with a scanning mobility particle sizer (SMPS). Filter-collected airborne particles were characterized with dynamic light scattering (DLS) and scanning electron microscopy (SEM). Human bronchial epithelial cells (HBEC-3KT) were exposed to the dusts in dose-effect experiments. Toxicity was measured with lactate dehydrogenase (LDH) assay and cell counting kit-8 (CCK8). Cellular uptake was observed with transmission electron microscopy (TEM). RESULTS Airborne ultrafine particles showed that most particles were in the size range 15-35 nm (SMPS). SEM analysis proved that more than 80% of the particles have a minimum Feret diameter less than 1 μm. In solution (DLS), the particles have larger diameters and tend to agglomerate. Cell toxicity (LDH, CCK8) is shown after 48 h and 72 h exposure times and at the highest doses. TEM showed presence of the particles within the cell cytoplasm. SIGNIFICANCE Prolonged and frequent exposure through inhalation may have negative health implications for dentists.
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Affiliation(s)
- L M A Camassa
- National Institute of Occupational Health, Oslo, Norway
| | - T K Ervik
- National Institute of Occupational Health, Oslo, Norway
| | - F D Zegeye
- National Institute of Occupational Health, Oslo, Norway
| | - I Mdala
- Institute of Health and Society, University of Oslo, Oslo, Norway; Oral Health Centres of Expertise in Eastern Norway, Oslo, Norway
| | - H Valen
- Nordic Institute of Dental Materials, Oslo, Norway
| | - V Ansteinsson
- Oral Health Centres of Expertise in Eastern Norway, Oslo, Norway
| | - S Zienolddiny
- National Institute of Occupational Health, Oslo, Norway.
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2
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Hung RJ, Warkentin MT, Brhane Y, Chatterjee N, Christiani DC, Landi MT, Caporaso NE, Liu G, Johansson M, Albanes D, Marchand LL, Tardon A, Rennert G, Bojesen SE, Chen C, Field JK, Kiemeney LA, Lazarus P, Zienolddiny S, Lam S, Andrew AS, Arnold SM, Aldrich MC, Bickeböller H, Risch A, Schabath MB, McKay JD, Brennan P, Amos CI. Assessing Lung Cancer Absolute Risk Trajectory Based on a Polygenic Risk Model. Cancer Res 2021; 81:1607-1615. [PMID: 33472890 PMCID: PMC7969419 DOI: 10.1158/0008-5472.can-20-1237] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 10/19/2020] [Accepted: 01/13/2021] [Indexed: 12/24/2022]
Abstract
Lung cancer is the leading cause of cancer-related death globally. An improved risk stratification strategy can increase efficiency of low-dose CT (LDCT) screening. Here we assessed whether individual's genetic background has clinical utility for risk stratification in the context of LDCT screening. On the basis of 13,119 patients with lung cancer and 10,008 controls with European ancestry in the International Lung Cancer Consortium, we constructed a polygenic risk score (PRS) via 10-fold cross-validation with regularized penalized regression. The performance of risk model integrating PRS, including calibration and ability to discriminate, was assessed using UK Biobank data (N = 335,931). Absolute risk was estimated on the basis of age-specific lung cancer incidence and all-cause mortality as competing risk. To evaluate its potential clinical utility, the PRS distribution was simulated in the National Lung Screening Trial (N = 50,772 participants). The lung cancer ORs for individuals at the top decile of the PRS distribution versus those at bottom 10% was 2.39 [95% confidence interval (CI) = 1.92-3.00; P = 1.80 × 10-14] in the validation set (P trend = 5.26 × 10-20). The OR per SD of PRS increase was 1.26 (95% CI = 1.20-1.32; P = 9.69 × 10-23) for overall lung cancer risk in the validation set. When considering absolute risks, individuals at different PRS deciles showed differential trajectories of 5-year and cumulative absolute risk. The age reaching the LDCT screening recommendation threshold can vary by 4 to 8 years, depending on the individual's genetic background, smoking status, and family history. Collectively, these results suggest that individual's genetic background may inform the optimal lung cancer LDCT screening strategy. SIGNIFICANCE: Three large-scale datasets reveal that, after accounting for risk factors, an individual's genetics can affect their lung cancer risk trajectory, thus may inform the optimal timing for LDCT screening.
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Affiliation(s)
- Rayjean J Hung
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Canada.
- Dalla Lana School of Public Health, University of Toronto, Toronto, Canada
| | - Matthew T Warkentin
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Canada
- Dalla Lana School of Public Health, University of Toronto, Toronto, Canada
| | - Yonathan Brhane
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Canada
| | - Nilanjan Chatterjee
- Department of Biostatistics, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland
| | - David C Christiani
- Department of Environmental Health, Harvard TH Chan School of Public Health, and Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts
| | - Maria Teresa Landi
- Division of Cancer Epidemiology and Genetics, NCI, NIH, Bethesda, Maryland
| | - Neil E Caporaso
- Division of Cancer Epidemiology and Genetics, NCI, NIH, Bethesda, Maryland
| | - Geoffrey Liu
- Princess Margaret Cancer Center, Toronto, Canada
| | | | - Demetrius Albanes
- Division of Cancer Epidemiology and Genetics, NCI, NIH, Bethesda, Maryland
| | | | | | - Gad Rennert
- Department of Community Medicine and Epidemiology, Carmel Medical Center and B. Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Stig E Bojesen
- Herlev and Gentofte Hospital, Copenhagen, Denmark. Department of Clinical Biochemistry, Herlev and Gentofte Hospital, Copenhagen University Hospital, Copenhagen, Denmark. Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Chu Chen
- Fred Hutchinson Cancer Research Center, Seattle, Washington
| | - John K Field
- University of Liverpool Cancer Research Centre, Liverpool, United Kingdom
| | | | | | | | - Stephen Lam
- University of British Columbia, Vancouver, Canada
| | | | | | - Melinda C Aldrich
- Department of Thoracic Surgery, Division of Epidemiology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Heike Bickeböller
- Department of Genetic Epidemiology, University Medical Center, Georg-August-University Göttingen, Göttingen, Germany
| | - Angela Risch
- University of Salzburg and Cancer Cluster Salzburg, Salzburg, Austria
| | | | - James D McKay
- International Agency for Research on Cancer, Lyon, France
| | - Paul Brennan
- International Agency for Research on Cancer, Lyon, France
| | - Christopher I Amos
- Institute for Clinical and Translational Research, Baylor Medical College, Houston, Texas
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3
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Thorgeirsson TE, Steinberg S, Reginsson GW, Bjornsdottir G, Rafnar T, Jonsdottir I, Helgadottir A, Gretarsdottir S, Helgadottir H, Jonsson S, Matthiasson SE, Gislason T, Tyrfingsson T, Gudbjartsson T, Isaksson HJ, Hardardottir H, Sigvaldason A, Kiemeney LA, Haugen A, Zienolddiny S, Wolf HJ, Franklin WA, Panadero A, Mayordomo JI, Hall IP, Rönmark E, Lundbäck B, Dirksen A, Ashraf H, Pedersen JH, Masson G, Sulem P, Thorsteinsdottir U, Gudbjartsson DF, Stefansson K. A rare missense mutation in CHRNA4 associates with smoking behavior and its consequences. Mol Psychiatry 2016; 21:594-600. [PMID: 26952864 PMCID: PMC5414061 DOI: 10.1038/mp.2016.13] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 12/17/2015] [Accepted: 01/04/2016] [Indexed: 11/22/2022]
Abstract
Using Icelandic whole-genome sequence data and an imputation approach we searched for rare sequence variants in CHRNA4 and tested them for association with nicotine dependence. We show that carriers of a rare missense variant (allele frequency=0.24%) within CHRNA4, encoding an R336C substitution, have greater risk of nicotine addiction than non-carriers as assessed by the Fagerstrom Test for Nicotine Dependence (P=1.2 × 10(-4)). The variant also confers risk of several serious smoking-related diseases previously shown to be associated with the D398N substitution in CHRNA5. We observed odds ratios (ORs) of 1.7-2.3 for lung cancer (LC; P=4.0 × 10(-4)), chronic obstructive pulmonary disease (COPD; P=9.3 × 10(-4)), peripheral artery disease (PAD; P=0.090) and abdominal aortic aneurysms (AAAs; P=0.12), and the variant associates strongly with the early-onset forms of LC (OR=4.49, P=2.2 × 10(-4)), COPD (OR=3.22, P=2.9 × 10(-4)), PAD (OR=3.47, P=9.2 × 10(-3)) and AAA (OR=6.44, P=6.3 × 10(-3)). Joint analysis of the four smoking-related diseases reveals significant association (P=6.8 × 10(-5)), particularly for early-onset cases (P=2.1 × 10(-7)). Our results are in agreement with functional studies showing that the human α4β2 isoform of the channel containing R336C has less sensitivity for its agonists than the wild-type form following nicotine incubation.
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Affiliation(s)
- T E Thorgeirsson
- deCODE genetics/Amgen, Reykjavik, Iceland,deCODE genetics/Amgen, Sturlugata 8, Reykjavik IS-101, Iceland. E-mail: or
| | | | | | | | - T Rafnar
- deCODE genetics/Amgen, Reykjavik, Iceland
| | - I Jonsdottir
- deCODE genetics/Amgen, Reykjavik, Iceland,Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | | | | | | | - S Jonsson
- Faculty of Medicine, University of Iceland, Reykjavik, Iceland,Department of Respiratory Medicine, Landspitali University Hospital, Reykjavik, Iceland
| | | | - T Gislason
- Faculty of Medicine, University of Iceland, Reykjavik, Iceland,Department of Respiratory Medicine, Landspitali University Hospital, Reykjavik, Iceland
| | - T Tyrfingsson
- SAA National Center of Addiction Medicine, Reykjavik, Iceland
| | - T Gudbjartsson
- Faculty of Medicine, University of Iceland, Reykjavik, Iceland,Department of Cardiothoracic Surgery, Landspitali University Hospital, Reykjavik, Iceland
| | - H J Isaksson
- Department of Pathology, Landspitali University Hospital, Reykjavik, Iceland
| | - H Hardardottir
- Department of Respiratory Medicine, Landspitali University Hospital, Reykjavik, Iceland
| | - A Sigvaldason
- Department of Respiratory Medicine, Landspitali University Hospital, Reykjavik, Iceland
| | - L A Kiemeney
- Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands,Department of Urology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - A Haugen
- Department for the Chemical and Biological Work Environment, National Institute of Occupational Health, Oslo, Norway
| | - S Zienolddiny
- Department for the Chemical and Biological Work Environment, National Institute of Occupational Health, Oslo, Norway
| | - H J Wolf
- Community & Behavioral Health, Colorado School of Public Health, University of Colorado Denver, Aurora, CO, USA
| | - W A Franklin
- Department of Pathology, University of Colorado Denver, Aurora, CO, USA
| | - A Panadero
- Division of Medical Oncology, Hospital Ciudad de Coria, Coria, Spain
| | - J I Mayordomo
- Division of Medical Oncology, University of Colorado School of Medicine, Denver, CO, USA
| | - I P Hall
- Division of Respiratory Medicine, Queens Medical Centre, University of Nottingham, Nottingham, UK
| | - E Rönmark
- The OLIN studies, Department of Medicine, Sunderby Central Hospital of Norrbotten, Luleå, Sweden,Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine, Umeå University, Umeå, Sweden
| | - B Lundbäck
- The OLIN studies, Department of Medicine, Sunderby Central Hospital of Norrbotten, Luleå, Sweden,Krefting Research Centre, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - A Dirksen
- Department of Respiratory Medicine, Gentofte Hospital, Copenhagen University, Hellerup, Denmark
| | - H Ashraf
- Department of Respiratory Medicine, Gentofte Hospital, Copenhagen University, Hellerup, Denmark,Centre for Diagnostic Imaging—Thoracic Section, Akershus University Hospital, Loerenskog, Norway
| | - J H Pedersen
- Department of Thoracic Surgery RT, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - G Masson
- deCODE genetics/Amgen, Reykjavik, Iceland
| | - P Sulem
- deCODE genetics/Amgen, Reykjavik, Iceland
| | | | | | - K Stefansson
- deCODE genetics/Amgen, Reykjavik, Iceland,Faculty of Medicine, University of Iceland, Reykjavik, Iceland,deCODE genetics/Amgen, Sturlugata 8, Reykjavik IS-101, Iceland. E-mail: or
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4
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Landvik NE, Tekpli X, Anmarkrud KH, Haugen A, Zienolddiny S. Molecular characterization of a cancer-related single nucleotide polymorphism in the pro-inflammatory interleukin-1B gene. Mol Carcinog 2012; 51 Suppl 1:E168-75. [PMID: 22467534 DOI: 10.1002/mc.21910] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Revised: 02/16/2012] [Accepted: 03/07/2012] [Indexed: 01/09/2023]
Abstract
Interleukin-1β is a key pro-inflammatory cytokine that has been associated with chronic inflammation and inflammation-related cancer initiation and progression. There are inter-individual differences in IL1B expression which may be due to single nucleotide polymorphisms (SNPs) in the regulatory regions of the gene. We have previously shown that a SNP located in the promoter of the IL1B gene (the IL1B T-31C SNP) was associated with lung cancer risk. Interestingly, the presence of the C allele was also associated with reduced IL1B expression in normal lung tissue of lung cancer patients. In the present study, we found that differential binding patterns of nuclear proteins to oligonucleotide probes containing the IL1B -31C allele compared to those with the T allele were due to specific binding of the transcription factor Yin Yang 1 (YY1). We further found evidence that specific recruitment of YY1 to the -31C region of the IL1B promoter regulated IL1B gene expression using siRNA directed towards YY1. The results indicate that the presence of a C allele at the -31 position may lead to decreased expression of the IL1B gene due to a specific binding of YY1 in lung epithelial cells. Our study provides functional significance of allelic variation at a single locus in the IL1B promoter and contributes to understanding the regulation of IL1B in inflammation-related carcinogenesis.
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Affiliation(s)
- N E Landvik
- Section of Toxicology, Department of Chemical and Biological Work Environment, National Institute of Occupational Health, Oslo, Norway
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5
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Kristoffersen T, Landvik N, Solbakken M, Karlsen H, Haugen A, Zienolddiny S. 883 Lack of interaction between functional polymorphisms in the MDM2 gene and exposure to 17-β estradiol in vitro. EJC Suppl 2010. [DOI: 10.1016/s1359-6349(10)71677-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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6
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Skaug V, Zienolddiny S, Ryberg D, Stangeland L, Haugen A. P-115 Cyclooxygenase 2 (COX-2) polymorphism and survival inadenocarcinoma of the lung. Lung Cancer 2005. [DOI: 10.1016/s0169-5002(05)80609-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Abstract
Carcinogenesis results from an accumulation of several genetic alterations. Mutations in the p53 gene are frequent and occur at an early stage of lung carcinogenesis. Loss of multiple chromosomal regions is another genetic alteration frequently found in lung tumours. We have examined the association between p53 mutations, loss of heterozygosity (LOH) at frequently deleted loci in lung cancer, and tobacco exposure in 165 tumours from non-small cell lung cancer (NSCLC) patients. A highly significant association between p53 mutations and deletions on 3p, 5q, 9p, 11p and 17p was found. There was also a significant correlation between deletions at these loci. 86% of the tumours with concordant deletion in the 4 most involved loci (3p21, 5q11-13, 9p21 and 17p13) had p53 mutations as compared to only 8% of the tumours without deletions at the corresponding loci (P< 0.0001). Data were also examined in relation to smoking status of the patients and histology of the tumours. The frequency of deletions was significantly higher among smokers as compared to non-smokers. This difference was significant for the 3p21.3 (hMLH1 locus), 3p14.2 (FHIT locus), 5q11-13 (hMSH3 locus) and 9p21 (D9S157 locus). Tumours with deletions at the hMLH1 locus had higher levels of hydrophobic DNA adducts. Deletions were more common in squamous cell carcinomas than in adenocarcinomas. Covariate analysis revealed that histological type and p53 mutations were significant and independent parameters for predicting LOH status at several loci. In the pathogenesis of NSCLC exposure to tobacco carcinogens in addition to clonal selection may be the driving force in these alterations.
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Affiliation(s)
- S Zienolddiny
- Department of Toxicology, National Institute of Occupational Health, P.O. Box 8149 Dep., Oslo, N-0033, Norway
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8
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Zienolddiny S, Ryberg D, Haugen A. Induction of microsatellite mutations by oxidative agents in human lung cancer cell lines. Carcinogenesis 2000; 21:1521-6. [PMID: 10910953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
Genomic instability has been associated with cancer development. Oxidative DNA damage seems to contribute to genetic instability observed in cancer. We have used human lung cancer cell lines carrying a plasmid vector containing a (CA)(13) microsatellite sequence to study frameshift mutations mediated by ROS-generating chemicals paraquat and hydrogen peroxide. Exposure of the cells to both paraquat and hydrogen peroxide resulted in significantly higher mutation frequencies compared with untreated control cells. Mutation frequencies up to 27-fold higher than the spontaneous mutation frequencies were obtained. The majority of the reversion mutants contained frameshift mutations within the target sequence. However, the pattern of deletions and additions was significantly different in the two cell lines. These results indicate that oxidative damage may play a role in instability of microsatellite sequences in vivo.
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Affiliation(s)
- S Zienolddiny
- Department of Toxicology, National Institute of Occupational Health, PO Box 8149 Dep., N-0033 Oslo, Norway
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9
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Abstract
Nickel(II) is a human carcinogen causing respiratory cancers. The purpose of this study was to determine whether Ni(II) may induce microsatellite mutations in human cells. We transfected the three human lung tumor cell lines A427, HCC15 and NCI-H2009 with a mammalian expression vector containing a (CA)(13) repeat in the coding sequences of the reporter hygromycin gene (hyg). A total of 33 clones carrying the integrated vector derived from the three cell lines was investigated for spontaneous and Ni(II)-induced hygromycin-resistant (hyg(r)) reversion mutants. Significantly higher frequencies of hyg(r) reversion mutations were observed in Ni(II)-treated cells (NCI-H2009 and HCC-15) than control cells. In the majority of the colonies hyg(r) phenotype was due to mutations within the integrated (CA) repeat sequence. The type of mutations consisted of both contraction and expansion of the (CA) repeat unit. The finding that Ni(II) promotes microsatellite mutations raises the possibility that genetic instability may be a mechanism involved in nickel carcinogenesis.
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Affiliation(s)
- S Zienolddiny
- Department of Toxicology, National Institute of Occupational Health, Oslo, Norway
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10
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Abstract
Gene-environment interactions are thought to be critical for several diseases such as cancer, diabetes, heart disease and asthma. Cancer is a result of multiple gene-environment interactions occurring over several decades. During tumor development the cell accumulates multiple genetic changes, which generate the transformed phenotype, i.e. a cell with increased genetic instability. Lung cancer is a useful model for the study of the interplay between genetic factors and environmental exposure since the primary etiology is well established. Several polymorphic enzymes that may be important determinants of susceptibility have been demonstrated. Data also provide evidence for sex differences in lung cancer susceptibility. Furthermore, certain chemical carcinogens may contribute to the carcinogenic process in the lung epithelial cells by inducing genomic instability either directly or indirectly through inflammatory processes.
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Affiliation(s)
- A Haugen
- Department of Toxicology, National Institute of Occupational Health, N-0033, Oslo, Norway.
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11
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Lindstedt BA, Ryberg D, Zienolddiny S, Khan H, Haugen A. Hras1 VNTR alleles as susceptibility markers for lung cancer: relationship to microsatellite instability in tumors. Anticancer Res 1999; 19:5523-7. [PMID: 10697610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
PURPOSE To further evaluate lung cancer risk associated with rare Hras1 VNTR alleles and possible biological mechanisms. MATERIALS AND METHODS The Hras1 VNTR was genotyped in 295 lung cancer patients and 500 healthy controls by PCR and high resolution electrophoresis. Microsatellite alterations were examined in 168 tumors by PCR and capillary electrophoresis. RESULTS 35 Hras1 VNTR alleles were found, of which 24 were defined as rare. A relative risk of 3.3 (95% CI; 1.9-6.0) associated with rare alleles was obtained using the total groups. Increased risk was significant both for males and females. When a matched control group was used, a relative risk of 12.7 (95% CI; 1.7-93.9) was calculated for individuals with rare alleles at the Hras1 VNTR locus. A low frequency of microsatellite alterations was observed (4.7%) in lung tumors. The frequency of altered microsatellite loci was higher among patients with rare Hras1 VNTR alleles than among patients with common alleles. CONCLUSION Rare Hras1 VNTR alleles are associated with lung cancer risk, and a genetic mechanism which increases allelic diversity may be involved.
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Affiliation(s)
- B A Lindstedt
- Department of Toxicology, National Institute of Occupational Health, Oslo, Norway
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12
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Abstract
Defects in mismatch repair (MMR) genes have been involved in several types of sporadic and hereditary cancers. In order to elucidate the role of MMR in human lung carcinogenesis we examined DNA mismatch binding in cell-free extracts of seven lung tumor cell lines and five corresponding lymphoblastoid cell lines from lung cancer patients. Using the technique of bandshift assay we have demonstrated that 2/7 of the tumor cell lines are aberrant in binding to specific DNA mismatches while all lymphoblastoid cell lines were proficient in binding to all tested mismatches. Both extracts were aberrant in binding to G/T mismatch whereas one of the cell lines showed deficiency in binding to the C:A mismatches as well. Immunoblotting analysis showed that all known DNA mismatch repair (MMR) proteins were present in these extracts. The cell line deficient in binding to both G:T and C:A mismatches showed microsatellite instability (MSI) in tumor DNA and higher resistance to the alkylating agent N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). This report indicates that DNA mismatch binding deficiencies may be implicated in at least a subgroup of human lung cancer.
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Affiliation(s)
- S Zienolddiny
- Department of Toxicology, National Institute of Occupational Health, Oslo, Norway
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13
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Ryberg D, Lindstedt BA, Zienolddiny S, Haugen A. A hereditary genetic marker closely associated with microsatellite instability in lung cancer. Cancer Res 1995; 55:3996-9. [PMID: 7664270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Alterations in 5 microsatellite loci were analyzed in tumors from 137 patients with primary non-small cell lung carcinomas that were also genotyped for the Hras1 variable number of tandem repeats (VNTR) locus. Twenty-nine patients (21%) had changes in at least one microsatellite locus. A majority of these cases (24 of 29, 83%) had VNTR alleles classified as rare in the population. The frequency of these rare alleles were significantly higher among lung cancer patients than in healthy controls (P = 0.016 or 1.80; 95% confidence interval = 1.13-2.85). Microsatellite alterations were significantly more frequent among patients with at least one rare Hras1 VNTR allele (24 of 40, 60%) compared to patients with two common alleles (5 of 97, 5%; P < 0.001 or 27.6; 95% confidence interval = 8.18-82.9). Microsatellite alterations were also more frequent among patients below 50 years of age (8 of 21, 38%) than for older patients (21 of 112, 19%).
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Affiliation(s)
- D Ryberg
- Department of Toxicology, National Institute of Occupational Health, Oslo, Norway
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