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Paustenbach DJ, Brown SE, Heywood JJ, Donnell MT, Eaton DL. Risk characterization of N-nitrosodimethylamine in pharmaceuticals. Food Chem Toxicol 2024; 186:114498. [PMID: 38341171 DOI: 10.1016/j.fct.2024.114498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 01/23/2024] [Accepted: 01/31/2024] [Indexed: 02/12/2024]
Abstract
Since 2018, N-nitrosodimethylamine (NDMA) has been a reported contaminant in numerous pharmaceutical products. To guide the pharmaceutical industry, FDA identified an acceptable intake (AI) of 96 ng/day NDMA. The approach assumed a linear extrapolation from the Carcinogenic Potency Database (CPDB) harmonic-mean TD50 identified in chronic studies in rats. Although NDMA has been thought to act as a mutagenic carcinogen in experimental animals, it has not been classified as a known human carcinogen by any regulatory agency. Humans are exposed to high daily exogenous and endogenous doses of NDMA. Due to the likelihood of a threshold dose for NDMA-related tumors in animals, we believe that there is ample scientific basis to utilize the threshold-based benchmark dose or point-of-departure (POD) approach when estimating a Permissible Daily Exposure limit (PDE) for NDMA. We estimated that 29,000 ng/kg/day was an appropriate POD for calculating a PDE. Assuming an average bodyweight of 50 kg, we expect that human exposures to NDMA at doses below 5800 ng/day in pharmaceuticals would not result in an increased risk of liver cancer, and that there is little, if any, risk for any other type of cancer, when accounting for the mode-of-action in humans.
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Affiliation(s)
- D J Paustenbach
- Paustenbach and Associates, 970 West Broadway, Suite E, Jackson, WY, USA
| | - S E Brown
- Paustenbach and Associates, 207 Canyon Blvd, Boulder, CO, USA.
| | - J J Heywood
- Paustenbach and Associates, 207 Canyon Blvd, Boulder, CO, USA
| | - M T Donnell
- Valeo Sciences LLC, 333 Corporate Drive, Suite 130, Ladera Ranch, CA, USA
| | - D L Eaton
- Professor Emeritus, Department of Environmental & Occupational Health Sciences, University of Washington, Seattle, WA, USA
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Myelotoxicity of Temozolomide Treatment in Patients with Glioblastoma Is It Time for a More Mechanistic Approach? Cancers (Basel) 2023; 15:cancers15051561. [PMID: 36900352 PMCID: PMC10000921 DOI: 10.3390/cancers15051561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 02/27/2023] [Indexed: 03/06/2023] Open
Abstract
Glioblastoma multiforme is the most common primary central nervous system tumor, with an incidence of 3 [...].
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MGMT in glial carcinogenesis. Roles from prevention to treatment. Eur J Cancer Prev 2022; 31:568-576. [DOI: 10.1097/cej.0000000000000746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Moitra P, Chatterjee A, Kota PK, Epari S, Patil V, Dasgupta A, Kowtal P, Sarin R, Gupta T. Temozolomide-induced myelotoxicity and single nucleotide polymorphisms in the MGMT gene in patients with adult diffuse glioma: a single-institutional pharmacogenetic study. J Neurooncol 2022; 156:625-634. [PMID: 35037156 DOI: 10.1007/s11060-022-03944-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 01/03/2022] [Indexed: 11/27/2022]
Abstract
PURPOSE Nearly 10% of patients with adult diffuse glioma develop clinically significant myelotoxicity while on temozolomide (TMZ) leading to treatment interruptions. This study aimed to assess single nucleotide polymorphisms (SNPs) in the O6-methylguanine-DNA methyltransferase (MGMT) gene in adults with biopsy-proven diffuse glioma who develop TMZ-induced myelotoxicity and correlate their presence with severity and duration of such toxicity. METHODS This study assessed 33 adults treated with TMZ for diffuse glioma who developed ≥ grade 2 thrombocytopenia and/or ≥ grade 3 neutropenia. Genomic DNA was extracted from peripheral blood cells for MGMT SNP analysis after written informed consent. TMZ-induced severe myelotoxicity (≥ grade 3) was correlated with three specified SNPs commonly seen in the MGMT gene (L84F, I143V/K178R) using chi-square test or Fischer's exact test as appropriate. RESULTS Of the 33 adults, 24 (72.7%) experienced ≥ grade 3 thrombocytopenia and/or neutropenia, while 9 (27.3%) developed grade 2 thrombocytopenia only. The variant T allele of L84F was expressed in 28.7% (19/66) of analyzed alleles, which was substantially higher than previously reported for South Asian ancestry. The variant G allele of I143V/K178R was expressed in 9.3% (6/64) of analyzed alleles. Of which 3 patients showed statistically significant association with prolonged myelosuppression for > 2 months (p = 0.03). No significant correlation was established between the mentioned SNPs and severe myelotoxicity. CONCLUSIONS There is substantially higher frequency of variant T allele (L84F) in Indian patients than previously reported for South Asians. The presence of specific SNPs in the MGMT gene correlates with prolonged duration but not severity of TMZ-induced myelotoxicity.
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Affiliation(s)
- Prithwijit Moitra
- Departments of Radiation Oncology, Tata Memorial Hospital (TMH)/Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Tata Memorial Centre, Homi Bhabha National Institute (HBNI), Mumbai, 410210, India
| | - Abhishek Chatterjee
- Departments of Radiation Oncology, Tata Memorial Hospital (TMH)/Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Tata Memorial Centre, Homi Bhabha National Institute (HBNI), Mumbai, 410210, India
| | - Priti Khatri Kota
- Sarin Lab, Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Tata Memorial Centre, Homi Bhabha National Institute (HBNI), Mumbai, India
| | - Sridhar Epari
- Department of Pathology, Tata Memorial Hospital (TMH)/Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Tata Memorial Centre, Homi Bhabha National Institute (HBNI), Mumbai, India
| | - Vijay Patil
- Department of Medical Oncology, Tata Memorial Hospital (TMH)/Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Tata Memorial Centre, Homi Bhabha National Institute (HBNI), Mumbai, India
| | - Archya Dasgupta
- Departments of Radiation Oncology, Tata Memorial Hospital (TMH)/Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Tata Memorial Centre, Homi Bhabha National Institute (HBNI), Mumbai, 410210, India
| | - Pradnya Kowtal
- Sarin Lab, Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Tata Memorial Centre, Homi Bhabha National Institute (HBNI), Mumbai, India
| | - Rajiv Sarin
- Departments of Radiation Oncology, Tata Memorial Hospital (TMH)/Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Tata Memorial Centre, Homi Bhabha National Institute (HBNI), Mumbai, 410210, India
- Sarin Lab, Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Tata Memorial Centre, Homi Bhabha National Institute (HBNI), Mumbai, India
| | - Tejpal Gupta
- Departments of Radiation Oncology, Tata Memorial Hospital (TMH)/Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Tata Memorial Centre, Homi Bhabha National Institute (HBNI), Mumbai, 410210, India.
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Kewitz-Hempel S, Kurch L, Cepelova M, Volkmer I, Sauerbrey A, Conrad E, Knirsch S, Pöpperl G, Steinbach D, Beer AJ, Kramm CM, Sahlmann CO, Erdlenbruch B, Reinbold WD, Odparlik A, Sabri O, Kluge R, Staege MS. Impact of rs12917 MGMT Polymorphism on [ 18F]FDG-PET Response in Pediatric Hodgkin Lymphoma (PHL). Mol Imaging Biol 2019; 21:1182-1191. [PMID: 30945122 DOI: 10.1007/s11307-019-01350-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE The enzyme O6-methylguanine-DNA methyltransferase (MGMT) is an important component of the DNA repair machinery. MGMT removes O6-methylguanine from the DNA by transferring the methyl group to a cysteine residue in its active site. Recently, we detected the single nucleotide polymorphism (SNP) rs12917 (C/T) in the MGMT sequence adjacent to the active site in Hodgkin lymphoma (HL) cell line KM-H2. We now investigated whether this SNP is also present in other HL cell lines and patient samples. Furthermore, we asked whether this SNP might have an impact on metabolic response in 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography ([18F]FDG-PET), and on overall treatment outcome based on follow-up intervals of at least 34 months. PROCEDURES We determined the frequency of this MGMT polymorphism in 5 HL cell lines and in 29 pediatric HL (PHL) patients. The patient cohort included 17 female and 12 male patients aged between 4 and 18 years. After characterization of the sequence, we tested a possible association between rs12917 and age, gender, Ann Arbor stage, treatment group, metabolic response following two courses of OEPA (vincristine, etoposide, prednisone, and doxorubicin) chemotherapy, radiotherapy indication, and relapse status. RESULTS We detected the minor T allele in four of five HL cell lines. 11/29 patients carried the minor T allele whereas 18/29 patients showed homozygosity for the major C allele. Interestingly, we observed significantly better metabolic response in PHL patients carrying the rs12917 C allele resulting in a lower frequency of radiotherapy indication. CONCLUSION MGMT polymorphism rs12917 seems to affect chemotherapy response in PHL. The prognostic value of this polymorphism should be investigated in a larger patient cohort.
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Affiliation(s)
- Stefanie Kewitz-Hempel
- Department of Pediatrics I, Martin Luther University Halle-Wittenberg, Ernst-Grube-Str. 40, 06120, Halle, Germany.,Department of Pediatric Hematology and Oncology, Justus Liebig University, Giessen, Germany.,Department of Dermatology and Venereology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Lars Kurch
- Department of Nuclear Medicine, University Hospital of Leipzig, 04103, Leipzig, Germany
| | - Michaela Cepelova
- Department of Pediatric Hematology and Oncology, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital, Praha, Czech Republic
| | - Ines Volkmer
- Department of Pediatrics I, Martin Luther University Halle-Wittenberg, Ernst-Grube-Str. 40, 06120, Halle, Germany
| | | | - Elke Conrad
- Department of Nuclear Medicine, Helios Hospital Erfurt, Erfurt, Germany
| | - Stephanie Knirsch
- Pediatrics 5 (Oncology, Hematology, and Immunology), Klinikum Stuttgart, Olgahospital, Stuttgart, Germany
| | - Gabriele Pöpperl
- Department of Nuclear Medicine, Klinikum Stuttgart, Olgahospital, Stuttgart, Germany
| | - Daniel Steinbach
- Department of Pediatric Hematology and Oncology, University Hospital Ulm, Ulm, Germany
| | - Ambros J Beer
- Department of Nuclear Medicine, University Hospital, Ulm, Germany
| | - Christof M Kramm
- Department of Pediatrics I, Martin Luther University Halle-Wittenberg, Ernst-Grube-Str. 40, 06120, Halle, Germany.,Division of Pediatric Hematology and Oncology, University Medical Center Göttingen, Göttingen, Germany
| | | | - Bernhard Erdlenbruch
- University Hospital for Children and Adolescents, Johannes Wesling Klinikum Minden, Ruhr University Hospital, Bochum, Germany
| | - Wolf-Dieter Reinbold
- Universitätsinstitut für Diagnostische Radiologie, Neuroradiologie und Nuklearmedizin, Johannes Wesling Klinikum Minden, Ruhr University Hospital, Bochum, Germany
| | - Andreas Odparlik
- Department of Nuclear Medicine, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Osama Sabri
- Department of Nuclear Medicine, University Hospital of Leipzig, 04103, Leipzig, Germany
| | - Regine Kluge
- Department of Nuclear Medicine, University Hospital of Leipzig, 04103, Leipzig, Germany.
| | - Martin S Staege
- Department of Pediatrics I, Martin Luther University Halle-Wittenberg, Ernst-Grube-Str. 40, 06120, Halle, Germany.
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Nagel ZD, Beharry AA, Mazzucato P, Kitange GJ, Sarkaria JN, Kool ET, Samson LD. Fluorescent reporter assays provide direct, accurate, quantitative measurements of MGMT status in human cells. PLoS One 2019; 14:e0208341. [PMID: 30811507 PMCID: PMC6392231 DOI: 10.1371/journal.pone.0208341] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 11/15/2018] [Indexed: 12/21/2022] Open
Abstract
The DNA repair protein O6-methylguanine DNA methyltransferase (MGMT) strongly influences the effectiveness of cancer treatment with chemotherapeutic alkylating agents, and MGMT status in cancer cells could potentially contribute to tailored therapies for individual patients. However, the promoter methylation and immunohistochemical assays presently used for measuring MGMT in clinical samples are indirect, cumbersome and sometimes do not accurately report MGMT activity. Here we directly compare the accuracy of 6 analytical methods, including two fluorescent reporter assays, against the in vitro MGMT activity assay that is considered the gold standard for measuring MGMT DNA repair capacity. We discuss the relative advantages of each method. Our data indicate that two recently developed fluorescence-based assays measure MGMT activity accurately and efficiently, and could provide a functional dimension to clinical efforts to identify patients who are likely to benefit from alkylating chemotherapy.
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Affiliation(s)
- Zachary D. Nagel
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Andrew A. Beharry
- Department of Chemistry, Stanford University, Stanford, California, United States of America
| | - Patrizia Mazzucato
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Gaspar J. Kitange
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Jann N. Sarkaria
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Eric T. Kool
- Department of Chemistry, Stanford University, Stanford, California, United States of America
| | - Leona D. Samson
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- * E-mail:
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Tyagi AK, Khoshbeen MB, Curtis PHD, Uppugunduri CRS, Ansari M. Development and validation of an allele-specific PCR assay for genotyping a promoter and exonic single nucleotide polymorphisms of MGMT gene. J Biol Methods 2018; 5:e92. [PMID: 31453242 PMCID: PMC6706101 DOI: 10.14440/jbm.2018.224] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 04/12/2018] [Accepted: 04/12/2018] [Indexed: 11/23/2022] Open
Abstract
DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) specifically remove the methyl/alkyl group from the O6-position of guanine and restore the guanine to its normal form without causing DNA strand breaks. Relationship between MGMT activity and resistance to alkylating therapeutic agents is well established. Non-availability of simple, cost-effective and efficient methods of genotyping may hinder investigations on genotype-phenotype associations. No simple genotyping procedures such as allele-discrimination Taqman Assays were available for two genetic variations in MGMT gene that had previously demonstrated to be affecting its function and expression. These two variants were included to genotype in a clinical study (Clinicaltrail.gov ID: NCT01257854). Hence, the present study is aimed at developing, validating a rapid and simple allele-specific PCR method that genotypes exonic variant rs2308321 (c.520A>G) and a promoter variant rs113813075 (c.-459C>A) with standard PCR instruments. Web-based allele-specific (AS) primer design application called web-based allele-specific primer was used to design primers. Genomic DNA of lymphoblastoid cell line obtained from the Coriell repository with known genotypes were used to standardize the genotyping procedure. The PCR products were analyzed by 3% Agarose gel electrophoresis and by DNA Screen Tape assay with the Agilent 4200 TapeStation. The allele-specific PCR assay described here is a suitable strategy for efficient and reliable genotyping for difficult variants. This method offers cost-effective strategy for genotyping in clinical cohort studies provided positive controls established by Sanger sequencing are available for the variant.
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Affiliation(s)
- Anuj Kumar Tyagi
- CANSEARCH Research Laboratory, Department of Pediatrics, Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Onco-Hematology Unit, Department of Pediatrics, Geneva University Hospitals, University of Geneva, Geneva, Switzerland
| | - Mary Boudal Khoshbeen
- CANSEARCH Research Laboratory, Department of Pediatrics, Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Onco-Hematology Unit, Department of Pediatrics, Geneva University Hospitals, University of Geneva, Geneva, Switzerland
| | - Patricia Huezo-Diaz Curtis
- CANSEARCH Research Laboratory, Department of Pediatrics, Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Onco-Hematology Unit, Department of Pediatrics, Geneva University Hospitals, University of Geneva, Geneva, Switzerland
| | - Chakradhara Rao S Uppugunduri
- CANSEARCH Research Laboratory, Department of Pediatrics, Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Onco-Hematology Unit, Department of Pediatrics, Geneva University Hospitals, University of Geneva, Geneva, Switzerland
| | - Marc Ansari
- CANSEARCH Research Laboratory, Department of Pediatrics, Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Onco-Hematology Unit, Department of Pediatrics, Geneva University Hospitals, University of Geneva, Geneva, Switzerland
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8
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Silva-Fernandes IJDL, Oliveira ESD, Santos JC, Ribeiro ML, Ferrasi AC, Pardini MIDMC, Burbano RMR, Rabenhorst SHB. The intricate interplay between MSI and polymorphisms of DNA repair enzymes in gastric cancer H.pylori associated. Mutagenesis 2017; 32:471-478. [DOI: 10.1093/mutage/gex013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 04/24/2017] [Indexed: 12/15/2022] Open
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Altinoz MA, Elmaci I, Bolukbasi FH, Ekmekci CG, Yenmis G, Sari R, Sav A. MGMT gene variants, temozolomide myelotoxicity and glioma risk. A concise literature survey including an illustrative case. J Chemother 2017; 29:238-244. [PMID: 28436299 DOI: 10.1080/1120009x.2017.1312752] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Temozolomide may cause thrombocytopenia or neutropenia in 3-4% of glioblastoma patients, respectively. However, pancytopenia is rarely reported. MGMT (O6-methylguanine-DNA-methyltransferase) enzyme repairs temozolomide-induced DNA mutations and associates both with antitumour efficacy and myelosuppression. Many studies on the effects of MGMT gene-methylation on temozolomide's effects exist, but much fewer publications concerning MGMT variants were documented. A full sequencing of the MGMT gene was performed in a female glioblastoma patient, who developed pancytopenia following temozolomide treatment. Results indicated the presence of all the rs2308321 (I143 V), rs2308327 (K178R) and rs12917 (L84F) MGMT-variants, which were previously associated with temozolomide myelotoxicity. rs12917 (L84F) variant was reported as associating with lesser risk of gallbladder tumours, yet with higher risk of non-Hodgkin lymphomas related with exposure to chlorinated solvents or hair dyes. DNA repair proteins may exert diverging effects on DNA injuries caused by different chemicals and therefore exerting complex effects on myelotoxicity, antitumour activity and carcinogenesis.
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Affiliation(s)
| | - Ilhan Elmaci
- a Neuroacademy Group , Istanbul , Turkey.,b Department of Neurosurgery , Memorial Hospital , Istanbul , Turkey
| | - Fatih Han Bolukbasi
- a Neuroacademy Group , Istanbul , Turkey.,b Department of Neurosurgery , Memorial Hospital , Istanbul , Turkey
| | | | - Guven Yenmis
- c Department of Genetics , Acibadem University , Istanbul , Turkey
| | - Ramazan Sari
- d Department of Neurosurgery , Hizmet Hastanesi , Istanbul , Turkey
| | - Aydin Sav
- e Nisantasi Pathology Group , Istanbul , Turkey
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Grundy A, Richardson H, Schuetz JM, Burstyn I, Spinelli JJ, Brooks-Wilson A, Aronson KJ. DNA repair variants and breast cancer risk. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2016; 57:269-281. [PMID: 27060854 DOI: 10.1002/em.22013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 03/13/2016] [Indexed: 06/05/2023]
Abstract
A functional DNA repair system has been identified as important in the prevention of tumour development. Previous studies have hypothesized that common polymorphisms in DNA repair genes could play a role in breast cancer risk and also identified the potential for interactions between these polymorphisms and established breast cancer risk factors such as physical activity. Associations with breast cancer risk for 99 single nucleotide polymorphisms (SNPs) from genes in ten DNA repair pathways were examined in a case-control study including both Europeans (644 cases, 809 controls) and East Asians (299 cases, 160 controls). Odds ratios in both additive and dominant genetic models were calculated separately for participants of European and East Asian ancestry using multivariate logistic regression. The impact of multiple comparisons was assessed by correcting for the false discovery rate within each DNA repair pathway. Interactions between several breast cancer risk factors and DNA repair SNPs were also evaluated. One SNP (rs3213282) in the gene XRCC1 was associated with an increased risk of breast cancer in the dominant model of inheritance following adjustment for the false discovery rate (P < 0.05), although no associations were observed for other DNA repair SNPs. Interactions of six SNPs in multiple DNA repair pathways with physical activity were evident prior to correction for FDR, following which there was support for only one of the interaction terms (P < 0.05). No consistent associations between variants in DNA repair genes and breast cancer risk or their modification by breast cancer risk factors were observed.
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Affiliation(s)
- Anne Grundy
- CRCHUM (Centre de Recherche du CHUM), Montreal, Quebec, Canada
| | - Harriet Richardson
- Department of Public Health Sciences and Cancer Research Institute, Queen's University, Kingston, Ontario, Canada
| | - Johanna M Schuetz
- Canada's Michael Smith Genome Sciences Centre, British Columbia Cancer Agency, Vancouver, British Columbia, Canada
| | - Igor Burstyn
- Department of Environmental and Occupational Health, Drexel University, Philadelphia, Pennsylvania
| | - John J Spinelli
- Department of Cancer Control Research, British Columbia Cancer Agency, Vancouver, British Columbia, Canada
- School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Angela Brooks-Wilson
- Canada's Michael Smith Genome Sciences Centre, British Columbia Cancer Agency, Vancouver, British Columbia, Canada
- Department of Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Kristan J Aronson
- Department of Public Health Sciences and Cancer Research Institute, Queen's University, Kingston, Ontario, Canada
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Clinical and Genetic Factors Associated With Severe Hematological Toxicity in Glioblastoma Patients During Radiation Plus Temozolomide Treatment: A Prospective Study. Am J Clin Oncol 2016; 38:514-9. [PMID: 24064758 DOI: 10.1097/coc.0b013e3182a790ea] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND Temozolomide (TMZ) administered daily with radiation therapy (RT) for 6 weeks, followed by adjuvant TMZ for 6 cycles, is the standard therapy for newly diagnosed glioblastoma (GBM) patients. Although TMZ is considered to be a safe drug, it has been demonstrated to cause severe myelotoxicity; in particular, some case reports and small series studies have reported severe myelotoxicity developing during TMZ and concomitant RT. We performed a prospective study to analyze the incidence of early severe myelotoxicity and its possible clinical and genetic factors. PATIENTS AND METHODS From November 2010 to July 2012, newly diagnosed GBM patients were enrolled. They were eligible for the study if they met the following criteria: pathologically proven GBM, age 18 years and older, an Eastern Cooperative Oncology Group performance status of 0 to 2, adequate renal and hepatic function, and adequate blood cell counts before starting TMZ plus RT. Grading of hematologic toxicity developing during radiation and TMZ was based on the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. Clinical factors from all patients were recorded. The methylation status and polymorphic variants of O-methylguanine-DNAmethyl-transferase gene in peripheral blood mononuclear cells, and polymorphic genetic variants of genes involved in the pharmacokinetics and pharmacodynamics of TMZ, were analyzed. For genetic analyses, patients with toxicity were matched (1:2) for age, performance status, anticonvulsants, and proton pump inhibitors with patients without myelotoxicity. RESULTS We enrolled 87 consecutive GBM patients: 32 women and 55 men; the average age was 60 years. During TMZ and RT, 4 patients (5%) showed grade 3-4 myelotoxicity, and its median duration was 255 days. Predictor factors of severe myelotoxicity were female sex, pretreatment platelet count of ≤3,00,000/mm, methylated O-methylguanine-DNA methyltransferase promoter in the hematopoietic cell system, and specific polymorphic variants of the cytochrome P450 oxidoreductase and methionine adenosyltransferase 1A genes. CONCLUSIONS Although we studied a small population, we suggest that both clinical and genetic factors might simultaneously be associated with severe myelosuppression developed during TMZ plus RT. However, our results deserve validation in larger prospective studies and, if the factors associated with severe myelotoxicity are validated, dose adjustments of TMZ for those patients may reduce the risk of severe myelotoxicity during the concomitant treatment.
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Dubois J, Etienne G, Laroche-Clary A, Lascaux A, Bidet A, Lippert E, Ait-ouferoukh S, Saada V, Micol JB, Bouabdallah K, Robert J. Identification of methylguanine methyltransferase polymorphisms as genetic markers of individual susceptibility to therapy-related myeloid neoplasms. Eur J Cancer 2013; 50:418-24. [PMID: 24238921 DOI: 10.1016/j.ejca.2013.10.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Revised: 10/08/2013] [Accepted: 10/18/2013] [Indexed: 11/30/2022]
Abstract
PURPOSE Myelodysplastic syndromes (MDS) are pre-leukaemic haematopoietic stem cell disorders. Among them, 10-20% occur after chemotherapy and/or radiotherapy, and are called 'therapy-related MDS' (t-MDS). The aim of this study was to identify genetic markers in t-MDS. METHODS A prospective cohort of 59 MDS patients (39 de novo MDS, 20 t-MDS) was studied. A total of 384 single nucleotide polymorphisms (SNP) selected among genes involved in DNA repair, drug metabolism and transport, signal transduction and oncogenesis, were genotyped using a custom-made SNP chip. RESULTS Two non-synonymous SNPs present in the methylguanine methyltransferase (MGMT) gene, in complete linkage disequilibrium, were significantly associated with t-MDS: rs2308321 and rs2308327, with a raw p value of 7.4 × 10(-5) and a corrected p value after Benjamini-Hochberg correction of 0.014. Other associations tested between clinical and cytogenetic features and SNP chip gene variants gave corrected p values above 0.05. A validation cohort was separately constituted of 43 patients (24 de novo MDS, 19 t-MDS) and the two MGMT SNPs were genotyped; it confirmed a significant association between the variant allele of MGMT and t-MDS (p=0.038). CONCLUSION We thus identified a putative marker of the risk to develop MDS after cancer treatment.
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Affiliation(s)
- Julie Dubois
- INSERM U916, Bordeaux, France; Department of Medical Biology, Institut Bergonié, Bordeaux, France.
| | - Gabriel Etienne
- Department of Hematology, Institut Bergonié, Bordeaux, France
| | | | - Axelle Lascaux
- Department of Hematology, Hôpital du Haut-Lévêque, CHU de Bordeaux, Pessac, France
| | - Audrey Bidet
- Department of Hematology, Hôpital du Haut-Lévêque, CHU de Bordeaux, Pessac, France
| | - Eric Lippert
- Department of Hematology, Hôpital du Haut-Lévêque, CHU de Bordeaux, Pessac, France; Université Bordeaux Segalen, Bordeaux, France
| | | | - Veronique Saada
- Department of Hematology, Institut Gustave-Roussy, Villejuif, France
| | | | - Krimo Bouabdallah
- Department of Hematology, Hôpital du Haut-Lévêque, CHU de Bordeaux, Pessac, France
| | - Jacques Robert
- INSERM U916, Bordeaux, France; Department of Medical Biology, Institut Bergonié, Bordeaux, France; Université Bordeaux Segalen, Bordeaux, France
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Chen Y, Zheng T, Lan Q, Kim C, Qin Q, Foss F, Chen X, Holford T, Leaderer B, Boyle P, Wang C, Dai M, Liu Z, Ma S, Chanock SJ, Rothman N, Zhang Y. Polymorphisms in DNA repair pathway genes, body mass index, and risk of non-Hodgkin lymphoma. Am J Hematol 2013; 88:606-11. [PMID: 23619945 DOI: 10.1002/ajh.23463] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 03/21/2013] [Accepted: 04/11/2013] [Indexed: 11/07/2022]
Abstract
We conducted a population-based case-control study in Connecticut women to test the hypothesis that genetic variations in DNA repair pathway genes may modify the relationship between body mass index (BMI) and risk of non-Hodgkin lymphoma (NHL). Compared to those with BMI <25, women with BMI ≥25 had significantly increased risk of NHL among women who carried BRCA1 (rs799917) CT/TT, ERCC2 (rs13181) AA, XRCC1 (rs1799782) CC, and WRN (rs1801195) GG genotypes, but no increase in NHL risk among women who carried BRCA1 CC, ERCC2 AC/CC, XRCC1 CT/TT, and WRN GT/TT genotypes. A significant interaction with BMI was only observed for WRN (rs1801195; P = 0.004) for T-cell lymphoma and ERCC2 (rs13181; P = 0.002) for diffuse large B-cell lymphoma. The results suggest that common genetic variation in DNA repair pathway genes may modify the association between BMI and NHL risk.
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Affiliation(s)
- Yingtai Chen
- Cancer Institute/Hospital, Chinese Academy of Medical Sciences; Beijing People's Republic of China
- Yale University School of Public Health; New Haven Connecticut
| | - Tongzhang Zheng
- Yale University School of Public Health; New Haven Connecticut
| | - Qing Lan
- Division of Cancer Epidemiology and Genetics, Department of Health and Human Services; National Cancer Institute, National Institutes of Health; Rockville Maryland
| | - Christopher Kim
- Yale University School of Public Health; New Haven Connecticut
- Division of Cancer Epidemiology and Genetics, Department of Health and Human Services; National Cancer Institute, National Institutes of Health; Rockville Maryland
| | - Qin Qin
- Wise Laboratory of Environmental and Genetic Toxicology, University of Southern Maine; Portland Maine
| | - Francine Foss
- Yale University School of Medicine; New Haven Connecticut
| | - Xuezhong Chen
- Gansu Provincial Cancer Hospital; Lanzhou People's Republic of China
| | | | - Brian Leaderer
- Yale University School of Public Health; New Haven Connecticut
| | - Peter Boyle
- International Preventive Research Institute; Lyon France
| | - Chengfeng Wang
- Cancer Institute/Hospital, Chinese Academy of Medical Sciences; Beijing People's Republic of China
| | - Min Dai
- Cancer Institute/Hospital, Chinese Academy of Medical Sciences; Beijing People's Republic of China
| | - Zhenjiang Liu
- Gansu Provincial College of Chinese Medicine; Lanzhou People's Republic of China
| | - Shuangge Ma
- Yale University School of Public Health; New Haven Connecticut
| | - Stephen J. Chanock
- Division of Cancer Epidemiology and Genetics, Department of Health and Human Services; National Cancer Institute, National Institutes of Health; Rockville Maryland
- Core Genotyping Facility, Advanced Technology Center, National Cancer Institute, NIH, DHHS; Gaithersburg Maryland
| | - Nathaniel Rothman
- Division of Cancer Epidemiology and Genetics, Department of Health and Human Services; National Cancer Institute, National Institutes of Health; Rockville Maryland
| | - Yawei Zhang
- Yale University School of Public Health; New Haven Connecticut
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Occupational solvent exposure, genetic variation of DNA repair genes, and the risk of non-Hodgkin's lymphoma. Eur J Cancer Prev 2013; 21:580-4. [PMID: 22430443 DOI: 10.1097/cej.0b013e328351c762] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The main objective of this study was to test the hypothesis that genetic variations in DNA repair genes may modify the association between occupational exposure to solvents and the risk of non-Hodgkin's lymphoma (NHL). A population-based case-control study was conducted on Connecticut women including 518 histologically confirmed incident NHL cases and 597 controls. Unconditional logistic regression models were used to estimate the odds ratios and effect modification from the 30 single nucleotide polymorphisms in 16 DNA repair genes of the association between solvent exposure and the risk of NHL overall and subtypes. Single nucleotide polymorphisms in MGMT (rs12917) and NBS1 (rs1805794) significantly modified the association between exposure to chlorinated solvents and the risk of NHL (Pfor interaction=0.0003 and 0.0048, respectively). After stratification by major NHL histological subtypes, MGMT (rs12917) modified the association between chlorinated solvents and the risk of diffuse large B-cell lymphoma (Pfor interaction=0.0027) and follicular lymphoma (Pfor interaction=0.0024). A significant interaction was also observed between occupational exposure to benzene and BRCA2 (rs144848) for NHL overall (Pfor interaction=0.0042). Our study results suggest that genetic variations in DNA repair genes modify the association between occupational exposure to solvents and the risk of NHL.
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Christmann M, Kaina B. O(6)-methylguanine-DNA methyltransferase (MGMT): impact on cancer risk in response to tobacco smoke. Mutat Res 2012; 736:64-74. [PMID: 21708177 DOI: 10.1016/j.mrfmmm.2011.06.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Revised: 05/23/2011] [Accepted: 06/08/2011] [Indexed: 05/31/2023]
Abstract
Tobacco, smoked, snuffed and chewed, contains powerful mutagens and carcinogens. At least three of them, N-dimethylnitrosamine, N'-nitrosonornicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, attack DNA at the O(6)-position of guanine. The resulting O(6)-alkylguanine adducts are repaired by the suicide enzyme O(6)-methylguanine-DNA methyltransferase (MGMT), which is known to protect against the mutagenic, genotoxic and carcinogenic effects of monofunctional alkylating agents. While in rat liver MGMT was shown to be subject to regulation by genotoxic stress leading to adaptive changes in its activity, in humans evidence of adaptive modulation of MGMT levels is still lacking. Several polymorphisms are known, which are suspected to impact on the risk of developing cancer. In this review we focus on three questions: (a) Has tobacco consumption by smoking or chewing an impact on MGMT expression and MGMT promoter methylation in normal and tumor tissue? (b) Is there an association between MGMT polymorphisms and cancer risk and is this risk related to smoking? (c) Does MGMT protect against tobacco-associated cancer? There are several lines of evidence for an increase of MGMT activity in the normal tissue of smokers compared to non-smokers. Furthermore, in tumors developed in smokers a tendency towards an increase of MGMT expression was found. The data points to the possibility that agents in tobacco smoke are able to trigger upregulation of MGMT in normal and tumor tissue. For MGMT promoter methylation data is conflicting. There is some evidence for an association between MGMT polymorphisms and smoking-induced cancer risk. The key question whether or not MGMT protects against tobacco smoke-induced cancer is difficult to answer since prospective studies on smokers versus non-smokers are lacking and appropriate animal studies with MGMT transgenic mice exposed to the complex mixture of tobacco smoke have not been performed, which indicates the need for further explorations.
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Affiliation(s)
- Markus Christmann
- Institute of Toxicology, University Medical Center Mainz, Mainz, Germany.
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Shah MA, Shaffi SM, Lone GN, Jan SM. Lack of Influence of MGMT Codon Leu84Phe and Codon Ileu143Val Polymorphisms on Esophageal Cancer Risk in the Kashmir Valley. Asian Pac J Cancer Prev 2012. [DOI: 10.7314/apjcp.2012.13.7.3047] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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Chuang SC, Agudo A, Ahrens W, Anantharaman D, Benhamou S, Boccia S, Chen C, Conway DI, Fabianova E, Hayes RB, Healy CM, Holcatova I, Kjaerheim K, Lagiou P, Lazarus P, Macfarlane TV, Mahimkar MB, Mates D, Matsuo K, Merletti F, Metspalu A, Morgenstern H, Muscat J, Cadoni G, Olshan AF, Purdue M, Ramroth H, Rudnai P, Schwartz SM, Simonato L, Smith EM, Sturgis EM, Szeszenia-Dabrowska N, Talamini R, Thomson P, Wei Q, Zaridze D, Zhang ZF, Znaor A, Brennan P, Boffetta P, Hashibe M. Sequence Variants and the Risk of Head and Neck Cancer: Pooled Analysis in the INHANCE Consortium. Front Oncol 2011; 1:13. [PMID: 22655231 PMCID: PMC3356135 DOI: 10.3389/fonc.2011.00013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2011] [Accepted: 06/13/2011] [Indexed: 01/22/2023] Open
Abstract
Previous molecular epidemiological studies on head and neck cancer have examined various single nucleotide polymorphisms (SNPs), but there are very few documented associations. In the International head and neck cancer epidemiology (INHANCE) consortium, we evaluated associations between SNPs in the metabolism, cell cycle, and DNA repair pathways and the risk of head and neck cancer. We analyzed individual-level pooled data from 14 European, North American, Central American, and Asia case-control studies (5,915 head and neck cancer cases and 10,644 controls) participating in the INHANCE consortium. Unconditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for SNP effects, adjusting for age, sex, race, and country. We observed an association between head and neck cancer risk and MGMT Leu84Phe heterozygotes (OR = 0.79, 95% CI = 0.68-0.93), XRCC1 Arg194Trp homozygotes Arg/Arg (OR = 2.3, 95% CI = 1.1-4.7), ADH1B Arg48His homozygotes Arg/Arg (OR = 2.7, 95% CI = 1.9-4.0), ADH1C Ile350Val homozygotes Ile/Ile (OR = 1.2, 95% CI = 1.1-1.4), and the GSTM1 null genotype (OR = 1.1, 95% CI = 1.0-1.2). Among these results, MGMT Leu84Phe, ADH1B Arg48His, ADH1C Ile350Arg, and the GSTM1 null genotype had fairly low false positive report probabilities (<20%). We observed associations between ADH1B Arg48His, ADH1C Ile350Arg, and GSTM1 null genotype and head and neck cancer risk. No functional study currently supports the observed association for MGMT Leu84Phe, and the association with XRCC1 Arg194Trp may be a chance finding.
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Affiliation(s)
- Shu-Chun Chuang
- Lifestyle and Cancer Group, International Agency for Research on CancerLyon, France
- Department of Epidemiology and Biostatistics, Imperial College LondonLondon, UK
| | - Antonio Agudo
- Catalan Institute of Oncology, Bellvitge Biomedical Research Institute, Hospitalet de LlobregatBarcelona, Spain
| | - Wolfgang Ahrens
- Bremen Institute for Prevention Research and Social MedicineBremen, Germany
| | - Devasena Anantharaman
- Cancer Research Institute, Advanced Centre for Treatment, Research, and Education in Cancer, Tata Memorial CenterMumbai, India
| | | | - Stefania Boccia
- Institute of Hygiene, Università Cattolica del Sacro CuoreRome, Italy
- Istituto di Ricovero e Cura a Carattere Scientifico San Raffaele PisanaRome, Italy
| | - Chu Chen
- Fred Hutchinson Cancer Research CenterSeattle, WA, USA
| | - David I. Conway
- Dental School, College of Medical, Veterinary and Life Sciences, University of GlasgowGlasgow, UK
| | - Eleonora Fabianova
- Department of Occupational Health, Specialized State Health InstituteBanská Bystrica, Slovakia
| | | | - Claire M. Healy
- School of Dental Science, Trinity College DublinDublin, Ireland
| | - Ivana Holcatova
- First Faculty of Medicine, Institute of Hygiene and Epidemiology, Charles UniversityPrague, Czech Republic
| | - Kristina Kjaerheim
- Cancer Registry of Norway, Institute for Population-Based Cancer ResearchOslo, Norway
| | - Pagona Lagiou
- Department of Hygiene, Epidemiology and Medical Statistics, School of Medicine, University of AthensAthens, Greece
| | | | | | - Manoj B. Mahimkar
- Cancer Research Institute, Advanced Centre for Treatment, Research, and Education in Cancer, Tata Memorial CenterMumbai, India
| | - Dana Mates
- Occupational Health Department, Institute of Public HealthBucharest, Romania
| | - Keitaro Matsuo
- Division of Epidemiology and Prevention, Aichi Cancer Center Research InstituteNagoya, Japan
| | | | - Andres Metspalu
- Laboratory of Gene Technology, Estonian BiocentreTartu, Estonia
| | - Hal Morgenstern
- Department of Epidemiology, Comprehensive Cancer Center, University of MichiganAnn Arbor, MI, USA
- Department of Environmental Health Sciences, Comprehensive Cancer Center, University of MichiganAnn Arbor, MI, USA
| | | | - Gabriella Cadoni
- Institute of Otorhinolaryngology, Catholic University of the Sacred HeartRome, Italy
| | - Andrew F. Olshan
- School of Public Health, University of North CarolinaChapel Hill, NC, USA
| | | | - Heribert Ramroth
- Institute of Public Health, University of HeidelbergHeidelberg, Germany
| | - Peter Rudnai
- Fodor József National Center for Public Health, National Institute of Environmental HealthBudapest, Hungary
| | | | - Lorenzo Simonato
- Department of Environmental Medicine and Public Health, University of PadovaPadova, Italy
| | - Elaine M. Smith
- College of Public Health, University of IowaIowa City, IA, USA
| | | | | | | | - Peter Thomson
- Oral and Maxillofacial Surgery School of Dental Sciences, Newcastle UniversityNewcastle, UK
| | - Qingyi Wei
- University of Texas MD Anderson Cancer CenterHouston, TX, USA
| | - David Zaridze
- Cancer Research Centre, Institute of CarcinogenesisMoscow, Russia
| | - Zuo-Feng Zhang
- Department of Epidemiology, University of California Los Angeles, School of Public HealthLos Angeles, CA, USA
| | - Ariana Znaor
- Croatian National Cancer Registry, Croatian National Institute of Public HealthZagreb, Croatia
| | - Paul Brennan
- Lifestyle and Cancer Group, International Agency for Research on CancerLyon, France
| | - Paolo Boffetta
- Lifestyle and Cancer Group, International Agency for Research on CancerLyon, France
- The Tisch Cancer Institute, Mount Sinai School of MedicineNew York, NY, USA
- International Prevention Research InstituteLyon, France
| | - Mia Hashibe
- Lifestyle and Cancer Group, International Agency for Research on CancerLyon, France
- Department of Family and Preventive Medicine, University of Utah School of MedicineSalt Lake City, UT, USA
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18
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Lau Q, Scheithauer B, Kovacs K, Horvath E, Syro LV, Lloyd R. MGMT immunoexpression in aggressive pituitary adenoma and carcinoma. Pituitary 2010; 13:367-79. [PMID: 20740317 DOI: 10.1007/s11102-010-0249-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Recent case reports have documented the efficacy of temozolomide therapy in some aggressive pituitary adenomas and pituitary carcinomas resistant to multimodality therapy. Evidence suggests that low O6-methylguanine-DNA methyltransferase (MGMT) immunoexpression correlates with response to temozolomide chemotherapy. Herein, we aimed to study MGMT immunoexpression in a spectrum of pituitary tumors, indolent, aggressive and malignant. A literature review of the use of temozolomide in pituitary tumors was also performed. Immunohistochemistry for MGMT was performed on 60 pituitary tumors identified in the Mayo Clinic Tissue Registry and the consultation files of one of us (BWS). The group included 30 pituitary carcinomas (15 ACTH, 10 PRL, 1 FSH/LH, 1 TSH, 1 silent subtype 3 and 2 null cell). Tissue from recurrences was available in 17 cases. In addition, 30 functionally different pituitary adenomas were studied, including 15 invasive and 15 non-invasive adenomas. Overall, 32 cases of pituitary tumors (54%) demonstrated low MGMT immunoexpression. This included 17 of 30 (57%) carcinomas, 9 of 15 (60%) invasive adenomas, and 6 of 15 cases (40%) of non-invasive pituitary adenomas. There was no significant change in MGMT immunoexpression between primary and recurrent tumors. Prolactin-producing carcinomas had the highest proportion of tumors (80%) with low expression. A significant proportion of pituitary adenomas and carcinomas demonstrate low MGMT immunoexpression. In an effort to anticipate the likelihood of a temozolomide response, all cases of aggressive pituitary tumors should be assessed for MGMT expression.
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Affiliation(s)
- Queenie Lau
- Department of Anatomical Pathology and Cytopathology, Royal Brisbane and Women's Hospital and Gold Coast Hospital, Queensland, Australia
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19
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Shi JY, Ren ZH, Jiao B, Xiao R, Yun HY, Chen B, Zhao WL, Zhu Q, Chen Z, Chen SJ. Genetic variations of DNA repair genes and their prognostic significance in patients with acute myeloid leukemia. Int J Cancer 2010; 128:233-8. [DOI: 10.1002/ijc.25318] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Huang SH, Chang PY, Liu CJ, Lin MW, Hsia KT. O6-methylguanine-DNA methyltransferase gene coding region polymorphisms and oral cancer risk. J Oral Pathol Med 2010; 39:645-50. [DOI: 10.1111/j.1600-0714.2009.00880.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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21
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Polymorphisms of the DNA repair gene MGMT and risk and progression of head and neck cancer. DNA Repair (Amst) 2010; 9:558-66. [PMID: 20206583 DOI: 10.1016/j.dnarep.2010.02.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Revised: 01/27/2010] [Accepted: 02/05/2010] [Indexed: 11/22/2022]
Abstract
Methylating agents are involved in carcinogenesis, and the DNA repair protein O(6)-methylguanine-DNA methyltransferase (MGMT) removes methyl group from O(6)-methylguanine. Genetic variation in DNA repair genes has been shown to contribute to susceptibility to squamous cell carcinoma of the head and neck (SCCHN). We hypothesize that MGMT polymorphisms are associated with risk of SCCHN. In a hospital-based case-control study of 721 patients with SCCHN and 1234 cancer-free controls frequency-matched by age, sex and ethnicity, we genotyped four MGMT polymorphisms, two in exon 3, 16195C>T and 16286C>T and two in the promoter region, 45996G>T and 46346C>A. We found that none of these polymorphisms alone had a significant effect on risk of SCCHN. However, when these four polymorphisms were evaluated together by the number of putative risk genotypes (i.e. 16195CC, 16286CC, 45996GT+TT, and 46346CA+AA), a statistically significantly increased risk of SCCHN was associated with the combined genotypes with three to four risk genotypes, compared with those with zero to two risk genotypes (adjusted odds ratio (OR)=1.27; 95% confidence interval (CI)=1.05-1.53). This increased risk was also more pronounced among young subjects (OR=1.81; 95% CI=1.11-2.96), men (OR=1.24; 95% CI=1.00-1.55), ever smokers (OR=1.25; 95%=1.01-1.56), ever drinkers (OR=1.29; 95% CI=1.04-1.60), patients with oropharyngeal cancer (OR=1.45; 95% CI=1.12-1.87), and oropharyngeal cancer with regional lymph node metastasis (OR=1.52; 95% CI=1.16-1.89). In conclusion, our results suggest that any one of MGMT variants may not have a substantial effect on SCCHN risk, but a joint effect of several MGMT variants may contribute to risk and progression of SCCHN, particularly for oropharyngeal cancer, in non-Hispanic whites.
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Loh YH, Mitrou PN, Bowman R, Wood A, Jeffery H, Luben RN, Lentjes MAH, Khaw KT, Rodwell SA. MGMT Ile143Val polymorphism, dietary factors and the risk of breast, colorectal and prostate cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk study. DNA Repair (Amst) 2010; 9:421-8. [PMID: 20096652 DOI: 10.1016/j.dnarep.2010.01.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2009] [Revised: 12/24/2009] [Accepted: 01/01/2010] [Indexed: 11/28/2022]
Abstract
O(6)-Methylguanine-DNA methyltransferase (MGMT) repairs DNA damage caused by alkylating agents including N-nitroso compounds from diet. MGMT Ile143Val polymorphism may lead to less DNA damage repair and increased cancer risk depending on the environmental exposures. We investigated interactions between dietary factors and the MGMT Ile143Val polymorphism in relation to breast, colorectal and prostate cancer risk. There were 276/1498, 273/2984 and 312/1486 cases/controls for the breast, colorectal and prostate cancer studies respectively; all nested within the EPIC-Norfolk study, a prospective cohort of approximately 25,000 men and women aged 40-79. Baseline 7-day food diary data were collected for dietary assessment. MGMT Ile143Val polymorphism was not overall associated with breast, colorectal and prostate cancer risk. There was a significant interaction between this polymorphism and intake of red and processed meat on colorectal cancer risk (P(interaction)=0.04) suggesting an increased risk among carriers of the variant genotype compared to the MGMT Ile143Ile common genotype. A lower colorectal cancer risk was seen with higher intake of vitamin E and carotene among the variant genotype group but not in the common genotype group (P(interaction)=0.009 and P(interaction)=0.005 for vitamin E and carotene, respectively). A higher prostate cancer risk was seen with higher alcohol intake among the variant genotype (OR=2.08, 95% CI=1.21-3.57, P(interaction)=0.0009) compared to the common genotype with lower alcohol intake. In this UK population, the MGMT Ile143Val polymorphism was not overall associated with breast, colorectal and prostate cancer risk. There was evidence for this polymorphism playing a role in modulating the risk of prostate cancer in presence of alcohol. For colorectal cancer, the MGMT Ile143Val polymorphism may confer increased or decreased risk depending on the dietary exposure.
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Affiliation(s)
- Yet Hua Loh
- MRC Centre for Nutritional Epidemiology in Cancer Prevention and Survival, Department of Public Health and Primary Care, University of Cambridge, Worts Causeway, United Kingdom.
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23
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Felsberg J, Rapp M, Loeser S, Fimmers R, Stummer W, Goeppert M, Steiger HJ, Friedensdorf B, Reifenberger G, Sabel MC. Prognostic significance of molecular markers and extent of resection in primary glioblastoma patients. Clin Cancer Res 2009; 15:6683-93. [PMID: 19861461 DOI: 10.1158/1078-0432.ccr-08-2801] [Citation(s) in RCA: 158] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Despite multimodal aggressive treatment glioblastoma patients still face a rather poor prognosis. Recent data indicate that certain molecular markers, in particular MGMT promoter hypermethylation, are associated with response to alkylating chemotherapy and longer survival. The clinical significance of other glioblastoma-associated molecular aberrations and their relationship to MGMT promoter hypermethylation is still poorly understood. EXPERIMENTAL DESIGN We conducted a translational study involving 67 newly diagnosed glioblastoma patients treated at our institution from 1998 to 2004. All patients were treated by open resection, followed by radiotherapy and adjuvant temozolomide chemotherapy. The tumors were investigated for MGMT promoter methylation, mRNA and protein expression, as well as presence of MGMT sequence polymorphisms. In addition, we screened for genetic aberrations of the EGFR, TP53, CDK4, MDM2, and PDGFRA genes as well as allelic losses on chromosomal arms 1p, 10q, and 19q. RESULTS Correlation of molecular findings with clinical data revealed significantly longer time to progression after onset of chemotherapy and longer overall survival of patients with MGMT-hypermethylated tumors. In contrast, MGMT protein expression, MGMT polymorphisms, and aberrations in any of the other genes and chromosomes were not significantly linked to patient outcome. Multivariate analysis identified MGMT promoter hypermethylation and near-complete tumor resection as the most important parameters associated with better prognosis. CONCLUSION Our study provides novel insights into the significance of molecular and clinical markers in predicting the prognosis of glioblastoma patients, which may improve stratification of patients into distinct prognostic subgroups.
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MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Biomarkers, Tumor/analysis
- Brain Neoplasms/genetics
- Brain Neoplasms/surgery
- Brain Neoplasms/therapy
- Chromosomes, Human, Pair 1
- Chromosomes, Human, Pair 10
- Chromosomes, Human, Pair 19
- Combined Modality Therapy
- DNA Methylation
- DNA Modification Methylases/analysis
- DNA Modification Methylases/genetics
- DNA Repair Enzymes/analysis
- DNA Repair Enzymes/genetics
- Female
- Glioblastoma/genetics
- Glioblastoma/surgery
- Glioblastoma/therapy
- Humans
- Loss of Heterozygosity
- Male
- Middle Aged
- Mutation
- Polymorphism, Single Nucleotide
- Prognosis
- Promoter Regions, Genetic
- RNA, Messenger/metabolism
- Survival Analysis
- Tumor Suppressor Proteins/analysis
- Tumor Suppressor Proteins/genetics
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Affiliation(s)
- Jörg Felsberg
- Department of Neuropathology, Heinrich-Heine-University, Düsseldorf, Germany
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Akbari MR, Malekzadeh R, Shakeri R, Nasrollahzadeh D, Foumani M, Sun Y, Pourshams A, Sadjadi A, Jafari E, Sotoudeh M, Kamangar F, Boffetta P, Dawsey SM, Ghadirian P, Narod SA. Candidate gene association study of esophageal squamous cell carcinoma in a high-risk region in Iran. Cancer Res 2009. [PMID: 19826048 DOI: 10.1158/0008-5472.can-09- 1149] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
There is a region with a high risk for esophageal squamous cell carcinoma (ESCC) in the northeast of Iran. Previous studies suggest that hereditary factors play a role in the high incidence of cancer in the region. We selected 22 functional variants (and 130 related tagSNPs) from 15 genes that have been associated previously with the risk of ESCC. We genotyped a primary set of samples from 451 Turkmens (197 cases and 254 controls). Seven of 152 variants were associated with ESCC at the P = 0.05 level; these single nucleotide polymorphisms were then studied in a validation set of 549 cases and 1,119 controls, which included both Turkmens and non-Turkmens. The association observed for a functional variant in ADH1B was confirmed in the validation set, and that of a tagSNP in MGMT, the association was borderline significant in the validation set, after correcting for multiple testing. The other 5 variants that were associated in the primary set were not significantly associated in the validation set. The histidine allele at codon 48 of ADH1B gene was associated with a significantly decreased risk of ESCC in the joint data set (primary and validation set) under a recessive model (odds ratio, 0.41; 95% confidence interval, 0.29-0.76; P = 4 x 10(-4)). The A allele of the rs7087131 variant of MGMT gene was associated with a decreased risk of ESCC under a dominant model (odds ratio, 0.79; 95% confidence interval, 0.64-0.96; P = 0.02). These results support the hypothesis that genetic predisposition plays a role in the high incidence of ESSC in Iran.
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Affiliation(s)
- Mohammad R Akbari
- Digestive Disease Research Center, Tehran University of Medical Sciences, Tehran, Iran
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25
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Akbari MR, Malekzadeh R, Shakeri R, Nasrollahzadeh D, Foumani M, Sun Y, Pourshams A, Sadjadi A, Jafari E, Sotoudeh M, Kamangar F, Boffetta P, Dawsey SM, Ghadirian P, Narod SA. Candidate gene association study of esophageal squamous cell carcinoma in a high-risk region in Iran. Cancer Res 2009; 69:7994-8000. [PMID: 19826048 DOI: 10.1158/0008-5472.can-09-1149] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
There is a region with a high risk for esophageal squamous cell carcinoma (ESCC) in the northeast of Iran. Previous studies suggest that hereditary factors play a role in the high incidence of cancer in the region. We selected 22 functional variants (and 130 related tagSNPs) from 15 genes that have been associated previously with the risk of ESCC. We genotyped a primary set of samples from 451 Turkmens (197 cases and 254 controls). Seven of 152 variants were associated with ESCC at the P = 0.05 level; these single nucleotide polymorphisms were then studied in a validation set of 549 cases and 1,119 controls, which included both Turkmens and non-Turkmens. The association observed for a functional variant in ADH1B was confirmed in the validation set, and that of a tagSNP in MGMT, the association was borderline significant in the validation set, after correcting for multiple testing. The other 5 variants that were associated in the primary set were not significantly associated in the validation set. The histidine allele at codon 48 of ADH1B gene was associated with a significantly decreased risk of ESCC in the joint data set (primary and validation set) under a recessive model (odds ratio, 0.41; 95% confidence interval, 0.29-0.76; P = 4 x 10(-4)). The A allele of the rs7087131 variant of MGMT gene was associated with a decreased risk of ESCC under a dominant model (odds ratio, 0.79; 95% confidence interval, 0.64-0.96; P = 0.02). These results support the hypothesis that genetic predisposition plays a role in the high incidence of ESSC in Iran.
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Affiliation(s)
- Mohammad R Akbari
- Digestive Disease Research Center, Tehran University of Medical Sciences, Tehran, Iran
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McCormack AI, McDonald KL, Gill AJ, Clark SJ, Burt MG, Campbell KA, Braund WJ, Little NS, Cook RJ, Grossman AB, Robinson BG, Clifton-Bligh RJ. Low O6-methylguanine-DNA methyltransferase (MGMT) expression and response to temozolomide in aggressive pituitary tumours. Clin Endocrinol (Oxf) 2009; 71:226-33. [PMID: 19067722 DOI: 10.1111/j.1365-2265.2008.03487.x] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
CONTEXT Recent case reports detail the successful use of temozolomide in the management of aggressive pituitary tumours. O(6)-methylguanine-DNA methyltransferase (MGMT) is a DNA repair protein that counteracts the effect of temozolomide. OBJECTIVE To study MGMT expression in pituitary tumours and consider whether MGMT expression is associated with response to temozolomide therapy in aggressive pituitary tumours. PATIENTS We report two patients with aggressive pituitary tumours treated with temozolomide, one who responded to temozolomide and the other who did not. MGMT expression was assessed in a further 88 archived pituitary tumour samples. DESIGN MGMT expression was assessed by immunohistochemistry. MGMT promoter methylation was studied by methylation-specific polymerase chain reaction (MSP), sequencing of MGMT was performed and loss of heterozygosity (LOH) analysis undertaken. RESULTS Low MGMT expression and MGMT promoter methylation were found in the pituitary tumour of the patient who responded to temozolomide. Conversely, high MGMT expression was seen in the patient demonstrating a poor response to temozolomide. Eleven out of 88 archived tumour samples (13%) had low MGMT expression. Prolactinomas were more likely to have low MGMT expression compared with other pituitary tumour subtypes (P < 0.001). There was no significant difference in MGMT expression between invasive and noninvasive tumours, or between recurrent and nonrecurrent tumours. A significant inverse correlation was found between MGMT expression and promoter methylation (P = 0.012). CONCLUSION MGMT expression as assessed by immunohistochemistry may predict response to temozolomide therapy in patients with aggressive pituitary tumours. MGMT promoter methylation is likely to explain low MGMT expression in some, but not all, pituitary tumours.
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Affiliation(s)
- Ann I McCormack
- Kolling Institute of Medical Research, Royal North Shore Hospital, Sydney, NSW, Australia.
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The associations of sequence variants in DNA-repair and cell-cycle genes with cancer risk: genotype–phenotype correlations. Biochem Soc Trans 2009; 37:527-33. [DOI: 10.1042/bst0370527] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
DNA-repair systems maintain the integrity of the human genome, and cell-cycle checkpoints are a critical component of the cellular response to DNA damage. Thus the presence of sequence variants in genes involved in these pathways that modulate their activity might have an impact on cancer risk. Many molecular epidemiological studies have investigated the association between sequence variants, particularly SNPs (single nucleotide polymorphisms), and cancer risk. For instance, ATM (ataxia telangiectasia mutated) SNPs have been associated with increased risk of breast, prostate, leukaemia, colon and early-onset lung cancer, and the intron 3 16-bp repeat in TP53 (tumour protein 53) is associated with an increased risk of lung cancer. In contrast, the variant allele of the rare CHEK2 (checkpoint kinase 2 checkpoint homologue) missense variant (accession number rs17879961) was significantly associated with a lower incidence of lung and upper aerodigestive cancers. For some sequence variants, a strong gene–environment interaction has also been noted. For instance, a greater absolute risk reduction of lung and upper aerodigestive cancers in smokers than in non-smokers carrying the I157T CHEK2 variant has been observed, as has an interaction between TP53 intron 3 16-bp repeats and multiple X-ray exposures on lung cancer risk. The challenge now is to understand the molecular mechanisms underlying these associations.
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Gu F, Qureshi AA, Kraft P, Guo Q, Hunter DJ, Han J. Polymorphisms in genes involved in DNA repair, cell growth, oxidative stress and inflammatory response, and melanoma risk. Br J Dermatol 2009; 161:209-12. [PMID: 19438866 DOI: 10.1111/j.1365-2133.2009.09219.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Liu Y, Scheurer ME, El-Zein R, Cao Y, Do KA, Gilbert M, Aldape KD, Wei Q, Etzel C, Bondy ML. Association and interactions between DNA repair gene polymorphisms and adult glioma. Cancer Epidemiol Biomarkers Prev 2009; 18:204-14. [PMID: 19124499 DOI: 10.1158/1055-9965.epi-08-0632] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
It is generally accepted that glioma develops through accumulation of genetic alterations. We hypothesized that polymorphisms of candidate genes involved in the DNA repair pathways may contribute to susceptibility to glioma. To address this possibility, we conducted a study on 373 Caucasian glioma cases and 365 cancer-free Caucasian controls to assess associations between glioma risk and 18 functional single-nucleotide polymorphisms in DNA repair genes. We evaluated potential gene-gene and gene-environment interactions using a multianalytic strategy combining logistic regression, multifactor dimensionality reduction and classification and regression tree approaches. In the single-locus analysis, six single-nucleotide polymorphisms [ERCC1 3' untranslated region (UTR), XRCC1 R399Q, APEX1 E148D, PARP1 A762V, MGMT F84L, and LIG1 5'UTR] showed a significant association with glioma risk. In the analysis of cumulative genetic risk of multiple single-nucleotide polymorphisms, a significant gene-dosage effect was found for increased glioma risk with increasing numbers of adverse genotypes involving the aforementioned six single-nucleotide polymorphisms (P(trend) = 0.0004). Furthermore, the multifactor dimensionality reduction and classification and regression tree analyses identified MGMT F84L as the predominant risk factor for glioma and revealed strong interactions among ionizing radiation exposure, PARP1 A762V, MGMT F84L, and APEX1 E148D. Interestingly, the risk for glioma was dramatically increased in ionizing radiation exposure individuals who had the wild-type genotypes of MGMT F84L and PARP1 A762V (adjusted odds ratios, 5.95; 95% confidence intervals, 2.21-16.65). Taken together, these results suggest that polymorphisms in DNA repair genes may act individually or together to contribute to glioma risk.
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Affiliation(s)
- Yanhong Liu
- Department of Epidemiology, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA
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Zhang M, Huang WY, Andreotti G, Gao YT, Rashid A, Chen J, Sakoda LC, Shen MC, Wang BS, Chanock S, Hsing AW. Variants of DNA repair genes and the risk of biliary tract cancers and stones: a population-based study in China. Cancer Epidemiol Biomarkers Prev 2008; 17:2123-7. [PMID: 18708406 DOI: 10.1158/1055-9965.epi-07-2735] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Biliary tract cancers, which encompass tumors of the gallbladder, extrahepatic ducts, and ampulla of Vater, are relatively rare tumors with a high fatality rate. Other than a close link with gallstones, the etiology of biliary tract cancers is poorly understood. We conducted a population-based case-control study in Shanghai, China, to examine whether genetic variants in several DNA repair genes are associated with biliary tract cancers or biliary stones. Genomic DNA from 410 patients with biliary tract cancers (236 gallbladder, 127 bile duct, and 47 ampulla of Vater), 891 patients with biliary stones, and 786 healthy subjects randomly selected from the Shanghai population were genotyped for putative functional single nucleotide polymorphisms in four DNA repair genes (MGMT, RAD23B, CCNH, and XRCC3). Of the five single nucleotide polymorphisms examined, only one (MGMT EX5-25C>T, rs12917) was associated with biliary tract cancer. Independent of gallstones, subjects carrying the CT genotype of the MGMT EX5-25C>T marker had a significantly reduced risk of gallbladder cancer [odds ratio (OR), 0.63; 95% confidence interval (95% CI), 0.41-0.97; P = 0.02] and nonsignificant reduced risks of bile duct (OR, 0.61; 95% CI, 0.35-1.06) and ampulla of Vater (OR, 0.85; 95% CI, 0.39-1.87) cancers. However, this marker was not associated with biliary stones, and the other markers examined were not significantly associated with either biliary tract cancers or stones. Findings from this population-based study in Shanghai suggest that MGMT gene variants may alter susceptibility to biliary tract cancer, particularly gallbladder cancer. Confirmation in future studies, however, is required.
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Remington M, Chtchetinin J, Ancheta K, Nghiemphu PL, Cloughesy T, Lai A. The L84F polymorphic variant of human O6-methylguanine-DNA methyltransferase alters stability in U87MG glioma cells but not temozolomide sensitivity. Neuro Oncol 2008; 11:22-32. [PMID: 18812520 DOI: 10.1215/15228517-2008-080] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
First-line therapy for patients with glioblastoma multiforme includes treatment with radiation and temozolomide (TMZ), an oral DNA alkylating chemotherapy. Sensitivity of glioma cells to TMZ is dependent on the level of cellular O(6)-methylguanine-DNA methyltransferase (MGMT) repair activity. Several common coding-region polymorphisms in the MGMT gene (L84F and the linked pair I143V/K178R) modify functional characteristics of MGMT and cancer risk. To determine whether these polymorphic changes influence the ability of MGMT to protect glioma cells from TMZ, we stably overexpressed enhanced green fluorescent protein (eGFP)-tagged MGMT constructs in U87MG glioma cells. We confirmed that the wild-type (WT) eGFP-MGMT protein is properly localized within the nucleus and found that L84F, I143V/K178R, and L84F/I143V/K178R eGFP-MGMT variants exhibited nuclear localization patterns indistinguishable from WT. Using MTT [3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide] proliferation and clonogenic survival assays, we confirmed that WT cells expressing eGFP-MGMT are resistant to TMZ treatment compared with control U87MG cells, and that each of the polymorphic eGFP-MGMT variants confers similar resistance to TMZ. However, upon exposure to O(6)-benzylguanine (O(6)-BG), a synthetic MGMT inhibitor, the L84F and L84F/I143V/K178R variants were degraded more rapidly than WT or I143V/K178R in a proteasome-dependent manner. Despite the increased O(6)-BG- stimulated protein turnover caused by the L84F alteration, cells expressing L84F eGFP-MGMT did not exhibit altered sensitivity to the combination of O(6)-BG and TMZ compared with WT cells. In conclusion, we demonstrated that the L84F polymorphic variant has altered protein turnover without modifying sensitivity of U87MG cells to TMZ or combined TMZ and O(6)-BG. These findings may provide a clue to determining the clinical significance of MGMT coding-region polymorphisms.
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Affiliation(s)
- Maya Remington
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
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Stern MC, Conti DV, Siegmund KD, Corral R, Yuan JM, Koh WP, Yu MC. DNA repair single-nucleotide polymorphisms in colorectal cancer and their role as modifiers of the effect of cigarette smoking and alcohol in the Singapore Chinese Health Study. Cancer Epidemiol Biomarkers Prev 2008; 16:2363-72. [PMID: 18006925 DOI: 10.1158/1055-9965.epi-07-0268] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Recently, we reported that among Singapore Chinese, cigarette smoking and alcohol drinking were independent risk factors for colorectal cancer. Both tobacco smoking and alcohol use are plausible colorectal cancer risk factors, partly due to their ability to induce mutations in the colorectal lumen. In the present study, we investigated the role in colorectal cancer of single-nucleotide polymorphisms in five DNA repair genes: XRCC1 (Arg(194)Trp and Arg(399)Gln), PARP (Val(762)Ala, Lys(940)Arg), XPD (Asp(312)Asn, Lys(751)Gln), OGG1 (Ser(326)Cys), and MGMT (Leu(84)Phe). We conducted this study within the Singapore Chinese Health Study, a population-based cohort of 63,257 middle-aged and older Singapore Chinese men and women enrolled between 1993 and 1998. Our study included 1,176 controls and 310 cases (180 colon and 130 rectum cancer). We observed a positive association between the PARP codon 940 Lys/Arg and Arg/Arg genotypes and colorectal cancer risk [odds ratio (OR), 1.8; 95% confidence interval (95% CI), 1.1-3.1], and an inverse association between the MGMT codon 84 Leu/Phe or Phe/Phe genotypes and colon cancer risk (OR, 0.6; 95% CI, 0.3-0.9), but not rectal cancer (test of heterogeneity by tumor site, P=0.027). We observed evidence that XRCC1 may modify the effects of smoking (interaction P=0.012). The effect of smoking among carriers of the Arg(194)-Gln(399) haplotype was OR=0.7 (95% CI, 0.4-1.1), whereas, among carriers of the Trp(194)-Arg(399) haplotype, it was OR=1.6 (95% CI, 1.1-2.5). We also observed a nonstatistically significant modification of XRCC1 on the effects of alcohol (P=0.245). Whereas alcohol had no effect among carriers of the codon 194 Arg/Arg (OR, 1.0; 95% CI, 0.6-1.7) or Arg/Trp genotypes (OR, 1.1; 95% CI, 0.6-1.9), there was a positive association among carriers of the Trp/Trp genotype (OR, 2.8; 95% CI, 1.0-8.1). Our results support a role for reactive oxygen species as relevant genotoxins that may account for the effects of both smoking and alcohol on colorectal cancer risk.
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Affiliation(s)
- Mariana C Stern
- Department of Preventive Medicine, Keck School of Medicine, Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Avenue, Room 5421A, Los Angeles, CA 90089, USA.
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Ishida E, Nakamura M, Shimada K, Higuchi T, Takatsu K, Yane K, Konishi N. DNA hypermethylation status of multiple genes in papillary thyroid carcinomas. Pathobiology 2007; 74:344-52. [PMID: 18087199 DOI: 10.1159/000110028] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2007] [Accepted: 08/17/2007] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE The aim of this study was hypermethylation of multiple genes for papillary thyroid carcinomas (PTCs). METHODS We examined 39 lesions using methylation-specific PCR to assess hypermethylation in genes, including p16(INK4a), p14(ARF), RB1, p27(Kip1)and 0(6)-MGMT. Homozygous deletions of p16(INK4a) and p14(ARF) were investigated by differential PCR, all with reference to clinicopathological factors. RESULTS We found methylation of p16(INK4a) in 35.9% (14/39); p14(ARF) in 2.6% (1/39); RB1 in 23.1% (9/39); p27(Kip1) in 15.4% (6/39),and 0(6)-MGMT in 15.4% (6/39). Hypermethylation of at least one of these genes was apparent in 66.7% (26/39). Homozygous deletions of p14(ARF) and p16(INK4a) were detected in 7.7 (3/39) and 2.6% (1/39), respectively. In cases with p16(INK4a) alterations, tumors were significantly increased. A history of chronic thyroid disease and lymphocytic infiltration was significantly associated with p14(ARF) alterations, without regional lymph node metastases. CONCLUSIONS Our data suggest that alterations in p16(INK4a), mainly hypermethylation, may be linked to tumor growth but not tumor development, while alterations in p14(ARF) may contribute to the induction of chronic inflammation-related PTCs.
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Affiliation(s)
- Eiwa Ishida
- Department of Pathology, Nara Medical University School of Medicine, Nara, Japan.
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