Strategies and testing methods for identifying mutagenic risks.

The evolution of testing strategies and methods for identification of mutagenic agents is discussed, beginning with the concern over potential health and population effects of chemical mutagens in the late 1940s that led to the development of regulatory guidelines for mutagenicity testing in the 1970s and 1980s. Efforts to achieve international harmonization of mutagenicity testing guidelines are summarized, and current issues and needs in the field are discussed, including the need for quantitative methods of mutagenic risk assessment, dose-response thresholds, indirect mechanisms of mutagenicity, and the predictivity of mutagenicity assays for carcinogenicity in vivo. Speculation is offered about the future of mutagenicity testing, including possible near-term changes in standard test batteries and the longer-term roles of expression profiling of damage-response genes, in vivo mutagenicity testing methods, and models that better account for differences in metabolism between humans and laboratory model systems.

[1]  B. Parsons,et al.  Genotypic selection methods for the direct analysis of point mutations. , 1997, Mutation research.

[2]  R. Mittelstaedt,et al.  Comparison of mutant frequencies and types of mutations induced by thiotepa in the endogenous Hprt gene and transgenic lacI gene of Big Blue rats. , 1998, Mutation research.

[3]  D. J. Kirkland,et al.  Genetic toxicology testing requirements: Official and unofficial views from europe , 1993, Environmental and molecular mutagenesis.

[4]  J. Haseman,et al.  LacI mutation spectra following benzo[a]pyrene treatment of Big Blue mice. , 2000, Carcinogenesis.

[5]  S. A. Bol,et al.  Mutational analysis of the liver, colon and kidney of Big Blue rats treated with 2-amino-3-methylimidazo[4,5-f]quinoline. , 2000, Carcinogenesis.

[6]  J. Vijg,et al.  LacZ transgenic mouse models: their application in genetic toxicology. , 1994, Mutation research.

[7]  J. Tischfield,et al.  Other transgenic mutation assays: APRT: A versatile in vivo resident reporter of local mutation and loss of heterozygosity , 1996, Environmental and molecular mutagenesis.

[8]  V. Thybaud,et al.  Kinetics of induction of DNA adducts, cell proliferation and gene mutations in the liver of MutaMice treated with 5,9-dimethyldibenzo[c,g]carbazole. , 1999, Carcinogenesis.

[9]  David J. Brusick,et al.  Screening Chemicals for Genotoxic Properties , 1987 .

[10]  Y. Kataoka,et al.  Induction of hprt mutations in mice after exposure to fission-spectrum neutrons or 60Co gamma rays. , 1993, Radiation research.

[11]  B. Parsons,et al.  Detection of basepair substitution mutation at a frequency of 1 × 10−7 by combining two genotypic selection methods, MutEx enrichment and allele‐specific competitive blocker PCR , 1998, Environmental and molecular mutagenesis.

[12]  J Ashby,et al.  The prospects for a simplified and internationally harmonized approach to the detection of possible human carcinogens and mutagens. , 1986, Mutagenesis.

[13]  L. Samson,et al.  Global response of Saccharomyces cerevisiae to an alkylating agent. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[14]  D. Beare,et al.  Hprt mutant frequencies in circulating lymphocytes: population studies using normal donors, exposed groups and cancer-prone syndromes. , 1991, Progress in clinical and biological research.

[15]  S Madle,et al.  Experience with mutagenicity testing of new drugs: viewpoint of a regulatory agency. , 1987, Mutation research.

[16]  E. Gocke,et al.  Autoradiographic detection of 6-thioguanine-resistant lymphocytes of mice. A novel system in somatic mutagenesis testing. , 1983, Mutation research.

[17]  T. Skopek,et al.  System Issues: Mutagenic response of the endogenous hprt gene and lacl transgene in benzo[a]pyrene‐treated Big Blue™ B6C3F1 mice , 1996 .

[18]  Chung-Xiou Wang,et al.  Diethylnitrosamine exposure-responses for DNA ethylation, hepatocellular proliferation, and initiation of carcinogenesis in rat liver display non-linearities and thresholds , 1999, Archives of Toxicology.

[19]  H. Vrieling,et al.  Carcinogen-induced loss of heterozygosity at the Aprt locus in somatic cells of the mouse. , 1998, Proceedings of the National Academy of Sciences of the United States of America.

[20]  A. Wyrobek,et al.  Numerical and structural chromosomal abnormalities detected in human sperm with a combination of multicolor FISH assays , 1999, Environmental and molecular mutagenesis.

[21]  E H Chu,et al.  Mammalian cell genetics. II. Chemical induction of specific locus mutations in Chinese hamster cells in vitro. , 1968, Proceedings of the National Academy of Sciences of the United States of America.

[22]  J. Neel,et al.  The detection of environmental mutagens. , 1969, The Medical clinics of North America.

[23]  S. Madle,et al.  Genotoxicity tests for new chemicals in Germany: routine in vitro test systems. , 1998, Mutation research.

[24]  D. Kirkland,et al.  Interpretation of the biological relevance of genotoxicity test results: the importance of thresholds. , 2000, Mutation research.

[25]  D. Pinkel,et al.  Fluorescence In situ hybridization to Y chromosomes in decondensed human sperm nuclei , 1990, Molecular reproduction and development.

[26]  B. Ames,et al.  Chemical carcinogenesis: too many rodent carcinogens. , 1990, Proceedings of the National Academy of Sciences of the United States of America.

[27]  R. Albertini,et al.  In vivo somatic mutations in humans: measurement and analysis. , 1990, Annual review of genetics.

[28]  D. Casciano,et al.  Other transgenic mutation assays: Development of a novel mouse tk+/− embryonic stem cell line for use in mutagenicity studies , 1996, Environmental and molecular mutagenesis.

[29]  R. Albertini,et al.  Enumeration of 6-thioguanine-resistant peripheral blood lymphocytes in man as a potential test for somatic cell mutations arising in vivo. , 1979, Mutation research.

[30]  V. Thybaud,et al.  Kinetics of DNA adduct formation and removal in mouse hepatocytes following in vivo exposure to 5,9-dimethyldibenzo[c,g]carbazole. , 2000, Carcinogenesis.

[31]  M C Cimino,et al.  Mutagenicity test schemes and guidelines: U.S. EPA office of pollution prevention and toxics and office of pesticide programs , 1993, Environmental and molecular mutagenesis.

[32]  J. Haseman,et al.  Carcinogenicity results for 114 laboratory animal studies used to assess the predictivity of four in vitro genetic toxicity assays for rodent carcinogenicity , 1990, Environmental and molecular mutagenesis.

[33]  R. Albertini.  Somatic gene mutations in vivo as indicated by the 6-thioguanine-resistant T-lymphocytes in human blood. , 1985, Mutation research.

[34]  D. Nelson,et al.  Lifetime Persistence and Clonality of Chromosome Aberrations in the Peripheral Blood of Mice Acutely Exposed to Ionizing Radiation , 2000, Radiation research.

[35]  Curtis D. Klaassen,et al.  Casarett and Doull's Toxicology. The Basic Science of Poisons , 1981 .

[36]  D L Putman,et al.  Spectra of spontaneous and mutagen-induced mutations in the lacI gene in transgenic mice. , 1991, Proceedings of the National Academy of Sciences of the United States of America.

[37]  V. Thybaud,et al.  Effect of mitogenic or regenerative cell proliferation on lacz mutant frequency in the liver of MutaTMMice treated with 5, 9-dimethyldibenzo[c,g]carbazole. , 1999, Carcinogenesis.

[38]  J. Mirsalis,et al.  Transgenic animal models for detection of in vivo mutations. , 1995, Annual review of pharmacology and toxicology.

[39]  A. Tates,et al.  Detection of somatic mutants in man: HPRT mutations in lymphocytes and hemoglobin mutations in erythrocytes. , 1989, Mutation research.

[40]  A. Tates,et al.  Development of a cloning assay with high cloning efficiency to detect induction of 6-thioguanine-resistant lymphocytes in spleen of adult mice following in vivo inhalation exposure to 1,3-butadiene. , 1994, Mutation research.

[41]  A. Wakata,et al.  Induction of lacZ mutation by 7,12-dimethylbenz[a]anthracene in various tissues of transgenic mice. , 1999, Mutation research.

[42]  F. Serres.  CHEMICAL MUTAGENS: PRINCIPLES AND METHODS FOR THEIR DETECTION , 1972 .

[43]  J. Heddle,et al.  Comparison of somatic mutation in a transgenic versus host locus. , 1993, Proceedings of the National Academy of Sciences of the United States of America.

[44]  R. Albertini,et al.  In vivo ionizing irradiations produce deletions in the hprt gene of human T-lymphocytes. , 1991, Mutation research.

[45]  J. Vijg,et al.  Evaluation of a plasmid-based transgenic mouse model for detecting in vivo mutations. , 1996, Mutagenesis.

[46]  E. Whorton,et al.  The mutagenic effects of low level sub-acute inhalation exposure to benzene in CD-1 mice. , 1992, Mutation research.

[47]  S. J. Culp,et al.  Lymphocyte mutant frequency in relation to DNA adduct formation in rats treated with tumorigenic doses of the mammary gland carcinogen 7,12-dimethylbenz[a]anthracene. , 1996, Mutation research.

[48]  L. Broschinski,et al.  ドイツの新規化学物質遺伝毒性試験 in vitroでのルーチン試験 , 1998 .

[49]  R. Mittelstaedt,et al.  Comparison of the types of mutations induced by 7,12‐dimethylbenz[a]anthracene in the lacI and hprt genes of Big Blue® rats , 1998, Environmental and molecular mutagenesis.

[50]  M. D. Shelby,et al.  Toxicology testing requirements and the U.S.–Japan Collaborative Study on in vitro tests for chromosomal aberrations , 1991, Environmental health perspectives.

[51]  P. Kasper,et al.  Human biological relevance and the use of threshold-arguments in regulatory genotoxicity assessment: experience with pharmaceuticals. , 2000, Mutation research.

[52]  L. Pluta,et al.  Assessment of the in vivo mutagenicity of ethylene oxide in the tissues of B6C3F1 lacI transgenic mice following inhalation exposure. , 1997, Mutation research.

[53]  S. Nesnow,et al.  International Commission for Protection Against Environmental Mutagens and Carcinogens. A method for combining and comparing short-term genotoxicity test data: preface. A report from ICPEMC Committee 1. , 1992, Mutation research.

[54]  T Sofuni,et al.  ICH-harmonised guidances on genotoxicity testing of pharmaceuticals: evolution, reasoning and impact. , 1999, Mutation research.

[55]  O. Ueda,et al.  Other transgenic mutation assays: A new transgenic mouse mutagenesis test system using Spi− and 6‐thioguanine selections , 1996, Environmental and molecular mutagenesis.

[56]  R. Mittelstaedt,et al.  Induction of 6‐thioguanine‐resistant lymphocytes in fischer 344 rats following in vivo exposure to n‐ethyl‐n‐nitrosourea and cyclophosphamide , 1991, Environmental and molecular mutagenesis.

[57]  I. M. Jones,et al.  Impact of age and environment on somatic mutation at the hprt gene of T lymphocytes in humans. , 1995, Mutation research.

[58]  P. Kasper,et al.  The quality of genotoxicity testing of drugs. Experiences of a regulatory agency with new and old compounds. , 1991, Mutagenesis.

[59]  S. Morris,et al.  Development and utilization of the rat lymphocyte hprt mutation assay. , 1997, Mutation research.

[60]  J. S. Wassom,et al.  Origins of genetic toxicology and the environmental Mutagen Society , 1989, Environmental and molecular mutagenesis.

[61]  M. Shelby,et al.  Mammalian in vivo cytogenetic assays. Analysis of chromosome aberrations in bone marrow cells. , 1987, Mutation research.

[62]  A. Tates,et al.  Induction of hprt gene mutations in splenic T-lymphocytes from the rat exposed in vivo to DNA methylating agents is correlated with formation of O6-methylguanine in bone marrow and not in the spleen. , 1996, Carcinogenesis.

[63]  T Sofuni,et al.  Summary of major conclusions from the International Workshop on Genotoxicity Test Procedures , 2000, Environmental and molecular mutagenesis.

[64]  R. Albertini,et al.  Somatic cell mutation. Detection and quantification of x-ray-induced mutation in cultured, diploid human fibroblasts. , 1973, Mutation research.

[65]  I. M. Jones,et al.  A method to quantify spontaneous and in vivo induced thioguanine-resistant mouse lymphocytes. , 1985, Mutation research.

[66]  F. Beland,et al.  DNA adduct formation and T-lymphocyte mutation induction in F344 rats implanted with tumorigenic doses of 1,6-dinitropyrene. , 1995, Cancer Research.

[67]  W. Thilly,et al.  Phenotypic lag and mutation to 6-thioguanine resistance in diploid human lymphoblasts. , 1978, Mutation research.

[68]  R. Tennant,et al.  Definitive relationships among chemical structure, carcinogenicity and mutagenicity for 301 chemicals tested by the U.S. NTP. , 1991, Mutation research.

[69]  A. Grosovsky,et al.  Isolation of an APRT heterozygote from TK6 human lymphoblasts: predominance of multi-locus loss of heterozygosity among spontaneous APRT-mutants. , 1997, Mutation research.

[70]  S Albertini,et al.  Comparative evaluation of the in vitro micronucleus test and the in vitro chromosome aberration test: industrial experience. , 1997, Mutation research.

[71]  T. Sofuni,et al.  Appropriate levels of cytotoxicity for genotoxicity tests using mammalian cells in vitro , 2000, Environmental and molecular mutagenesis.

[72]  J. O’Neill,et al.  The use of Chinese hamster ovary cells to quantify specific locus mutation and to determine mutagenicity of chemicals. A report of the gene-tox program. , 1981, Mutation research.

[73]  D. Eastmond,et al.  Detection of hyperdiploidy and chromosome breakage in interphase human lymphocytes following exposure to the benzene metabolite hydroquinone using multicolor fluorescence in situ hybridization with DNA probes. , 1994, Mutation research.

[74]  A. Morley,et al.  Measurement of in vivo mutant frequency in lymphocytes in the mouse. , 1986, Environmental mutagenesis.

[75]  I. M. Jones,et al.  Factors that affect the frequency of thioguanine-resistant lymphocytes in mice following exposure to ethylnitrosourea. , 1987, Environmental mutagenesis.

[76]  R. Tennant,et al.  Chemical structure, Salmonella mutagenicity and extent of carcinogenicity as indicators of genotoxic carcinogenesis among 222 chemicals tested in rodents by the U.S. NCI/NTP. , 1988, Mutation research.

[77]  Y Shirasu,et al.  The Japanese mutagenicity studies guidelines for pesticide registration. , 1988, Mutation research.

[78]  J Preston,et al.  IPCS harmonization of methods for the prediction and quantification of human carcinogenic/mutagenic hazard, and for indicating the probable mechanism of action of carcinogens. , 1996, Mutation research.

[79]  J Vijg,et al.  Efficient rescue of integrated shuttle vectors from transgenic mice: a model for studying mutations in vivo. , 1989, Proceedings of the National Academy of Sciences of the United States of America.

[80]  E. Pennisi.  Finally, the Book of Life and Instructions for Navigating It , 2000, Science.

[81]  W. Bradley,et al.  High-frequency nonrandom mutational event at the adenine phosphoribosyltransferase (aprt) locus of sib-selected CHO variants heterozygous foraprt , 1982, Somatic cell genetics.

[82]  L. Recio,et al.  In vivo mutagenicity of ethylene oxide at the hprt locus in T-lymphocytes of B6C3F1 lacI transgenic mice following inhalation exposure. , 1997, Mutation research.

[83]  D. Tweats,et al.  Genotoxicity testing: current practices and strategies used by the pharmaceutical industry. , 1995, Mutagenesis.

[84]  J. T. Macgregor.  Environmental mutagenesis: Past and future directions , 1994, Environmental and molecular mutagenesis.

[85]  V. Wixler,et al.  Mutant frequency at the H-2K class 1 and HPRT genes in T lymphocytes from the X-ray-exposed mouse. , 1995, International journal of radiation biology.

[86]  R. Branda,et al.  Factors influencing mutation at the hprt locus in T‐lymphocytes: Studies in normal women and women with benign and malignant breast masses , 1992, Environmental and molecular mutagenesis.

[87]  K. El-Bayoumy,et al.  Mutagenic activity of 4-nitroquinoline-N-oxide in upper aerodigestive tissue in lacZ mice (MutaMouse) and the effects of 1, 4-phenylenebis(methylene)selenocyanate. , 2000, Mutation research.

[88]  T. Sofuni,et al.  Procarbazine genotoxicity in the MutaMouse; strong clastogenicity and organ-specific induction of lacZ mutations. , 1999, Mutation research.

[89]  D Brusick,et al.  International Commission for Protection Against Environmental Mutagens and Carcinogens. Genotoxicity under extreme culture conditions. A report from ICPEMC Task Group 9. , 1991, Mutation research.

[90]  T. Skopek,et al.  A mouse model for the study of in vivo mutational spectra: sequence specificity of ethylene oxide at the hprt locus. , 1993, Mutation research.

[91]  Errol Zeiger,et al.  Evaluation of four in vitro genetic toxicity tests for predicting rodent carcinogenicity: Confirmation of earlier results with 41 additional chemicals , 1990, Environmental and molecular mutagenesis.

[92]  R. S. Tan,et al.  Molecular analysis of hypoxanthine phosphoribosyl transferase mutants induced by glycidyl 1‐naphthyl ether in mouse spleen cells in vivo , 1993, Environmental and molecular mutagenesis.

[93]  B. Ames,et al.  Too many rodent carcinogens: mitogenesis increases mutagenesis. , 1990, Science.

[94]  D. Casciano,et al.  Calorie restriction modulates chemically induced in vivo somatic mutation frequency , 1996, Environmental and molecular mutagenesis.

[95]  Michael D. Waters,et al.  The GENE-TOX Program: genetic activity evaluation , 1981, J. Chem. Inf. Comput. Sci..

[96]  E. O. George,et al.  The effect of time after treatment, treatment schedule and animal age on the frequency of 6-thioguanine-resistant T-lymphocytes induced in Fischer 344 rats by N-ethyl-N-nitrosourea. , 1993, Mutation research.

[97]  L Müller,et al.  Series: current issues in mutagenesis and carcinogenesis, No. 65. The genotoxicity and carcinogenicity of paracetamol: a regulatory (re)view. , 1996, Mutation research.

[98]  J. T. Macgregor.  Transgenic animal models for mutagenesis studies: Role in mutagenesis research and regulatory testing , 1998, Environmental and molecular mutagenesis.

[99]  T. Skopek,et al.  Frequency and spectrum of ethylnitrosourea-induced mutation at the hprt and lacI loci in splenic lymphocytes of exposed lacI transgenic mice. , 1996, Cancer research.

[100]  T Sofuni,et al.  Evaluation of the rodent micronucleus assay in the screening of IARC carcinogens (groups 1, 2A and 2B) the summary report of the 6th collaborative study by CSGMT/JEMS MMS. Collaborative Study of the Micronucleus Group Test. Mammalian Mutagenicity Study Group. , 1997, Mutation research.

[101]  T R Skopek,et al.  Relative sensitivity of the endogenous hprt gene and lacl transgene in ENU‐treated big blue™ B6C3F1 mice , 1995, Environmental and molecular mutagenesis.

[102]  D. Clive,et al.  A mutational assay system using the thymidine kinase locus in mouse lymphoma cells. , 1972, Mutation research.

[103]  J. Trosko,et al.  Challenge to the simple paradigm that 'carcinogens' are 'mutagens' and to the in vitro and in vivo assays used to test the paradigm. , 1997, Mutation research.

[104]  C. Ramel,et al.  Genetic toxicology of environmental chemicals. Part B: Genetic effects and applied mutagenesis. Proceedings of the Fourth International Conference on Environmental Mutagens. Stockholm, Sweden, June 24-28, 1985. , 1986, Progress in clinical and biological research.

[105]  B. Ames,et al.  Detection of carcinogens as mutagens in the Salmonella/microsome test: assay of 300 chemicals. , 1975, Proceedings of the National Academy of Sciences of the United States of America.

[106]  M. Green,et al.  A further assessment of factors influencing measurements of thioguanine-resistant mutant frequency in circulating T-lymphocytes. , 1988, Mutation research.

[107]  J. O’Neill,et al.  Cytotoxicity and mutagenicity of alkylating agents in cultured mammalian cells (CHO/HGPRT system): mutagen treatment in the presence or absence of serum. , 1979, Mutation research.

[108]  S. Sutou.  Achievements by CSGMT/JEMS.MMS: the Collaborative Study Group for the Micronucleus Test in the Mammalian Mutagenesis Study Group of the Environmental Mutagen Society of Japan. , 1996, Mutation research.

[109]  J. O’Neill,et al.  A quantitative assay of mutation induction at the hypoxanthine-guanine phosphoribosyl transferase locus in Chinese hamster ovary cells (CHO/HGPRT system): development and definition of the system. , 1977, Mutation research.

[110]  T. Hara,et al.  Target organ and time-course in the mutagenicity of five carcinogens in MutaMouse: a summary report of the second collaborative study of the transgenic mouse mutation assay by JEMS/MMS. , 1999, Mutation research.

[111]  J. Ashby,et al.  The influence of chemical structure on the extent and sites of carcinogenesis for 522 rodent carcinogens and 55 different human carcinogen exposures. , 1993, Mutation research.

[112]  B. Blaydes,et al.  Assessment of DNA adducts and the frequency of 6-thioguanine resistant T-lymphocytes in F344 rats fed 2,4-toluenediamine or implanted with a toluenediisocyanate-containing polyester polyurethane foam. , 1996, Mutation research.

[113]  D. Casciano,et al.  Tk+/- mouse model for detecting in vivo mutation in an endogenous, autosomal gene. , 1999, Mutation research.

[114]  S. Galloway.  Cytotoxicity and chromosome aberrations in vitro: Experience in industry and the case for an upper limit on toxicity in the aberration assay , 2000, Environmental and molecular mutagenesis.

[115]  R. Tice,et al.  Single cell gel/comet assay: Guidelines for in vitro and in vivo genetic toxicology testing , 2000, Environmental and molecular mutagenesis.

[116]  T. Sofuni,et al.  In vivo genotoxicity of 2-amino-3,8-dimethylimidazo[4, 5-f]quinoxaline in lacI transgenic (Big Blue) mice. , 2000, Mutation research.

[117]  D. Casciano,et al.  Comparison of in vivo mutagenesis in the endogenous Hprt gene and the lacI transgene of Big Blue(R) rats treated with 7, 12-dimethylbenz[a]anthracene. , 1998, Mutation research.

[118]  T. Sofuni,et al.  Evaluation of the micronucleus test using a Chinese hamster cell line as an alternative to the conventional in vitro chromosomal aberration test. , 1992, Mutation research.

[119]  R. Albertini,et al.  T-cell cloning to detect the mutant 6-thioguanine-resistant lymphocytes present in human peripheral blood. , 1982, Proceedings of the National Academy of Sciences of the United States of America.

[120]  H. Sone,et al.  Increase in mutation frequency in lung of Big Blue rat by exposure to diesel exhaust. , 2000, Carcinogenesis.

[121]  B. Ames,et al.  Carcinogens are mutagens: a simple test system combining liver homogenates for activation and bacteria for detection. , 1973, Proceedings of the National Academy of Sciences of the United States of America.

[122]  T. Skopek,et al.  In vivo transgenic mutation assays , 2000, Environmental and molecular mutagenesis.

[123]  Sense and non-sense in toxicity assessment of medicinal products , 1997 .

[124]  A. Morley,et al.  Enumeration of thioguanine-resistant lymphocytes using autoradiography , 1982 .

[125]  J. Robson,et al.  Chemical Production of Mutations , 1946, Nature.

[126]  F. Staedtler,et al.  4-chloro-o-phenylenediamine induces a dose-related increase in G:C > T:A transversions and one major DNA adduct in the liver of Big Blue mice after 26 weeks in feed treatment. , 1999, Mutation research.

[127]  B. Burkhart,et al.  ENU-induced mutagenesis at a single A: T base pair in transgenic mice containing phi X174. , 1993, Mutation research.

[128]  T. Skopek,et al.  Mutagenicity of butadiene and its epoxide metabolites: II. Mutational spectra of butadiene, 1,2-epoxybutene and diepoxybutane at the hprt locus in splenic T cells from exposed B6C3F1 mice. , 1994, Carcinogenesis.