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Darroudi F, Natarajan AT. Induction of Sister-chromatid Exchanges, Micronuclei and Gene Mutations by Indirectly Acting Promutagens Using Human Hepatoma Cells as an Activation System. Altern Lab Anim 2020. [DOI: 10.1177/026119299402200612] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
An established human hepatoma cell strain (designated Hep G2) was used in sister-chromatid exchange (SCE) and micronuclei (MN) assays to study, in vitro, the genotoxic potentials of indirectly acting promutagenic carcinogens, such as 2-acetylaminofluorene (2-AAF) and hexamethylphosphoramide (HMPA), and a non-carcinogen, 4-acetylaminofluorene (4-AAF). In addition, Hep G2 S9-fractions were isolated and used to activate the same chemicals using Chinese hamster ovary (CHO) cells as target cells in vitro. The percentage survival and the frequencies of MN, SCEs and point mutations (at the HPRT locus) were used as biological endpoints. A dose-dependent increase in the frequencies of SCEs, MN, cytotoxicity, and/or point mutations was found in Hep G2 cells, and in CHO cells in the presence of Hep G2 S9-fractions, with 2-AAF and HMPA, but with 4-AAF no increase was found. The results obtained demonstrate that the Hep G2 cells and their S9-fractions are capable of activating different classes of mutagens to form biologically active metabolites.
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Affiliation(s)
- Firouz Darroudi
- Medical Genetics Centre, Department of Radiation Genetics and Chemical Mutagenesis, State University of Leiden, Wassenaarseweg 72, 2333AL Leiden, The Netherlands and J.A. Cohen Institute of Radiopathology and Radiation Protection, Interuniversity Institute, 3200 RA Leiden, The Netherlands
| | - Adayapalam T. Natarajan
- Medical Genetics Centre, Department of Radiation Genetics and Chemical Mutagenesis, State University of Leiden, Wassenaarseweg 72, 2333AL Leiden, The Netherlands and J.A. Cohen Institute of Radiopathology and Radiation Protection, Interuniversity Institute, 3200 RA Leiden, The Netherlands
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Totsuka Y, Kawanishi M, Nishigaki R, Matsukawa K, Yagi T, Takamura-Enya T, Watanabe M, Sugimura T, Wakabayashi K. Analysis of HPRT and supF mutations caused by pierisin-1, a guanine specific ADP-ribosylating toxin derived from the cabbage butterfly. Chem Res Toxicol 2003; 16:945-52. [PMID: 12924921 DOI: 10.1021/tx034052o] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Pierisin-1, an ADP-ribosylating toxin derived from the cabbage butterfly, Pieris rapae, induces apoptosis in various mammalian cell lines. We recently reported that the target for ADP ribosylation by pierisin-1 is the 2'-deoxyguanosine residue in DNA. To examine whether pierisin-1 would induce mutations in mammalian cell genes, we conducted a mutational analysis for the hypoxanthine-guanine phosphoribosyltransferase (HPRT) locus in pierisin-1-treated Chinese hamster lung (CHL) cells. N(2)-(ADP-ribos-1-yl)-2'-deoxyguanosine was detected by the (32)P-postlabeling method in CHL cells after treatment with pierisin-1 at doses of 2-32 ng/mL; adduct levels were 1.1-12.0 per 10(6) nucleotides. Pierisin-1 induced mutations in the HPRT gene dose-dependently, and the frequency was 38 times higher than the control, at a dose of 32 ng/mL. To confirm that mono(ADP-ribosyl)ated dG itself leads to mutations, the pierisin-1-treated DNA of plasmid pMY189 bearing the supF gene was used for mutational analysis. The mutation frequency of the supF gene treated with 2-8 micro g/mL of pierisin-1 was 17-40-fold the control value. Mutation spectrum analysis showed that single base substitutions dominated in both HPRT and supF genes. Among these, transversions were predominant, and more than 70% of the base substitutions occurred at G:C base pairs in both genes. The most frequent mutations were G:C to C:G, followed by G:C to T:A in HPRT gene, whereas G:C to T:A transversions dominated in the supF gene. Our results indicate that pierisin-1 produced N(2)-(ADP-ribos-1-yl)-2'-deoxyguanosine and this guanine-adduct could lead to mutations in the HPRT and supF genes. These findings could provide very useful information for understanding the biological significance of pierisin-1.
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Affiliation(s)
- Yukari Totsuka
- Cancer Prevention Basic Research Project, National Cancer Center Research Institute, 1-1 Tsukiji 5-Chome, Chuo-ku, Tokyo 104-0045, Japan
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Yamada T, Odawara K, Kaneko H. Concurrent detection of gene mutations and chromosome aberrations induced by five chemicals in a CHL/IU cell line incorporating a gpt shuttle vector. Mutat Res 2000; 471:29-36. [PMID: 11080658 DOI: 10.1016/s1383-5718(00)00115-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We previously established a transgenic Chinese hamster CHL/IU cell line, designated as KN63, for concurrent analysis of gene mutations and chromosome aberrations. The KN63 cell line contains copies of a shuttle vector with the Escherichia coli gpt gene as a mutational target in its chromosome. To evaluate the sensitivity of the cell line to various types of mutagens, methyl methanesulfonate (MMS), N-ethyl-N-nitrosourea (ENU), mitomycin C (MMC), vincristine sulfate (VIN) and C.I. basic red 9 hydrochloride (CIB) were assayed. KN63 cells were treated with each test chemical and gene mutations were detected in the gpt gene of the shuttle vector rescued from the KN63 cell genome into an E. coli host. Chromosome aberrations were concurrently evaluated by conventional metaphase analysis. MMS, ENU and MMC induced both gene mutations and structural chromosome aberrations in KN63 cells, with more efficient induction of the latter. VIN, a well-known aneugen, produced only numerical changes to chromosomes, while CIB was negative for both types of alteration. KN63 cells were as sensitive to MMS, ENU, MMC and VIN as Chinese hamster cell lines such as CHL, CHO and V79 cells. The characteristics of test chemicals indicated by this system should be useful for understanding endpoints in chemical mutagenesis.
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Affiliation(s)
- T Yamada
- Environmental Health Science Laboratory, Sumitomo Chemical Co. Ltd., 1-98, 3-Chome, Kasugade-naka, Konohana-ku, Osaka 554-8558, Japan.
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Sawada M, Kamataki T. Genetically engineered cells stably expressing cytochrome P450 and their application to mutagen assays. Mutat Res 1998; 411:19-43. [PMID: 9675235 DOI: 10.1016/s1383-5742(98)00005-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Genetically engineered cells transiently and stably expressing cytochrome P450 (P450), a key enzyme for biotransformation of a wide variety of compounds, have provided new tools for investigation of P450 functions such as P450-mediated metabolic activation of chemicals. This review will focus on the development of mammalian cell lines stably expressing P450s and application to toxicology testings. Stable expression systems have an advantage over transient ones in that a series of the process from metabolic activation of test compounds to the appearance of toxicological consequences occurs entirely in the same intact cells. Indeed, many cell lines stably expressing a single form of mammalian P450 have been established so far and applied to cytotoxic or genotoxic assays, the endpoints of which contained mutations at hprt and other gene loci, chromosomal aberrations, sister chromatid exchanges, micronuclei, morphological transformation, and 32P-postlabeling. Analyses of metabolites of toxic substances have also been carried out, using the intact cells or microsomal fractions prepared from the cells. The stable expression systems clearly indicate the form of P450 enzyme capable of activating a certain chemical. More recently, coexpression of P450 together with other components of microsomal electron transfer systems such as NADPH-cytochrome P450 reductase has been successfully performed to increase the metabolic capacity of the heterologously expressed P450. In addition, to reconstruct the entire metabolic activation system for certain heterocyclic amines, cell lines which simultaneously express a form of human P450 and a phase II enzyme, N-acetyltransferase, were established. These cells were highly sensitive to some carcinogenic heterocyclic amines. In genetic toxicology, such a coexpression system for two or more enzymes will provide useful materials which mimic in vivo activation systems.
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Affiliation(s)
- M Sawada
- Division of Environmental Hygiene, Hokkaido College of Pharmacy, Katsuraoka-cho 7-1, Otaru, Hokkaido 047-02, Japan
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Yamakage K, Kusakabe H, Tanaka N. Comparative studies of MCL-5 cells and human lymphocytes for detecting indirect-acting clastogens. Mutat Res 1998; 412:55-61. [PMID: 9508364 DOI: 10.1016/s1383-5718(97)00170-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The MCL-5 cell line was established from human lymphoblastoid TK+/- cells transfected with cDNAs of human cytochrome P450s (CYP1A2, CYP2A6, CYP2E1, and CYP3A4) and microsomal epoxide hydrolase. The TK+/- cells constitutively express a relatively high level of endogenous CYP1A1. To study metabolic activities to indirect-acting clastogens, MCL-5 cells were treated with four clastogens, i.e. aflatoxin B1 (AFB1), diethylnitrosamine (DEN), cyclophosphamide (CPA), and 7,12-dimethylbenz[a]anthracene (DMBA). Human lymphocytes from peripheral blood were used as control cells under the assay conditions with or without induced rat liver metabolic activation (S9). All chemicals tested without S9 induced chromosomal aberrations (CA) in MCL-5 cells but not in human lymphocytes. All chemicals induced CA in both cell types in the presence of S9.
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Affiliation(s)
- K Yamakage
- Department of Cellular and Genetic Toxicology, Hatano Research Institute, Food and Drug Safety Center, Hadano, Kanagawa, Japan
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Yamada T, Odawara K, Kishida F, Nakatsuka I, Yoshitake A. Development of a novel CHL/IU cell line with an incorporated gpt shuttle vector for concurrent analysis of gene mutations and chromosome aberrations. Mutat Res 1997; 393:295-306. [PMID: 9393622 DOI: 10.1016/s1383-5718(97)00114-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A cosmid shuttle vector containing the target gene of Escherichia coli gpt coding xanthine-guanine phosphoribosyl transferase was constructed. The shuttle vector was designed to be rescued into the gpt-deficient Escherichia coli from Chinese hamster CHL/IU cells through an in vitro packaging method. Mutations occurred at the target gene can be detected with a selective agent, 6-thioguanine (6-TG). The shuttle vector was stably transfected into CHL/IU cells to give several cell lines containing copies of the shuttle vector in the chromosomes. Each cell line exhibited a characteristic rescue efficiency (0 to 1.9 x 10(5) CFU/microgram of genomic DNA) of the shuttle vector and spontaneous mutation frequency (3.9 x 10(-5) to over 10(-2)) at the 6-TG selection. One transgenic cell line (KN63), which showed a higher rescue efficiency and a low spontaneous mutation frequency, was selected and tested for the ability to respond to a genotoxic agent, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). MNNG increased both the mutation frequency at the target gene and the number of the cells with chromosome aberrations. DNA sequence analysis of 6-TG mutants showed that predominant mutations (10/14) were identified as G:C to A:T transitions in MNNG-induced mutants, whereas transversions were predominant (5/9) in spontaneous mutants. These results suggest that this transgenic CHL/IU cell line can be a useful tool for analyzing the relation between gene mutations and chromosome aberrations.
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Affiliation(s)
- T Yamada
- Environmental and Health Science Laboratory, Sumitomo Chemical Co., Ltd., Osaka, Japan.
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Nakagawa T, Sawada M, Gonzalez FJ, Yokoi T, Kamataki T. Stable expression of human CYP2E1 in Chinese hamster cells: high sensitivity to N,N-dimethylnitrosamine in cytotoxicity testing. Mutat Res 1996; 360:181-6. [PMID: 8692217 DOI: 10.1016/s0165-1161(96)90015-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Involvement of human CYP2E1 expressed in genetically engineered cells in the metabolic activation of promutagens and procarcinogens was studied. An expression plasmid containing an insert of CYP2E1 cDNA and SR alpha promoter was constructed and transfected into the cultured cell line CR-119 which had previously been established by introducing a cDNA coding for NADPH-cytochrome P450 reductase. Among newly established cell lines, ER-181 showed the highest expression of CYP2E1 mRNA. Production of the CYP2E1 protein was confirmed by Western blot analysis using anti-rat CYP2E1 antibodies. Assay of 7-ethoxycoumarin O-deethylase activity demonstrated that ER-181 cells acquired the catalytic function of CYP2E1. ER-181 cells showed higher sensitivity to N,N-dimethylnitorosamine (DMN) in cytotoxicity assays as compared to parental CR-119 cells. Hypersensitivity to DMN of ER-181 cells was completely suppressed by 3-amino-1,2,4-triazole, a known inhibitor of CYP2E1. These results indicate that ER-181 cells which express human CYP2E1 are a useful tool to investigate toxicological functions of the cytochrome.
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Affiliation(s)
- T Nakagawa
- Division of Drug Metabolism, Faculty of Pharmaceutical Sciences, Hokkaido University N12, Sapporo, Japan
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Itoh S, Satoh M, Abe Y, Hashimoto H, Yanagimoto T, Kamataki T. A novel form of mouse cytochrome P450 3A (Cyp3a-16). Its cDNA cloning and expression in fetal liver. EUROPEAN JOURNAL OF BIOCHEMISTRY 1994; 226:877-82. [PMID: 7813478 DOI: 10.1111/j.1432-1033.1994.t01-1-00877.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A complementary DNA clone coding for a novel form of cytochrome P450, Cyp3a-16, in mouse fetal livers was isolated and completely sequenced. This clone encoded a polypeptide of 504 deduced amino acids and showed 87.3% and 66.6% amino acid identities with mouse Cyp3a-11 and Cyp3a-13, respectively. Cyp3a-16 transcript was detectable before birth and remarkably diminished five weeks after birth in mice. We conclude that Cyp3a-16 is a fetal- and puberty-specific cytochrome P450 in mice.
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Affiliation(s)
- S Itoh
- Division of Drug Metabolism, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
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Weaver RJ, Thompson S, Smith G, Dickins M, Elcombe CR, Mayer RT, Burke MD. A comparative study of constitutive and induced alkoxyresorufin O-dealkylation and individual cytochrome P450 forms in cynomolgus monkey (Macaca fascicularis), human, mouse, rat and hamster liver microsomes. Biochem Pharmacol 1994; 47:763-73. [PMID: 8135852 DOI: 10.1016/0006-2952(94)90475-8] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The expression of constitutive and inducible cytochrome P450 forms was measured in cynomolgus monkey liver and compared with man, rat, mouse and hamster. Four alkoxyresorufin O-dealkylation (AROD) activities widely used as indicators of P450 induction were measured: methoxyresorufin O-demethylation (MROD), ethoxyresorufin O-deethylation (EROD), pentoxyresorufin O-dealkylation (PROD) and benzyloxyresorufin O-dealkylation (BROD). In monkeys there were no sex-differences in untreated, phenobarbitone (PB)- or beta-naphthoflavone (BNF)-treated animals in AROD activities, or in individual P450 proteins detected by immunoblotting. Basal MROD and EROD activities varied by less than 7-fold between the five species, but the comparative pattern of basal MROD, EROD, PROD and BROD activities (the "MEPB profile") was very species-specific, with monkeys being similar to rats but different from man, mouse and hamster. The induction of AROD activities by PB and BNF was also highly species-specific. Monkeys expressed constitutive proteins immunorelated to the CYP1A, CYP2A, CYP2B, CYP2C and CYP3A sub-families (human CYP2A6 cross-reacted with the anti-rat CYP2B1 antibodies used, and so CYP2A and CYP2B forms could not be separately identified in the monkey). Single constitutive immunoblot bands were identified in monkey for CYP1A (54 kDa), CYP2A/CYP2B (51 kDa) and CYP3A (51 kDa), respectively, but two strong (51 and 52 kDa) plus two weak (49 and 49.5 kDa) bands were shown for CYP2C. Human liver expressed CYP1A2 (54 kDa), CYP2A6 (51 kDa), CYP3A4 (50.5 kDa) and three CYP2C9-immunorelated protein bands (48, 50 and 54 kDa). In monkeys BNF induced the 54 kDa CYP1A protein and CYP1A-dependent MROD, EROD and PROD activities (18-, 15- and 6-fold increases in activity, respectively), whereas PB strongly induced the 51 kDa CYP2A/CYP2B protein but did not induce PROD activity. PB also induced non-constitutive CYP2A/CYP2B protein bands at 49 and 52 kDa in some monkeys. BROD activity was induced less that four-fold by either PB or BNF in monkeys. In conclusion, cynomolgus monkeys expressed a range of constitutive CYP1A, CYP2A or CYP2B, CYP2C and CYP3A proteins similar to man, and a range of AROD monooxygenase reaction rates similar to both man and rat, but the basal MEPB profile of AROD activities in monkeys was more similar to rat than to man. MROD and EROD were good measures of CYP1A induction by polycyclic aromatic hydrocarbons in cynomolgus monkeys, but neither PROD nor BROD were indices of CYP2B induction by PB.
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Affiliation(s)
- R J Weaver
- Department of Biomedical Sciences, University of Aberdeen, Marischal College
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