Abstract
In this article, we examine existing data on the use of transgenic mouse models for identification of human carcinogens. We focus on the three most extensively studied of these mice, Trp53+/-, Tg/AC, and RasH2, and compare their performance with the traditional 2-year rodent bioassay. Data on 99 chemicals were evaluated. Using the International Agency for Research on Cancer/Report on Carcinogens determinations for the carcinogenicity of these chemicals to humans as the standard for comparison, we evaluated a variety of potential testing strategies ranging from individual transgenic models to combinations of these three models with each other and with traditional rodent assays. The individual transgenic models made the "correct" determinations (positive for carcinogens; negative for noncarcinogens) for 74-81% of the chemicals, with an increase to as much as 83% using combined strategies (e.g., Trp53+/- for genotoxic chemicals and RasH2 for all chemicals). For comparison, identical analysis of chemicals in this data set that were tested in the 2-year, two-species rodent bioassay yielded correct determinations for 69% of the chemicals. However, although the transgenic models had a high percentage of correct determinations, they did miss a number of known or probable human carcinogens, whereas the bioassay missed none of these chemicals. Therefore, we also evaluated mixed strategies using transgenic models and the rat bioassay. These strategies yielded approximately 85% correct determinations, missed no carcinogens, and cut the number of positive determinations for human noncarcinogens in half. Overall, the transgenic models performed well, but important issues of validation and standardization need further attention to permit their regulatory acceptance and use in human risk assessment.
Full Text
The Full Text of this article is available as a PDF (183.1 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Albert R. E., French J. E., Maronpot R., Spalding J., Tennant R. Mechanism of skin tumorigenesis by contact sensitizers: the effect of the corticosteroid fluocinolone acetonide on inflammation and tumor induction by 2,4 dinitro-1-fluorobenzene in the skin of the TG.AC (v-Ha-ras) mouse. Environ Health Perspect. 1996 Oct;104(10):1062–1068. doi: 10.1289/ehp.961041062. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Artandi S. E., DePinho R. A. Mice without telomerase: what can they teach us about human cancer? Nat Med. 2000 Aug;6(8):852–855. doi: 10.1038/78595. [DOI] [PubMed] [Google Scholar]
- Ashby J., Tennant R. W. Definitive relationships among chemical structure, carcinogenicity and mutagenicity for 301 chemicals tested by the U.S. NTP. Mutat Res. 1991 May;257(3):229–306. doi: 10.1016/0165-1110(91)90003-e. [DOI] [PubMed] [Google Scholar]
- Battershill J. M., Fielder R. J. Mouse-specific carcinogens: an assessment of hazard and significance for validation of short-term carcinogenicity bioassays in transgenic mice. Hum Exp Toxicol. 1998 Apr;17(4):193–205. doi: 10.1177/096032719801700401. [DOI] [PubMed] [Google Scholar]
- Berns A. Cancer. Improved mouse models. Nature. 2001 Apr 26;410(6832):1043–1044. doi: 10.1038/35074238. [DOI] [PubMed] [Google Scholar]
- Blanchard K. T., Ball D. J., Holden H. E., Furst S. M., Stoltz J. H., Stoll R. E. Dermal carcinogenicity in transgenic mice: relative responsiveness of male and female hemizygous and homozygous Tg.AC mice to 12-O-tetradecanoylphorbol 13-acetate (TPA) and benzene. Toxicol Pathol. 1998 Jul-Aug;26(4):541–547. doi: 10.1177/019262339802600410. [DOI] [PubMed] [Google Scholar]
- Blanchard K. T., Barthel C., French J. E., Holden H. E., Moretz R., Pack F. D., Tennant R. W., Stoll R. E. Transponder-induced sarcoma in the heterozygous p53+/- mouse. Toxicol Pathol. 1999 Sep-Oct;27(5):519–527. doi: 10.1177/019262339902700505. [DOI] [PubMed] [Google Scholar]
- Bos J. L. ras oncogenes in human cancer: a review. Cancer Res. 1989 Sep 1;49(17):4682–4689. [PubMed] [Google Scholar]
- Bucher J. R. Update on national toxicology program (NTP) assays with genetically altered or "transgenic" mice. Environ Health Perspect. 1998 Oct;106(10):619–621. doi: 10.1289/ehp.98106619. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Campbell S. L., Khosravi-Far R., Rossman K. L., Clark G. J., Der C. J. Increasing complexity of Ras signaling. Oncogene. 1998 Sep 17;17(11 REVIEWS):1395–1413. doi: 10.1038/sj.onc.1202174. [DOI] [PubMed] [Google Scholar]
- Cannon R. E., Spalding J. W., Trempus C. S., Szczesniak C. J., Virgil K. M., Humble M. C., Tennant R. W. Kinetics of wound-induced v-Ha-ras transgene expression and papilloma development in transgenic Tg.AC mice. Mol Carcinog. 1997 Sep;20(1):108–114. doi: 10.1002/(sici)1098-2744(199709)20:1<108::aid-mc12>3.0.co;2-5. [DOI] [PubMed] [Google Scholar]
- Carmichael N. G., Debruyne E. L., Bigot-Lasserre D. The p53 heterozygous knockout mouse as a model for chemical carcinogenesis in vascular tissue. Environ Health Perspect. 2000 Jan;108(1):61–65. doi: 10.1289/ehp.0010861. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Delker D. A., Yano B. L., Gollapudi B. B. V-Ha-ras gene expression in liver and kidney of transgenic Tg.AC mice following chemically induced tissue injury. Toxicol Sci. 1999 Jul;50(1):90–97. doi: 10.1093/toxsci/50.1.90. [DOI] [PubMed] [Google Scholar]
- Donehower L. A., Harvey M., Slagle B. L., McArthur M. J., Montgomery C. A., Jr, Butel J. S., Bradley A. Mice deficient for p53 are developmentally normal but susceptible to spontaneous tumours. Nature. 1992 Mar 19;356(6366):215–221. doi: 10.1038/356215a0. [DOI] [PubMed] [Google Scholar]
- Dunnick J. K., Hardisty J. F., Herbert R. A., Seely J. C., Furedi-Machacek E. M., Foley J. F., Lacks G. D., Stasiewicz S., French J. E. Phenolphthalein induces thymic lymphomas accompanied by loss of the p53 wild type allele in heterozygous p53-deficient (+/-) mice. Toxicol Pathol. 1997 Nov-Dec;25(6):533–540. doi: 10.1177/019262339702500601. [DOI] [PubMed] [Google Scholar]
- Eastin W. C., Haseman J. K., Mahler J. F., Bucher J. R. The National Toxicology Program evaluation of genetically altered mice as predictive models for identifying carcinogens. Toxicol Pathol. 1998 Jul-Aug;26(4):461–473. doi: 10.1177/019262339802600401. [DOI] [PubMed] [Google Scholar]
- Eastin W. C., Mennear J. H., Tennant R. W., Stoll R. E., Branstetter D. G., Bucher J. R., McCullough B., Binder R. L., Spalding J. W., Mahler J. F. Tg.AC genetically altered mouse: assay working group overview of available data. Toxicol Pathol. 2001;29 (Suppl):60–80. doi: 10.1080/019262301753178483. [DOI] [PubMed] [Google Scholar]
- Finch G. L., March T. H., Hahn F. F., Barr E. B., Belinsky S. A., Hoover M. D., Lechner J. F., Nikula K. J., Hobbs C. H. Carcinogenic responses of transgenic heterozygous p53 knockout mice to inhaled 239PuO2 or metallic beryllium. Toxicol Pathol. 1998 Jul-Aug;26(4):484–491. doi: 10.1177/019262339802600404. [DOI] [PubMed] [Google Scholar]
- Germolec D. R., Spalding J., Boorman G. A., Wilmer J. L., Yoshida T., Simeonova P. P., Bruccoleri A., Kayama F., Gaido K., Tennant R. Arsenic can mediate skin neoplasia by chronic stimulation of keratinocyte-derived growth factors. Mutat Res. 1997 Jun;386(3):209–218. doi: 10.1016/s1383-5742(97)00006-9. [DOI] [PubMed] [Google Scholar]
- Greenblatt M. S., Bennett W. P., Hollstein M., Harris C. C. Mutations in the p53 tumor suppressor gene: clues to cancer etiology and molecular pathogenesis. Cancer Res. 1994 Sep 15;54(18):4855–4878. [PubMed] [Google Scholar]
- Griesemer R. A., Cueto C., Jr Toward a classification scheme for degrees of experimental evidence for the carcinogenicity of chemicals for animals. IARC Sci Publ. 1980;(27):259–281. [PubMed] [Google Scholar]
- Gupta S., Plattner R., Der C. J., Stanbridge E. J. Dissection of Ras-dependent signaling pathways controlling aggressive tumor growth of human fibrosarcoma cells: evidence for a potential novel pathway. Mol Cell Biol. 2000 Dec;20(24):9294–9306. doi: 10.1128/mcb.20.24.9294-9306.2000. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Harvey M., McArthur M. J., Montgomery C. A., Jr, Butel J. S., Bradley A., Donehower L. A. Spontaneous and carcinogen-induced tumorigenesis in p53-deficient mice. Nat Genet. 1993 Nov;5(3):225–229. doi: 10.1038/ng1193-225. [DOI] [PubMed] [Google Scholar]
- Haseman J. K., Elwell M. R. Evaluation of false positive and false negative outcomes in NTP long-term rodent carcinogenicity studies. Risk Anal. 1996 Dec;16(6):813–820. doi: 10.1111/j.1539-6924.1996.tb00832.x. [DOI] [PubMed] [Google Scholar]
- Hollstein M., Sidransky D., Vogelstein B., Harris C. C. p53 mutations in human cancers. Science. 1991 Jul 5;253(5015):49–53. doi: 10.1126/science.1905840. [DOI] [PubMed] [Google Scholar]
- Hruban R. H., van Mansfeld A. D., Offerhaus G. J., van Weering D. H., Allison D. C., Goodman S. N., Kensler T. W., Bose K. K., Cameron J. L., Bos J. L. K-ras oncogene activation in adenocarcinoma of the human pancreas. A study of 82 carcinomas using a combination of mutant-enriched polymerase chain reaction analysis and allele-specific oligonucleotide hybridization. Am J Pathol. 1993 Aug;143(2):545–554. [PMC free article] [PubMed] [Google Scholar]
- Jiang W., Ananthaswamy H. N., Muller H. K., Kripke M. L. p53 protects against skin cancer induction by UV-B radiation. Oncogene. 1999 Jul 22;18(29):4247–4253. doi: 10.1038/sj.onc.1202789. [DOI] [PubMed] [Google Scholar]
- Johnson L., Mercer K., Greenbaum D., Bronson R. T., Crowley D., Tuveson D. A., Jacks T. Somatic activation of the K-ras oncogene causes early onset lung cancer in mice. Nature. 2001 Apr 26;410(6832):1111–1116. doi: 10.1038/35074129. [DOI] [PubMed] [Google Scholar]
- Karstadt M., Haseman J. K. Effect of discounting certain tumor types/sites on evaluations of carcinogenicity in laboratory animals. Am J Ind Med. 1997 May;31(5):485–494. doi: 10.1002/(sici)1097-0274(199705)31:5<485::aid-ajim1>3.0.co;2-t. [DOI] [PubMed] [Google Scholar]
- Katsuki M., Ando K., Saitoh A., Doi S., Kimura M., Takahashi R., Hasegawa T., Yokoyama M., Nomura T., Izawa M. Chemically induced tumors in transgenic mice carrying prototype human c-Ha-ras genes. Princess Takamatsu Symp. 1991;22:249–257. [PubMed] [Google Scholar]
- Kemp C. J., Donehower L. A., Bradley A., Balmain A. Reduction of p53 gene dosage does not increase initiation or promotion but enhances malignant progression of chemically induced skin tumors. Cell. 1993 Sep 10;74(5):813–822. doi: 10.1016/0092-8674(93)90461-x. [DOI] [PubMed] [Google Scholar]
- Kemp C. J., Wheldon T., Balmain A. p53-deficient mice are extremely susceptible to radiation-induced tumorigenesis. Nat Genet. 1994 Sep;8(1):66–69. doi: 10.1038/ng0994-66. [DOI] [PubMed] [Google Scholar]
- Knudson A. G. Hereditary cancer: two hits revisited. J Cancer Res Clin Oncol. 1996;122(3):135–140. doi: 10.1007/BF01366952. [DOI] [PubMed] [Google Scholar]
- Knudson A. G., Jr, Hethcote H. W., Brown B. W. Mutation and childhood cancer: a probabilistic model for the incidence of retinoblastoma. Proc Natl Acad Sci U S A. 1975 Dec;72(12):5116–5120. doi: 10.1073/pnas.72.12.5116. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Koujitani T., Yasuhara K., Usui T., Nomura T., Onodera H., Takagi H., Hirose M., Mitsumori K. Lack of susceptibility of transgenic mice carrying the human c-Ha-ras proto-oncogene (rasH2 mice) to phenolphthalein in a 6-month carcinogenicity study. Cancer Lett. 2000 May 1;152(2):211–216. doi: 10.1016/s0304-3835(00)00338-4. [DOI] [PubMed] [Google Scholar]
- Leder A., Kuo A., Cardiff R. D., Sinn E., Leder P. v-Ha-ras transgene abrogates the initiation step in mouse skin tumorigenesis: effects of phorbol esters and retinoic acid. Proc Natl Acad Sci U S A. 1990 Dec;87(23):9178–9182. doi: 10.1073/pnas.87.23.9178. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lijinsky W., Reuber M. D., Blackwell B. N. Liver tumors induced in rats by oral administration of the antihistaminic methapyrilene hydrochloride. Science. 1980 Aug 15;209(4458):817–819. doi: 10.1126/science.7403848. [DOI] [PubMed] [Google Scholar]
- Lugari R., Dell'Anna C., Ugolotti D., Dei Cas A., Barilli A. L., Zandomeneghi R., Marani B., Iotti M., Orlandini A., Gnudi A. Effect of nutrient ingestion on glucagon-like peptide 1 (7-36 amide) secretion in human type 1 and type 2 diabetes. Horm Metab Res. 2000 Oct;32(10):424–428. doi: 10.1055/s-2007-978665. [DOI] [PubMed] [Google Scholar]
- Maronpot R. R., Mitsumori K., Mann P., Takaoka M., Yamamoto S., Usui T., Okamiya H., Nishikawa S., Nomura T. Interlaboratory comparison of the CB6F1-Tg rasH2 rapid carcinogenicity testing model. Toxicology. 2000 May 5;146(2-3):149–159. doi: 10.1016/s0300-483x(00)00168-2. [DOI] [PubMed] [Google Scholar]
- Marsella J. M., Liu B. L., Vaslet C. A., Kane A. B. Susceptibility of p53-deficient mice to induction of mesothelioma by crocidolite asbestos fibers. Environ Health Perspect. 1997 Sep;105 (Suppl 5):1069–1072. doi: 10.1289/ehp.97105s51069. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Martin K. R., Trempus C., Saulnier M., Kari F. W., Barrett J. C., French J. E. Dietary N-acetyl-L-cysteine modulates benzo[a]pyrene-induced skin tumors in cancer-prone p53 haploinsufficient Tg.AC (v-Ha-ras) mice. Carcinogenesis. 2001 Sep;22(9):1373–1378. doi: 10.1093/carcin/22.9.1373. [DOI] [PubMed] [Google Scholar]
- Maruyama C., Tomisawa M., Wakana S., Yamazaki H., Kijima H., Suemizu H., Ohnishi Y., Urano K., Hioki K., Usui T. Overexpression of human H-ras transgene is responsible for tumors induced by chemical carcinogens in mice. Oncol Rep. 2001 Mar-Apr;8(2):233–237. doi: 10.3892/or.8.2.233. [DOI] [PubMed] [Google Scholar]
- McCormick D. L., Ryan B. M., Findlay J. C., Gauger J. R., Johnson T. R., Morrissey R. L., Boorman G. A. Exposure to 60 Hz magnetic fields and risk of lymphoma in PIM transgenic and TSG-p53 (p53 knockout) mice. Carcinogenesis. 1998 Sep;19(9):1649–1653. doi: 10.1093/carcin/19.9.1649. [DOI] [PubMed] [Google Scholar]
- Mitsumori K., Onodera H., Shimo T., Yasuhara K., Takagi H., Koujitani T., Hirose M., Maruyama C., Wakana S. Rapid induction of uterine tumors with p53 point mutations in heterozygous p53-deficient CBA mice given a single intraperitoneal administration of N-ethyl-N-nitrosourea. Carcinogenesis. 2000 May;21(5):1039–1042. doi: 10.1093/carcin/21.5.1039. [DOI] [PubMed] [Google Scholar]
- Mori I., Yasuhara K., Hayashi S. M., Nonoyama T., Nomura T., Mitsumori K. Carcinogen dose-dependent variation in the transgene mutation spectrum in urethane-induced lung tumors in transgenic mice carrying the human prototype c-Ha-ras gene. Cancer Lett. 2000 May 29;153(1-2):199–209. doi: 10.1016/s0304-3835(00)00372-4. [DOI] [PubMed] [Google Scholar]
- Morimura K., Salim E. I., Yamamoto S., Wanibuchi H., Fukushima S. Dose-dependent induction of aberrant crypt foci in the colons but no neoplastic lesions in the livers of heterozygous p53-deficient mice treated with low dose 2-amino-3-methylimidazo [4,5-f]quinoline. Cancer Lett. 1999 Apr 26;138(1-2):81–85. doi: 10.1016/s0304-3835(98)00377-2. [DOI] [PubMed] [Google Scholar]
- Nylander-French L. A., French J. E. Tripropylene glycol diacrylate but not ethyl acrylate induces skin tumors in a twenty-week short-term tumorigenesis study in Tg.AC (v-Ha-ras) mice. Toxicol Pathol. 1998 Jul-Aug;26(4):476–483. doi: 10.1177/019262339802600403. [DOI] [PubMed] [Google Scholar]
- Ozaki K., Sukata T., Yamamoto S., Uwagawa S., Seki T., Kawasaki H., Yoshitake A., Wanibuchi H., Koide A., Mori Y. High susceptibility of p53(+/-) knockout mice in N-butyl-N-(4-hydroxybutyl)nitrosamine urinary bladder carcinogenesis and lack of frequent mutation in residual allele. Cancer Res. 1998 Sep 1;58(17):3806–3811. [PubMed] [Google Scholar]
- Popp J. A. Criteria for the evaluation of studies in transgenic models. Toxicol Pathol. 2001;29 (Suppl):20–23. doi: 10.1080/019262301753178447. [DOI] [PubMed] [Google Scholar]
- Prives C., Hall P. A. The p53 pathway. J Pathol. 1999 Jan;187(1):112–126. doi: 10.1002/(SICI)1096-9896(199901)187:1<112::AID-PATH250>3.0.CO;2-3. [DOI] [PubMed] [Google Scholar]
- Pruitt K., Der C. J. Ras and Rho regulation of the cell cycle and oncogenesis. Cancer Lett. 2001 Sep 28;171(1):1–10. doi: 10.1016/s0304-3835(01)00528-6. [DOI] [PubMed] [Google Scholar]
- Robinson D. E., MacDonald J. S. Background and framework for ILSI's collaborative evaluation program on alternative models for carcinogenicity assessment. International Life Sciences Institute. Toxicol Pathol. 2001;29 (Suppl):13–19. doi: 10.1080/019262301753178438. [DOI] [PubMed] [Google Scholar]
- Rudolph K. L., Millard M., Bosenberg M. W., DePinho R. A. Telomere dysfunction and evolution of intestinal carcinoma in mice and humans. Nat Genet. 2001 Jun;28(2):155–159. doi: 10.1038/88871. [DOI] [PubMed] [Google Scholar]
- Sagartz J. E., Curtiss S. W., Bunch R. T., Davila J. C., Morris D. L., Alden C. L. Phenobarbital does not promote hepatic tumorigenesis in a twenty-six-week bioassay in p53 heterozygous mice. Toxicol Pathol. 1998 Jul-Aug;26(4):492–500. doi: 10.1177/019262339802600405. [DOI] [PubMed] [Google Scholar]
- Saitoh A., Kimura M., Takahashi R., Yokoyama M., Nomura T., Izawa M., Sekiya T., Nishimura S., Katsuki M. Most tumors in transgenic mice with human c-Ha-ras gene contained somatically activated transgenes. Oncogene. 1990 Aug;5(8):1195–1200. [PubMed] [Google Scholar]
- Shelby M. D. The genetic toxicity of human carcinogens and its implications. Mutat Res. 1988 Jan;204(1):3–15. doi: 10.1016/0165-1218(88)90113-9. [DOI] [PubMed] [Google Scholar]
- Spalding J. W., French J. E., Stasiewicz S., Furedi-Machacek M., Conner F., Tice R. R., Tennant R. W. Responses of transgenic mouse lines p53(+/-) and Tg.AC to agents tested in conventional carcinogenicity bioassays. Toxicol Sci. 2000 Feb;53(2):213–223. doi: 10.1093/toxsci/53.2.213. [DOI] [PubMed] [Google Scholar]
- Spalding J. W., French J. E., Tice R. R., Furedi-Machacek M., Haseman J. K., Tennant R. W. Development of a transgenic mouse model for carcinogenesis bioassays: evaluation of chemically induced skin tumors in Tg.AC mice. Toxicol Sci. 1999 Jun;49(2):241–254. doi: 10.1093/toxsci/49.2.241. [DOI] [PubMed] [Google Scholar]
- Spalding J. W., Momma J., Elwell M. R., Tennant R. W. Chemically induced skin carcinogenesis in a transgenic mouse line (TG.AC) carrying a v-Ha-ras gene. Carcinogenesis. 1993 Jul;14(7):1335–1341. doi: 10.1093/carcin/14.7.1335. [DOI] [PubMed] [Google Scholar]
- Stoll R. E., Holden H. E., Barthel C. H., Blanchard K. T. Oxymetholone: III. Evaluation in the p53+/- transgenic mouse model. Toxicol Pathol. 1999 Sep-Oct;27(5):513–518. doi: 10.1177/019262339902700503. [DOI] [PubMed] [Google Scholar]
- Storer R. D., French J. E., Haseman J., Hajian G., LeGrand E. K., Long G. G., Mixson L. A., Ochoa R., Sagartz J. E., Soper K. A. P53+/- hemizygous knockout mouse: overview of available data. Toxicol Pathol. 2001;29 (Suppl):30–50. doi: 10.1080/019262301753178465. [DOI] [PubMed] [Google Scholar]
- Suemizu Hiroshi, Muguruma Kaori, Maruyama Chika, Tomisawa Masashi, Kimura Minoru, Hioki Kyoji, Shimozawa Nobuhiro, Ohnishi Yasuyuki, Tamaoki Norikazu, Nomura Tatsuji. Transgene stability and features of rasH2 mice as an animal model for short-term carcinogenicity testing. Mol Carcinog. 2002 May;34(1):1–9. doi: 10.1002/mc.10045. [DOI] [PubMed] [Google Scholar]
- Tennant R. W., French J. E., Spalding J. W. Identifying chemical carcinogens and assessing potential risk in short-term bioassays using transgenic mouse models. Environ Health Perspect. 1995 Oct;103(10):942–950. doi: 10.1289/ehp.95103942. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tennant R. W., Stasiewicz S., Mennear J., French J. E., Spalding J. W. Genetically altered mouse models for identifying carcinogens. IARC Sci Publ. 1999;(146):123–150. [PubMed] [Google Scholar]
- Tennant R. W. Stratification of rodent carcinogenicity bioassay results to reflect relative human hazard. Mutat Res. 1993 Mar;286(1):111–118. doi: 10.1016/0027-5107(93)90006-2. [DOI] [PubMed] [Google Scholar]
- Tice R. R., Nylander-French L. A., French J. E. Absence of systemic in vivo genotoxicity after dermal exposure to ethyl acrylate and tripropylene glycol diacrylate in Tg.AC (v-Ha-ras) mice. Environ Mol Mutagen. 1997;29(3):240–249. [PubMed] [Google Scholar]
- Trempus C. S., Mahler J. F., Ananthaswamy H. N., Loughlin S. M., French J. E., Tennant R. W. Photocarcinogenesis and susceptibility to UV radiation in the v-Ha-ras transgenic Tg.AC mouse. J Invest Dermatol. 1998 Sep;111(3):445–451. doi: 10.1046/j.1523-1747.1998.00237.x. [DOI] [PubMed] [Google Scholar]
- Usui T., Mutai M., Hisada S., Takoaka M., Soper K. A., McCullough B., Alden C. CB6F1-rasH2 mouse: overview of available data. Toxicol Pathol. 2001;29 (Suppl):90–108. doi: 10.1080/019262301753178500. [DOI] [PubMed] [Google Scholar]
- Venkatachalam S., Shi Y. P., Jones S. N., Vogel H., Bradley A., Pinkel D., Donehower L. A. Retention of wild-type p53 in tumors from p53 heterozygous mice: reduction of p53 dosage can promote cancer formation. EMBO J. 1998 Aug 17;17(16):4657–4667. doi: 10.1093/emboj/17.16.4657. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Vogelstein B., Civin C. I., Preisinger A. C., Krischer J. P., Steuber P., Ravindranath Y., Weinstein H., Elfferich P., Bos J. RAS gene mutations in childhood acute myeloid leukemia: a Pediatric Oncology Group study. Genes Chromosomes Cancer. 1990 Jul;2(2):159–162. doi: 10.1002/gcc.2870020212. [DOI] [PubMed] [Google Scholar]
- Weinberg R. A. Tumor suppressor genes. Science. 1991 Nov 22;254(5035):1138–1146. doi: 10.1126/science.1659741. [DOI] [PubMed] [Google Scholar]
- Weisburger E. K. Bioassay program for carcinogenic hazards of cancer chemotherapeutic agents. Cancer. 1977 Oct;40(4 Suppl):1935–1949. doi: 10.1002/1097-0142(197710)40:4+<1935::aid-cncr2820400827>3.0.co;2-r. [DOI] [PubMed] [Google Scholar]
- Yamamoto M., Tsukamoto T., Sakai H., Shirai N., Ohgaki H., Furihata C., Donehower L. A., Yoshida K., Tatematsu M. p53 knockout mice (-/-) are more susceptible than (+/-) or (+/+) mice to N-methyl-N-nitrosourea stomach carcinogenesis. Carcinogenesis. 2000 Oct;21(10):1891–1897. doi: 10.1093/carcin/21.10.1891. [DOI] [PubMed] [Google Scholar]
- Yamamoto S., Mitsumori K., Kodama Y., Matsunuma N., Manabe S., Okamiya H., Suzuki H., Fukuda T., Sakamaki Y., Sunaga M. Rapid induction of more malignant tumors by various genotoxic carcinogens in transgenic mice harboring a human prototype c-Ha-ras gene than in control non-transgenic mice. Carcinogenesis. 1996 Nov;17(11):2455–2461. doi: 10.1093/carcin/17.11.2455. [DOI] [PubMed] [Google Scholar]
- Yamamoto S., Urano K., Koizumi H., Wakana S., Hioki K., Mitsumori K., Kurokawa Y., Hayashi Y., Nomura T. Validation of transgenic mice carrying the human prototype c-Ha-ras gene as a bioassay model for rapid carcinogenicity testing. Environ Health Perspect. 1998 Feb;106 (Suppl 1):57–69. doi: 10.1289/ehp.98106s157. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Yamamoto S., Urano K., Nomura T. Validation of transgenic mice harboring the human prototype c-Ha-ras gene as a bioassay model for rapid carcinogenicity testing. Toxicol Lett. 1998 Dec 28;102-103:473–478. doi: 10.1016/s0378-4274(98)00341-5. [DOI] [PubMed] [Google Scholar]
- Yunis J. J., Boot A. J., Mayer M. G., Bos J. L. Mechanisms of ras mutation in myelodysplastic syndrome. Oncogene. 1989 May;4(5):609–614. [PubMed] [Google Scholar]
- el-Deiry W. S. Regulation of p53 downstream genes. Semin Cancer Biol. 1998;8(5):345–357. doi: 10.1006/scbi.1998.0097. [DOI] [PubMed] [Google Scholar]