Journal article
Development and validation of a new transgenic hairless albino mouse as a mutational model for potential assessment of photocarcinogenicity
Mutation research. Genetic toxicology and environmental mutagenesis, Vol.791, pp.42-52
09/2015
Handle:
https://hdl.handle.net/2376/106715
PMID: 26338542
Abstract
•Development of a transgenic hairless albino (THA) mouse model.•Ultraviolet B irradiation for validation of THA mice.•Skin mutant frequency in the gpt and red/gam (Spi−) genes.
Short-term phototoxicity testing is useful in selecting test agents for the longer and more expensive photocarcinogenesis safety tests; however, no validated short-term tests have been proven reliable in predicting the outcome of a photocarcinogenesis safety test. A transgenic, hairless, albino (THA) mouse model was developed that carries the gpt and red/gam [Spi−] genes from the gpt delta mouse background and the phenotypes from the SKH-1 mouse background to use as a short-term test in lieu of photocarcinogenesis safety tests. Validation of the THA mouse model was confirmed by exposing groups of male mice to sub-erythemal doses of ultraviolet B (UVB) irradiation for three consecutive days emitted from calibrated overhead, Kodacel-filtered fluorescent lamps and measuring the mutant frequencies (MFs) in the gpt and red/gam (Spi−) genes and types of mutations in the gpt gene. The doses or irradiation were monitored with broad-spectrum dosimeters that were calibrated to a NIST-traceable standard and cumulative CIE-weighted doses were 20.55 and 41.0mJ/cm2 (effective). Mice were sacrificed 14 days after the final UVB exposure and MFs in both the gpt and red/gam genes were evaluated in the epidermis. The exposure of mice to UVB induced significant ten- to twelve-fold increases in the gpt MF and three- to five-fold increases in the Spi− MF over their respective background MF, 26±3×10−6 and 9±1×10−6. The gpt mutation spectra were significantly different between that of the UVB-irradiated and that of non-irradiated mice although the mutation spectra of both groups were dominated by C→T transitions (84% and 66%). In mice exposed to UVB, the C→T transitions occurred almost exclusively at dipyrimidine sites (92%), whereas in non-irradiated control mice, the C→T transitions occurred at CpG sites (86%). These results suggest that the newly developed THA mice are a useful and reliable model for testing UVB-induced mutagenicity in skin tissue. The application of this model for short-term prediction of solar-induced skin carcinogenicity is presently under investigation.
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Details
- Title
- Development and validation of a new transgenic hairless albino mouse as a mutational model for potential assessment of photocarcinogenicity
- Creators
- Mugimane G Manjanatha - National Center for Toxicological Research, Division of Genetic and Molecular Toxicology, USFDA, Jefferson, AR, United StatesSharon D Shelton - National Center for Toxicological Research, Division of Genetic and Molecular Toxicology, USFDA, Jefferson, AR, United StatesYing Chen - National Center for Toxicological Research, Division of Genetic and Molecular Toxicology, USFDA, Jefferson, AR, United StatesShobhan Gaddameedhi - Department of Experimental and Systems Pharmacology, Washington State University College of Pharmacy, Spokane, WA, United StatesPaul C Howard - National Center for Toxicological Research, Office of Scientific Coordination, USFDA, Jefferson, AR, United StatesMary D Boudreau - National Center for Toxicological Research, Division of Biochemical Toxicology, USFDA, Jefferson, AR, United States
- Publication Details
- Mutation research. Genetic toxicology and environmental mutagenesis, Vol.791, pp.42-52
- Academic Unit
- UNKNOWN
- Publisher
- Elsevier B.V
- Identifiers
- 99900547000001842
- Language
- English
- Resource Type
- Journal article