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Comparison of in vitro micronucleus and gene mutation assay results for p53-competent versus p53-deficient human lymphoblastoid cells.
MedLine Citation:
PMID:  20963812     Owner:  NLM     Status:  In-Data-Review    
Abstract/OtherAbstract:
The high frequency of false or irrelevant positive results in in vitro mammalian cell genotoxicity tests is a critical concern for regulators. Here, we tested whether such results may be due to the mammalian cells used in the tests being deficient in p53, which is involved in the maintenance of genomic stability. We compared the in vitro responses of two human lymphoblastoid cell lines derived from the same progenitor cell-p53-competent (TK6) and p53-deficient (WTK-1) cells-in a micronucleus (MN) test and a thymidine kinase gene (TK) mutation assay. We tested 14 chemicals including three mutagens and 11 clastogens and spindle poisons. The three mutagens evoked clear positive responses in both assays in both cell lines. The responses to the clastogens and spindle poisons, on the other hand, depended on the assay endpoint and/or the cell line. Most of clastogens and spindle poisons were positive in the MN test in both cell lines. In the TK mutation assay, on the other hand, WTK-1 cells but not TK6 cells detected spindle poisons, which may have been due to the disturbance of the spindle checkpoint and lack of apoptosis in the p53-deficient cells. Some chemicals that induced chromosome aberrations in rodent cells were negative in both TK6 and WTK-1 cells, indicating that a species-specific factor rather than p53 status was associated with the response. In conclusion, the p53 status did not seriously influence the MN test results but it did influence the TK mutation assay results. Environ. Mol. Mutagen., 2011. © 2010 Wiley-Liss, Inc.
Authors:
Masamitsu Honma; Makoto Hayashi
Publication Detail:
Type:  Journal Article     Date:  2010-10-20
Journal Detail:
Title:  Environmental and molecular mutagenesis     Volume:  52     ISSN:  1098-2280     ISO Abbreviation:  Environ. Mol. Mutagen.     Publication Date:  2011 Jun 
Date Detail:
Created Date:  2011-06-01     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8800109     Medline TA:  Environ Mol Mutagen     Country:  United States    
Other Details:
Languages:  eng     Pagination:  373-84     Citation Subset:  IM    
Copyright Information:
Copyright © 2010 Wiley-Liss, Inc.
Affiliation:
National Institute of Health Sciences, Division of Genetics and Mutagenesis, Tokyo, Japan. honma@nihs.go.jp.
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