Toxicogenomics: regulatory perspective on current position.

Published studies on the utility of toxicogenomic approaches (transcriptomics, proteomics and metabonomics) in screening for toxicological mechanisms and evaluation of dose response effects have been reviewed. The information supports the use of transcriptomics to screen for specific toxicological mechanisms for which there is an a priori hypothesis, although in some areas such as mutagenicity testing, toxicogenomics appear to have limited value for identifying mutagens. Data from such screening approaches cannot be used to exclude the possibility of toxicity. Targeted transcriptomics might be valuable for screening for specific mechanisms of toxicity considered to be irrelevant for assessing risk to humans, which would help to reduce the need for detailed testing of some chemicals. An integrated approach is suggested where data from more than one toxicogenomic approach could be used as an adjunct to conventional toxicology to assess dose-response in toxicological tests. An outline preliminary proposal for use by regulators is suggested although it is noted that more data are required before this could be formally used in a decision-making process.