Genomics and the search for novel biomarkers in toxicology.

The advent of 'genomics' technology, in particular transcript profiling, has already had a measurable impact on the drug discovery process in the areas of target identification and validation. This review is concerned with the potential application of this technology to toxicology and drug safety assessment, with particular emphasis on biomarker discovery and characterization. An advantage (or possibly a drawback!) of transcript profiling is that candidate biomarkers of toxicity can be speedily identified, with the caveat that a significant amount of subsequent experimental and bioinformatic effort needs to be expended in order to evaluate and validate them. Attention is also drawn to the critical need for robust experimental design with studies of this type and to issues associated with the analysis of large data sets. In summary, while genomics technology undoubtedly offers much that can assist drug safety assessment, its potential has yet to be realized fully in this area. However, a large amount of resource continues to be applied to 'toxicogenomics'. Tangible benefits, in terms of new biomarkers of toxicity and reduced numbers of adverse drug effects, remain realistic objectives.