ABSTRACT
This chapter focuses on the basic design, interpretation, and application of toxicogenomic studies as they relate to characterization of toxicity and carcinogenicity bioassays in toxicologic pathology. To date, the "-omics" technologies have provided massive amounts of biologic information and fewer-than-expected applications in predictive profiling in toxicologic pathology as well as human medicine. The pathologist will ultimately play an integral role in connecting such changes in gene expression at such early time-points with lesions associated with pre-neoplasia that will ultimately progress to neoplasia. The classification of compounds as genotoxic or nongenotoxic in nature for cancer risk assessment and drug development is very important, and means to predict the carcinogenic response to various genotoxic and nongenotoxic carcinogens is great interest. The advent of microarray technology allows the assessment of the expression of literally thousands of genes at a time from a single sample of mRNA, revolutionizing the field of toxicology and significantly advancing the understanding of toxic mechanisms relevant to human health.
