Chapter 34 – Toxicogenomics in Preclinical Development

It is widely accepted that the adverse effect evoked by a toxicant can be captured by analyzing an organism's genome, because through various mechanisms such compounds alter cellular homeostasis, which the cell tries to maintain by switching on or off the expression of specific genes. In the field of toxicogenomics continuous development of new technologies has led to the possibility to analyze thousands of genes simultaneously. With the large amounts of data generated, sophisticated biostatistical tools are required that allow understanding of these complex gene-expression results. Generally, transcriptomics allow a holistic approach to studying gene-expression changes, thus being a popular technique for identification and qualification of novel biomarkers. As part of safety assessment during preclinical drug development, toxicogenomics can deliver valuable information about alterations on the molecular level. This increased understanding of a drug candidate, earlier in preclinical research, can help refine standard regulatory test procedures by directing attention to relevant pathologies.