Toxicogenomics — Applications in Systems Toxicology

Human exposure to toxic chemicals is almost unavoidable. The toxicity owing to human exposure to chemicals may result in adverse health effects such as illnesses and even death. It is therefore important to determine whether human exposure to chemicals may result in toxicity and, if so, to obtain a full understanding of the mechanism(s) underlying the toxicity. Recent developments in genomics and their application in toxicology (toxicogenomics) have facilitated a better understanding of chemical toxicity. Unlike traditional toxicity studies, toxicogenomics studies have the potential to detect toxicity pre-clinically (before the onset of clinical manifestations of toxicity) and this may have implications even in predicting the toxicity of chemicals. Recent studies have demonstrated the potential application of genomics-based toxicity determination in surrogate tissues such as blood, for monitoring human exposure to toxic chemicals. The potential of toxicogenomics in determining the toxicity of chemicals is best illustrated in the case of hepatotoxic chemicals. It is anticipated that toxicogenomics studies, in conjunction with the traditional toxicity determination approaches, may be useful to determine the systems toxicity of chemicals. Keywords: blood; gene expression; hepatotoxicity; microarray; surrogate tissue; toxicogenomics