Toxicogenomics combines transcript, protein and metabolite profiling with conventional toxicology to investigate the interaction between genes and environmental stress in disease causation. The patterns of altered molecular expression that are caused by specific exposures or disease outcomes have revealed how several toxicants act and cause disease. Despite these success stories, the field faces noteworthy challenges in discriminating the molecular basis of toxicity. We argue that toxicology is gradually evolving into a systems toxicology that will eventually allow us to describe all the toxicological interactions that occur within a living system under stress and use our knowledge of toxicogenomic responses in one species to predict the modes-of-action of similar agents in other species.

Gene, protein and metabolite-expression profiles can be thought of as 'snapshots' of a currently poorly mapped molecular landscape. The ultimate aim of toxicogenomics is to fully map this landscape and to realize a systems toxicology. Systems toxicology is the description of all the toxicological interactions within a living system. Like systems biology, systems toxicology attempts to define the behaviour and relationships of all of the components of a biological system on the premise that global-molecular data can be integrated and modelled computationally. The science of systems toxicology must capture data from experiments in molecular expression and toxicology and convert them into knowledge about the toxicological responses of cells and organisms under stress. This will be accomplished through the development of knowledgebases that support the integration of data from multiple domains, as well as through computational modelling.

Toxicogenomics experiments have succeeded in defining several molecular signatures of exposure to drugs and chemicals and expression patterns corresponding to various histopathologies and diseases; however, much more remains to be done to delineate the toxicity response of many target organs and to predict disease outcomes following exposures to toxicants.

Regards

Jun Ray

Assistant Mnaging Editor

Environmental Toxicology and Studies Journal