[Toxicogenomics as a tool for evaluation of chemical effects]

Concern about the toxicity of chemicals released into the environment has been increasing recently. Many chemicals are suspected to have hazardous effects, but evaluation of their toxicity is still difficult and challenging. One of these difficulties is the presence of chemicals that are reported to have an adverse effect on organisms despite negative results in conventional toxicity tests. Thus, a new technique has been desired in order to evaluate the effects of chemicals, Recent advances in molecular biology have provided a technique for better understanding the responses of organisms to chemicals; this emerging field is known as toxicogenomics. Toxicogenomics is defined as an integration of genomics (transcriptomics, proteomics, metabolomics) and toxicology. For example, the DNA microarray can be used to explore the gene expression profiles (transcriptomics) of organisms in response to chemicals. Exposure to chemicals results in characteristic gene expression profiles, suggesting that the DNA microarray can be used to evaluate chemical effects. Toxicogenomics is also expected to be useful in gaining a mechanistic understanding of these effects. Although it still has some limitations, this technique can be developed to assess chemicals.