LGC demonstrates potential of toxicogenomics in REACH compliance
10 Oct 2011
Microarray technology offers alternative approach for toxicity testing
LGC scientists have published* the results of a study to determine the reproducibility of in vitro toxicogenomics data, which indicate that these methods are sufficiently robust and reproducible to allow their further investigation in regulatory risk assessment.
In vitro studies offer quicker, cheaper and more ethical alternatives to animal testing. Driven by the introduction of legislation such as REACH**, as well as an amendment to the Cosmetics Directive, banning marketing of cosmetic products containing ingredients tested on animals, there has been a concerted effort to develop in vitro assays for regulatory toxicity risk assessment.
In collaboration with the Fund for the Replacement of Animals in Medical Experiments (FRAME), Unilever, Agilent and the Institute for Health and Consumer Protection of the European Commission's Joint Research Centre, LGC designed an inter- and intra-laboratory study to assess whether the current generation of microarray technology is capable of generating robust, reproducible data of sufficient quality to show promise as a tool for regulatory risk assessment.
Toxicogenomics merges toxicology with genomics and bioinformatics to investigate global molecular and cellular effects of chemicals in biological systems. While this platform has been evaluated over the past 10 to15 years in the pharmaceutical and chemical industries, improvements in microarray technology have made the platform more robust, thereby potentially offering a suitable alternative to costly animal testing.
As a case study, three of the laboratories analysed a human liver cell model (HepG2) for gene expression, following 24 hours’ exposure to the genotoxic carcinogen benzo[a]pyrene (B[a]P). Exposure of HepG2 cells to B[a]P has been used as an archetypal model for research into the mechanisms of genetic toxicology and forms the basis for many standardised testing studies. The abundance of existing data from previous toxicogenomic studies enabled direct comparisons with results from this research.
Mimicking a real-life regulatory testing environment and incorporating a well controlled standard operating procedure, the inter-laboratory study produced reproducible datasets, with each laboratory identifying the same key biological responses characteristic of a B[a]P response. This provides further evidence that toxicogenomics can predict chemical toxicity in vitro and, importantly, it also shows that the technology can produce data of sufficient quality to show promise as a tool for toxicity testing in a regulatory setting.
Dr Daniel Scott, who managed the project at LGC said: “The success of this collaboration highlights the increasing maturity of toxicogenomics and its potential as a predictive risk assessment tool. This data should provide encouragement within the toxicology community that an in vitro toxicogenomic approach is worthy of further development and validation and may become part of a risk assessment paradigm without animal testing. With further development, this in vitro approach can potentially save industry millions of pounds in chemical hazard testing whilst also addressing compliance with REACH and Cosmetic Directive legislation.”