‘Omics in (Eco)toxicology: Case Studies and Risk Assessment

Introduction

In 2007, ECETOC organised a Workshop on the application of “omics technologies in toxicology and ecotoxicology (see Workshop Report 11). This year a workshop was held in Malaga on 22 and 23 February to review the progress made since then on the application of “omics technologies to chemical safety, and assess the potential impact of these new technologies on the risk assessment of chemical substances.

Attended by selected industry experts and invited external scientists, seven case studies were presented as well as sessions on future perspectives, system biology and modelling. These were followed by syndicate discussions on baseline, new descriptors, adverse effects, identification of mode of action and its qualitative application to risk assessment.

Conclusions and recommendations

The following conclusions were drawn in a final plenary session:

• “Omics data are particularly valuable for understanding modes of action (MoA) via underlying molecular patterns and by exploring responses to model compounds in highly standardised systems.
• Novel patterns or biomarkers (e.g. gene signatures, metabolome profiles) can also be developed this way for screening chemical properties of novel compounds.
• Within the context of risk assessment “omics data can already add value to risk assessment by improving mechanistic understanding and the identification of modes of action.
• To enhance the acceptance of “omics data, for such risk assessment purposes, high quality data and a careful design of the biological experiment are essential.
• Mode of action recognition by fingerprints or biomarkers can be enhanced if the changes observed can be causally linked to the toxicological pathway.
• These technologies can potentially serve as a tool for the prioritisation of chemical testing and could help to provide a better (biology based) rationale for chemical grouping under the REACH legislation.
• To better assess the quantitative aspects of “omics data, more information concerning the sensitivity of “omics relative to classical toxicology testing is needed. It would seem that transcriptomic information may be more sensitive than classical toxicology, whereas metabolomics appears to be equally sensitive.

In addition, there is a need for better standardisation of methods within the various activities in this dynamic field, particularly in the area of transcriptomics. The participants also agreed that in the near future, “omics technologies could help to bridge in vitro testing to in vivo relevance.

Guidance (communication of best practices), rather than guidelines will encourage improvements and adaptation to new technical developments.

The workshop concluded that better standardisation, data interpretation and evaluation will build confidence in the value of “omics technologies - this being essential to increase their (regulatory) use. The workshop therefore called for an international effort to bring together scientists from academia, industry, agencies as well as the risk assessors themselves, to discuss and evaluate the necessary modifications that may be needed to enhance the use of “omics data in risk assessment.

Publications

The Workshop Report is available at the ECETOC website (Workshop Report 19).