In vitro approaches for carcinogenicity testing

Background

The potential for a compound to cause cancer is often assessed with a two year rodent bioassay, which uses large numbers of animals, is expensive and time consuming. These assays can no longer be conducted for cosmetics following the revisions of the EU cosmetics directive, nor are they practical for large scale chemical testing programmes such as REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals). Alternative in vitro approaches, for example the cell biotransformation assay, have potential to address these limitations. However before regulators will accept these alternative methods for the prediction of carcinogenicity in place of the two year bioassay, there is a need to increase the understanding of the mechanistic basis of the alternative tests.

This project aimed to increase the mechanistic understanding and objectivity of cell biotransformation assays, and support their acceptance for regulatory purposes. Increased use of ths assay in regulatory safety assessment could reduce the numbers of in vivo carcinogenicity screens being carried out.

Key activities

• Workshop held in November 2010, “Cell transformation assays: state of the science, future research needs and potential role in risk assessment”. This was an international workshop co-sponsored by the UK Environmental Mutagen Society.

• Strategic research award funding in 2011 seeking proposals to develop novel human cell-based systems that could provide mechanistic information to help support a weight of evidence, mode of action based evaluation of the carcinogenic potential of chemicals.

Key findings and impacts

• A review paper outlining the key points discussed at the workshop was published in Mutagenesis [1].

• Two awards were made in response to the strategic funding call, to Professor Robert Newbold (Brunel University) and Professor Gareth Jenkins (Swansea University).