Developing an in vitro repeat-dose approach to non-genotoxic carcinogen

Human exposure to chemicals is primarily chronic (i.e. repeated exposure over time) rather than acute and thus it is important that in vitro tests are adapted to mirror this. The aim of this research project is to investigate the effect of chronic dosing in vitro upon DNA damage, compared to acute (single) dosing. Specifically, this research will aim to highlight previously defined non-genotoxic carcinogens (NGCs) under acute dosing regimes and reassess this categorisation following chronic exposure. If under chronic dosing a positive genotoxic response is observed, analysis into potential mechanisms of action will be addressed. NGCs each act via unique modes of action, so a range of 10 NGCs will be incorporated in order to identify a variety of the pathways utilised. Furthermore, it could be identified that multiple mechanisms may be adopted by a single NGC in order to elicit tumour formation. Key genotoxic mechanisms previously identified are DNA methylation, elevated oxidative stress, inhibition of DNA repair, unregulated proliferation and mitotic signalling which all indirectly lead to mutational events. Therefore, given NGCs ability to modify aspects of genome leading to instability, we hypothesise that a genotoxic response should be detectable with modified in vitro approaches aimed at identifying DNA damage. Providing this in vitro technique is successful in identifying NGCs, this will reduce the need for extensive animal testing therefore agreeing with NC3Rs principles. Some of the research methods that will be used are the Cytokinesis blocked micronucleus assay, flow cytometry and oxidative stress analysis. Additional techniques will be selected based on the mechanism deployed by the NGCs investigated.


EPSRC Research Areas:

Statistics and applied probability