Next Generation Testing Strategies for Assessment of Genotoxicity

Project SummaryIt is well recognized that current batteries of genetic toxicology assays exhibit two critical deficiencies.
First, the throughput capacity of in vitro mammalian cell genotoxicity tests is low, and does not meet current
needs. Second, conventional assays provide simplistic binary calls, genotoxic or non-genotoxic. In this scheme
there is little or no consideration for potency, and virtually no information is provided about molecular targets
and mechanisms. These deficiencies in hazard characterization prevent genotoxicity data from optimally
contributing to modern risk assessments, where this information is essential. We will address these major
problems with current in vitro mammalian cell genetic toxicity assays by developing methods and associated
commercial assay kits that dramatically enhance throughput capacity, and delineate genotoxicantsandapos; primary
molecular targets, while simultaneously providing information about potency. Once biomarkers and a family of
multiplexed assays have been developed for these purposes, an interlaboratory trial will be performed with
prototype assay kits to assess the transferability of the methods.Project NarrativeDNA damage that cannot be faithfully repaired results in gene mutation and/or chromosomal
aberrations, and these effects are known to contribute to cancer and other severe diseases. Thus, there is an
important need for sensitive assays to evaluate chemicals for genotoxic and other deleterious effects. The
work proposed herein will address issues that have plagued genotoxicity assessments for the last several
decades: low throughput, lack of potency metrics, and little to no information about molecular targets. We will
address these major problems with current genetic toxicity assays by developing new methods and associated
commercial assay kits.