University of North Carolina at Chapel Hill Graduate School
Doi
Abstract
The current regulatory framework in toxicology is expanding beyond traditional animal toxicity testing to include new approach methodologies (NAMs) like computational models built using rapidly generated dose-response information like US Environmental Protection Agency’s Toxicity Forecaster (ToxCast) and the interagency collaborative Tox21 initiative. These programs have provided new opportunities for research but also introduced challenges in application of this information to current regulatory needs. One such challenge is linking in vitro chemical bioactivity to adverse outcomes like cancer or other complex diseases. To utilize NAMs in prediction of complex disease, information from traditional and new sources must be interoperable for easy integration. The work presented here describes the development of a bioinformatic tool, a database of traditional toxicity information with improved interoperability, and efforts to use these new tools together to inform prediction of cancer and complex disease. First, a bioinformatic tool was developed to provide a ranked list of Medical Subject Heading (MeSH) to gene associations based on literature support, enabling connection of complex diseases to genes potentially involved. Second, a seminal resource of traditional toxicity information, Toxicity Reference Database (ToxRefDB), was redeveloped, including a controlled vocabulary for adverse events used to map identifiers in the Unified Medical Language System (UMLS), thus enabling a connection to MeSH terms. Finally, gene to MeSH associations were used to evaluate the biological coverage of ToxCast for cancer to understand the capacity to use ToxCast to identify chemical hazard potential. ToxCast covers many gene targets putatively linked to cancer; however, more information on pathways in cancer progression is needed to identify robust associations between chemical exposure and risk of complex disease. The findings herein demonstrate that increased interoperability between data resources is necessary to leverage the large amount of data currently available to understand the role environmental exposures play in etiologies of complex diseases.Doctor of Philosoph
