As a master regulator of gene expression, the epigenome is responsive to a diverse range of environmental factors including toxicant exposure, diet, stress, and socioeconomic circumstances. Traditional toxicological paradigms have relied on factors such as age, genetic polymorphisms, and disease status to identify variability in responsiveness to environmental toxicant exposure; however, these factors are neither sufficient to faithfully identify differentially responsive individuals, nor are they modifiable factors that can be leveraged to mitigate adverse health effects of toxicant exposures. An individual’s epigenome, on the other hand, is malleable and shaped by interactions with chemical and nonchemical aspects of the environment, giving it potential as a tool for the promotion of public health.
While it is common to refer to this field as “epigenetic toxicology,” we believe it is more appropriate to use the term “toxicoepigenetics” because the former connotes a narrow focus on epigenetic mechanisms underlying toxicity. We are using toxicoepigenetics as a more inclusive term to refer to the particular type(s) of epigenetic alterations at specific loci in the genome that might arise following environmental exposures, including chemical and nonchemical stressors and their possible interactions, and the role of the epigenome as a possible mediator of exposure effects. We will also explore the emerging field of toxicoepigenomics, which refers to attempts to understand toxicoepigenetic data with regard to the global role of epigenetic alterations across the genome with respect to adverse outcomes and risk of exposure effects. Emphasis is placed on discerning if and how particular epigenetic states might contribute to the ability of a potential toxicant to cause adverse health outcomes. During this meeting we will discuss both toxicoepigenetic and toxicoepigenomic approaches to give attendees a comprehensive view of the interactions between the epigenome and the environment at different biological levels.
The field of toxicoepigenetics is rapidly evolving to provide novel insights into the mechanisms underlying exposure-related susceptibility and disease; however, the utility and practicality of using epigenetic data in public health and risk assessment remains unclear. Thus, it is critical to examine the “state of the science” and discuss potential applications and predictable limitations facing the integration of epigenetic data into human health risk assessment paradigms. Toxicoepigenetics has the potential to address critical needs in both basic science and applied fields of toxicology, including:
- Identification of predictors of inter-individual variability in exposure responsiveness within traditional risk groups
- Providing insight into the mechanisms underlying acute, chronic, and multi- and trans-generational exposure effects
- Identification of modifiable factors that may be leveraged as interventions to mitigate the risk of exposure effects
- Development of epigenetic biomarkers of exposure and effects.
This conference will take an intuitive approach to presenting cutting-edge research on the role of the epigenome as a central mechanism linking environmental exposures to adverse health outcomes. Following a summary of current data, the focus will shift to presentations outlining both a model for the use of epigenetic and epigenomic data from mechanistic studies and identifying current limitations to the incorporation of epigenetic data into future risk assessment paradigms.