Vet Med Associate Professor Christiane Lohr, and a team of researchers from the OSU Department of Environmental and Molecular Toxicology, have developed a faster, more accurate method to assess cancer risk from exposure to polycyclic aromatic hydrocarbons (PAHs).
PAHs are molecules found in fossil fuels and are produced when insufficient oxygen or other factors result in incomplete combustion of organic matter (e.g. engines and incinerators). PAHs can also be found at high levels in meat cooked at high temperatures over open flame. PAHs have been identified as carcinogenic and are considered a concern for the potency of potential adverse health impacts.
The results of the PAH study were recently published in the Journal of Toxicological Sciences and was also highlighted in the current issue of NIEHS Environmental Factor.
People are primarily exposed to PAHs in the form of mixtures, and this proof-of-concept study demonstrated a first step toward moving away from risk assessments based on individual components of PAH mixtures, to using methods that examine the whole mixture.
To determine the carcinogenic risk of PAH mixtures, the researchers measured the chemical bioactivity profile in skin cells of mice just after short-term PAH exposure. The bioactivity profile, which provides a unique fingerprint of genes and pathways activated by chemicals after exposure, can be used for predicting long-term consequences such as cancer. They tested PAH mixtures found in coal tar, diesel exhaust, and cigarette smoke. After only 12 hours, the researchers could predict the ability of certain PAH mixtures to cause cancer. Other methods take months for tumors to develop.
Although the method needs further testing, the findings demonstrate that long-term cancer outcome for PAH mixtures can be predicted by evaluating bioactivity after short-term exposure. Since the bioactivity profile provides gene signatures that are tied to chemical mechanisms of action, this information could also provide insight into alternate mechanisms of PAH carcinogenesis and related mechanisms for complex mixtures.
