It’s common knowledge that exposure to high-molecular weight polycyclic aromatic hydrocarbons (PAHs) increases the risk of cancer, which has led to the regulation of compounds like benzo(a)pyrene (BAP). Less was known about the effects of low-molecular weight PAHs, but a University of Colorado Cancer Center (UCCC) study shows that cancer-promoting changes occur in lung cells as rapidly as 30 minutes after exposure to low-molecular weight PAHs.
The results suggest that the risk from these compounds, commonly found in secondhand cigarette and marijuana smoke and through other exposures, has been underestimated.
Investigators exposed lung cells to a mixture of low-molecular weight PAHs including 1-methylanthracene and fluoranthene, which are abundant in secondhand smoke and have been shown to produce cancer-supporting changes. Within as little as 30 minutes, the low-molecular weight PAHs were activating lipid signaling that partly initiates cellular changes associated with early cancer development.
PAH researchers have long believed that PAHs must be metabolized before causing adverse events, but the UCCC researchers noted effects before metabolism. They are now planning future experiments using slices of lung tissue, hoping to show the effects of low-molecular weight PAHs in models closer to the human lung.
Source: University of Colorado Cancer Center, February 11, 2019