Benzo[ghi]perylene Induces Morphological and Genotoxic Effects in Human Bronchial Cells Independently of The AhR Pathway

Polycyclic aromatic hydrocarbons (PAH) are organic compounds found in the contaminated atmosphere of Mexico City, where the PAH present with highest concentration is benzo[ghi]perylene [B[ghi]p]. We recently demonstrated that double-stranded breaks in DNA appear after 3h of exposure, whereas cellular changes and activation of aryl hydrocarbon receptor (AHR) pathway occur after 48h in bronchial cells under exposure to B[ghi]p, these findings have led us to explore if the AHR pathway participates in morphological changes and genotoxic effects due to B[ghi]p in human NL-20 bronchial cells. Cells of the NL-20 human bronchial line were exposed to B[ghi]p in the presence, or absence, of the AHR receptor antagonist, CH-223191. Cell viability was quantified by the MTT assay, which revealed 76 and 66% at 6h and 24h, respectively (p<0.001), regardless of the presence of CH-223191. RT-qPCR showed an increase in the expression of the AHR and CYP1A1 cytochrome genes only after 24h of exposure, and the expression was inhibited by CH-223191. Genotoxicity assays revealed the presence of comets, nuclear buds (NB) and DNA fragmentation in cells exposed to B[ghi]p after 6h and in cells exposed to B[ghi]p plus CH-223191 at 24h. These results verify that B[ghi]p induces morphological and genotoxic effects, and these effects are independent of the AHR pathway.