Nanoparticle carbon black driven DNA damage induces growth arrest and AP-1 and NFkappaB DNA binding in lung...

To assess whether nanoparticle (NP) driven DNA damage induces the expression of proinflammatory transcription factors such as NFB and AP-1 A549, lung epithelial cells were treated with Carbon Black (CB), nanoparticulate CB (NPCB), NPCB coated with BaP (BaP-NPCB) for various times ranging from 30 min to 24 h. DNA strand break was determined by the comet assay and cell cycle status was analyzed using flow cytometry. Nuclear extracts were used for WB analysis of P approximately Ser15-p53. EMSA was used to detect DNA binding. Tested NP caused single strand breaks and significantly altered cell cycle kinetics. NF-kappaB and AP-1 DNA binding were increased at early time points (2.3 and 2.6 fold at 1 hour, respectively). Effects were also found on Ser15-p53 phosphorylation. N-acetylcysteine blocked NP driven effects. In conclusion, NPCB and BaP-NPCB induce DNA damage, activating p53, proteins related to DNA repair and proinflammatory transcription factors.