title: Fluoranthene enhances p53 expression and decreases mutagenesis induced by benzo[a]pyrene.
abstract: Fluoranthene (Fla) is the most abundant polycyclic aromatic hydrocarbon (PAH) in diesel particulate extracts. Benzo[a]pyrene (BaP) is genotoxic and is a prototype of PAH carcinogens. Fla's toxicity and mutagenicity are minor relative to BaP's. Our data showed that Fla enhanced BaP-induced p53 expression and promoted BaP-induced cell death. In contrast, Fla decreased BaP-induced mutagenesis. Fla had almost no influence on the cell cycle. However, the effect of cotreatment with BaP (1μM) and Fla (10μM) in regulating the cell cycle was greater than that of BaP (2μM) alone. It is known that BaP activates the aryl hydrocarbon receptor (AhR), and, in turn, the AhR induces cytochrome P450 (Cyp)1a1 expression. The expression of Cyp1a1 corresponds well with the induction of apoptosis and mutagenesis by BaP. Fla did not activate the AhR or antagonize BaP's induction of AhR activity and Cyp1a1 expression. Therefore, the actions of Fla on BaP's toxicity were independent of the AhR signal and Cyp1a1. In summary, results indicated that Fla directs BaP-treated cells into death rather than mutagenesis, consequently preventing cells from being transformed. The novel cooperation between Fla and BaP provides valuable information for how to increase expression of the p53 tumor suppressor.
authors: Department of Biochemical Science and Technology, National Chiayi University, Chiayi 600, Taiwan, ROC.
authors: Min-Cong
authors: MC
authors: Huang
authors: Fei-Yun
authors: FY
authors: Chen
authors: Mou-Tsy
authors: MT
authors: Chou
authors: Jyan-Gwo J
authors: JG
authors: Su
mesh_terms: D000818:Animals; D001564:Benzo(a)pyrene / Q000633:toxicity*; D015153:Blotting, Western; D002273:Carcinogens / Q000633:toxicity*; D002453:Cell Cycle / Q000187:drug effects; D016923:Cell Death / Q000187:drug effects; D004347:Drug Interactions; D005449:Fluorenes / Q000633:toxicity*; D056945:Hep G2 Cells; D006801:Humans; D051379:Mice; D008856:Microscopy, Fluorescence; D009152:Mutagenicity Tests; D012313:RNA / Q000737:chemistry / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D002273:Carcinogens; D005449:Fluorenes; D016159:Tumor Suppressor Protein p53; D001564:Benzo(a)pyrene; C007738:fluoranthene; D012313:RNA