Differential effects of polycyclic aromatic hydrocarbons on transactivation of AP-1 and NF-kappaB in mouse epidermal cl41 cells.
Polycyclic aromatic hydrocarbons (PAHs) and their derivatives, such as benzo[a]pyrene (B[a]P), (+/-)-anti-benzo[a]pyrene-7,8-diol-9,10-epoxide (B[a]PDE), and 5-methylchrysene-1,2-diol-3,4-epoxide (5-MCDE), are complete carcinogens. However, the tumor promotion effects of PAHs remain unclear. We therefore investigated the possible activation of activator protein-1 (AP-1) and nuclear factor-kappaB (NFkappaB) in mouse epidermal Cl41 cells after different PAHs treatments, including B[a]P, B[a]PDE, chrysene-1,2-diol-3,4-epoxid (CDE), and 5-MCDE. The results showed that B[a]PDE and 5-MCDE were able to activate AP-1 and NF-kappaB, whereas B[a]P showed only marginal effect on AP-1 activation, and B[a]P and CDE had no effect on NF-kappaB activation. Treatment with either B[a]PDE or 5-MCDE also resulted in mitogen-activated protein kinases (MAPKs) activation as well as inhibitory subunit kappa-B (IkappaBalpha) phosphorylation and degradation, whereas B[a]P and CDE had no effect. Pretreatment with PD98059, a specific inhibitor for extracellular signal-regulated protein kinases (ERKs) upstream kinase MEK1/2, or SB202190, a p38 kinase inhibitor, resulted in a dramatic inhibition of B[a]PDE-induced AP-1 transactivation. In addition, B[a]PDE-induced AP-1 activation was also inhibited by overexpressing a dominant negative mutant of JNK1 in the cells. All these suggest ERKs, c-jun N-terminal kinases (JNKs), and p38 kinase signal transduction pathways are required for AP-1 induction by B[a]PDE. Taken together, B[a]PDE and 5-MCDE are the active compounds of PAHs to initiate signaling pathways. Considering the important roles of AP-1 and NF-kappaB in tumor promotion, we speculated the activation of AP-1 and NF-kappaB by B[a]PDE and 5-MCDE may involve in their or their parent compounds' tumor promotion effects. This study may help in better understanding the tumor promotion effects of PAHs.
Li
Jingxia
J
Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, New York, USA.
Chen
Haobin
H
Ke
Qingdong
Q
Feng
Zhaohui
Z
Tang
Moon-Shong
MS
Liu
Bingci
B
Amin
Shantu
S
Costa
Max
M
Huang
Chuanshu
C
D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide / Q000633:toxicity; D000818:Animals; D001564:Benzo(a)pyrene / Q000633:toxicity; D002273:Carcinogens / Q000633:toxicity*; D002478:Cells, Cultured; D002911:Chrysenes / Q000633:toxicity; D004791:Enzyme Inhibitors / Q000494:pharmacology; D000078404:Epidermal Cells; D004817:Epidermis / Q000187:drug effects* / Q000378:metabolism; D005419:Flavonoids / Q000494:pharmacology; D020672:I-kappa B Proteins / Q000187:drug effects / Q000378:metabolism; D007093:Imidazoles / Q000494:pharmacology; D048031:JNK Mitogen-Activated Protein Kinases; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000378:metabolism; D016328:NF-kappa B / Q000187:drug effects* / Q000378:metabolism; D010766:Phosphorylation; D011084:Polycyclic Aromatic Hydrocarbons / Q000633:toxicity*; D011725:Pyridines / Q000494:pharmacology; D015398:Signal Transduction; D018808:Transcription Factor AP-1 / Q000187:drug effects* / Q000378:metabolism; D015533:Transcriptional Activation / Q000187:drug effects
D002273:Carcinogens; D002911:Chrysenes; D004791:Enzyme Inhibitors; D005419:Flavonoids; D020672:I-kappa B Proteins; D007093:Imidazoles; D016328:NF-kappa B; D011084:Polycyclic Aromatic Hydrocarbons; D011725:Pyridines; D018808:Transcription Factor AP-1; D001564:Benzo(a)pyrene; D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide; C021977:chrysene,2-diol-3,4-epoxide-1; C037783:1,2-dihydroxy-epoxy-1,2,3,4-tetrahydro-5-methylchrysene; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; C090942:4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)imidazole; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one