title: Induction of carbonyl reductase 1 (CBR1) expression in human lung tissues and lung cancer cells by the cigarette smoke constituent benzo[a]pyrene.
abstract: Carbonyl reductase 1 (CBR1) reduces various xenobiotic carbonyl substrates to corresponding alcohol metabolites. Here we demonstrated that benzo[a]pyrene (B[a]P), a potent pro-carcinogen and predominant polycyclic aromatic hydrocarbon (PAH) compound in cigarette smoke and air pollutants, upregulates CBR1 gene expression in vitro and in vivo, and that a proximal xenobiotic response element (XRE) motif (₋₁₂₂XRE) mediates the induction effect of B[a]P. First, we observed 46% and 50% increases in CBR1 mRNA and CBR1 protein levels, respectively, in human lung tissue samples from smokers compared to never-smokers. Second, we detected 3.0-fold (p<0.0001) induction of CBR1 mRNA and 1.5-fold (p<0.01) induction of CBR1 protein levels in cells of the human lung cancer cell line A549 incubated with 2.5 μM B[a]P for 24h. Third, results from experiments with CBR1 promoter constructs indicated that a proximal XRE motif ₋₁₂₂XRE) mediates induction of reporter activity in response to B[a]P. Furthermore, we detected enhanced nuclear translocation of aryl hydrocarbon receptor (AhR) following B[a]P exposure in A549 cells. Finally, we demonstrated increased binding of specific protein complexes to ₋₁₂₂XRE in nuclear extracts from B[a]P-treated cells and the presence of the AhR/Arnt complex in the specific nuclear protein ₋₁₂₂XRE complexes.
authors.affiliation: Department of Pharmaceutical Sciences, The State University of New York at Buffalo, Buffalo, NY 14260, USA.
authors.forename: James L
authors.initials: JL
authors.lastname: Kalabus
authors.forename: Qiuying
authors.initials: Q
authors.lastname: Cheng
authors.forename: Raqeeb G
authors.initials: RG
authors.lastname: Jamil
authors.forename: Erin G
authors.initials: EG
authors.lastname: Schuetz
authors.forename: Javier G
authors.initials: JG
authors.lastname: Blanco
mesh_terms: D000429:Alcohol Oxidoreductases / Q000096:biosynthesis* / Q000235:genetics; D001564:Benzo(a)pyrene / Q000633:toxicity*; D015153:Blotting, Western; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D004785:Environmental Pollutants / Q000633:toxicity*; D004790:Enzyme Induction / Q000187:drug effects; D006801:Humans; D008156:Luciferases / Q000235:genetics; D008168:Lung / Q000187:drug effects / Q000201:enzymology*; D008175:Lung Neoplasms / Q000201:enzymology*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D018336:Receptors, Aryl Hydrocarbon / Q000502:physiology; D012906:Smoke / Q000009:adverse effects / Q000032:analysis; D012907:Smoking / Q000378:metabolism; D014026:Nicotiana / Q000009:adverse effects* / Q000737:chemistry; D014162:Transfection
chemical_list: D004785:Environmental Pollutants; D012333:RNA, Messenger; D018336:Receptors, Aryl Hydrocarbon; D012906:Smoke; D001564:Benzo(a)pyrene; D000429:Alcohol Oxidoreductases; C531129:CBR1 protein, human; D008156:Luciferases