Induction and regulation of xenobiotic-metabolizing cytochrome P450s in the human A549 lung adenocarcinoma cell line.

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Hukkanen J, Lassila A, Paivarinta K, Valanne S, Sarpo S, Hakkola J, Pelkonen O, Raunio H

Induction and regulation of xenobiotic-metabolizing cytochrome P450s in the human A549 lung adenocarcinoma cell line.

Am J Respir Cell Mol Biol. 2000 Mar;22(3):360-6.

PubMed ID

10696073 [ View in PubMed

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Abstract

Several cytochrome P450 (CYP) enzymes are expressed in the human lung, where they participate in metabolic inactivation and activation of numerous exogenous and endogenous compounds. In this study, the expression pattern of all known xenobiotic-metabolizing CYP genes was characterized in the human alveolar type II cell-derived A549 adenocarcinoma cell line using qualitative reverse transcriptase/polymerase chain reaction (RT-PCR). In addition, the mechanisms of induction by chemicals of members in the CYP1 and CYP3A subfamilies were assessed by quantitative RT-PCR. The expression of messenger RNAs (mRNAs) of CYPs 1A1, 1B1, 2B6, 2C, 2E1, 3A5, and 3A7 was detected in the A549 cells. The amounts of mRNAs of CYPs 1A2, 2A6, 2A7, 2A13, 2F1, 3A4, and 4B1 were below the limit of detection. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induced CYP1A1 and CYP1B1 mRNAs 56-fold and 2.5-fold, respectively. CYP3A5 was induced 8-fold by dexamethasone and 11-fold by phenobarbital. CYP3A4 was not induced by any of the typical CYP3A4 inducers used. The tyrosine kinase inhibitor genistein and the protein kinase C inhibitor staurosporine blocked TCDD-elicited induction of CYP1A1, but they did not affect CYP1B1 induction. Protein phosphatase inhibitors okadaic acid and calyculin A enhanced TCDD-induction of CYP1B1 slightly, but had negligible effects on CYP1A1 induction. These results suggest that CYP1A1 and CYP1B1 are differentially regulated in human pulmonary epithelial cells and give the first indication of the induction of CYP3A5 by glucocorticoids in human lung cells. These results establish that having retained several characteristics of human lung epithelial cell CYP expression, the A549 lung cell line is a valuable model for mechanistic studies on induction of the pulmonary CYP system.

DrugBank Data that Cites this Article

Drug Enzymes

Drug	Enzyme	Kind	Organism	Pharmacological Action	Actions
Dexamethasone	Cytochrome P450 3A5	Protein	Humans	Unknown	Substrate Inducer	Details
Dexamethasone acetate	Cytochrome P450 3A5	Protein	Humans	Unknown	Substrate Inducer	Details
Phenobarbital	Cytochrome P450 3A5	Protein	Humans	No	Inducer	Details

Pharmaco-transcriptomics

Drug	Drug Groups	Gene	Gene ID	Change	Interaction	Chromosome
Dexamethasone	Approved Investigational Vet Approved	CYP3A5	1577	upregulated	Dexamethasone results in increased expression of CYP3A5 mRNA	7q22.1
Phenobarbital	Approved Investigational	CYP3A5	1577	upregulated	Phenobarbital results in increased expression of CYP3A5 mRNA	7q22.1