title: Metabolically competent human skin models: activation and genotoxicity of benzo[a]pyrene.
abstract: The polycyclic aromatic hydrocarbon (PAH) benzo[a]pyrene (BP) is metabolized into a complex pattern of BP derivatives, among which the ultimate carcinogen (+)-anti-BP-7,8-diol-9,10-epoxide (BPDE) is formed to certain extents. Skin is frequently in contact with PAHs and data on the metabolic capacity of skin tissue toward these compounds are inconclusive. We compared BP metabolism in excised human skin, commercially available in vitro 3D skin models and primary 2D skin cell cultures, and analyzed the metabolically catalyzed occurrence of seven different BP follow-up products by means of liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). All models investigated were competent to metabolize BP, and the metabolic profiles generated by ex vivo human skin and skin models were remarkably similar. Furthermore, the genotoxicity of BP and its derivatives was monitored in these models via comet assays. In a full-thickness skin, equivalent BP-mediated genotoxic stress was generated via keratinocytes. Cultured primary keratinocytes revealed a level of genotoxicity comparable with that of direct exposure to 50-100 nM of BPDE. Our data demonstrate that the metabolic capacity of human skin ex vivo, as well as organotypic human 3D skin models toward BP, is sufficient to cause significant genotoxic stress and thus cutaneous bioactivation may potentially contribute to mutations that ultimately lead to skin cancer.
authors.affiliation: German Federal Institute for Risk Assessment (BfR), Department of Product Safety, 10589 Berlin, Germany.
authors.forename: Joep
authors.initials: J
authors.lastname: Brinkmann
authors.forename: Kristin
authors.initials: K
authors.lastname: Stolpmann
authors.forename: Susanne
authors.initials: S
authors.lastname: Trappe
authors.forename: Timo
authors.initials: T
authors.lastname: Otter
authors.forename: Doris
authors.initials: D
authors.lastname: Genkinger
authors.forename: Udo
authors.initials: U
authors.lastname: Bock
authors.forename: Manfred
authors.initials: M
authors.lastname: Liebsch
authors.forename: Frank
authors.initials: F
authors.lastname: Henkler
authors.forename: Christoph
authors.initials: C
authors.lastname: Hutzler
authors.forename: Andreas
authors.initials: A
authors.lastname: Luch
mesh_terms: D001564:Benzo(a)pyrene / Q000378:metabolism / Q000493:pharmacokinetics / Q000633:toxicity*; D001711:Biotransformation; D002478:Cells, Cultured; D002853:Chromatography, Liquid; D006801:Humans; D008954:Models, Biological; D009152:Mutagenicity Tests; D009153:Mutagens / Q000378:metabolism / Q000493:pharmacokinetics / Q000633:toxicity*; D012867:Skin / Q000166:cytology / Q000187:drug effects*; D053719:Tandem Mass Spectrometry
chemical_list: D009153:Mutagens; D001564:Benzo(a)pyrene