title: Phosphorylation of hepatocyte growth factor receptor and epidermal growth factor receptor of human hepatocytes can be maintained in a (3D) collagen sandwich culture system.
abstract: In vitro culture models that employ human liver cells could be potent tools for predictive studies on drug toxicity and metabolism in the pharmaceutical industry. However, an adequate receptor responsiveness is necessary to allow intracellular signalling and metabolic activity. We tested the ability of three-dimensionally arranged human hepatocytes to respond to the growth factors hepatocyte growth factor (HGF) or epidermal growth factor (EGF). Isolated adult human hepatocytes were cultivated within a three-dimensional collagen gel (sandwich) or on a two-dimensional collagen matrix. Cells were treated with HGF or EGF and expression and phosphorylative activity of HGF receptors (HGFr, c-met) or EGF receptors (EGFr) were measured by flow cytometry and Western blot. Increasing HGFr and EGFr levels were detected in hepatocytes growing two-dimensionally. However, both receptors were not activated in presence of growth factors. In contrast, when hepatocytes were plated within a three-dimensional matrix, HGFr and EGFr levels remained constantly low. However, both receptors became strongly phosphorylated by soluble HGF or EGF. We conclude that cultivation of human hepatocytes in a three-dimensionally arranged in vitro system allows the maintenance of specific functional activities. The necessity of cell dimensionality for HGFr and EGFr function should be considered when an adequate in vitro system has to be introduced for drug testing.
authors.affiliation: Zentrum der Chirurgie, Klinik für Urologie und Kinderurologie, Johann Wolfgang Goethe-Universitaetsklinik, Wissenschaftliches Labor, Haus 23 A, EG 7, Theodor-Stern-Kai 7, D60590 Frankfurt am Main, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Engl
authors.forename: Kim A
authors.initials: KA
authors.lastname: Boost
authors.forename: Kerstin
authors.initials: K
authors.lastname: Leckel
authors.forename: Wolf-Dietrich
authors.initials: WD
authors.lastname: Beecken
authors.forename: Dietger
authors.initials: D
authors.lastname: Jonas
authors.forename: Elsie
authors.initials: E
authors.lastname: Oppermann
authors.forename: Marcus K H
authors.initials: MK
authors.lastname: Auth
authors.forename: André
authors.initials: A
authors.lastname: Schaudt
authors.forename: Wolf-Otto
authors.initials: WO
authors.lastname: Bechstein
authors.forename: Roman A
authors.initials: RA
authors.lastname: Blaheta
mesh_terms: D015153:Blotting, Western; D002450:Cell Communication; D018929:Cell Culture Techniques; D002478:Cells, Cultured / Q000502:physiology; D003094:Collagen; D066246:ErbB Receptors / Q000378:metabolism* / Q000502:physiology*; D005434:Flow Cytometry; D022781:Hepatocytes; D006801:Humans; D008099:Liver / Q000187:drug effects / Q000473:pathology; D010766:Phosphorylation; D019859:Proto-Oncogene Proteins c-met / Q000378:metabolism* / Q000502:physiology*; D015398:Signal Transduction
chemical_list: D003094:Collagen; D066246:ErbB Receptors; D019859:Proto-Oncogene Proteins c-met