title: Comparison of growth-inhibitory agents by fluorescence imaging of human skin re-epithelialization in vitro.
abstract: Drug screening procedures should preferably utilize experimental settings mimicking the in vivo situation. The aim of this study was to evaluate a skin explant model as a tool to identify topical agents with anti-proliferative properties in human epidermis. Re-epithelialization was initiated from a skin punch biopsy explanted onto de-epidermized dermis and cultured at the air-liquid interface in the presence of epidermal growth factor receptor inhibitor PKI166, tacrolimus or established topical anti-psoriatic drugs: betamethasone, calcipotriol, dithranol and tazarotene. Neo-epidermal extension was traced by fluorescence microscopy prior to histomorphometric analysis. PKI166 at 1 microM decreased the mean radial outgrowth rate (-19%), frequency of BrdU-positive (-37%) and laminin 5-positive (-45%) cells, indicating reduced proliferation and migration of neo-epidermal keratinocytes. However, the papillomatosis index and epithelial thickness were not significantly affected. Calcipotriol at 1 microM had a similar effect on the outgrowth rate (-15%) and fraction of laminin 5-stained keratinocytes (-40%). Furthermore, calcipotriol significantly reduced mean neo-epidermal thickness. Equimolar concentrations of the other test compounds had no apparent effect on histology or outgrowth parameters. This study exemplifies the versatility of combined dynamic and morphological analysis and emphasizes the potential of epidermal growth factor receptor-directed inhibition in hyperproliferative disorders of the epidermis.
authors.affiliation: Department of Medical Sciences, Dermatology and Venereology, Uppsala University Hospital, Sweden.
authors.forename: Sofi
authors.initials: S
authors.lastname: Forsberg
authors.forename: Ulpu
authors.initials: U
authors.lastname: Saarialho-Kere
authors.forename: Ola
authors.initials: O
authors.lastname: Rollman
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects*; D003879:Dermatologic Agents / Q000494:pharmacology*; D004353:Drug Evaluation, Preclinical; D000078404:Epidermal Cells; D004817:Epidermis / Q000187:drug effects; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects*; D006801:Humans; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D008856:Microscopy, Fluorescence; D011565:Psoriasis; D012867:Skin / Q000166:cytology* / Q000187:drug effects; D000097794:Kalinin
chemical_list: D015815:Cell Adhesion Molecules; D003879:Dermatologic Agents; D000097794:Kalinin