title: Species-specific fibroblasts required for triggering invasiveness of partially transformed oral keratinocytes.
abstract: This study tests the hypothesis that invasion of partially transformed keratinocytes is initiated by diffusible, proinvasive signals provided by species-specific fibroblasts. In vitro organotypic cultures of neoplastic human oral mucosa were constructed by growing a partially transformed, nontumorigenic keratinocytic cell line isolated from a dysplastic human oral lesion (DOK-ECACC94122104) on top of various types of connective tissue equivalents. Cultured tissues were analyzed by histomorphometry (depth and area of invasion: Dinv, Ainv) and immunohistochemistry. Presence of human fibroblasts in the matrix induced a local invasion of DOK (Dinv = 95.6 +/- 7.1 microm, Ainv = 45.8 +/- 3.5%). Minimal invasion (P < 0.05) was observed when DOK grew on simple collagen matrix (Dinv = 14.1 +/- 2.1 microm, Ainv = 3.7 +/- 0.8%) or matrices containing fibroblasts from mouse (Dinv = 11.5 +/- 4.0 microm, Ainv = 4.3 +/- 1.0%) or rat (Dinv = 15.6 +/- 1.2 microm, Ainv = 6.1 +/- 0.5%). In these cultures, local invasion could be induced by the presence of human fibroblasts in a bottom layer of the collagen matrix (P < 0.05) or by conditioned medium from organotypic cultures of DOK on human fibroblast-containing matrix (P < 0.05) but not by conditioned medium from human fibroblast monocultures (P > 0.05). Deposition of human collagen IV was observed at epithelial-matrix interface only when DOK behaved invasively. In conclusion, invasion of partially transformed oral keratinocytes was triggered by keratinocyte-induced fibroblast-derived diffusible factor(s) in a species-specific manner and associated with de novo synthesis of collagen IV.
authors.affiliation: Department of Odontology, Oral Pathology and Forensic Odontology, University of Bergen, The Gade Institute, Haukeland University Hospital, N-5021, Bergen, Norway. daniela.costea@odfa.uib.no
authors.forename: Daniela Elena
authors.initials: DE
authors.lastname: Costea
authors.forename: Keerthi
authors.initials: K
authors.lastname: Kulasekara
authors.forename: Evelyn
authors.initials: E
authors.lastname: Neppelberg
authors.forename: Anne Christine
authors.initials: AC
authors.lastname: Johannessen
authors.forename: Olav Karsten
authors.initials: OK
authors.lastname: Vintermyr
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques / Q000379:methods*; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D018920:Coculture Techniques; D003094:Collagen / Q000737:chemistry; D004847:Epithelial Cells / Q000166:cytology; D005347:Fibroblasts / Q000166:cytology* / Q000378:metabolism; D006801:Humans; D015603:Keratinocytes / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D009061:Mouth Mucosa / Q000378:metabolism; D051381:Rats; D013045:Species Specificity
chemical_list: D003094:Collagen