Species-specific fibroblasts required for triggering invasiveness of partially transformed oral keratinocytes.
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.
Costea
Daniela Elena
DE
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
Kulasekara
Keerthi
K
Neppelberg
Evelyn
E
Johannessen
Anne Christine
AC
Vintermyr
Olav Karsten
OK
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
D003094:Collagen