Figure 3.

Effects of species-specific fibroblasts on growth and invasion of in vitro neoplastic oral epithelium reconstructed from partially transformed keratinocytes. Neoplastic oral epithelium was in vitro reconstituted by growing DOK cell line on top of mouse fibroblast-containing matrix (A, D–F), rat fibroblast-containing matrix (B), or on sandwich models with a bottom layer of human fibroblast-containing matrix and an intermediate layer of mouse fibroblast-containing matrix (C). Conditioned medium from parallel organotypic co-cultures of DOK on human fibroblast-containing matrices (D), from human fibroblasts in monolayer (E), or a cocktail of known human growth factors (F) were added at day 3 of co-culture. H&E staining (A–F) is shown. Epithelial growth (total epithelial thickness and cell proliferation index) and invasion (depth and area of invasion) were assessed (G). Data represent mean ± SEM of six different experiments. ^¤Statistically significant difference when compared with DOK cultures on human fibroblast-containing matrix; ^#statistically significant difference when compared with DOK cultures on mouse or rat fibroblast only-containing matrix. Scale bar, 50 μm.