title: Influence of fibroblasts on the invasion and migration of highly or weakly metastatic B16 melanoma cells.
abstract: We have examined the influence of fibroblasts on the invasive and migratory potential of highly metastatic melanoma B16-BL6 and weakly metastatic B16-F1 cells in vitro. Co-culture of B16-BL6 cells with a fibroblast monolayer without cellular contact in a Transwell chamber more effectively induced tumor-cell invasion into Matrigel basement membrane than co-culture of B16-F1 cells with a fibroblast monolayer. The activity was closely correlated with the chemotactic migration of tumor cells toward the fibroblast monolayer. We also found that the conditioned medium (CM) from the co-culture of fibroblasts with B16-BL6 cells without cellular contact, i.e., CM (B16-BL6/fibroblast), rather than from co-culture with B16-F1 cells, could potentially promote the migration of tumor cells of both types. Tumor cells did not chemotactically migrate to the CM (B16-BL6), CM (B16-F1) or CM (fibroblast). Antibodies against TGF-beta 1 or FN almost completely abolished the chemotactic migration of B16-BL6 cells to the CM (B16-BL6/fibroblast) or CM (TGF-beta 1-treated fibroblast) when these antibodies were co-incubated with fibroblasts and either B16-BL6 or TGF-beta 1. In contrast, the anti-EGF antibody did not show any inhibitory effects. Analysis of amounts of TGF-beta 1 or FN in various CM using ELISA plates, and using their specific antibodies, revealed that the concentration of TGF-beta 1 in the CM (B16-BL6) was slightly higher than in the CM (B16-F1), and the amount of FN in the CM (B16-BL6/fibroblast) was twice as high as in the CM (B16-F1/fibroblast). These results suggest that TGF-beta 1 released from B16-BL6 cells can stimulate fibroblasts to produce FN; consequently, the tumor cells were able to chemotactically migrate toward the released FN, and the differences in invasive and migratory activities towards fibroblasts in B16-BL6 and B16-F1 cells may in part be due to the amounts of TGF-beta 1 from tumor cells and of FN from TGF-beta 1-stimulated fibroblasts.
authors.affiliation: Institute of Immunological Science, Hokkaido University, Sapporo, Japan.
authors.forename: I
authors.initials: I
authors.lastname: Saiki
authors.forename: J
authors.initials: J
authors.lastname: Murata
authors.forename: J
authors.initials: J
authors.lastname: Yoneda
authors.forename: H
authors.initials: H
authors.lastname: Kobayashi
authors.forename: I
authors.initials: I
authors.lastname: Azuma
mesh_terms: D000818:Animals; D001485:Basement Membrane / Q000473:pathology; D002450:Cell Communication / Q000502:physiology; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology*; D005347:Fibroblasts / Q000502:physiology*; D005353:Fibronectins / Q000032:analysis; D006133:Growth Substances / Q000494:pharmacology; D008546:Melanoma, Experimental / Q000473:pathology* / Q000503:physiopathology; D051379:Mice; D009361:Neoplasm Invasiveness; D010446:Peptide Fragments / Q000494:pharmacology; D017469:Receptors, Fibronectin / Q000032:analysis
chemical_list: D005353:Fibronectins; D006133:Growth Substances; D010446:Peptide Fragments; D017469:Receptors, Fibronectin