Melanoma cell-derived factors stimulate glycosaminoglycan synthesis by fibroblasts cultured as monolayers and within contracted collagen lattices

Background Various tumours exhibit glycosaminoglycan rich, and in particular hyaluronan rich matrices surrounding them that facilitate tumour growth and invasion. In many tumours, this matrix is predominantly synthesized by fibroblasts following stimulation by tumour cell-derived factors. Objectives To determine what effect tumour cell-conditioned medium has upon fibroblast glycosaminoglycan synthesis when cells were cultured as monolayers and within contracted collagen lattices. Methods Serum-free conditioned medium from melanoma cell lines (C8161, MV3, A375 and Hs294T) was examined for its ability to stimulate the incorporation of H-3-glucosamine and (SO4)-S-35 into glycosaminoglycans synthesized by fibroblasts. Results Conditioned medium from all four melanoma cell lines exhibited potent glycosaminoglycan-stimulating activity. In monolayer culture, C8161-conditioned medium stimulated a 4.2-fold increase in fibroblast hyaluronan, and a 9.9-fold increase in sulphated glycosaminoglycan synthesis, while (SO4)-S-35 incorporation was increased only 2.1-fold. In collagen lattice cultures, C8161-conditioned medium stimulated a 4.9-fold increase in hyaluronan synthesis, a 5.4-fold increase in sulphated glycosaminoglycans, and a 1.3-fold increase in (SO4)-S-35 incorporation. Conclusions Melanoma cells produce factors that are potent stimulators of fibroblast glycosaminoglycan synthesis, in both monolayer culture and within contracted collagen lattices. Synthesis of both hyaluronan and sulphated glycosaminoglycans with a reduced degree of polymer sulphation is stimulated. Such changes are likely to promote tumour cell proliferation and migration.