Characterization of human melanoma cell lines according to their migratory properties in vitro.

The migratory responses of four human melanoma cell lines (A-2058, DEMEL, HTB-63, and HTB-72), using chemotaxis (CTX) and haptotaxis (HPTX) assays, were studied. The attractants were three extracellular matrix components (EMCs), fibronectin, laminin, and collagen type IV. The conditioned media (CM) of each cell line were used to study autocrine and paracrine responses. A screening and sensitive CTX assay was performed, using pertussis toxin (PTX)- treated A-2058 as responder cells; the other melanoma cells and normal cells were used as secretory cells. Autotaxin (ATX), a purified autocrine motility factor, was also used as a chemoattractant. Reverse transcriptase-polymerase chain reaction was used to detect the expression of ATX by all cell lines. The secretion of ATX was determined by Western blot. The invasive capacity of the cell lines was evaluated using Matrigel and ATX as attractant. Chemotaxis responses to EMCs varied. Except for the A-2058 cells, HPTX migration was low. Autocrine and paracrine responses also varied. The migration of PTX-treated A-2058 cells to ATX and to their own CM was abolished. All the melanoma cells expressed ATX, and except for the HTB-72 and normal cells, all secreted ATX. Matrigel was invaded by all the melanoma cell lines except the HTB-72 and normal cells. The migratory properties of human melanoma cells in vitro suggest that they could correlate to their metastatic potential in vivo.