Profiles of Human Melanoma Cell Surface Proteins: Effects of Culturing on Two Different Substrates

Three human melanoma cell lines of differing invasive and metastatic potentials were cultured on either a plastic surface or a denuded amniotic basement membrane, and alterations in their cell surface proteins, invasive profiles, and the presence or absence of the 69 Kd high‐affinity metastasis‐associated laminin receptor were examined. Our data indicate that the labeled, precipitatable cell surface proteins are different from the three cell lines when they are cultured on the same substrate, and change when the cells are cultured on a different substrate. Furthermore, the invasive potential (as measured in the in vitro Membrane Invasion Culture System) is decreased for all of the cell lines after culturing the cells on a basement membrane matrix compared to a plastic surface. Finally, we show that the 69 Kd high‐affinity metastasis‐associated laminin receptor can be isolated from all three cell lines cultured on the two different substrates by labeling the cell surface with trinitrobenzene sulfonic acid and immunoprecipitating these targeted proteins.