Metastatic potential correlates with cell-surface protein alterations in B16 melanoma variants

Abstract

The invasive properties of metastatic cells may be related to their ability to form cell–cell and cell–endothelial matrix interactions, behaviour which may be mediated by tumour cell-surface proteins. However, efforts to find qualitative differences in surface protein between cells with different metastatic potential have been disappointing^1–5. The in vivo metastatic ability of B16 melanoma cell lines has been correlated with their ability to aggregate with platelets^5,6 and 1 M urea extracts of metastatic cells are known to be more effective in platelet aggregation than those from their less metastatic counterparts⁷. In addition, recent in vivo experiments have shown that plasma membrane vesicles from highly metastatic tumour cells can modify the metastatic behaviour of poorly metastatic sublines when fused with the latter⁸. We have now examined possible differences in the surface macromolecules of B16 metastatic variants; our results show novel qualitative differences in surface protein that correlate with differing metastatic behaviour of the melanoma cells.