Cell surface properties of B16 melanoma variants with differing metastatic potential.

Abstract Several cell surface properties of three B16 melanoma variant lines, which exhibit differing lung-colonizing capacities, have been examined. Equal numbers of cells from the B16-F10 Lr and B16-F1 lines, injected i.v. into syngeneic mice, produced significantly fewer lung nodules than did cells of the B16-F10 line. These wide differences in biological behavior could not, however, be ascribed to major qualitative differences in the cell surface properties studied. The 3 cell lines displayed similar quantitative and qualitative patterns of exposed surface proteins. The quantity of radioactive labeling of the major sialoglycoprotein (78,000 daltons) was inversely proportional to the capacity of cells to produce lung tumor colonies. Lectin-binding assays revealed that B16-F10 Lr cells bound 50% less concanavalin A than did the B16-F1 or B16-F10 cells; the B16-F10 cells bound 40% less wheat germ agglutinin than did the B16-F1 or B16-F10 Lr cells. Levels of 5′-nucleotidase activity were lower in B16-F10 cells than in B16-F1 and B16-F10 Lr cells. At the same time, there was no reduction in levels of the cytoplasm-associated enzyme, acid phosphatase. No differences in membrane lipid fluidity among the cell lines were detected by either fluorescent polarization or photobleaching techniques. The kinetics of adhesion of B16-F10 Lr and B16-F10 to a variety of substrates were very similar. The present data suggest that wide differences in metastatic behavior of B16 melanoma cells need not be correlated with major qualitative changes in a single cell surface biochemical or morphological characteristic.