Alteration of cell surfaces with increased tumorigenicity.

A comparison of four mouse tumorigenic cell lines derived from transformed peritoneal macrophages is reported. Tumorigenicity of various cell concentration inocula was compared with their saturation densities, agglutinability by Con A, and their surface morphologies as revealed by SEM. It is shown that increase in tumorigenicity after repeated passage through syngeneic mice is associated with changes in their growth characteristics, Con A agglutinability, and correlates with surface changes observed by SEM. The results show that after repeated transfer of transformed cells in syngeneic mice the cells become more tumorigenic, have a higher degree of agglutinability, and show progressive changes of their surface morphology.