A structural difference between the surfaces of normal and of carcinomatous epidermal cells.

The behavior of the cancer cell is determined in part by peculiarities of its external surface. For example, the cancer cell is unable adequately to bind calcium (7), and, as a consequence, cancer cells do not adhere to one another tightly (5, 10) but tend to separate, migrate (8), and to invade the surrounding tissues. Thus, the invasive or malignant features of cancer may be attributed largely to alterations of the cell surface. It, therefore, becomes of interest to inquire into the characteristics of the cancer cell surface, especially into its ultrastructure and, if possible, its chemical composition. As a first step in this direction, it would be pertinent to compare, on a macromolecular level, the appearance of the sur face of a cancer cell with that of a normal cell. As has been suggested recently (6), inability to bind calcium may be correlated with a surface ab normality, but, even aside from this possibility, any structural difference from the normal might well prove of significance to an eventual under standing of the behavior of cancer cells. Accordingly, experiments were planned to make visible the ultrastructure of the cell surface and to compare in this regard a cancer cell with its normal prototype. Vx@2 carcinoma cells were selected for comparison with the epidermal cells of the rabbit skin.