A comparison of surface ultrastructures of normal, papillomatous, and carcinomatous epidermal cells.

The surface ultrastructure of normal rabbit epidermal, cells and Vx~ carcinoma cells was investigated by Coman and Anderson (3) by means of electron microscopy, using replica methods. They found differences between the two types of cells and concluded that a change in the ultrastructure of the cell surface accompanies the transformation from a normal to a carcinomatous state. I t is possible that this structural change reflects the invasive character of cancer cells. If so, such a change would not be expected in the pre-invasive stage of the neoplastic transformation. This hypothesis can be tested by examination of the Shope papilloma cells, which can be considered a transitional stage between normal rabbit epidermis and the Vxe carcinoma. The surface ultrastructure of the papilloma, as a non-invasive neoplasm, might be expected to resemble the surface of the normal cell rather than that of the malignant. Experiments were therefore designed to compare the surface ultrastructures of Shope papilloma cells, normal rabbit epidermal cells, and Vx~ carcinoma cells.