Immunological studies on the membrane systems of cancer cells. I. Immunochemical analysis of membrane fractions from cancer cells

The present investigation was conducted with the purpose to search for the specific cancer antigenicity at subcellular level, as its first object. The aim is on the immunochemical consideration and comparison of fractions such as cell homogenate, nuclei, mitochondria, microsomes, and plasma membrane etc. obtained by ultracentrifugation from cancer cells (AH 130 rat ascites hepatoma), and to compare the antigenicity of individual fractions from normal rat liver cells. 1. The highest antigenicity is found in the mitochondria in membrane systems of cancer cells. 2. The high antigenicity of mitochondria is cancer specific, and is not common to that of normal cell mitochondria. 3. The plasma membrane prepared from cancer cell nuclear fraction was a highly pure cancer cell plasma membrane. 4. As far as tested by precipitin reaction the antigenicity of the cancer cell plasma membrane is almost the same as that of normal cell plasma membrane, and it is hard to say that the antigenicity of cancer cell plasma membrane is cancer specific. Antigenicity of plasma membrane hardly diminishes at the stage of carcinogenic transformation of cells.