Absence of liver antigens in transplantable hepatomas. A possible relationship to the tumor aggressiveness.

Presence of liver antigens in transplantable Morris hepatomas of varying aggressiveness was investigated by immunodiffusion and absorption methods. The most malignant and undifferentiated of these, hepatoma 7777, was found defective in two liver antigens, whereas the less malignant hepatomas, 5123tc and 9618A, did have them. Both antigens had distinct occurrence in tissues and hepatic subcellular fractions and behaved like proteins of electrophoretic mobilities of serum gamma globulins with molecular weights of 51,000 and 240,000, respectively. Since hepatoma 7777 is the least differentiated, fastest growing, and more metastatic of the tumors studied, these properties would appear to be associated with the absence of the antigens.