Enzyme Patterns in Rat Liver and Morris Hepatoma 5123 during Metabolic Transitions

Abstract

The definitive enzymatic difference between a cancer cell and the normal cell from which it arose is yet to be established in a single instance. Recognizing the difficulties inherent in the study of tumor cells without knowing which normal cells are their progenitors, we set out to find a hepatoma cell that would resemble normal liver so closely that detailed comparisons with liver would be justifiable. Ten different hepatoma strains were studied, and one was unique in the extent to which it resembled normal liver. The Morris hepatoma 5123 grows slowly, but it kills the host, is invasive, and metastasizes. It contains about 30 enzymes previously reported to be lacking in the Novikoff hepatoma, and examination of eight other hepatomas showed them to have properties intermediate between the Morris hepatoma and the Novikoff hepatoma. It was suggested that the biochemistry of carcinogenesis, i.e., the explanation of the definitive change...