Tissue Proteins and Carcinogenesis

It has been known that certain azo dyes will produce cancer of the liver. During the precancerous stages the liver appears to undergo some definite changes. The activity of these azo dye carcinogens is influenced by several dietary factors. Thus the liver can be protected partiahy from the effects of the dye by simultaneous intake of increased amounts of riboflavin (1). This conforms with the fact that administration of these aso dye carcinogens brings about a decrease in the amount of riboflavin normally present in the liver (2, 3). Feeding of m’-methyl-p-dimethylaminoazobenzene increases the desoxyribonucleic acid content of the liver (4). Opie (5) and Price et al. (6) have observed that a similar dye, p-dimethylaminoazobenzene, reduces the ribonucleic acid content of this organ. Miller and Miller (7) have found that p-dimethylaminoazobenzene or a metabohte of this compound is bound by a protein constituent of the liver. They found that this azo compound is not bound appreciably by other tissues. However, they observed low levels of bound dye in the proteins of the bIood plasma. In connection with studies on azo dye carcinogenesis, it was considered of interest to determine any changes which might occur in the proteins of the blood serum during the development of liver tumors, hence the investigations reported in this present paper.