Loss of Liver Cell Antigens in Azo-dye Induced Hepatomas of Rats

Abstract

THE immunizing ability of several chemically and virus induced tumours and immuno-chemical studies suggest that neoplasms of animals and man are characterized by a changed antigenic composition^1–3. As yet, however, no regularity in these changes has been observed, probably due to the small amount of data available. It remains unknown whether the cell type of a tumour, the carcinogens used for tumour induction, or the genetic composition of the neoplastic cells affect the kind and degree of these antigenic changes. To obtain information about some of these problems we compared the loss of liver antigens in fourteen hepatomas. Although these tumours were selected on the basis of the histological features characteristic of hepatomas it is doubtful whether they are strictly comparable. First, the deoxyribonucleic acid (DNA) content of the stemline is not the same in different hepatomas. This agrees with our previous observation that even two hepatomas of the same liver lobe can consist of cells with different DNA values⁴. Secondly, some of these hepatomas consist of a uniform population of cells whereas others are characterized by a heterogenous population of cells with varying amounts of DNA.