Multiplicity of newly established monoclonal antibodies against hepatocellular carcinomas.

To identify tumour-associated cell surface antigens of human hepatocellular carcinoma (HCC), we established three monoclonal antibodies against a well established human HCC line, hu-H2. One of these, designated as KY-1, reacted with several HCC lines and a majority of peripheral blood lymphocytes. A second monoclonal antibody, KY-2, reacted only with HCC cell lines but not with others. With this KY-2 antibody, which was highly specific for HCC, HCC tissue was positively stained. A third monoclonal antibody, KY-3, reacted with HCC lines and many other malignant cell lines, but not with non-malignant cells. These results indicate that at least three different tumour-associated molecules are expressed on human HCC.