EXPRESSION OF INTERCELLULAR-ADHESION MOLECULE-1 IN HUMAN HEPATOCELLULAR-CARCINOMA

We investigated the expression of intercellular adhesion molecule 1 (I CAM-1) in ex vivo human hepatocellular carcinoma (HCC) cells and in vi tro in eight liver cancer cell lines, including six HCC cell lines and two combined hepatocholangiocarcinoma (CHC) cell Lines. Immunohistoch emistry showed the expression of ICAM-1 on the HCC cell surface with h oneycomblike appearance in most cases (96.2%), On the other hand, hepa tocytes in noncancerous areas did not express ICAM-1, except those hep atocytes in the periportal and intra-acinar areas with inflammation. I mmunohistochemical study on cultured cells revealed that four cultured HCC cell lines and one CHC cell line constitutively expressed ICAM-1 on the cell surface and in the cytoplasm. Flow cytometric analysis rev ealed that immunostain-positive cells expressed surface ICAM-1 with mo re than a 90% positive cell rate, and their expressions were upregulat ed by incubation of cells with inflammatory cytokines, such as interfe ron alfa, interferon gamma, tumor necrosis factor-alpha, and interleuk in 1 beta. Soluble ICAM-1 was detected in supernatants of cell lines e xpressing cell surface ICAM-1, in addition to one HCC cell line withou t surface ICAM-1 expression, and was increased in amounts 2- to 20-fol d by inflammatory cytokines, These findings suggest that liver cancer cells in ex vivo may express not only surface but also a soluble form of ICAM-1, differently from normal hepatocytes, and that both expressi ons are upregulated by inflammatory cytokines.