DENOVO EXPRESSION OF INTERCELLULAR-ADHESION MOLECULE-1 (ICAM-1, CD54) IN PANCREAS CANCER

We examined the expression of intercellular-adhesion molecule-1 (ICAM-1, CD54) in 6 surgically removed pancreatic tumors and 8 pancreatic tumor cell lines. Immunohistochemistry revealed a varying percentage of ICAM-1-positive pancreas tumor cells, while normal pancreatic tissue (except for slight reactivity of endothelial cells) was not stained. The presence of the ICAM-1 molecule on the cell surface and the expression of ICAM-1 mRNA were investigated for 8 different pancreatic tumor cell lines. Three of these (Capan-1, Capan-2, QGP-1) expressed ICAM-1 constitutively. In 4 of the ICAM-1-negative pancreas cancer cell lines, it was possible to induce a remarkable expression of ICAM-1 by incubating the cells in the presence of inflammatory cytokines, whereas one cell line, 818-4, remained ICAM-1-negative. The responsiveness to either IFN-gamma, TNF-alpha, or IL-1beta treatment was shown to vary from cell line to cell line, indicating complex mechanisms that regulate the expression of ICAM-1 at both, the transcriptional and the post-transcriptional level. Interestingly, ICAM-1 is shed by pancreatic tumor cells, since soluble sICAM-1 was detected in the cell-culture supernatants. In comparison with normal sera, the mean level of sICAM-1 in sera of patients with pancreas carcinoma is elevated 2-fold.