Leukocyte Function‐associated Antigen‐1‐dependent Adhesion of Rat Ascites Hepatoma AH66F to Mesentery‐derived Mesothelial Cells

Rat ascites hepatoma AH66F cells adhered better than AH130 cells to mesentery‐derived mesothelial cells (M‐cells), though both cells secreted M, 92,000 matrix metalloproteinase on a gelatin zymogram with similar activity. AH66F cells expressed leukocyte function‐associated antigen‐1 (LFA‐1) and intercellular adhesion molecule‐1 (ICAM‐1), a ligand of LFA‐1, on the cell surface, while AH130 cells had ICAM‐1 alone. The adhesion to M‐cells of AH66F cells was inhibited to the adhesion level of AH130 cells by anti‐rat LFA‐1 α‐ and/or β‐chain monoclonal antibody (mAb) and also by anti‐rat ICAM‐1 mAb. This is the first report to show the LFA‐1‐dependent adhesion of cells other than leukocytes, because AH66F cells did not express CD45, T cell‐αβ receptor or CD11b/c (Mac‐1/p150,95). These results indicate that a part of the adhesion of AH66F cells to M‐cells is due to LFA‐1/ICAM‐1 interaction, and we suggest that this characteristic feature of AH66F cells may be related to the malignant properties.