Adhesive interaction of highly malignant hepatoma AH66F cells with mesothelial cells.

We investigated the mechanism of adhesion of highly malignant ascites hepatoma AH66F cells to mesothelial cells. The adhesion rate of AH66F cells to mesentery-derived mesothelial cells (M-cells) was about 46% at 37 degrees C, but it decreased to about 27% at 4 degrees C. The adhesion rate of AH66F cells was about 25% in the presence of leukocyte function-associated antigen 1 (LFA-1) mAb at both 4 C and 37 C. When M-cells were treated with hyaluronidase, the AH66F/M-cell adhesion was decreased to half at 37 degrees C and had nearly disappeared at 4 degrees C. The residual adhesion of AH66F cells to M-cells treated with hyaluronidase almost disappeared in the presence of LFA-1 mAb. AH66F cells strongly adhered to a hyaluronate (HA)-coated plate, but not to a bovine serum albumin-coated plate. AH66F cells expressed a CD44 molecule (a HA receptor) in the plasma membrane, with a molecular size of about 85 to 90 kDa, corresponding to the CD44H isoform. These results indicated that the adhesion of AH66F cells to mesothelial cells is composed of pathways of CD44/HA and LFA-1/ICAM-1.