Mobilization of cell-bound HGF by soluble syndecan-1.

The myeloma cell line JJN-3 produces large amounts of HGF that can be detected on the cell surface by flow cytometry. Before incubation with anti-HGF antibody 3F4 and labeling with FITC-conjugated antimouse antibody, cells were washed with (A) 10 μg/mL soluble heparin, which releases the HGF from the cell surface, (B) 10 μg/mL purified syndecan-1, which releases HGF from the cell surface in an identical manner, and (C) PBS, leaving HGF on the cell surface.