The heparin-binding proteins HGF and OPG bind specifically to the uropod of polarized myeloma cells.

CAG (A-F and I-J) and ARP-1 cells (G-H) were incubated with 4 μg/mL of HGF alone (A-E and G-H), with HGF and 40 μg/mL heparin (F) or with 10 μg/mL OPG (I-J) at 37°C, fixed, and stained with a mab against HGF (A-H) or OPG (I-J) as described in “Patients, materials, and methods.” (A-B), (C-D), and (I-J) are corresponding visual fields. Strong uropod restriction of HGF and OPG binding is seen. Heparin prevented binding of HGF to the uropod (F).