HGF increases the DR5 expression and enhances TRAIL-induced DISC formation. A. FACScan analysis of DR5 expression in DAOY cell surface after HGF treatment. Cells treated with HGF for 24 – 72 h were incubated with PE-conjugated anti-DR5 antibody for 30 min. Mouse IgG was used as negative control. At baseline ~61.5% cells were DR5 positive. After 24 h incubation with HGF, the DR5 positive pool increased to 83.5%. B. Compared to control, there was a significant increase in DR5 positive cells after 24 – 72 h incubation with HGF (N = 6, * P < 0.05). C. DAOY cells were pre-treated with HGF for 72 h followed by TRAIL for 2 h. Equal amounts of total cell protein (500 μg) were immunoprecipitated with anti-DR5 antibody and then subjected to Western blot analysis with antibodies to caspase 8, FLIP, FADD, c-Met and DR5 antibody. There was a distinct increased in DISC in cells treated with TRAIL + HGF.