Modulation of pro- and anti-apoptotic proteins by HGF. A. Western blot analysis of FADD, FLIP, Bax, Bcl-xl and Bim protein levels in response to HGF, TRAIL and HGF + TRAIL. Cells were treated with HGF for 72 h before incubation with TRAIL for another 24 h. FADD and Bim were slightly down regulated by HGF + TRAIL. B. Northern blot analysis of DR5 mRNA levels in response to HGF. DAOY cells were treated with HGF for the indicated times. Total cell RNA was hybridized with probes for DR5 and 28S RNA (control) as described in Materials and Methods. DR5 isoform 1 mRNA levels were increased between 1–72 h as shown (* P < 0.001). C. DAOY cells were pre-incubated with inhibitors for 30 min, and then treated with HGF for 24 h followed by Northern blot analysis for DR5 expression. The PI3K inhibitor LY294002 (30 μM) or wortmannin (1 μM) did not affect the DR5 up-regulation induced by HGF. The MAPK inhibitor PD98059 (30 μM) reversed up-regulation of DR5 by HGF (# P < 0.05). Data represent mean ± SE (N = 6).