Fig. 6.

Effects of combined FGFR, ERBB family, and MET inhibition on ERK signaling and PARP cleavage. (A) UMSCC25 cells were treated with the indicated doses (μM) of DMSO, AZ8010, AZD8931, or PF1066 alone and in combination for 6 hours in full media. Extracts were prepared and proteins resolved by SDS-PAGE. The filters were immunoblotted for pERK, pSTAT3, and pAKT. The filters were then stripped and reprobed for total ERK1/2, total STAT3, total AKT, and the α-subunit of Na/K-ATPase as a loading control. (B) UMSCC25 cells were treated as with the drugs indicated in (A) with the doses (μM) shown for 72 hours. Extracts were prepared and proteins resolved by SDS-PAGE. The filters were immunoblotted for PARP. The filters were then stripped and reprobed for the α-subunit of Na/K-ATPase as a loading control. (C) UMSCC25 cells were treated as described in (B) and caspase activity was measured as described in the Materials and Methods. SDS-PAGE, SDS-polyacrylamide gel electrophoresis. *P < 0.05; **P < 0.005; ***P < 0.0005.