Fig. 3.

Confirmation of ERBB2 and MET as synthetic lethal genes with FGFR inhibition by targeted knockdown. (A) Pooled UMSCC25 cells expressing either a negative control shRNA targeting GFP (green fluorescent protein) or two independent shRNAs targeting either ERBB2 or MET were generated and ERBB2 or MET protein expression was measured by immunoblotting. The protein level of the α-subunit of Na/K-ATPase was measured as a loading control. (B) Pooled UMSCC25 cells expressing the control shRNA or one of two shRNAs targeting ERBB2 were used in a clonogenic growth assay in the presence or absence of 1.0 μM AZ8010. After 2 weeks, colonies were stained and quantified as described in the Materials and Methods. (C) Pooled UMSCC25 cells expressing the control shRNA or one of two shRNAs targeting MET were used in a clonogenic growth assay in the presence or absence of 1.0 μM AZ8010. After 2 weeks, colonies were stained and quantified as described in the Materials and Methods. The data are the means and S.E.M. of three replicates from three independent experiments. ns, not significant. NSC, non-silencing control. *P < 0.05; ***P < 0.0005; ****P < 0.0001 using a two-tailed t test.