AZD9291-resistant PC9 cells contain an HRAS mutation.

<p>(A) Summary of genetic alterations in PC9 and PC9/AZDR cells. (B) Cell viability was measured by CCK-8 assay of cells transfected with HRAS siRNA for 48 h. The data are mean ± SE of six replicates. **, <i>P</i> < 0.01 for comparison of the indicated pairs. C. Cells were transfected with either nontargeting control siRNA (siCTL) or HRAS siRNA (siHRAS) for 48 h. HRAS knockdown and phosphorylation of AKT and ERK were detected by Western blotting. β-actin was used as a loading control.