TAZ knockdown in PC9/GR cells suppresses anchorage-independent growth, tumorigenesis and resistant to gefitinib in vivo. (A) Two hundred stable GR-shNC, GR-shTAZ1 and GR-shTAZ2 cells were plated onto 6-well plates and a colony formation assay was assessed and photographed. The rate of colony formation was calculated as follows: colony-forming rate = (average colony number/ plated single cell number) × 100%. The colony-forming rates of GR-shTAZ cells were reduced drastically compared with control group. Results are expressed as means ± SEM from three independent experiments (**P<0.01, ***P<0.001). (B) PC9/GR cells with stable expression of shTAZ2 and shNC were inoculated subcutaneously into right and left flanks of nude mice (n = 6 per group), respectively. Representative photographs of nude mice 29 days after inoculation are shown. (C) Tumor growth curve is indicated. (D) Mice bearing PC9/GR xenografts were treated daily with gefitinib at indicated doses. Data represent means ± SEM (*P<0.05, **P<0.01). Statistical analyses were carried out using Student’s t-test.