Fig. 2

EGFR kinase activity is essential for maintenance of SCD1 protein stability and intracellular MUFA level in lung cancer. a HCC827 cells were transfected with different siRNAs against EGFR or a control scramble siRNA for 72 h, and the lysates were subjected to IB. b HCC827 and H1975 cells were treated with 0.1% dimethyl sulfoxide (DMSO) as control, erlotinib (1 μM) or AG1478 (1 μM) for 24 h and the lysates were blotted with the antibodies as indicated. c HCC827 cells were pre-incubated with 0.1% DMSO or erlotinib (1 μM) for 12 h and 100 μg/ml cycloheximide (CHX) was then added for the indicated time. The lysates were subjected to IB. Densitometry quantitative data (SCD1/Tubulin) are mean ± SEM from three independent experiments. d and e In the presence or absence of erlotinib (1 μM), HCC827 and H1975 cells were treated with MG132 (10 μM) for 12 h and the lysates were subjected to IB or IP/IB with the indicated antibody. f HCC827 and H1975 cells were incubated with 0.1% DMSO or erlotinib (1 μM) for 24 h. Total cell lipids were extracted and the ratio of monounsaturated fatty acids (18:1) to saturated fatty acid (18:0) was determined by liquid chromatography-mass spectrometry (LC-MS). Data are mean ± SD (n = 3). ***p < 0.001; NS, nonsignificance. Densitometry quantification of SCD1/Tubulin (a, b and d) level is shown