EKC affected the activities of Rac1 and Arf6 GTPases. A. Cells were incubated with EKC as indicated, cell lysates were subjected to immunoblotting for Arf6 and Rac1. GAPDH was used as loading control. Bar graphs represented the relative express level of proteins. B. EKC downregulated the mRNA level of Arf6, but did not affect the mRNA level of Rac1. mRNA was extracted from NCI-H292 cells treated with EKC as indicated, and subjected to qRT-PCR analysis. C. NCI-H292 cells were incubated with DMSO or 12.5 μM EKC for 12 h. Pull-down assays were performed for activated Rac1 (Rac1-GTP) and Arf6 (Arf6-GTP). D. NCI-H292 cells were pretreated for 24 h with 10 μM EHT 1864 prior to addition of EKC or DMSO. Cell viability was tested by MTT assay after 48 h treatment. Values are expressed as mean ± SD, n = 3. *P < 0.05, **P < 0.01, and ***P < 0.001. E. NCI-H292 cells were pretreated for 24 h in the presence or absence of 10 μM EHT 1864 prior to addition of 15 μM EKC or DMSO for additional 16 h treatment. Images were captured by optical microscopy. Bar = 20 μM. F. A549 cells were incubated with DMSO or 25 μM EKC for 24 h. Pull-down assays were performed for activated Rac1 (Rac1-GTP) and Arf6 (Arf6-GTP). G. A549 cells were pretreated for 24 h in the presence or absence of 10 μM EHT 1864 prior to addition of 25 μM EKC or DMSO for additional 16 h treatment. Images were captured by optical microscopy. Bar = 20 μM.