Compound AZA197 promotes LDH release and inhibits Cdc42 activation. A Cytotoxicity was assessed by LDH release in SW620 colon cancer cells and S3T3 fibroblasts after 24 h exposure to AZA197 (1–100 μM). Co, untreated control; DMSO, solvent control; *, significantly different from untreated control. B Rac1, Cdc42 and RhoA activation in SW620 colon cancer cells after incubation (24 h) with different concentrations of compound AZA197. AZA197 suppresses Cdc42 activity in colon cancer cells in a dose-dependent manner. Means of three independent experiments are shown. *, significantly different from untreated control. C AZA197 inhibits Cdc42 GDP/GTP exchange stimulated by GEF. AZA197 significantly inhibits the GEF activity of Dbs on Cdc42 assessed by mant fluoresence. Experiments were performed in triplicate and data from one representative experiment are presented. The bar chart shows the statistical analysis of relative Cdc42 GEF activity from these measurements. *, significantly different from untreated controls.