Figure 4. Cdc42 regulates the activated phenotype of ALCL cells.

A, TS cells were transduced with two different lentiviral contructs inducible for specific sh-RNAs against Cdc42 and a control sequence. Cells were treated with 1 μg/ml doxycycline for 72 hours, then lysed and immunoblotted with the indicated antibodies. B, inducible sh-Cdc42 TS cells were treated with 1 μg/ml doxycycline for 72 hours. The movements of the membrane protrusions of single cells were traced as indicated in Fig. 1B. Path lengths in both axes are measured in microns (μm). A magnified view of the paths of Cdc42 depleted TS cells is shown in the insert. C, left panel: inducible sh-Cdc42 TS cells were treated with 1 μg/ml doxycycline for 72 hours and then analyzed by immunofluorescence using PE-conjugated phalloidin staining to detect actin filaments. Right panel: SU-DHL1 cells were treated with 15μM Cdc42 inhibitor Secramine A for 1 hour and then analyzed by immunofluorescence using PE-conjugated phalloidin staining to detect actin filaments. D, inducible sh-Cdc42 TS cells were treated with 1 μg/ml doxycycline for 72 hours and then used for a transwell assay in response to SDF-1α. The histograms represent the numbers of migrated cells. Statistical analyses was performed by student's t-test. Data are represented as mean +/− SD. The graph represents one of three independent experiments performed using triplicate wells for each experimental point. Similar results were obtained using the sh-Cdc42#2 sequence. * p < 0.005.