Fig. 3.

Oncogenic RAC proteins as therapeutic targets. (A) HT1080 cells were transfected with control, RAC1, or NRAS siRNAs; lysed; and subjected to immunoblot analysis with antibodies to RAC1, NRAS, or ACTB (loading control). (B) HT1080 cells were transfected with control, RAC1, or NRAS siRNAs, as indicated, and cultured under the presence of 10% (vol/vol) FBS. Cell number was counted at the indicated times after the onset of transfection. Data are means ± SD from three independent experiments. (C) HT1080 cells were infected with a retrovirus encoding green fluorescent protein (EGFP) as well as a control or RAC1 shRNA. They were also infected with a retrovirus encoding shRNA-resistant wild-type RAC1 or RAC1(N92I), as indicated. The number of EGFP-positive cells was determined by flow cytometry after culture of the cells for the indicated times, and the size of the EGFP-positive fraction relative to that at 2 d was calculated. Data are means ± SD from three independent experiments. (D) MDA-MB-157 cells were infected with a retrovirus encoding EGFP as well as a control or RAC1 shRNA. They were also infected with a retrovirus encoding shRNA-resistant wild-type RAC1 or RAC1(P29S), as indicated. The number of EGFP-positive cells was determined by flow cytometry after culture of the cells for the indicated times, and the size of the EGFP-positive fraction relative to that at 3 d was calculated. Data are means ± SD from three independent experiments.