Figure 6.

Rac1 and stathmin but not EB1 are required for IGF-I-induced invasion of MDA-MB-231 cells. Cells after incubation for 48 h with mismatch negative control small interfering RNA and 2 different small interfering RNAs of Rac1 (a), stathmin (b), or EB1 (c) were lysed and the same amounts of total cell lysates were immunoblotted with antibodies to β-actin and Rac1 (a), stathmin (b), or EB1 (c). Cells transfected with control small interfering RNA and Rac1-1 (a), stathmin-1 (b), or EB1-1 small interfering RNA (c) were incubated for 6 h toward medium containing (+) or lacking (−) IGF-I. The mean (SD) values of triplicate assays are given as the number of invaded cells relative to that in unstimulated control MDA-MB-231 cells.