Figure 2

Knock-down of p110γ inhibits cell migration and phosphorylation of Akt in MDA-MB-231 cells after IGF stimulation. (A) MDA-MB-231 cells in which p110γ had been knocked down by RNAi, or control knockdown cell (expressing scrambled RNAi) were assessed for growth in culture for 5 days, or growth in soft agar for 2 weeks. (B) Control and p110γ knockdown cells were tested for their chemotactic response to various concentrations of IGF-I. All panels are expressed as the mean ± SEM from at least three separate experiments, each performed in triplicate. Asterisks indicate significantly different from the control values (Student’s unpaired t test) at *, p<0.05. (C) Akt phosphorylation on S473 of MDA-MB-231 cells or p110γ knock-down cells was assessed in response to 0.1 nM IGF-I at the time points indicated. These data are representative of at least 3 independent experiments conducted with similar results. (D) Akt phosphorylation was quantified by densitometry, normalized to the level of β-actin and expressed as a value relative to the 10 minute control-treated values (mean ± SEM of three independent experiments) as described in Materials and Methods. Asterisks indicate significantly different from the control values (2-way ANOVA with Bonferroni post-test) at ***, p<0.001.