Fig. 5.

IGGi-11me blocks GIV-dependent tumor cell migration. (A) Basal-like invasive breast cancer (BRCA) cell lines express higher amounts of GIV (GIV^High) than luminal-like noninvasive BRCA cell lines (GIV^Low) as determined by immunoblotting. (B) IGGi-11me inhibits cell migration more potently in MDA-MB-231 cells (GIV^High) than in MCF-7 cells (GIV^Low). Chemotactic cell migration toward FBS was determined in the presence of the indicated concentrations of IGGi-11me using a modified Boyden-chamber assay. (C and D) IGGi-11me-mediated inhibition of tumor cell migration is lost upon depletion of GIV from MDA-MB-231 (C) or HeLa (D) cells. GIV-depleted cells (shGIV) or control cells (shControl) were processed as described in B. (E) IGGi-11me impairs tumor cell migration without affecting cell viability. Heatmap comparing the half-maximal inhibitory concentration (IC₅₀) of IGGi-11me on cell migration or viability of the indicated cell lines. IC₅₀ values were determined from results shown in this figure or in SI Appendix, Fig. S8. Cell viability was determined upon incubation with IGGi-11me for 24 h, which is longer than the times cells were exposed to the compound in cell migration assays. All results are mean ± SEM (N ≥ 3).