EHop-016 (1-10 μM; 24 hours; MDA-MB-435 cells) treatment inhibits Rac1 and Rac3 activity. At higher concentrations, EHop-016 inhibits the close homolog Cdc42. In MDA-MB-435 cells that demonstrate high active levels of the Rac GEF Vav2, EHop-016 inhibits the association of Vav2 with a nucleotide-free Rac1(G15A) . EHop-016 also inhibits the Rac activity of MDA-MB-231 metastatic breast cancer cells and reduces Rac-directed lamellipodia formation in both cell lines. EHop-016 decreases Rac downstream effects of PAK1 (p21-activated kinase 1) activity and directed migration of metastatic cancer cells. EHop-016 affectes cell viability by down-regulating Akt and Jun kinase activities and c-Myc and Cyclin D expression, as well as increasing caspase 3/7 activities in metastatic cancer cells.
Western Blot Analysis
EHop-016 (10-25 mg/kg; intraperitoneal injection; 3 times a week; for 55 days; nu/nu mice) treatment significantly reduces mammary fat pad tumor growth, metastasis, and angiogenesis.