EHT 1864 is an inhibitor of the Rac subfamily of Rho GTPases, that binds to Rac1, Rac1b, Rac2, and Rac3 with Kd values of 40, 50, 50, and 250 nM, respectively. It can reverse transformation of NIH 3T3 fibroblasts caused by constitutively activated Rac1, as well as Rac-dependent transformation caused by Tiam1 or Ras. EHT 1864 inhibits APP processing by γ-secretase, reducing Αβ40 and Αβ42 accumulation. It blocks breast cancer cell invasion in a collagen matrix assay and, at 10 μM, increases the size but decreases the density of dendritic spines of hippocampal neurons in culture.
