1A-116 is a specific Rac1 inhibitor.
1A-116 shows lesser effect on MCF7::pcDNA.3 cells than on MCF7::C1199 cells. 1A-116 treatment decreases phospho-PAK1 levels in a time-dependent manner. The presence of 1A-116 reverts the PAK1 phosphorylation induced by 4-hydroxytamoxifen (Tam). The presence of 1A-116 also effectively reverts Rac1-PAK1-mediated estrogen receptor (ER) phosphorylation at Ser305. 1A-116 shows a significant increase in antiproliferative activity on F3II cells, showing an IC50 value of 4 µM. A-116 also dramatically impairs Rac1 activation at low micromolar range (1 µM).