The Small Molecule Iodva1 Inhibits The Rac Guanine Nucleotide Exchange Factor Vav3 And Overcomes Tki-Resistance In Ph+(Bcr-Abl1) B-All

Aberrant activation of Rho guanine nucleotide exchange factors (RhoGEFs) is a chief mechanism driving abnormal activation of their RhoGTPase targets in cancer. Thus, small molecule inhibitor of RhoGEF activities can be used as a drug lead to treat leukemia and other malignancies. We have identified an active small molecule, IODVA1, in several xenograft mouse models of cancer including Ras-driven cancers. Here, we used cellular and mouse models of Ph+(BCR-ABL1) B-ALL to identify Vav3, the multi-domain tyrosine phosphorylation-dependent RacGEF as the target of the small molecule IODVA1.