In vitro activity: UM-164 is a potent Src/p38 inhibitor with potential anticancer activity for Triple-Negative Breast Cancer (TNBC). It is a promising lead compound for developing the first targeted therapeutic strategy against TNBC. c-Src has been shown to play a pivotal role in breast cancer progression, metastasis, and angiogenesis. In the clinic, however, the limited efficacy and high toxicity of existing c-Src inhibitors have tempered the enthusiasm for targeting c-Src. UM-164 binds the inactive kinase conformation of c-Src. Kinome-wide profiling of UM-164 identified that Src and p38 kinase families were potently inhibited by UM-164. UM-164 alters the cell localization of c-Src in TNBC cells. In xenograft models of TNBC, UM-164 resulted in a significant decrease of tumor growth compared with controls, with limited in vivo toxicity.

Kinase Assay: UM-164 is a potent and dual inhibitor of the Src/p38 kinase with potential anticancer activity. UM-164 binds the inactive kinase conformation of c-Src. Kinome-wide profiling of UM-164 identified that Src and p38 kinase families were potently inhibited by UM-164.

Cell Assay: MDA-MB 468 cells were trypsinized and allowed to adhere overnight to #1.5 cover glass in a 6-well plate. Cells were then treated with 5 μmol/L dasatinib, 5 μmol/L UM-164, or vehicle (DMSO) for 4 hours. Cells were then fixed with 4% paraformaldehyde for 15 minutes at room temperature followed by three washes with PBS. The fixed cells were treated with 1 μmol/L of an irreversible turn-on Src fluorophore for 1 hour followed by three washes with PBS. Cells were then mounted on slides with UltraCruz Hard-set Mounting Medium w/DAPI (Santa Cruz Biotechnology; sc-359850) and stored for 30 minutes at 4°C in the dark.