BI8626 is a specific inhibitor of the ubiquitin ligase HUWE1 with an IC50 of 0.9 μM[1].
BI8626 induces HUWE1 ectopically expresses to abolishe ubiquitination of MCL1 in HeLa cells[1].BI8626 suppresses colony formation of Ls174T cells with estimated IC50 value of 0.7 μM, and BI8622 (1-4 days) treatment retards passage of Ls174T cells through all phases of the cell cycle, with the effect being strongest for G1[1].BI8626 (0-50 μM; 0-6 hours) retards the degradation of MCL1 in response to UV irradiation to the same extent as depletion of HUWE1 in U2OS cells[1].
[1]. Peter S, et al. Tumor cell-specific inhibition of MYC function using small molecule inhibitors of the HUWE1 ubiquitin ligase.EMBO Mol Med. 2014 Dec;6(12):1525-41.