Background:

UMI-77 is a novel small-molecule inhibitor of Mcl-1 with Ki and IC50 values of 0.49 μM and 0.31 μM [1].

Myeloid cell leukemia-1 (Mcl-1) is a member of the prosurvival Bcl-2 family and is a potent anti-apoptotic protein. Mcl-1 acts as an important survival factor in a broad range of human cancers [1].

UMI-77 is a novel small-molecule Mcl-1 inhibitor. In FP-based binding assays, UMI-77 potently and selectively displaced fluorescent labeled BID-BH3 peptide from Mcl-1 protein with Ki value of 0.49μM and bound to the BH3 binding pocket of Mcl-1 protein. UMI-77 bound to A1/Bfl-1, Bcl-w, Bcl-2 and Bcl-xL with Ki values of 5.33, 8.19, 23.83 and 32.99μM. In a pull-down assay, UMI-77 at 10 μM effectively and dose-dependently inhibited the interactions between BL-Noxa and cellular Mcl-1. It was reported that Mcl-1 regulates pro-apoptotic Bax and Bak proteins and preventing their pro-apoptotic activity. UMI-77 dose-dependently inhibited the binding of Mcl-1 to Bax with IC50 value of 1.43μM. In PC cells, UMI-77 inhibited cell growth and induced apoptosis in a time and dose-dependent way [1].

In BxPC-3 xenografted SCID mice model, UMI-77 exhibited robust anti-tumor efficacy with no toxicity. Also, UMI-77 decreased the anti-apoptotic protein survivin, which potently inhibited apoptosis by antagonizing caspase activity [1].

Reference:
[1].  Abulwerdi F, Liao C, Liu M, Azmi AS, et al. A novel small-molecule inhibitor of mcl-1 blocks pancreatic cancer growth in vitro and in vivo. Mol Cancer Ther, 2014, 13(3): 565-575.