NI-42 is an inhibitor of the bromodomain and PHD finger-containing 1 (BRPF1) bromodomain (IC50 = 7.9 nM). It is selective for BRPF1 over BRPF2/BRD1, BRPF3, BRD9, and BRD4/BD1 (IC50s = 48, 260, 310, and 4,500 nM, respectively). NI-42 inhibits the growth of OCI-AML2, Nomo-1, THP-1, KG-1, and MV-4-11 acute myeloid leukemia (AML) cells (GI50s = 1.3, 4.6, 5.7, 7, and 9.9 μM, respectively) and a variety of non-AML cells (GI50s = 1-10 μM). It also inhibits the growth of DMS114 lung, HRA-19 colon, and RERF-LC-Sq1 lung cancer cells (GI50s = 16.6, 15.6, and 17.1 μM, respectively) but not NCI H1703 lung cancer cells (GI50 = >30 μM).
