Bisindolylmaleimide III

Bisindolylmaleimide III is a protein kinase C (PKC) inhibitor with IC₅₀ values of 0.26, 5.7, and 6 μM against PKCα, PKCδ, and PKCμ, respectively. Bisindolylmaleimide III also exhibits inhibitory activity against other off-targets, with IC₅₀ values of 0.17, 1, and 2 μM against SLK, adenosine kinase (AK), and CDK2, respectively; its K_i for NQO2 is 16.5 μM. Bisindolylmaleimide III selectively binds to activated Rsk1 following EGF stimulation, and serves as a tool for detecting the activation status of intracellular Rsk1 and PKCα, as well as for functional analysis of SLK. Bisindolylmaleimide III can be used in studies of signal transduction and colorectal cancer^[1][2][3]. In Vitro:Bisindolylmaleimide III (75 min) potently and selectively inhibits PKCα in human IM-9 lymphocytes, reducing PDBu (HY-18985)-induced hGH-BP release with an IC₅₀ of 0.33 μM^[2].
Bisindolylmaleimide III (0.1-2.5 μM; 45 min) inhibits the phosphorylation of PDBu-enhanced 42, 45, 53 and 83 kDa extracellular proteins in human IM-9 lymphocytes, with IC₅₀ values ranging from 0.23 to 0.32 μM^[2].
Bisindolylmaleimide III (20 μM; 6-24 h) hydrochlorid does not sensitize human colon adenocarcinoma COLO 205 cells to TNF-α-dependent apoptosis, which is evidenced by unchanged procaspase-3 levels and only a mild decrease in cell viability within 24 hours^[3].
Bisindolylmaleimide III (20 μM; 21 h) hydrochlorid does not interfere with the TNF-α-dependent apoptosis-sensitizing activity of Bisindolylmaleimide IX in human colon adenocarcinoma COLO 205 cells^[3].