Marizomib

Marizomib (Salinosporamide A) is a second-generation, irreversible, brain-penetrant, pan-proteasome inhibitor. Marizomib inhibits the CT-L (β5), CT-T-laspase-like (C-L, β1) and trypsin-like (T-L, β2) activities of the 20S proteasome (IC₅₀=3.5, 28, and 430 nM, respectively)^[1][2][3]. IC50 & Target:IC50: 3.5 nM (CT-L), 28 nM (CT-T-laspase-like), 430 nM (trypsin-like)^[1] In Vitro:Marizomib (Salinosporamide A) (0.1-10000 nM; 72 hours) effectively reduces survival of D-54 and U-251 cells in a dose-dependent manner. The IC₅₀s are ～52 nM for U-251 and ～20 nM for D-54^[1].
Marizomib (24 hours; 60 nM) induces apoptosis and caspase-3 activation in glioma cells^[1]. In Vivo:Marizomib (Salinosporamide A) (0.15 mg/kg; i.v; twice a week for three weeks) significantly decreases tumor growth, and is not associated with any toxicity^[3].