Lactacystin is a specific and an irreversible inhibitor of proteasome with IC50 value of 4.8 μM [1].
Lactacystin binds to the catalytic subunits of the 20 S proteasome and inhibits all the three peptidase activities of the proteasome, chymotrypsin-like, trypsin-like and caspase-like. With this feature, lactacystin is used to study the role of the proteasome. In Neuro-2a cells, lactacystin treatment resulted in the induction of neurite outgrowth. It caused a transient increase in cAMP levels and the bipolar morphology of the cells. Lactacystin also inhibited cell cycle progression in MG-63 human osteosarcoma cells. Moreover, lactacystin was reported to have therapeutic effects on glioma cells. In rat C6 glioma cells, lactacystin significantly inhibited cell growth with IC50 value of about 10 μM. Besides that, in a mouse gliomaxenograft model, administration of lactacystin resulted in tumor size reduction at a dose of 1-5 μg / 20 g body weight [2, 3].
References:
1.?Csizmadia V, Csizmadia E, Silverman L, et al. Effect of proteasome inhibitors with different chemical structures on the ubiquitin–proteasome system in vitro. Veterinary Pathology Online, 2010, 47(2): 358-367.
2.?Fenteany G, Schreiber S L. Lactacystin, proteasome function, and cell fate. Journal of Biological Chemistry, 1998, 273(15): 8545-8548.
3.?Wang H, Zhang S, Zhong J, et al. The proteasome inhibitor lactacystin exerts its therapeutic effects on glioma via apoptosis: An in vitro and in vivo study. Journal of International Medical Research, 2013, 41(1): 72-81.
