MG132


133407-82-6 is a potent cell-permeable inhibitor of proteasome and calpain with IC50 of 100 nM and 1.2 μM respectively. MG132 inhibited the growth of HeLa cells via inducing the cell cycle arrest as well as triggering apoptosis. MG132 also inhibits NF-κB activation with an IC50 of 3 µM and prevents β-secretase cleavage. MG132 induces cell apoptosis through formation of reactive oxygen species or the upregulation and downregulation of these factors, which is ultimately dependent upon the activation of the caspase family of cysteine proteases.

In vitro, it induces neurite outgrowth in PC12 cells and has anticancer properties. Besides its apoptotic effect alone, MG132 also enhanced the antiglioma effect of the chemotherapeutics cisplatin, taxol and doxorubicin in C6 and U138MG cells, indicating an adjuvant/chemosensitizer potential.
Cell viability assay. Cell viability was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cells were seeded in 96-well plates at a density of 2.5x103/well 1 day prior to treatment. Then, cells were treated with MG132 or/and irradiation. After treatment, 20 µl of 5 mg/ml MTT solution was added into each well and incubated for 4 h. After the supernatant was removed, 100 µl of DMSO was added, and then placed in a microplate reader to measure OD value. Cell viability rate (vR) was calculated according to the following formula: vR = (OD in observed group/OD in 0 Gy group) x 100%. All assays were repeated 3 times in quintuplicate.