MG-132 CAS NO.1211877-36-9

MG-132 displays >1000 times more activity than ZLLal in inhibiting the ZLLL-MCA-degrading activity of 20S proteasome with IC50 of 100 nM versus 110 μM. MG-132 also inhibits calpain with IC50 of 1.2 μM. MG-132 induces neurite outgrowth in PC12 cells at an optimal concentration of 20 nM, displaying 500 times more potency than ZLLal. [1] MG-132 (10 μM) potently inhibits TNF-α-induced NF-κB activation, interleukin-8 (IL-8) gene transcription, and IL-8 protein release in A549 cells by inhibition of proteasome-mediated IκBα degradation. [2] MG-132 treatment potently induces p53-dependent apoptosis in KIM-2 cells by 26S proteasome inhibition. [3] Unlike BzLLLCOCHO or PS-341, MG-132 treatment results in weak inhibition of the chymotrypsinlike (CT-L) and peptidylglutamyl peptide hydrolysing (PGPH) activities of the 26S proteasome, whereas multiple myeloma cells (U266 and OPM-2) are more sensitive to induction of apoptosis by MG-132 than BzLLLCOCHO. [4] MG-132 (1 μM) sensitizes TRAIL-resistant prostate cancer cells by activating the AP-1 family members c-Fos and c-Jun, which, in turn, repress the antiapoptotic molecule c-FLIP(L). [5] MG-132 significantly enhances the ability of inositol hexakisphosphate (IP6) to reduce cellular metabolic activity in both PC3 and DU145 androgen-independent prostate cancer (AIPCa) cell lines. [6]

Administration of MG-132 effectively rescues the expression levels and plasma membrane localization of dystrophin, β-dystroglycan, α-bdystroglycan, and α-sarcoglycan in skeletal muscle fibers from mdx mice, reduces muscle membrane damage, and ameliorates the histopathological signs of muscular dystrophy. [7] MG-132 treatment significantly reduces immobilization-induced skeletal muscle atrophy in mice, by downregulating the muscle-specific ubiquitin ligases atrogin-1/MAFbx and MuRF-1 mRNA. [8]