(S)-MG132 is a reversible



MG132 is a reversible, cell-permeable inhibitor of proteasome activity (IC₅₀ = 100 nM; Kisselev & Goldberg) and calpain (IC₅₀ = 1.2 µM; Tsubuki et al.). The ubiquitin-proteasome pathway selectively degrades intracellular proteins, thereby clearing damaged or misfolded proteins, and regulating the availability of key proteins involved in the control of inflammatory processes and cell cycle regulation. (S)-MG132 suppresses NF-κB activation by preventing IκB degradation (IC₅₀ = 3 µM; Arlt et al., Palombella et al., Ortiz-Lazareno et al.).

CANCER RESEARCH
· Blocks apoptosis triggered by DNA damage in HeLa cells (Zhang et al.).
· Inhibits NF-κB activation, sensitizing a variety of carcinoma cell lines to apoptosis (Arlt et al.).
· Cytotoxic effects on a variety of human cancer cell lines (Banerjee & Liefshitz).
· Inhibits growth of mouse melanoma (B16) and human ocular melanoma (IPC227F) cell lines (Vivier et al.).
MG132 proteasome inhibitor modulates proinflammatory cytokines production and expression of their receptors in U937 cells: involvement of nuclear factor-kappaB and activator protein-1.