VR23

VR23 is a small molecule that potently inhibits the activities of trypsin-like proteasomes (IC₅₀=1 nM), chymotrypsin-like proteasomes (IC₅₀=50-100 nM), and caspase-like proteasomes (IC₅₀=3 μM). IC50 & Target: IC50: 1 nM (trypsin-like proteasome), 50-100 nM (chymotrypsin-like proteasome), 3 μM (caspase-like proteasome) In Vitro: VR23 is a novel proteasome inhibitor targeting β2 of the 20S proteasome subunit. VR23 produces a synergistic effect in killing multiple myeloma cells, including those that were resistant to PS-341. VR23 as a structurally novel proteasome inhibitor with desirable properties as an anticancer agent. In Vivo: VR23 shows effective antitumor and antiangiogenic activities in mice.