Synthesis and Biological Evaluation of Novel Anti-leukemia Proteolysis-Targeting Chimeras in Degradating Inosine Monophosphate Dehydrogenase.

Abstract

Proteolysis-targeting chimera (PROTAC) is a bifunctional molecule comprising a ligand to recognize the targeted protein to be degraded. To use the advantages of the PROTAC technique, we have synthesized novel compounds to degrade inosine monophosphate dehydrogenase (IMPDH) by the proteasome system. We describe the synthesis of new PROTACs based on a combination of mycophenolic acid (MPA) as the potent IMPDH inhibitor and pomalidomide as a ligand of E3 ubiquitin ligase via linkers formed from Cu(I)-catalyzed cycloaddition reaction. All synthesized compounds were investigated against Jurkat cells as acute T-cell leukemia and were potent apoptosis inducers at 50 nM. The effect of compound 2 in 0.05 μM on IMPDH degradation can be almost prevented by competition with bortezomib as the proteasome inhibitor at 0.1 and 0.5 μM.