Recent studies have demonstrated that Glycogen Synthase Kinase 3β (GSK-3β) is overexpressed in human colon and pancreatic carcinomas contributing to cancer cell proliferation and survival. Here, we report the design, synthesis, and biological evaluation of benzofuran-3-yl-(indol-3-yl) maleimides, potent GSK-3β inhibitors. Some of these compounds show picomolar inhibitory activity toward GSK-3β and an enhanced selectivity against Cyclin-dependent Kinase 2 (CDK-2). Selected GSK-3β inhibitors were tested in the pancreatic cancer cell lines MiaPaCa-2, BXPC-3, and HupT3. We determined that some of these compounds, namely compounds 5, 6, 11, 20 and 26, demonstrate antiproliferative activity against some or all of the pancreatic cancer cells at low micromolar to nanomolar concentrations. We found that the treatment of pancreatic cancer cells with GSK-3β inhibitors 5 and 26 resulted in suppression of GSK-3β activity and a distinct decrease of the X-linked Inhibitor of Apoptosis (XIAP) expression leading to significant apoptosis. The present data suggest a possible role for GSK-3β inhibitors in cancer therapy, in addition to their more prominent applications in CNS disorders.

Readily prepared amino thioacids react at room temperature in DMF in the presence of cesium carbonate with 2,4-dinitrobenzenesulfonamides to give amides. When the sulfonamide is derived from an amino acid the method results in peptide bond formation, whereas the use of carbohydrate derived sulfonamides gives neoglycoconjugates.