Abstract
Although bortezomib (BTZ) displays efficacy in treating multiple myeloma (MM), BTZ resistance in MM patients has been reported. Meanwhile, treating BTZ resistant MM cells with β-catenin inhibitors have demonstrated the ability to reserve BTZ resistance. Thus, the present study aimed to investigate the synergistic effect of the β-catenin inhibitors, ICG-001 and pyrvinium (PP), with BTZ in the treatment of BTZ-resistant MM cells. Different concentrations of ICG-001 (0-32 µM) or PP (0-32 nM) were used to treat the BTZ-resistant RPMI-8226 (RPMI-8226BR) and BTZ-resistant KMS-11 (KMS-11BR) cell lines, followed by a BTZ combination treatment. Subsequently, cell viability and apoptosis in these two cell lines were determined by CCK-8 assay and flow cytometry, respectively. The proteins involved in the Wnt/β-catenin signaling pathway were detected using western blotting. The Wnt/β-catenin signaling pathway was activated in the RPMI-8226BR and the KMS-11BR cells. In addition, the cell viability of RPMI-8226BR and KMS-11BR cells were decreased following β-catenin inhibitor (ICG-001 and PP) treatment alone. Furthermore, the β-catenin inhibitors, ICG-001 and PP, plus BTZ combination treatment revealed a notable decrease in cell viability and a marked increase in cell apoptosis rate, compared with that in cells treated with ICG-001, PP or BTZ alone in the RPMI-8226BR and KMS-11BR cell lines. In conclusion, the β-catenin inhibitors, ICG-001 and PP not only increased apoptosis, but also sensitized BTZ-resistant MM cells to BTZ, indicating their potential therapeutic application in MM.