Inhibiting the anaphase promoting complex/cyclosome induces a metaphase arrest and cell death in multiple myeloma cells

Abstract

The anaphase promoting complex/cyclosome (APC/C) is an ubiquitin ligase involved in cell cycle. During the metaphase-anaphase transition the APC/C is activated by Cdc20. The aim of this study is to elucidate the importance and therapeutic potential of APC/C and its co-activator Cdc20 in multiple myeloma (MM). Gene expression analysis revealed that Cdc20 was expressed at higher levels in gene expression-based high-risk MM patients. Moreover, high Cdc20 expression correlated with poor prognosis. Treatment of human myeloma cell lines with proTAME, an APC/C inhibitor, resulted in an accumulation of APC/CCdc20 substrate cyclin B1 and an accumulation of cells in metaphase. Moreover we observed a significant dose-dependent decrease in viability and increase in apoptosis in MM cells upon proTAME treatment. The induction of apoptosis was accompanied with caspase 3, 8, 9 and PARP cleavage. A similar metaphase arrest and induction of apoptosis were obtained with specific knockdown of Cdc20. In addition, we demonstrated the accumulation of Bim was partially responsible for the observed cell death. Combining proTAME with another APC/C inhibitor apcin or the alkylating agent melphalan resulted in enhanced anti-MM activity. This study suggests that the APC/C and its co-activator Cdc20 could be a new and promising target especially in high-risk MM patients.

Cdc20 inhibitor apcin inhibits the growth and invasion of osteosarcoma cells

“…As such, targeting and manipulating Bim expression or activity may affect the outcomes of human cancers. Pharmacological inhibition of APC/C with proTAME induced apoptosis in multiple myeloma cells and was partially mediated by Bim, as well as the phosphorylation of Bcl-2 and Bcl-xL (27). It was reported that Bim expression was upregulated by proTAME treatment, while the apoptotic consequences of Cdc20 depletion have been attributed to the accumulation of Bim.…”

“…It is accepted that apcin prevents substrate recognition by binding to Cdc20. Furthermore, apcin has been reported to induce metaphase arrest and apoptotic cell death in multiple myeloma (27). de Lange et al (28) demonstrated that several cancer cell lines with cohesion fatigues exhibited an increased response to apcin, indicating that APC/C-Cdc20 inhibitors may be effective therapeutic agents targeting cohesion defective cancers.…”

APC/CCDC20 and APC/C play pivotal roles in the process of embryonic development in Artemia sinica

“…For example, 51.9% of gastric cancer tissues showed high CDC20 expression, but only 18.3% showed high expression in the adjacent noncancerous tissues. This implied that inhibiting the expression of cdc20 could slow down the growth of tumor cells and induce cell stagnation at the G2/M phase4142. From the qPCR and western blotting results, As- CDC20 existed in the gastrula stage as a maternal protein, and at 5 h, A. sinica broke the diapause status and cells began to divide rapidly; the amounts of As-cdc20 transcripts were suddenly upregulated.…”

Hyperphosphorylation of CDH1 in Glioblastoma Cancer Stem Cells Attenuates APC/CCDH1 Activity and Pharmacologic Inhibition of APC/CCDH1/CDC20 Compromises Viability

“…It was also shown that the addition of proTAME enhanced the impact of apcin as proTAME inhibits CDH1/CDC20 via a distinct mechanism from apcin (17). Therefore, these drugs can elicit a mitotic arrest independently, but a greater impact on both mitotic arrest and cell death is seen when the drugs are used in combination and APC/C CDC20 is more efficiently inhibited (17,33). Our studies are the first to demonstrate an impact on GBM cell viability using these inhibitors and support these previous findings whereby we observed the greatest impact on both CSC and NSTC mitotic progression and cell growth when apcin and proTAME were used in combination.…”

“…Both apcin, which disrupts the interaction of CDC20 with APC/C substrates, and proTAME, which disrupts the interaction between APC/C and CDC20 or CDH1, previously demonstrated an impact on mitotic progression (17). These drugs also led to increased cell death when tested in vitro on multiple myeloma cells and osteosarcoma cells (33,34). We first performed a colony formation assay on CSCs and NSTCs from two independent PDX specimens that were treated with vehicle (DMSO), 12 mmol/L proTAME, 48 mmol/L apcin, or the combination of proTAME and apcin, with the concentrations used on the basis of previous reports and calculated dose-response curves for CSCs and NSTCs, which fell within or just outside of the range of the concentrations used in previous reports ( Supplementary Fig.…”