Dimethylenastron suppresses human pancreatic cancer cell migration and invasion in vitro via allosteric inhibition of mitotic kinesin Eg5

Abstract

Aim:The mitotic kinesin Eg5 plays a critical role in bipolar spindle assembly, and its inhibitors have shown impressive anticancer activity in preclinical studies. This study was undertaken to investigate the effect of dimethylenastron, a specific inhibitor of Eg5, on the migration and invasion of pancreatic cancer cells. Methods: Human pancreatic cancer cell lines PANC1, EPP85, BxPC3, CFPAC1, and AsPAC1 were used. Eg5 expression was examined using immunofluorescence microscopy. Cell migration and invasion were analyzed with wound healing and transwell assays. Cell proliferation was examined using sulforhodamine B and MTT assays. The binding of dimethylenastron to Eg5 was analyzed with a molecular modeling study, and the ADP release rate was examined with the MANT-ADP reagent. Results: Eg5 expression was 9-16-fold up-regulated in the 5 pancreatic cancer cell lines. Treatment of PANC1 pancreatic cancer cells with dimethylenastron (3 and 10 μmol/L) for 24 h suppressed the migratory ability of the cancer cells in a concentration-dependent manner. The invasion ability of the cancer cells was also reduced by the treatment. However, treatment of PANC1 cells with dimethylenastron (3 and 10 μmol/L) for 24 h had no detectable effect on their proliferation, which was inhibited when the cancer cells were treated with the drug for 72 h. Molecular modeling study showed that dimethylenastron could allosterically inhibit the motor domain ATPase of Eg5 by decreasing the rate of ADP release. Conclusion: Dimethylenastron inhibits the migration and invasion of PANC1 pancreatic cancer cells, independent of suppressing the cell proliferation. The findings provide a novel insight into the mechanisms of targeting Eg5 for pancreatic cancer chemotherapy.

Impaired angiogenesis and tumor development by inhibition of the mitotic kinesin Eg5

“…These changes in the cytoskeleton are most likely responsible for the reduced migratory and adhesive capacity after Eg5 inhibition. Just recently, it has been shown that Eg5 also has a function in normal and malignant cell migration [14, 15]. There is evidence from the literature that DMN is highly specific for Eg5 kinesin, it binds to a region of the protein composed of loop 5, helix α2 and α3, which is not conserved in other kinesins [34, 35].…”

“…Beside their role in mitosis, an increasing number of reports point to the possibility that they may exert other biological functions. KIF11/Eg5 plays an important role in normal and cancer cell migration [14, 15]. Only recently, an important role of Eg5 in protein translation has been discovered [16] and KIF4A has been shown to be implicated in neuronal survival [17].…”

Kinesin-5 Eg5 is essential for spindle assembly and chromosome alignment of mouse spermatocytes

“…STLC tightly binds to Eg5 to disrupt the mitotic spindle during metaphase without direct influences on microtubule dynamics [34,39,40]. Dimethylenastron allosterically inhibits Eg5 through decreasing ADP release [41,42]. These three cell-permeable inhibitors are effective tools for the long-term inhibition of Eg5 in vivo.…”

“…The final concentrations of each specific inhibitor are listed as follows. The concentrations of Monastrol [19,40], STLC [37], and Dimethylenastron [41,63] were chosen according to previous studies. For Eg5 inhibition in mouse testes, Monastrol (50 μM), STLC (10 μM) and Dimethylenastron (20 μM) were used, respectively.…”

Role of FOXM1 in ovarian cancer tumorigenesis and chemoresistance

“…KIF11 is found to be significantly associated with tumour stage, grade and poor survival for patients with renal cell carcinoma (Sun et al, 2013). Up-regulation of KIF11 has also been reported in pancreatic cancer cells (Sun et al, 2011).…”