Conclusion
Ivalin induced microtubule depolymerization, then blocked cells in mitotic phase, and eventually resulted in apoptosis in SMMC-7721 cells. Collectively, these data indicate that Ivalin, acting as a novel inhibitor of microtubules, could be considered as a promising lead in anticancer drug development.
Methods
We used the 3-(4,5-dimethylthiazol)-2,5-diphenyltetrazolium bromide (MTT) assay to evaluate the cell proliferation effect of Ivalin and flow cytometry analysis to detect the apoptotic and cell cycle arrest effects of Ivalin. Immunofluorescence staining was used to measure the effect of Ivalin on the cytoskeleton network, and Western blotting was used to detect the expression levels of Bax, Bcl-2, Cdc2, phosphor-Cdc2, Cdc25A, Cyclin B1, and tubulin.
Results
Ivalin induced cell cycle G2/M arrest and subsequent triggered apoptosis in human hepatocellular carcinoma SMMC-7721 cells. Furthermore, microtubules were shown to be involved in Ivalin-meditated apoptosis. In this connection, Ivalin treatment suppressed cellular microtubule network formation by regulating microtubule depolymerization. Moreover, Western blotting revealed Cdc25A and Cyclin B1 were upregulated in Ivalin-meditated cell cycle arrest. Subsequently, the induction of Bax (a proapoptotic protein) and reduction of Bcl-2 (an anti-apoptotic protein) expression were observed in Ivalin-treated SMMC-7721 cells.