METHODS: Immunofluorescence staining was used to observe the structural features of PC12 cells after culturing in medium with nerve growth factor (NGF). After different doses and different durations of alcohol treatment, CCK-8 assay was performed to detect the viability of PC12 cells, flow cytometry assay was carried out to detect the apoptosis rate of PC12 cells, dual-luciferase reporter assay was used to definitude the regulatory relationship between miR-96-5p and Tp73, and western blot was used to detect the protein expression of TAp73.
RESULTS: The result of immunofluorescence staining demonstrated that PC12 cells abundantly expressed Map2, CCK-8 assay illustrated alcohol exposure significantly downregulated the cell viability of PC12 cells, Treatment with miR-96-5p inhibitor induced apoptosis and upregulated the expression of TAp73 in PC12 cells. Contrastingly, miR-96-5p mimic reversed the above effects and downregulation of TAp73 inhibited the apoptosis of PC12 cells.
CONCLUSION: The present study demonstrated that miR-96-5p participates in alcohol-induced apoptosis in PC12 cells via negatively regulating TAp73.
PURPOSE: Here, we investigated whether OSCC cells were sensitive towards zerumbone treatment and further determined the molecular pathways involved in the mechanism of action.
METHODS: Cytotoxicity, anti-proliferative, anti-migratory and anti-invasive effects of zerumbone were tested on a panel of OSCC cell lines. The mechanism of action of zerumbone was investigated by analysing the effects on the CXCR4-RhoA and PI3K-mTOR pathways by western blotting.
RESULTS: Our panel of OSCC cells was broadly sensitive towards zerumbone with IC50 values of less than 5 µM whereas normal keratinocyte cells were less responsive with IC50 values of more than 25 µM. Representative OSCC cells revealed that zerumbone inhibited OSCC proliferation and induced cell cycle arrest and apoptosis. In addition, zerumbone treatment inhibited migration and invasion of OSCC cells, with concurrent suppression of endogenous CXCR4 protein expression in a time and dose-dependent manner. RhoA-pull down assay showed reduction in the expression of RhoA-GTP, suggesting the inactivation of RhoA by zerumbone. In association with this, zerumbone also inhibited the PI3K-mTOR pathway through the inactivation of Akt and S6 proteins.
CONCLUSION: We provide evidence that zerumbone could inhibit the activation of CXCR4-RhoA and PI3K-mTOR signaling pathways leading to the reduced cell viability of OSCC cells. Our results suggest that zerumbone is a promising phytoagent for development of new therapeutics for OSCC treatment.