Cyanidin Inhibits Glioma Stem Cells Proliferation through the Wnt Signaling Pathway.

BACKGROUND
Cyanidin has a protective effect on the nervous system and has been reported to treat tumor effectively. However, its impact on glioma stem cells (GSC) is unknown.


METHODS
Using seven GSC lines, the anti-tumor effect of cyanidin is tested. The effect of cyanidin on the cell viability in each cell line is evaluated. Wnt signaling pathway-related genes are checked after treatment of cyanidin. Cytoplasmic/nuclear β-catenin protein levels post cyanidin treatment is detected. Protein levels of c-Myc after cyanidin treatment are determined. Twist1 and Snail1 protein levels after cyanidin treatment are checked as well.


RESULTS
Cyanidin significantly reduces the cell viability of all GSCs, and exhibited the most substantial effect in GBM2 but no apparent effect in 293T cells. It can regulate the Wnt signaling pathway of all GSC lines. In the GBM2, GBM7, G166, and G179 cell lines, there is upregulation of WNT1 and MYC genes, while in the G144 and GliNS2 cell line, these two genes are down-regulated after cyanidin treatment. Cytoplasmic and nuclear protein levels of β-catenin in all cell lines are down-regulated. Cyanidin treatment significantly decreases the protein level for c-Myc in the GBM2 cell line compared with untreated cells, not in G144 or GliNS2 cells. Furthermore, cyanidin strongly reduces the expression of Twist1 and Snail1 in GBM2, G179, and G144 cell lines, while the GliNS2 cells show an opposite change in the cytoplasm and no change in nuclear.


CONCLUSION
Cyanidin exerts an anti-tumor effect in glioma stem cell lines, probably through the Wnt signaling pathway.