Galangin increases ERK1/2 phosphorylation to decrease ADAM9 expression and prevents invasion in A172 glioma cells

Galangin (3,5,7-trihydroxyflavone), is a natural flavonoid present in plants. Galangin is reported to exhibit anti-cancer properties against various cancer types. The aim of the present study was to display the effects of galangin on glioma and its mechanism of action in A172 human glioma cancer cells. The results clearly indicated that treatment of galangin inhibited A172 cell migration and invasion under non-toxic doses. A human proteinase array assay was conducted to elucidate the potential effects of galangin, and the obtained results demonstrated that treatment of galangin inhibited ADAM9 protein expression and mRNA expression, that are known to contribute to cancer progression. Sustained extracellular signal-regulated kinase (Erk)1/2 activation was also monitored, which contributed to ADAM9 protein expression and mRNA inhibition as investigated using western blotting analysis and reverse transcription-quantitative polymerase chain reaction experiment. Erk1/2 inhibition by inhibitor or small interfering (si)Erk transfection markedly terminated galangin-inhibited A172 migration and invasion via an Erk1/2 activation mechanism. Collective results suggested that galangin may act as an effective chemotherapeutic agent for glioma cancer depending on its ability to bring about ADAM9 and Erk1/2 activation.