Resveratrol inhibits hypoxia-induced glioma cell migration and invasion by the p-STAT3/miR-34a axis.

Abstract

Hypoxia promotes aggressiveness, angiogenesis and resistance in glioma. It has been reported that resveratrol has strong anti-tumor ability and can inhibit migration and invasion of varieties of tumor including glioma. However, whether resveratrol inhibits hypoxia-induced migration and invasion of glioma cells is still unknown. In this study, we found glioma U87 and U251 cells migration and invasion was reduced by resveratrol under hypoxia condition and higher doses led to stronger block, while proliferation of U87 and U251 cells was hardly effected. Mechanically, hypoxia-induced upregulation of phosphorylated signal transducer and activator of transcription 3(p-STAT3) was blocked by resveratrol. MicroRNA-34a (miR-34a) is a tumor suppressor whose promoter region has a conserved STAT3-binding site and can be negatively regulated by STAT3. Interestingly, miR-34a was downregulated under hypoxia but upregulated by resveratrol which was perhaps relevant to changes in level of p-STAT3. The effect of resveratrol on p-STAT3 and miR-34a was both time-and dose-dependent. Summarizing, resveratrol inhibits hypoxia-induced migration and invasion possibly via p-STAT3/miR-34a axis and this effect is both time-and dose-dependent.